JP7401180B2 - current sensor - Google Patents

Description

The disclosure described herein relates to a current sensor that detects a current to be measured.

As shown in Patent Document 1, a current detection system (current sensor) is known that detects a current by converting a magnetic field generated by a current flowing through a bus bar into an electric signal.

Japanese Patent Application Publication No. 2015-194472

As described in Patent Document 1, in the technical field of current sensors, there is a problem of a decrease in detection accuracy of current (current to be measured).

Therefore, an object of the disclosure described in this specification is to provide a current sensor in which a decrease in detection accuracy of a current to be measured is suppressed.

The disclosed one includes a conductive member (30) through which a current to be measured flows;
a first magnetoelectric converter (21, 25) that converts a magnetic field to be measured generated by the flow of a current to be measured into an electrical signal of a first polarity; a wiring board (20) on which a second magnetoelectric conversion unit (22, 25) is mounted;
a difference unit (29, 801, 802) that takes the difference between the electrical signal of the first magnetoelectric conversion unit and the electrical signal of the second magnetoelectric conversion unit;
a sensor housing (50) that houses a conductive member and a wiring board, with the wiring board facing the conductive member;
a board adhesive (56e) for adhering the surface (20a) of the wiring board facing the conductive member to the sensor housing;
Assuming that the three directions that are orthogonal to each other are the x direction, y direction, and z direction,
The center point (CP) of the conductive member, the first magnetoelectric conversion unit, and the second magnetoelectric conversion unit exist on one plane perpendicular to the y direction, which is the extension direction of the conductive member, and the center point of the conductive member The first magnetoelectric conversion section and the second magnetoelectric conversion section are arranged on opposing surfaces or on the back surface so that the first magnetoelectric conversion section and the second magnetoelectric conversion section are lined up in the x direction via (CP) ,
Each of the first magnetoelectric conversion unit and the second magnetoelectric conversion unit has a magnetoresistance effect in which the resistance value changes depending on the component along the y direction of the magnetic field that passes through the unit and the component along the x direction, which is the lateral direction of the conductive member. It has a plurality of elements (25a, 25b).
Another aspect of the disclosure is a conductive member (30) through which a current to be measured flows;
a first magnetoelectric converter (21, 25) that converts a magnetic field to be measured generated by the flow of a current to be measured into an electrical signal of a first polarity; a wiring board (20) on which a second magnetoelectric conversion unit (22, 25) is mounted;
a difference unit (29, 801, 802) that takes the difference between the electrical signal of the first magnetoelectric conversion unit and the electrical signal of the second magnetoelectric conversion unit;
a sensor housing (50) that houses a conductive member and a wiring board, with the wiring board facing the conductive member;
a board adhesive (56e) for adhering the surface (20a) of the wiring board facing the conductive member to the sensor housing;
Assuming that the three directions that are orthogonal to each other are the x direction, y direction, and z direction,
The center point (CP) of the conductive member, the first magnetoelectric conversion unit, and the second magnetoelectric conversion unit exist on one plane perpendicular to the y direction , which is the extension direction of the conductive member, and the center point of the conductive member The first magnetoelectric conversion section and the second magnetoelectric conversion section are arranged on opposing surfaces or on the back surface so that the first magnetoelectric conversion section and the second magnetoelectric conversion section are lined up in the x direction via (CP) ,
The sensor housing includes a board support part (56a) that supports a wiring board, and a board adhesive part (56b) provided with a board adhesive,
The mounting surface (56d) on which the board adhesive (56e) is provided in the board bonding part is farther away from the wiring board than the support surface (56c) of the wiring board in the board support part;
A wiring board is mounted on the support surface of the board support part, and a board adhesive is provided between the mounting surface of the board adhesive part and the wiring board.

In this manner, in the present disclosure, the center line passing through the center point (CP) of the conductive member (30) is defined as the axis of symmetry (AS), and the first magnetoelectric conversion unit (21, 25) and the second magnetoelectric conversion unit (22, ) are arranged line-symmetrically on the opposing surface (20a) or the back surface (20b). As a result, the absolute values of the magnetic fields to be measured that pass through the first magnetoelectric conversion section (21, 25) and the second magnetoelectric conversion section (22, 25) become equal. Therefore, the absolute values of the electric signals output from the first magnetoelectric conversion section (21, 25) and the second magnetoelectric conversion section (22, 25) are equal.

However, the wiring board (20) on which the first magnetoelectric converter (21, 25) and the second magnetoelectric converter (22, 25) are mounted is attached to the sensor housing (50) via the board adhesive (56e). Fixed. The substrate adhesive (56e) expands and contracts due to changes in environmental temperature, and deteriorates over time such as creep. For this reason, the relative position between the wiring board (20) and the conductive member (30) changes. As a result, the absolute values of the magnetic fields to be measured that pass through the first magnetoelectric conversion section (21, 25) and the second magnetoelectric conversion section (22, 25) are no longer equal. The absolute values of the electric signals output from the first magnetoelectric conversion section (21, 25) and the second magnetoelectric conversion section (22, 25) are no longer equal.

However, both the first magnetoelectric conversion section (21, 25) and the second magnetoelectric conversion section (22, 25) are mounted on the wiring board (20). Therefore, even if the relative position between the wiring board (20) and the conductive member (30) changes due to deformation of the board adhesive (56e) as described above, the first magnetoelectric converter mounted on the wiring board (20) The relative distance between the section (21, 25) and the second magnetoelectric conversion section (22, 25) does not change. Therefore, when the relative position between the wiring board (20) and the conductive member (30) changes due to deformation of the board adhesive (56e), the first magnetoelectric converter (21, 25) and the second magnetoelectric converter (22, 25), the magnetic field to be measured that passes through one of them decreases, and the magnetic field to be measured that passes through the other increases. When the relative position of the wiring board (20) and the conductive member (30) changes in the direction along the opposing surface (20a) or the back surface (20b), the amount of decrease and increase of the magnetic field to be measured that passes through the magnetoelectric converter is It is expected that they will be equivalent.

Therefore, as in the present disclosure, the difference between the electrical signals of the first magnetoelectric converter (21, 25) and the electrical signal of the second magnetoelectric converter (22, 25), which have mutually different polarities, is determined in the difference section (29, 801, 802). Take. By doing so, the decrease and increase in the electrical signal due to the change in the relative position between the wiring board (20) and the conductive member (30) due to the deformation of the board adhesive (56e) is canceled. This suppresses a decrease in detection accuracy of the current to be measured.

Note that the reference numbers in parentheses above merely indicate correspondence with the configurations described in the embodiments described later, and do not limit the technical scope in any way.

FIG. 2 is a block diagram for explaining an in-vehicle system. It is a perspective view showing a 1st current sensor. It is an exploded perspective view showing a 1st current sensor. It is a chart showing a first current sensor. It is a chart showing a first current sensor. It is a diagram showing a wiring board. FIG. 3 is a block diagram for explaining a sensing section. It is a diagram showing a conductive bus bar. It is a diagram showing a first shield. It is a diagram showing a second shield. It is a diagram showing a sensor housing. It is a diagram for explaining board support pins and board adhesive pins. 12 is a sectional view taken along the line XIII-XIII shown in column (b) of FIG. 12. FIG. It is a diagram for explaining a shield support pin and a shield adhesive pin. 14 is a cross-sectional view taken along the line XV-XV shown in column (b) of FIG. 14. FIG. FIG. 2 is a perspective view showing two individual sensors. It is a perspective view showing a wiring case. FIG. 3 is a perspective view for explaining how the individual sensors are assembled into the wiring case. It is a perspective view showing a 2nd current sensor. It is a diagram showing a wiring case. It is a diagram showing a wiring case. It is a chart showing a 2nd current sensor. It is a chart showing a 2nd current sensor. It is a chart for explaining magnetic saturation of the first shield. It is a chart showing simulation results of magnetic saturation. It is a chart for explaining the second shield of the second embodiment. FIG. 3 is a schematic diagram for explaining a magnetic field passing through a shield. It is a chart showing a modification of the shield. It is a chart showing a modification of the shield. It is a perspective view showing the 1st current sensor of a 3rd embodiment. 31 is a sectional view taken along the XXXI-XXXI line shown in FIG. 30. FIG. It is a chart for explaining the fixing form of a 1st current sensor. It is a chart showing arrangement of a magnetoelectric conversion part and a conductive bus bar of a 4th embodiment. It is a chart for explaining the output change of a magnetoelectric conversion part. It is a block diagram for explaining the sensing part of a 4th embodiment. FIG. 2 is a block diagram showing a differential circuit. It is a schematic diagram for demonstrating the shielding property of the shield of 5th Embodiment. It is a schematic diagram for explaining the shielding property of a shield. It is a chart showing a modification of the shield. It is a chart showing a modification of the shield. It is a perspective view which shows the modification of a 2nd current sensor. It is a chart showing a modification of the second current sensor. It is a chart showing a modification of the second current sensor. FIG. 3 is a perspective view showing how the individual sensors are assembled into the wiring case. It is a chart for explaining types of detection forms.

Hereinafter, embodiments will be described based on the drawings.

(First embodiment)
<In-vehicle system>
First, an in-vehicle system 100 to which a current sensor is applied will be described. This in-vehicle system 100 constitutes a hybrid system. As shown in FIG. 1, the in-vehicle system 100 includes a battery 200, a power converter 300, a first motor 400, a second motor 500, an engine 600, and a power distribution mechanism 700.

Furthermore, the in-vehicle system 100 includes multiple ECUs. FIG. 1 shows a battery ECU 801 and an MGECU 802 as representatives of these plural ECUs. These plurality of ECUs mutually transmit and receive signals via bus wiring 800 to cooperatively control the hybrid vehicle. Through this cooperative control, regeneration and power running of the first motor 400, power generation of the second motor 500, output of the engine 600, etc. are controlled according to the SOC of the battery 200. SOC is an abbreviation for state of charge. ECU is an abbreviation for electronic control unit.

Note that the ECU includes at least one arithmetic processing unit (CPU) and at least one memory device (MMR) as a storage medium that stores programs and data. The ECU is provided by a microcomputer with a computer readable storage medium. A storage medium is a non-transitory tangible storage medium that non-temporarily stores a computer readable program. The storage medium may be provided by a semiconductor memory, a magnetic disk, or the like. The components of the in-vehicle system 100 will be individually outlined below.

Battery 200 includes a plurality of secondary batteries. These plurality of secondary batteries constitute a battery stack connected in series. As the secondary battery, a lithium ion secondary battery, a nickel hydride secondary battery, an organic radical battery, etc. can be employed.

Secondary batteries generate electromotive voltage through chemical reactions. Secondary batteries have the property of accelerating deterioration if the amount of charge is too high or too low. In other words, secondary batteries have the property of accelerating deterioration when the SOC is overcharged or overdischarged.

The SOC of the battery 200 corresponds to the SOC of the battery stack described above. The SOC of a battery stack is the sum of the SOCs of a plurality of secondary batteries. Overcharging and overdischarging of the SOC of the battery stack are avoided by the above cooperative control. On the other hand, overcharging and overdischarging of the SOC of each of the plurality of secondary batteries is avoided by equalization processing that equalizes the SOC of each of the plurality of secondary batteries.

The equalization process is performed by individually charging and discharging a plurality of secondary batteries. Battery 200 includes a switch for individually charging and discharging a plurality of secondary batteries. The battery 200 also includes a voltage sensor, a temperature sensor, and the like for detecting the SOC of each of the plurality of secondary batteries. The battery ECU 801 controls opening and closing of the switch based on the outputs of these sensors and the first current sensor 11, which will be described later. This equalizes the SOC of each of the plurality of secondary batteries.

Power conversion device 300 performs power conversion between battery 200 and first motor 400. The power conversion device 300 also performs power conversion between the battery 200 and the second motor 500. The power conversion device 300 converts the DC power of the battery 200 into AC power at a voltage level suitable for powering the first motor 400 and the second motor 500. The power converter 300 converts AC power generated by the first motor 400 and the second motor 500 into DC power at a voltage level suitable for charging the battery 200 . The power conversion device 300 will be explained in detail later.

The first motor 400, the second motor 500, and the engine 600 are each connected to a power distribution mechanism 700. The first motor 400 is directly connected to an output shaft of a hybrid vehicle (not shown). The rotational energy of the first motor 400 is transmitted to the running wheels via the output shaft. Conversely, the rotational energy of the running wheels is transmitted to the first motor 400 via the output shaft.

The first motor 400 is powered by AC power supplied from the power conversion device 300. The rotational energy generated by this power running is distributed to the engine 600 and the output shaft of the hybrid vehicle by the power distribution mechanism 700. This accomplishes cranking of the crankshaft and application of propulsive force to the running wheels. Further, the first motor 400 is regenerated by rotational energy transmitted from the running wheels. The AC power generated by this regeneration is converted to DC power by the power conversion device 300 and is stepped down. This DC power is supplied to battery 200. The DC power is also supplied to various electrical loads installed in the hybrid vehicle.

The second motor 500 generates electricity using rotational energy supplied from the engine 600. The AC power generated by this power generation is converted to DC power by the power conversion device 300 and is stepped down. This DC power is supplied to the battery 200 and various electrical loads.

The engine 600 generates rotational energy by burning fuel. This rotational energy is distributed to the second motor 500 and the output shaft via the power distribution mechanism 700. This allows the second motor 500 to generate electricity and provide propulsive force to the running wheels.

Power distribution mechanism 700 has a planetary gear mechanism. Power distribution mechanism 700 includes a ring gear, a planetary gear, a sun gear, and a planetary carrier.

The ring gear has an annular shape. A plurality of teeth are formed on each of the outer circumferential surface and the inner circumferential surface of the ring gear so as to be lined up in the circumferential direction.

Each of the planetary gear and sun gear has a disk shape. A plurality of teeth are formed on the circumferential surface of each of the planetary gear and the sun gear so as to be lined up in the circumferential direction.

The planetary carrier forms a ring. A plurality of planetary gears are connected to a flat surface connecting an outer peripheral surface and an inner peripheral surface of the planetary carrier. The flat surfaces of the planetary carrier and the planetary gear face each other.

The plurality of planetary gears are located on a circumference centered on the rotation center of the planetary carrier. The adjacent spacing between these plurality of planetary gears is equal. In this embodiment, three planetary gears are arranged at 120° intervals.

A sun gear is provided at the center of the ring gear. The inner circumferential surface of the ring gear and the outer circumferential surface of the sun gear face each other. Three planetary gears are provided between the two. The teeth of each of the three planetary gears mesh with the teeth of the ring gear and sun gear. This provides a configuration in which the rotations of the ring gear, planetary gear, sun gear, and planetary carrier are mutually transmitted.

The output shaft of the first motor 400 is connected to the ring gear. A crankshaft of an engine 600 is connected to the planetary carrier. The output shaft of the second motor 500 is connected to the sun gear. As a result, the rotational speeds of the first motor 400, the engine 600, and the second motor 500 have a linear relationship in the collinear diagram.

By supplying AC power from the power conversion device 300 to the first motor 400 and the second motor 500, torque is generated in the ring gear and the sun gear. Torque is generated in the planetary carrier by the combustion drive of the engine 600. By doing so, the first motor 400 performs power running and regeneration, the second motor 500 generates electricity, and the driving force is applied to the running wheels.

The behavior of the first motor 400, the second motor 500, and the engine 600 is cooperatively controlled by a plurality of ECUs. For example, the MGECU 802 determines target torques for the first motor 400 and the second motor 500 based on physical quantities detected by various sensors mounted on the hybrid vehicle, vehicle information input from other ECUs, and the like. Then, the MGECU 802 performs vector control so that the torques generated by the first motor 400 and the second motor 500 each become the target torque.

<Power converter>
Next, the power conversion device 300 will be explained. Power conversion device 300 includes a converter 310, a first inverter 320, and a second inverter 330. Converter 310 functions to step up and down the voltage level of DC power. The first inverter 320 and the second inverter 330 function to convert DC power into AC power. The first inverter 320 and the second inverter 330 function to convert AC power into DC power.

In the in-vehicle system 100, the converter 310 boosts the DC power of the battery 200 to a voltage level suitable for powering the first motor 400 and the second motor 500. The first inverter 320 and the second inverter 330 convert this DC power into AC power. This AC power is supplied to the first motor 400 and the second motor 500. Further, the first inverter 320 and the second inverter 330 convert AC power generated by the first motor 400 and the second motor 500 into DC power. Converter 310 steps down this DC power to a voltage level suitable for charging battery 200.

As shown in FIG. 1, converter 310 is electrically connected to battery 200 via first power line 301 and second power line 302. Converter 310 is electrically connected to first inverter 320 and second inverter 330 via third power line 303 and fourth power line 304, respectively.

One end of the first power line 301 is electrically connected to the positive electrode of the battery 200. One end of the second power line 302 is electrically connected to the negative electrode of the battery 200. The other ends of the first power line 301 and the second power line 302 are electrically connected to the converter 310.

A first smoothing capacitor 305 is connected to the first power line 301 and the second power line 302. One of the two electrodes of the first smoothing capacitor 305 is connected to the third power line 303 and the other is connected to the fourth power line 304.

Note that the battery 200 has a system main relay (SMR) not shown. The electrical connection between the battery stack of the battery 200 and the power conversion device 300 is controlled by opening and closing this system main relay. That is, the continuation and interruption of power supply between the battery 200 and the power conversion device 300 is controlled by opening and closing the system main relay.

One end of the third power line 303 is electrically connected to a high-side switch 311 of a converter 310, which will be described later. One end of the fourth power line 304 is electrically connected to the other end of the second power line 302. The other ends of the third power line 303 and the fourth power line 304 are electrically connected to the first inverter 320 and the second inverter 330, respectively.

A second smoothing capacitor 306 is connected to the third power line 303 and the fourth power line 304. One of the two electrodes of the second smoothing capacitor 306 is connected to the third power line 303 and the other is connected to the fourth power line 304.

The first inverter 320 is electrically connected to the first U-phase stator coil 401 to the first W-phase stator coil 403 of the first motor 400 via the first to third energized bus bars 341 to 343. The second inverter 330 is electrically connected to the second U-phase stator coil 501 to the second W-phase stator coil 503 of the second motor 500 via the fourth energized bus bar 344 to the sixth energized bus bar 346.

<Converter>
Converter 310 includes a high-side switch 311, a low-side switch 312, a high-side diode 311a, a low-side diode 312a, and a reactor 313. As these high-side switch 311 and low-side switch 312, IGBT, power MOSFET, etc. can be adopted. In this embodiment, n-channel IGBTs are used as the high-side switch 311 and the low-side switch 312.

Note that when MOSFETs are employed as the high-side switch 311 and the low-side switch 312, a body diode is formed in the MOSFETs. Therefore, the high side diode 311a and the low side diode 312a may be omitted. The semiconductor element constituting converter 310 can be manufactured using a semiconductor such as Si or a wide gap semiconductor such as SiC.

The high side diode 311a is connected in antiparallel to the high side switch 311. That is, the collector electrode of the high-side switch 311 is connected to the cathode electrode of the high-side diode 311a. The emitter electrode of the high side switch 311 is connected to the anode electrode of the high side diode 311a.

Similarly, the low side diode 312a is connected in antiparallel to the low side switch 312. A cathode electrode of a low-side diode 312a is connected to a collector electrode of the low-side switch 312. The emitter electrode of the low-side switch 312 is connected to the anode electrode of the low-side diode 312a.

As shown in FIG. 1, a third power line 303 is electrically connected to the collector electrode of the high-side switch 311. The emitter electrode of the high-side switch 311 and the collector electrode of the low-side switch 312 are connected. A second power line 302 and a fourth power line 304 are electrically connected to the emitter electrode of the low-side switch 312 . Thereby, the high-side switch 311 and the low-side switch 312 are connected in series in order from the third power line 303 to the second power line 302. In other words, the high-side switch 311 and the low-side switch 312 are connected in series in order from the third power line 303 to the fourth power line 304.

A midpoint between the series-connected high-side switch 311 and low-side switch 312 and one end of the reactor 313 are electrically connected via the current-carrying bus bar 307 . The other end of the reactor 313 is electrically connected to the other end of the first power line 301.

As described above, the DC power of the battery 200 is supplied to the midpoint of the series-connected high-side switch 311 and low-side switch 312 via the reactor 313 and the current-carrying bus bar 307. The collector electrode of the high-side switch 311 is supplied with AC power from the motor that has been converted to DC power by at least one of the first inverter 320 and the second inverter 330 . The alternating current power of the motor converted to direct current power is supplied to the battery 200 via the high side switch 311, the energizing bus bar 307, and the reactor 313.

In this way, DC power that inputs and outputs the battery 200 flows through the current-carrying bus bar 307 . To limit the physical quantity that flows, a direct current that inputs and outputs the battery 200 flows through the current-carrying bus bar 307 .

The opening and closing of high side switch 311 and low side switch 312 of converter 310 is controlled by MGECU 802. MGECU 802 generates a control signal and outputs it to gate driver 803. The gate driver 803 amplifies the control signal and outputs it to the gate electrode of the switch. Thereby, MGECU 802 increases or decreases the voltage level of the DC power input to converter 310.

The MGECU 802 generates a pulse signal as a control signal. The MGECU 802 adjusts the step-up/down level of the DC power by adjusting the on-duty ratio and frequency of this pulse signal. The voltage increase/decrease level is determined according to the target torque and the SOC of the battery 200.

When boosting the DC power of the battery 200, the MGECU 802 alternately opens and closes the high side switch 311 and the low side switch 312. For this purpose, the MGECU 802 inverts the voltage levels of the control signals output to the high-side switch 311 and the low-side switch 312.

When a high level is input to the gate electrode of the high side switch 311, a low level is input to the gate electrode of the low side switch 312. In this case, DC power from the battery 200 is supplied to the first inverter 320 and the second inverter 330 via the reactor 313 and the high-side switch 311. At this time, electrical energy is accumulated in the reactor 313 due to the flow of current. Further, charge is stored in the second smoothing capacitor 306. The second smoothing capacitor 306 is charged.

When a low level is input to the gate electrode of the high side switch 311, a high level is input to the gate electrode of the low side switch 312. In this case, a closed loop passing through the first smoothing capacitor 305, reactor 313, and low-side switch 312 is configured. As described above, electrical energy is stored in the reactor 313. For this reason, the reactor 313 tries to cause current to flow. A current caused by the electrical energy of this reactor 313 flows through the above closed loop.

Further, in this case, the supply of DC power to the first inverter 320 and the second inverter 330 via the high-side switch 311 is interrupted. However, the second smoothing capacitor 306 is charged. For this purpose, power is supplied from the second smoothing capacitor 306 to the first inverter 320 and the second inverter 330. Power supply to the first inverter 320 and the second inverter 330 is continued.

After this, a high level is input to the high side switch 311 and a low level is input to the low side switch 312. At this time, the electric energy accumulated in the reactor 313 together with the DC power of the battery 200 is supplied to the first inverter 320 and the second inverter 330 as DC power. As a result, the DC power of the battery 200 whose voltage has been increased on a time-average basis is supplied to the first inverter 320 and the second inverter 330. Further, as the charge of the second smoothing capacitor 306 is restored, the amount of charge thereof increases. As a result, the voltage level of the DC power supplied from the second smoothing capacitor 306 to the first inverter 320 and the second inverter 330 also increases.

When stepping down the DC power supplied from at least one of the first inverter 320 and the second inverter 330, the MGECU 802 fixes the control signal output to the low-side switch 312 at a low level. At the same time, the MGECU 802 sequentially switches the control signal output to the high side switch 311 between high level and low level.

When a high level is input to the gate electrode of high-side switch 311 , DC power from at least one of first inverter 320 and second inverter 330 is supplied to battery 200 via high-side switch 311 and reactor 313 .

When a low level is input to the gate electrode of high-side switch 311 , DC power from at least one of first inverter 320 and second inverter 330 is no longer supplied to battery 200 . As a result, time-averaged DC power is supplied to battery 200.

Strictly speaking, when a high level is input to the gate electrode of the high side switch 311 as described above, the first smoothing capacitor 305 is charged. Electrical energy is stored in the reactor 313. After this, when a low level is input to the gate electrode of the high side switch 311, if there is a difference in the output voltage and time constant of the second smoothing capacitor 306 and the battery 200, the difference between the second smoothing capacitor 306 and the battery 200 Charging and discharging are performed. Further, a diode (not shown) connects the first power line 301 and the second power line 302. The anode electrode of this diode is connected to the second power line 302, and the cathode electrode is connected to the first power line 301. Therefore, a closed loop passing through this diode, reactor 313, and first smoothing capacitor 305 is configured. Current due to the electrical energy of reactor 313 flows through this closed loop.

<Inverter>
The first inverter 320 has a first switch 321 to a sixth switch 326, and a first diode 321a to a sixth diode 326a. IGBTs, power MOSFETs, and the like can be used as the first switch 321 to the sixth switch 326. In this embodiment, n-channel IGBTs are used as the first switch 321 to the sixth switch 326. When MOSFETs are used as these switches, the above-mentioned diodes may be omitted. The semiconductor elements constituting the first inverter 320 can be manufactured using a semiconductor such as Si or a wide gap semiconductor such as SiC.

The first diode 321a to the sixth diode 326a corresponding to the first switch 321 to the sixth switch 326 are connected in antiparallel. That is, when k is a natural number from 1 to 6, the cathode electrode of the k-th diode is connected to the collector electrode of the k-th switch. The anode electrode of the kth diode is connected to the emitter electrode of the kth switch.

The first switch 321 and the second switch 322 are connected in series in order from the third power line 303 to the fourth power line 304. The first switch 321 and the second switch 322 constitute a first U-phase leg. One end of the first energizing bus bar 341 is connected to the midpoint between the first switch 321 and the second switch 322. The other end of the first energized bus bar 341 is connected to the first U-phase stator coil 401 of the first motor 400 .

The third switch 323 and the fourth switch 324 are connected in series in order from the third power line 303 to the fourth power line 304. The third switch 323 and the fourth switch 324 constitute a first V-phase leg. One end of the second energizing bus bar 342 is connected to the midpoint between the third switch 323 and the fourth switch 324 . The other end of the second energized bus bar 342 is connected to the first V-phase stator coil 402 of the first motor 400.

The fifth switch 325 and the sixth switch 326 are connected in series in order from the third power line 303 to the fourth power line 304. The fifth switch 325 and the sixth switch 326 constitute a first W-phase leg. One end of the third energizing bus bar 343 is connected to the midpoint between the fifth switch 325 and the sixth switch 326. The other end of the third energized bus bar 343 is connected to the first W-phase stator coil 403 of the first motor 400 .

The second inverter 330 has a similar configuration to the first inverter 320. The second inverter 330 has a seventh switch 331 to a twelfth switch 336, and a seventh diode 331a to a twelfth diode 336a.

A seventh diode 331a to a twelfth diode 336a corresponding to a seventh switch 331 to a twelfth switch 336 are connected in antiparallel. When n is a natural number from 7 to 12, the cathode electrode of the n-th diode is connected to the collector electrode of the n-th switch. The anode electrode of the n-th diode is connected to the emitter electrode of the n-th switch.

The seventh switch 331 and the eighth switch 332 are connected in series between the third power line 303 and the fourth power line 304 to form a second U-phase leg. One end of a fourth energizing bus bar 344 is connected to a midpoint between the seventh switch 331 and the eighth switch 332. The other end of the fourth energized bus bar 344 is connected to the second U-phase stator coil 501 of the second motor 500.

The ninth switch 333 and the tenth switch 334 are connected in series between the third power line 303 and the fourth power line 304 to form a second V-phase leg. One end of the fifth energizing bus bar 345 is connected to the midpoint between the ninth switch 333 and the tenth switch 334. The other end of the fifth energizing bus bar 345 is connected to the second V-phase stator coil 502 of the second motor 500.

The eleventh switch 335 and the twelfth switch 336 are connected in series between the third power line 303 and the fourth power line 304 to form a second W-phase leg. One end of a sixth energizing bus bar 346 is connected to a midpoint between the eleventh switch 335 and the twelfth switch 336. The other end of the sixth energized bus bar 346 is connected to the second W-phase stator coil 503 of the second motor 500.

As described above, each of the first inverter 320 and the second inverter 330 has three-phase legs corresponding to the U-phase to W-phase stator coils of the motor. A control signal of the MGECU 802 amplified by the gate driver 803 is input to the gate electrodes of the switches forming each of these three-phase legs.

When the motor is powered, each switch is PWM controlled by the output of a control signal from the MGECU 802. As a result, three-phase alternating current is generated by the inverter. When the motor generates electricity, the MGECU 802 stops outputting the control signal, for example. This causes the AC power generated by the motor to pass through the diode. As a result, AC power is converted to DC power.

The AC power input and output from the first motor 400 described above flows through the first to third energized bus bars 341 to 343 that connect the first inverter 320 and the first motor 400. Similarly, the AC power input to and output from the second motor 500 flows through the fourth energized bus bar 344 to the sixth energized bus bar 346 that connect the second inverter 330 and the second motor 500.

To limit the physical quantity that flows, the alternating current that inputs and outputs the first motor 400 flows through the first energized bus bar 341 to the third energized bus bar 343. The alternating current that inputs and outputs the second motor 500 flows through the fourth energizing bus bar 344 to the sixth energizing bus bar 346.

<Current sensor>
Next, a current sensor applied to the vehicle-mounted system 100 described above will be described.

The current sensors include a first current sensor 11, a second current sensor 12, and a third current sensor 13. First current sensor 11 detects the current flowing through converter 310. The second current sensor 12 detects the current flowing through the first motor 400. The third current sensor 13 detects the current flowing through the second motor 500.

The first current sensor 11 is provided on the current-carrying bus bar 307 . As described above, the DC current that inputs and outputs the battery 200 flows through the current-carrying bus bar 307 . The first current sensor 11 detects this direct current.

The DC current detected by the first current sensor 11 is input to the battery ECU 801. The battery ECU 801 monitors the SOC of the battery 200 based on the DC current detected by the first current sensor 11 and the battery stack voltage detected by a voltage sensor (not shown).

The second current sensor 12 is provided on the first to third energized bus bars 341 to 343. As described above, an alternating current that inputs and outputs the first motor 400 flows through the first to third energizing bus bars 341 to 343. The second current sensor 12 detects this alternating current.

The alternating current detected by the second current sensor 12 is input to the MGECU 802. The MGECU 802 vector-controls the first motor 400 based on the alternating current detected by the second current sensor 12 and the rotation angle of the first motor 400 detected by a rotation angle sensor (not shown).

The third current sensor 13 is provided at the fourth to sixth energizing bus bars 344 to 346. As described above, an alternating current that inputs and outputs the second motor 500 flows through the fourth energizing bus bar 344 to the sixth energizing bus bar 346. The third current sensor 13 detects this alternating current.

The alternating current detected by the third current sensor 13 is input to the MGECU 802. The MGECU 802 vector-controls the second motor 500 based on the alternating current detected by the third current sensor 13 and the rotation angle of the second motor 500 detected by a rotation angle sensor (not shown).

Note that the first U-phase stator coil 401, the first V-phase stator coil 402, and the first W-phase stator coil 403 of the first motor 400 are star-connected. Similarly, the second U-phase stator coil 501, the second V-phase stator coil 502, and the second W-phase stator coil 503 of the second motor 500 are star-connected. Therefore, by detecting the currents in two of these three phases of stator coils, the current in the remaining one phase can be detected.

It is also possible to employ a configuration in which these three-phase stator coils are delta-connected. Also in this configuration, by detecting the currents of the two-phase stator coils, the current of the remaining one phase can be detected.

The second current sensor 12 is provided on two of the first to third energized bus bars 341 to 343 connected to the first U-phase stator coil 401 to the first W-phase stator coil 403. More specifically, the second current sensor 12 is provided on the first energized bus bar 341 and the second energized bus bar 342.

For this purpose, the second current sensor 12 detects the current flowing through the first U-phase stator coil 401 and the current flowing through the first V-phase stator coil 402. The MGECU 802 detects the current flowing through the first W-phase stator coil 403 based on the current flowing through the first U-phase stator coil 401 and the first V-phase stator coil 402.

Similarly, the third current sensor 13 is provided on two of the fourth to sixth energized bus bars 344 to 346 connected to the second U-phase stator coil 501 to the second W-phase stator coil 503. More specifically, the third current sensor 13 is provided on the fourth energized bus bar 344 and the fifth energized bus bar 345.

For this purpose, the third current sensor 13 detects the current flowing through the second U-phase stator coil 501 and the current flowing through the second V-phase stator coil 502. The MGECU 802 detects the current flowing through the second W-phase stator coil 503 based on the current flowing through the second U-phase stator coil 501 and the second V-phase stator coil 502.

The DC current that inputs and outputs from the battery 200 described above and the AC current that inputs and outputs from the first motor 400 and the second motor 500 each correspond to the current to be measured. The magnetic field generated by the flow of these currents corresponds to the magnetic field to be measured.

<First current sensor>
As described above, the first current sensor 11 is provided on the current-carrying bus bar 307. The energizing bus bar 307 is divided into a reactor 313 side and a high side switch 311 (low side switch 312) side. The first current sensor 11 is provided on the current-carrying bus bar 307 in such a manner that it bridges the reactor 313 side and the high-side switch 311 side of the divided current-carrying bus bar 307. As a result, a current flowing through the current-carrying bus bar 307 , that is, a direct current that inputs and outputs the battery 200 flows through the first current sensor 11 .

Of course, the configuration in which the energizing bus bar 307 is divided into the reactor 313 side and the high side switch 311 side is only one example. For example, when the energized bus bar 307 is not separated and is connected only to the high side switch 311 side, the first current sensor 11 bridges the reactor 313 and the energized bus bar 307.

As shown in FIGS. 2 to 5, the first current sensor 11 includes a wiring board 20, a conductive bus bar 30, a shield 40, and a sensor housing 50. The conductive busbar 30 bridges the above-mentioned current-carrying busbar 307. Therefore, a direct current flows through the conductive bus bar 30. The conductive bus bar 30 corresponds to a conductive member.

Column (a) in FIG. 4 shows a top view of the first current sensor 11. The column (b) in FIG. 4 shows a front view of the first current sensor. Column (c) in FIG. 4 shows a bottom view of the first current sensor. Column (a) in FIG. 5 shows a front view of the first current sensor 11. The column (b) in FIG. 5 shows a side view of the first current sensor. Column (c) in FIG. 5 shows a rear view of the first current sensor. Note that the same drawings are shown in column (b) of FIG. 4 and column (a) of FIG. 5.

As clearly shown in these drawings, a portion of the conductive bus bar 30 is insert molded into the sensor housing 50. This sensor housing 50 is provided with a wiring board 20 and a shield 40. The sensor housing 50 is made of an insulating resin material.

The wiring board 20 is fixed to the sensor housing 50 in such a manner that it faces a portion of the conductive bus bar 30 that is insert-molded into the sensor housing 50 . A magnetoelectric converter 25, which will be described later, is mounted on the wiring board 20 at a portion facing the conductive bus bar 30. The magnetoelectric converter 25 converts the magnetic field generated by the direct current flowing through the conductive bus bar 30 into an electric signal.

The shield 40 has a first shield 41 and a second shield 42. The first shield 41 and the second shield 42 are fixed to the sensor housing 50 so as to be spaced apart from each other. Portions of the wiring board 20 and the conductive bus bar 30 that face each other are located between the first shield 41 and the second shield 42 .

The first shield 41 and the second shield 42 are made of a material with higher magnetic permeability than the sensor housing 50. Therefore, electromagnetic noise (external noise) that attempts to pass from the outside to the inside of the first current sensor 11 actively tries to pass through the first shield 41 and the second shield 42 . This suppresses input of external noise to the magnetoelectric converter 25.

Note that a connection terminal 60 shown in FIG. 4 is insert-molded in the sensor housing 50. This connection terminal 60 is electrically and mechanically connected to the wiring board 20 by solder 61. This connection terminal 60 is electrically connected to the battery ECU 801 via a wire harness or the like. The electrical signal converted by the magnetoelectric converter 25 is input to the battery ECU 801 via the connection terminal 60 and a wire harness (not shown).

Next, the components of the first current sensor 11 will be individually explained in detail. In this regard, hereinafter, three directions that are orthogonal to each other will be referred to as an x direction, a y direction, and a z direction. The x direction corresponds to the horizontal direction. The y direction corresponds to the extension direction.

<Wiring board>
As shown in FIG. 6, the wiring board 20 has a flat plate shape. The wiring board 20 has a flat shape with a small thickness in the z direction. The wiring board 20 is formed by laminating a plurality of insulating resin layers and conductive metal layers in the z direction. The widest opposing surface 20a of the wiring board 20 and its back surface 20b face the z direction. Column (a) in FIG. 6 shows a top view of the wiring board. The column (b) in FIG. 6 shows a bottom view of the wiring board.

A first sensing section 21 and a second sensing section 22 shown in column (a) of FIG. 6 and FIG. 7 are mounted on the opposing surface 20a of the wiring board 20. The first sensing section 21 and the second sensing section 22 each include an ASIC 23 and a filter 24. The ASIC 23 and the filter 24 are electrically connected via a wiring pattern on the wiring board 20. A connection terminal 60 is electrically connected to this wiring pattern. ASIC is an abbreviation for application specific integrated circuit. Note that it is also possible to adopt a configuration in which the first sensing section 21 and the second sensing section 22 are mounted on the back surface 20b.

<ASIC>
The ASIC 23 includes a magnetoelectric conversion section 25, a processing circuit 26, a connecting pin 27, and a resin section 28. The magnetoelectric converter 25 and the processing circuit 26 are electrically connected. One end of the connection pin 27 is electrically connected to the processing circuit 26. The other end of the connection pin 27 is electrically and mechanically connected to the wiring board 20. One end side of the connection pin 27, the processing circuit 26, and the magnetoelectric conversion section 25 are covered with a resin section 28. The other end of the connecting pin 27 is exposed from the resin portion 28.

The magnetoelectric conversion unit 25 includes a plurality of magnetoresistive elements whose resistance value varies depending on the magnetic field that passes through the unit (transmitted magnetic field). The resistance value of this magnetoresistive element changes depending on the transmitted magnetic field along the opposing surface 20a. That is, the resistance value of the magnetoresistive element changes depending on the component along the x direction and the component along the y direction of the transmitted magnetic field.

On the other hand, the resistance value of the magnetoresistive element does not change due to the transmitted magnetic field along the z direction. Therefore, even if external noise along the z direction passes through the magnetoresistive element, the resistance value of the magnetoresistive element does not change.

A magnetoresistive element has a pinned layer whose magnetization direction is fixed, a free layer whose magnetization direction changes depending on a transmitted magnetic field, and a nonmagnetic intermediate layer provided between the two. When the intermediate layer is non-conductive, the magnetoresistive element is a giant magnetoresistive element. When the intermediate layer has conductivity, the magnetoresistive element is a tunnel magnetoresistive element. Note that the magnetoresistive element may be an anisotropic magnetoresistive element (AMR). Furthermore, the magnetoelectric conversion section 25 may include a Hall element instead of the magnetoresistive element.

The resistance value of the magnetoresistive element changes depending on the angle formed by the magnetization directions of the pinned layer and the free layer. The magnetization direction of the pinned layer is along the opposing surface 20a. The magnetization direction of the free layer is determined by the transmitted magnetic field along the opposing surface 20a. The resistance value of the magnetoresistive element is lowest when the magnetization directions of the free layer and the pinned layer are parallel to each other. The resistance value of the magnetoresistive element is highest when the magnetization directions of the free layer and the pinned layer are antiparallel.

The magnetoelectric conversion unit 25 includes a first magnetoresistive element 25a and a second magnetoresistive element 25b as the above-mentioned magnetoresistive elements. The magnetization directions of the pinned layers of the first magnetoresistive element 25a and the second magnetoresistive element 25b differ by 90 degrees. For this reason, the increases and decreases in the resistance values of the first magnetoresistive element 25a and the second magnetoresistive element 25b are reversed. When the resistance value of one of the first magnetoresistive element 25a and the second magnetoresistive element 25b decreases, the resistance value of the other increases by the same amount.

The magnetoelectric conversion section 25 includes two first magnetoresistive elements 25a and two second magnetoresistive elements 25b. The first magnetoresistive element 25a and the second magnetoresistive element 25b are sequentially connected in series from the power supply potential to the reference potential to form a first half-bridge circuit. The second magnetoresistive element 25b and the first magnetoresistive element 25a are connected in series in order from the power supply potential to the reference potential to form a second half-bridge circuit.

In this way, in the two half-bridge circuits, the arrangement of the first magnetoresistive element 25a and the second magnetoresistive element 25b is reversed. For this reason, the midpoint potential of the two half-bridge circuits is configured such that when the potential of one goes down, the potential of the other goes up. In the magnetoelectric converter 25, a full bridge circuit is configured by combining these two half bridge circuits.

The magnetoelectric converter 25 includes a differential amplifier 25c, a feedback coil 25d, and a shunt resistor 25e in addition to the magnetoresistive element forming the full bridge circuit described above. The midpoint potential of the two half-bridge circuits is input to the inverting input terminal and non-inverting input terminal of the differential amplifier 25c. A feedback coil 25d and a shunt resistor 25e are connected in series in order from the output terminal of the differential amplifier 25c toward the reference potential.

With the connection configuration described above, the output terminal of the differential amplifier 25c outputs an output according to the fluctuation in the resistance value of the first magnetoresistive element 25a and the second magnetoresistive element 25b that constitute the full bridge circuit. Ru. This change in resistance value occurs when a magnetic field along the opposing surface 20a passes through the magnetoresistive element. A magnetic field (magnetic field to be measured) generated from a current flowing through the conductive bus bar 30 passes through the magnetoresistive element. Therefore, a current corresponding to the magnetic field to be measured flows through the input terminal of the differential amplifier 25c.

The input terminal and output terminal of the differential amplifier 25c are connected via a feedback circuit (not shown). Therefore, the differential amplifier 25c is virtually shorted. Therefore, the differential amplifier 25c operates so that the inverting input terminal and the non-inverting input terminal have the same potential. That is, the differential amplifier 25c operates so that the current flowing to the input terminal and the current flowing to the output terminal become zero. As a result, a current (feedback current) corresponding to the magnetic field to be measured flows from the output terminal of the differential amplifier 25c.

The feedback current flows between the output terminal of the differential amplifier 25c and the reference potential via the feedback coil 25d and the shunt resistor 25e. Due to the flow of this feedback current, a canceling magnetic field is generated in the feedback coil 25d. This canceling magnetic field passes through the magnetoelectric converter 25. As a result, the magnetic field to be measured that passes through the magnetoelectric converter 25 is canceled out. As described above, the magnetoelectric converter 25 operates so that the magnetic field to be measured that passes through itself and the canceling magnetic field are in equilibrium.

A feedback voltage corresponding to the amount of feedback current that generates the canceling magnetic field is generated at the midpoint between the feedback coil 25d and the shunt resistor 25e. This feedback voltage is output to the subsequent processing circuit 26 as an electrical signal that detects the current to be measured.

The processing circuit 26 includes an adjustment amplifier 26a and a threshold power supply 26b. A midpoint between the feedback coil 25d and the shunt resistor 25e is connected to the non-inverting input terminal of the adjustment amplifier 26a. A threshold power supply 26b is connected to an inverting input terminal of the adjustment amplifier 26a. As a result, a differentially amplified feedback voltage is output from the adjustment amplifier 26a.

The respective resistance values of the first magnetoresistive element 25a and the second magnetoresistive element 25b that constitute the full bridge circuit have a property that depends on temperature. Therefore, the output of the adjustment amplifier 26a fluctuates due to temperature changes. Therefore, the processing circuit 26 includes a temperature detection element (not shown), a nonvolatile memory that stores the relationship between the temperature and resistance value of the magnetoresistive element, and the like. This nonvolatile memory is electrically rewritable. By rewriting the values stored in the nonvolatile memory, the gain and offset of the adjustment amplifier 26a are adjusted. This cancels fluctuations in the output of the adjustment amplifier 26a due to temperature changes.

<Filter>
Filter 24 has a resistor 24a and a capacitor 24b. As shown in FIG. 7, on the wiring board 20, a power supply wiring 20c, a first output wiring 20d, a second output wiring 20e, and a ground wiring 20f are formed as wiring patterns.

The ASIC 23 of the first sensing section 21 is connected to the power supply wiring 20c, the first output wiring 20d, and the ground wiring 20f, respectively. The output terminal of the adjustment amplifier 26a of the ASIC 23 of the first sensing section 21 is connected to the first output wiring 20d.

The resistor 24a of the filter 24 of the first sensing section 21 is provided on the first output wiring 20d. The capacitor 24b connects the first output wiring 20d and the ground wiring 20f. Thereby, the filter 24 of the first sensing section 21 constitutes a low-pass filter by the resistor 24a and the capacitor 24b. The output of the ASIC 23 of the first sensing section 21 is output to the battery ECU 801 via this low-pass filter. As a result, the output of the first sensing section 21 from which high frequency noise has been removed is input to the battery ECU 801.

The ASIC 23 of the second sensing unit 22 is connected to the power supply wiring 20c, the second output wiring 20e, and the ground wiring 20f, respectively. The output terminal of the adjustment amplifier 26a of the ASIC 23 of the first sensing section 21 is connected to the second output wiring 20e.

The resistor 24a of the filter 24 of the second sensing section 22 is provided on the second output wiring 20e. The capacitor 24b connects the second output wiring 20e and the ground wiring 20f. Thereby, the filter 24 of the second sensing section 22 constitutes a low-pass filter by the resistor 24a and the capacitor 24b. The output of the ASIC 23 of the second sensing section 22 is output to the battery ECU 801 via this low-pass filter. As a result, the output of the second sensing section 22 from which high frequency noise has been removed is input to the battery ECU 801.

As shown above, the first sensing section 21 and the second sensing section 22 of this embodiment have the same configuration. The magnetoelectric conversion sections 25 of the first sensing section 21 and the second sensing section 22 are arranged in the y direction. As will be explained in detail later, the magnetic fields passing through the magnetoelectric converters 25 of the first sensing section 21 and the second sensing section 22 are the same.

Therefore, the electrical signal input from the first sensing section 21 to the battery ECU 801 and the electrical signal input from the second sensing section 22 to the battery ECU 801 are the same. The battery ECU 801 determines whether an abnormality has occurred in either the first sensing section 21 or the second sensing section 22 by comparing these two input electric signals. In this way, the first current sensor 11 according to this embodiment has redundancy.

Note that the shunt resistor 25e described above may be provided within the resin portion 28 or may be provided outside thereof. When provided outside the resin portion 28, the shunt resistor 25e is mounted on the wiring board 20. The shunt resistor 25e is externally attached to the ASIC 23.

Further, each of the four resistors forming the full bridge circuit does not need to be a magnetoresistive element. At least one of these four resistors may be a magnetoresistive element. Instead of a full bridge circuit, only one half bridge circuit may be configured.

If the above redundancy is not required, the first current sensor 11 may have one of the first sensing section 21 and the second sensing section 22.

<Conductive bus bar>
The conductive bus bar 30 is made of a conductive material such as copper, brass, and aluminum. The conductive bus bar 30 can be manufactured, for example, by the method listed below. The conductive bus bar 30 can be manufactured by pressing a flat plate. The conductive bus bar 30 can be manufactured by integrally connecting a plurality of flat plates. The conductive bus bar 30 can be manufactured by welding a plurality of flat plates. The conductive bus bar 30 can be manufactured by pouring a molten conductive material into a mold. The method for manufacturing the conductive bus bar 30 is not particularly limited.

As shown in FIG. 8, the conductive bus bar 30 has a flat shape with a small thickness in the z direction. The front surface 30a and the back surface 30b of the conductive bus bar 30 each face the z direction. Column (a) in FIG. 8 shows a top view of the conductive bus bar. The column (b) in FIG. 8 shows a side view of the conductive bus bar.

The conductive bus bar 30 extends in the y direction. As shown separated by two broken lines in FIG. 8, the conductive bus bar 30 includes a covering portion 31 that covers the sensor housing 50, and a first exposed portion 32 and a second exposed portion 33 that are exposed from the sensor housing 50. has. The first exposed portion 32 and the second exposed portion 33 are lined up in the y direction with the covering portion 31 interposed therebetween. The first exposed portion 32 and the second exposed portion 33 are integrally connected via the covering portion 31.

As shown in column (b) of FIG. 8, the lengths (thicknesses) in the z direction of the covering portion 31, the first exposed portion 32, and the second exposed portion 33 are equal to each other. That is, the distances in the z direction between the front surface 30a and the back surface 30b of each of the covering portion 31, the first exposed portion 32, and the second exposed portion 33 are equal.

A bolt hole 30c is formed in each of the first exposed portion 32 and the second exposed portion 33 for electrically and mechanically connecting to the current-carrying bus bar 307 through the bolt. This bolt hole 30c passes through the front surface 30a and the back surface 30b.

As described above, the energizing bus bar 307 is divided into the reactor 313 side and the high side switch 311 side. Attachment holes corresponding to the bolt holes 30c are formed on the reactor 313 side and the high side switch 311 side of the energizing bus bar 307, respectively.

The attachment hole on the reactor 313 side of the energizing bus bar 307 and the bolt hole 30c of the first exposed portion 32 are aligned in the z direction. The mounting hole on the high-side switch 311 side of the current-carrying bus bar 307 and the bolt hole 30c of the second exposed portion 33 are aligned in the z direction. In this state, the shaft portion of the bolt is passed through the bolt hole 30c and the mounting hole. Then, tighten the nut from the tip of the bolt shaft toward the head. The current-carrying bus bar 307 and the conductive bus bar 30 are held between the head of the bolt and the nut. This brings the current-carrying bus bar 307 and the conductive bus bar 30 into contact and electrically and mechanically connects them. As described above, the reactor 313 side and the high side switch 311 side of the divided current-carrying bus bar 307 are bridged by the conductive bus bar 30. A common current flows through current-carrying bus bar 307 and conductive bus bar 30 .

As shown in column (a) of FIG. 8, a narrowed portion 31a having a locally short length in the x direction is formed in the covering portion 31. The length of the narrowed portion 31a in the present embodiment in the x direction is gradually reduced. The length of the narrowed portion 31a in the x direction decreases in two steps from the first exposed portion 32 side of the covering portion 31 toward the center point CP of the covering portion 31 in the y direction. Similarly, the length of the narrowed portion 31a in the x direction decreases in two steps from the second exposed portion 33 side of the covering portion 31 toward the center point CP of the covering portion 31 in the y direction. Note that the length of the narrowed portion 31a in the x direction may be shortened in multiple steps or may be shortened continuously.

The center point CP mentioned above is equivalent to the center of gravity of the covering portion 31. The covering portion 31 and the narrowing portion 31a have a line-symmetric shape with a center line passing through the center point CP in the z direction as an axis of symmetry AS.

The narrowed portion 31a has a length shorter in the x direction than each of the first exposed portion 32 and the second exposed portion 33. Therefore, the density of the current flowing through the narrowed portion 31a is higher than the density of the current flowing through the first exposed portion 32 and the second exposed portion 33. As a result, the intensity of the magnetic field to be measured emitted from the current flowing through the narrowed portion 31a is increased.

As shown in columns (a) and (b) of FIG. 8, respectively, the magnetoelectric conversion units 25 of the first sensing unit 21 and the second sensing unit 22 are roughly surrounded by broken lines. The sensing portion 22 is arranged to face and be spaced apart from the narrowed portion 31a in the z direction. Therefore, a high-intensity measured magnetic field generated from the current flowing through the narrowed portion 31a passes through each of the first sensing portion 21 and the second sensing portion 22.

As described above, the conductive bus bar 30 extends in the y direction. Therefore, current flows in the conductive bus bar 30 in the y direction. This flow of current in the y direction generates a magnetic field to be measured in the circumferential direction around the y direction in accordance with Ampere's law. The magnetic field to be measured flows annularly around the conductive bus bar 30 in a plane defined by the x direction and the z direction. The first sensing section 21 and the second sensing section 22 detect a component of the magnetic field to be measured along the x direction.

As shown by broken lines in FIG. 8, the magnetoelectric conversion units 25 of the first sensing unit 21 and the second sensing unit 22 are arranged in the y direction. These two magnetoelectric conversion units 25 are arranged symmetrically with respect to the axis of symmetry AS. The positions of the two magnetoelectric converters 25 in the x direction and the position of the symmetry axis AS (center point CP) in the x direction are the same. Therefore, the two magnetoelectric converters 25 are arranged in the y direction with the center point CP interposed therebetween.

Furthermore, the distances in the z direction between the two magnetoelectric conversion sections 25 and the covering section 31 are the same. As described above, the covering portion 31 and the narrowing portion 31a have a line-symmetric shape with respect to the axis of symmetry AS. As a result of the above, the magnetic fields to be measured with the same x-direction components are transmitted through the two magnetoelectric conversion units 25.

Note that the conductive bus bar 30 of this embodiment is manufactured by pressing a conductive flat plate. In this press process, a flat plate is placed on a die, a punch is brought close to the die, and a tensile force is applied to the flat plate. In this way, the flat plate is separated into the conductive bus bar 30 and the chips, and the conductive bus bar 30 is manufactured.

When the conductive bus bar 30 is manufactured by the above-described press working, a sheared surface is formed in the conductive bus bar 30. Sag occurs on the sheared surface of the conductive bus bar 30 on the side that first comes into contact with the punch. This may cause the perpendicularity of the shear plane to be impaired. As a result, the distribution of the magnetic field to be measured generated by the current flowing through the conductive bus bar 30 may deviate from the design.

In the conductive bus bar 30 of this embodiment, the surface that is last separated by the punch is provided on the wiring board 20 side, not the surface that first comes into contact with the punch. That is, the surface that first comes into contact with the punch is the back surface 30b, and the surface that is finally separated by the punch is the front surface 30a. The sheared surface corresponds to the side surface between the front surface 30a and the back surface 30b. Therefore, the perpendicularity of the side surface of the conductive bus bar 30 on the surface 30a side is less likely to be impaired. A surface 30a of this conductive bus bar 30 faces the wiring board 20. Therefore, deviation from the designed distribution of the magnetic field to be measured passing through the first sensing section 21 and the second sensing section 22 mounted on the wiring board 20 is suppressed.

Note that, after manufacturing the conductive bus bar 30 by press working as described above, it is necessary to determine whether sag occurs on the front surface 30a side or the back surface 30b side of the side surface. A notch 33a for identifying this is formed in the second exposed portion 33 of the conductive bus bar 30 as a mark. The notch 33a of this embodiment has a semicircular shape.

<Shield>
As described above, the shield 40 includes the first shield 41 and the second shield 42. As shown in FIGS. 9 and 10, each of the first shield 41 and the second shield 42 has a plate shape with a thin thickness in the z direction. The widest surface 41a and the back surface 41b of the first shield 41 face the z direction. The widest surface 42a and the back surface 42b of the second shield 42 face the z direction.

As shown in FIGS. 2 and 3, the first shield 41 and the second shield 42 are provided in the sensor housing 50 such that one surface 41a and one surface 42a face each other in the z direction. The back surface 41b of the first shield 41 and the back surface 42b of the second shield 42 are each exposed outside the sensor housing 50. Each of the back surface 41b and the back surface 42b constitutes a part of the outermost surface of the first current sensor 11.

Column (a) in FIG. 9 shows a top view of the first shield. The column (b) in FIG. 9 shows a bottom view of the first shield. Column (a) in FIG. 10 shows a top view of the second shield. The column (b) in FIG. 10 shows a bottom view of the second shield.

The first shield 41 and the second shield 42 can be manufactured by compressing a plurality of flat plates made of a soft magnetic material with high magnetic permeability such as permalloy. Alternatively, the first shield 41 and the second shield 42 can be manufactured by rolling electromagnetic steel.

Each of the first shield 41 and the second shield 42 of this embodiment is manufactured by compressing a plurality of flat plates made of a soft magnetic material. Each of the plurality of flat plates is formed with four convex portions that protrude from the main surface toward the back surface. Accordingly, each of the plurality of flat plates is formed with four recesses that are recessed from the back surface toward the main surface. Each of the plurality of flat plates is arranged so that the main surface and the back surface face each other. Then, a plurality of flat plates are stacked so that the convex part of one of the two facing flat plates fits into the concave part of the other flat plate. A plurality of flat plates are crimped together in this laminated state. As a result, the first shield 41 and the second shield 42 are manufactured.

Note that when manufacturing the first shield 41 and the second shield 42 by rolling electromagnetic steel, the direction in which the electromagnetic steel is extended by rolling is, for example, the x direction. This aligns the atomic arrangement (crystal) of the electromagnetic steel in the x direction. As a result, the magnetic permeability is higher in the x direction than in the y direction. By specifying the rolling direction of the electromagnetic steel in this way, the magnetic permeability of the shield can be made anisotropic.

<1st shield>
The planar shape of the first shield 41 is a rectangle whose longitudinal direction is in the x direction, as shown in FIG. Cutouts 41c are formed at the four corners of the first shield 41 of this embodiment. In FIG. 9, two broken lines extending in the x direction are given to the first shield 41 in order to make the boundary between the center and both ends of the first shield 41 in the y direction clear. In the following, the center of the first shield 41 in the y direction will be referred to as a first central portion 41d. Both ends of the first shield 41 in the y direction are referred to as first both ends 41e. The first central portion 41d is located between the two end portions of the first both end portions 41e in the y direction.

As clearly indicated by the dashed lines, the first end portions 41e are shorter in length in the x direction than the first central portion 41d. Therefore, the first end portions 41e have lower magnetic permeability in the x direction than the first central portion 41d. The magnetic field is difficult to penetrate into the first both ends 41e. Therefore, a magnetic field is transmitted from one of the two ends of the first end portion 41e to the other through the portion (parallel portion) of the first central portion 41d that is directly connected to the first end portion 41e and lined up in the y direction. Transmission is suppressed. It is difficult for the magnetic field to pass through the parallel portions of the first central portion 41d. As a result, the parallel portions of the first central portion 41d are less likely to be magnetically saturated.

This parallel portion of the first central portion 41d in which magnetic saturation is suppressed and the first sensing portion 21 and the second sensing portion 22 mounted on the wiring board 20 are lined up in the z direction. The magnetoelectric conversion sections 25 of the first sensing section 21 and the second sensing section 22 are located between the first central section 41d and the narrowed section 31a.

<Second shield>
The planar shape of the second shield 42 is a rectangle whose longitudinal direction is in the x direction, as shown in FIG. In FIG. 10, two broken lines extending in the x direction are given to the second shield 42 in order to make the boundary between the center and both ends of the second shield 42 in the y direction clear. In the following, the center of the second shield 42 in the y direction will be referred to as a second central portion 42d. Both ends of the second shield 42 in the y direction are referred to as second both ends 42e. The second central portion 42d is located between the two end portions of the second end portions 42e in the y direction.

The second shield 42 has two end sides 42f aligned in the x direction. An extending portion 42c extending in the z direction is formed on each of the two end sides 42f on the second center portion 42d side. These two extending portions 42c extend in the z direction from the back surface 42b toward the first surface 42a. The extending portion 42c has a rectangular parallelepiped shape whose longitudinal direction is in the y direction. As described above, the extended portion 42c is formed by pressing and bending a plurality of flat plates made of a soft magnetic material when manufacturing the second shield 42.

As described above, the first shield 41 and the second shield 42 are provided in the sensor housing 50 in such a manner that one surface 41a of the first shield 41 and one surface 42a of the second shield 42 face each other in the z direction. In the state provided in this sensor housing 50, the extension portion 42c extends toward the first shield 41. The end surface of the extended portion 42c and one surface 41a of the first central portion 41d of the first shield 41 face each other in the z direction.

As a result, the distance between the first central portion 41d of the first shield 41 and the extension portion 42c of the second shield 42 is greater than the distance in the z direction between the one surface 41a of the first shield 41 and the one surface 42a of the second shield 42. The separation distance in the z direction is shorter. Therefore, the magnetic field that has entered the first shield 41 is easily transmitted to the second shield 42 via this extension portion 42c.

As described above, the extending portion 42c extends in the z direction from the second center portion 42d side of the end side 42f. The extending portion 42c is not formed on the second both end portions 42e side of the end side 42f. Therefore, the magnetic field that has entered the first shield 41 is easily transmitted to the second central portion 42d of the second shield 42 via the extension portion 42c.

The second central portion 42d and the first sensing portion 21 and the second sensing portion 22 mounted on the wiring board 20 face each other in the z direction. The magnetoelectric conversion section 25 and the narrowing section 31a of the first sensing section 21 and the second sensing section 22 are located between the first central section 41d and the second central section 42d.

Further, the position of the magnetoelectric converter 25 in the x direction is between the two extending portions 42c formed on each of the two end sides 42f. Therefore, when external noise along the x direction attempts to pass through the area between the first shield 41 surface 41a and the second shield 42 surface 42a where the magnetoelectric conversion section 25 is located, the external noise will pass through the magnetoelectric conversion section. 25 but attempts to invade the extended portion 42c. External noise that has entered the extended portion 42c is bent in its transmission direction so that it is transmitted through the second shield 42. As a result, external noise is suppressed from passing through the magnetoelectric conversion section 25.

<Sensor housing>
As shown in FIGS. 3 and 11, a conductive bus bar 30 and a connection terminal 60 are insert-molded in the sensor housing 50. The sensor housing 50 is provided with a wiring board 20 and a shield 40. The conductive bus bar 30, the wiring board 20, and the shield 40 are spaced apart from each other in the z direction. Column (a) in FIG. 11 shows a top view of the sensor housing. The column (b) in FIG. 11 shows a bottom view of the sensor housing.

As shown in FIGS. 5 and 11, the sensor housing 50 includes a base portion 51, an insulating portion 52, a first surrounding portion 53, a second surrounding portion 54, and a connector portion 55.

The base portion 51 has a rectangular parallelepiped shape whose longitudinal direction is in the x direction. For this purpose, the base 51 has six sides. The base 51 has a left surface 51a and a right surface 51b facing the y direction. The base 51 has an upper surface 51c facing the x direction and a lower surface 51d. The base portion 51 has an upper end surface 51e and a lower end surface 51f facing the z direction.

As shown in column (a) of FIG. 5 and column (c) of FIG. 5, the insulating portion 52 is formed on a portion of each of the left surface 51a and right surface 51b of the base portion 51. These two insulating parts 52 extend in the y direction away from the base 51. The two insulating parts 52 are lined up in the y direction with the base 51 in between. The covering portion 31 of the conductive bus bar 30 is covered by the two insulating portions 52 and the base portion 51, respectively.

Roughly speaking, the two insulating parts 52 cover the first exposed part 32 side and the second exposed part 33 side of the covering part 31. The base portion 51 covers the narrowed portion 31 a of the covering portion 31 . Therefore, the narrowed portion 31a is located between the upper end surface 51e and the lower end surface 51f of the base portion 51 in the z direction. An insulating resin material constituting the base portion 51 is located between the narrowed portion 31a and the upper end surface 51e and between the narrowed portion 31a and the lower end surface 51f.

As shown in column (a) of FIG. 11, the first surrounding portion 53 is formed on the upper end surface 51e of the base portion 51. The first enclosing portion 53 has a left wall 53a and a right wall 53b arranged in the y direction. The first enclosing portion 53 has an upper wall 53c and a lower wall 53d arranged in the x direction.

The walls constituting these first surrounding portions 53 are formed along the edge of the upper end surface 51e. In the circumferential direction around the z direction, the left wall 53a, the upper wall 53c, the right wall 53b, and the lower wall 53d are connected in this order. As a result, the first enclosing portion 53 has an annular shape that is open in the z direction. The upper end surface 51e is surrounded by the first enclosing portion 53. The wiring board 20 and the first shield 41 are provided in the first storage space formed by the first surrounding portion 53 and the upper end surface 51e.

As shown in column (b) of FIG. 11, the second surrounding portion 54 is formed on the lower end surface 51f of the base portion 51. The second enclosing portion 54 has a left wall 54a and a right wall 54b arranged in the y direction. The second enclosing portion 54 has an upper wall 54c and a lower wall 54d arranged in the x direction.

The walls constituting these second surrounding portions 54 are formed around a portion of the lower end surface 51f that is lined up with the narrowed portion 31a of the base portion 51 in the z direction. In the circumferential direction around the z direction, the left wall 54a, the upper wall 54c, the right wall 54b, and the lower wall 54d are connected in this order. As a result, the second enclosing portion 54 has an annular shape that is open in the z direction. A portion of the lower end surface 51f is surrounded by the second enclosing portion 54. The second shield 42 is provided in the second storage space formed by the second surrounding portion 54 and the lower end surface 51f.

The second storage space has a smaller size in a plane perpendicular to the z direction than the first storage space. The second storage space is lined up with a part of the first storage space in the z direction. A portion of the first storage space that is not lined up in the z-direction with the second storage space and the connector portion 55 are lined up in the z-direction.

As shown in column (b) of FIG. 5 and column (b) of FIG. 11, the connector portion 55 is formed on the lower end surface 51f of the base portion 51. The connector portion 55 extends in the z direction away from a portion of the lower end surface 51f that is not surrounded by the second surrounding portion 54 (non-enclosed portion). The connector portion 55 constitutes a part of the lower wall 54d.

The connector portion 55 has a column portion 55a extending in the z direction from the lower end surface 51f, and an enclosing portion 55c surrounding the tip surface 55b of the column portion 55a in the circumferential direction around the z direction. The connection terminal 60 extends in the z direction. The connection terminal 60 is covered by the column portion 55a and a portion of the base portion 51 that is aligned with the column portion 55a in the z direction.

One end of the connection terminal 60 is exposed to the outside of the column portion 55a from the tip surface 55b. One end of the connection terminal 60 exposed from the tip surface 55b is surrounded by the above-described enclosing portion 55c. As a result, the enclosing portion 55c and one end of the connecting terminal 60 constitute a connector. A connector such as a wire harness is connected to this connector.

The other end of the connection terminal 60 is exposed to the outside of the base 51 from the upper end surface 51e. The other end of the connection terminal 60 is provided in the first storage space. The connection terminal 60 is separated from the portion (narrowed portion 31a) of the conductive bus bar 30 covered by the base portion 51 in the x direction. The other end of the connection terminal 60 is located on the lower wall 53d side in the x direction. The narrowed portion 31a is located on the upper wall 53c side. An insulating resin material constituting the base portion 51 is located between the connection terminal 60 and the portion insert-molded in the sensor housing 50 of each of the narrowed portions 31a.

As described above, a direct current flows through the conductive bus bar 30 to input and output the battery 200 . An electrical signal having a smaller current amount than a direct current flows through the connection terminal 60 between the wiring board 20 and the battery ECU 801. If the creepage distance between the conductive bus bar 30 and the connection terminal 60 is short, there is a risk that the two may be electrically connected and cause a short circuit.

Ribs 52a are formed on the insulating portion 52 to prevent such problems from occurring. The ribs 52a protrude from the insulating portion 52 in the z direction. The ribs 52a extend in the x direction. The length of the rib 52a in the x direction is longer than the length of each of the first exposed portion 32 and the second exposed portion 33 in the x direction.

The rib 52a is located between the first exposed portion 32 and the second exposed portion 33 of the conductive bus bar 30 located outside the insulating portion 52, and the other end of the connecting terminal 60 exposed from the upper end surface 51e. This rib 52a increases the creeping distance between the conductive bus bar 30 and the connection terminal 60 on the surface of the sensor housing 50. Thereby, short circuit between the conductive bus bar 30 and the connection terminal 60 is suppressed.

Further, the rib 52a is located between the first exposed portion 32 and the second exposed portion 33, and the first shield 41 and the second shield 42. This also prevents short circuits between the conductive bus bar 30 and the shield 40.

By extending the creepage distance by the ribs 52a, the length of the insulating portion 52 in the y direction can be shortened. The length of the insulating section 52 in the y direction can be reduced by approximately 85%. This suppresses an increase in the size of the first current sensor 11.

<Fixing form of wiring board to sensor housing>
As shown in column (a) of FIG. 11 and column (a) of FIG. 12, substrate support pins 56a and substrate adhesive pins 56b that locally extend in the z direction are formed on the upper end surface 51e of the base 51. . A plurality of these substrate support pins 56a and substrate adhesive pins 56b are formed on the upper end surface 51e. Column (a) in FIG. 12 shows a perspective view of the sensor housing. The column (b) in FIG. 12 shows a perspective view of the sensor housing provided with the wiring board. In FIG. 12, in order to explain these pins, some symbols are omitted.

Each of the plurality of substrate support pins 56a has a tip surface 56c facing the z direction. The positions of these plurality of tip surfaces 56c in the z direction are equal to each other. Similarly, each of the plurality of substrate adhesive pins 56b has a tip surface 56d facing the z direction. The positions of these plurality of tip surfaces 56d in the z direction are equal to each other.

As shown in FIG. 13, the length in the z direction between the tip end surface 56c and the upper end surface 51e of the substrate support pin 56a is L1. The length in the z direction between the tip end surface 56d and the upper end surface 51e of the substrate adhesive pin 56b is L2. As clearly shown in the drawings, length L1 is longer than length L2.

Therefore, the tip surface 56c of the substrate support pin 56a is further away from the upper end surface 51e in the z direction than the tip surface 56d of the substrate adhesive pin 56b. The wiring board 20 is mounted on the sensor housing 50 in such a manner that the opposing surface 20a contacts the tip end surface 56c of the board support pin 56a. The board support pin 56a corresponds to a board support part. The tip surface 56c corresponds to a support surface.

When mounted on the tip surface 56c of the board support pin 56a, the opposing surface 20a of the wiring board 20 and the tip surface 56d of the board adhesive pin 56b are separated in the z direction. A board adhesive 56e is provided between the wiring board 20 and the board adhesive pins 56b to adhesively fix the two. The substrate bonding pin 56b corresponds to a substrate bonding portion. The tip surface 56d corresponds to the mounting surface.

When bonding and fixing the wiring board 20 and the sensor housing 50 using the board adhesive 56e, the temperature of the board adhesive 56e is set higher than the environmental temperature where the first current sensor 11 is provided. The temperature of the substrate adhesive 56e at this time can be set to about 150° C., for example. At this temperature, the substrate adhesive 56e has fluidity. A silicon adhesive can be used as the substrate adhesive 56e.

A substrate adhesive 56e having fluidity of about 150° C. is applied to the tip surface 56d of the substrate adhesive pin 56b. Then, the wiring board 20 is installed in the sensor housing 50 so that the front end surface 56c of the board support pin 56a and the board adhesive 56e are in contact with the opposing surface 20a of the wiring board 20, respectively. Thereafter, the substrate adhesive 56e is cooled to room temperature and solidified.

As a result, residual stress that condenses toward the center of the substrate adhesive 56e is generated in the substrate adhesive 56e at the environmental temperature where the first current sensor 11 is provided. This residual stress causes the wiring board 20 and the board adhesive pins 56b to approach each other. The contact state between the opposing surface 20a of the wiring board 20 and the tip end surface 56c of the board support pin 56a is maintained.

As a result, the positional deviation of the wiring board 20 with respect to the sensor housing 50 does not depend on the shape variation of the board adhesive 56e having fluidity when it is bonded and fixed. Misalignment of the wiring board 20 with respect to the sensor housing 50 results in a manufacturing error of the sensor housing 50. In other words, misalignment of the wiring board 20 with respect to the conductive bus bar 30 insert-molded in the sensor housing 50 results in a manufacturing error of the sensor housing 50 .

In this embodiment, three substrate support pins 56a are formed on the upper end surface 51e. Two of these three substrate support pins 56a are spaced apart from each other in the y direction. The remaining one substrate support pin 56a is spaced apart in the x direction from the midpoint between the two substrate support pins 56a lined up in the y direction. The tip surfaces 56c of the three substrate support pins 56a form the vertices of an isosceles triangle. The narrowed portion 31a of the conductive bus bar 30 is located between the two substrate support pins 56a lined up in the y direction and the remaining one substrate support pin 56a.

In this embodiment, three substrate adhesive pins 56b are formed on the upper end surface 51e. Two of these three substrate adhesive pins 56b are spaced apart from each other in the y direction. The remaining one substrate adhesive pin 56b is spaced apart in the x direction from the midpoint between the two substrate support pins 56a lined up in the y direction. The tip surfaces 56d of the three substrate adhesive pins 56b form the vertices of an isosceles triangle.

The other ends of the plurality of connection terminals 60 are lined up between two board support pins 56a lined up in the y direction. The remaining one substrate support pin 56a is located at the midpoint between the two substrate adhesive pins 56b arranged in the y direction. Therefore, this remaining one substrate support pin 56a is lined up with the remaining one substrate adhesive pin 56b in the x direction. The center point CP of the narrowed portion 31a is located between the remaining one substrate support pin 56a and the remaining one substrate adhesive pin 56b in the x direction.

With the configuration described above, the isosceles triangle formed by connecting the tip surfaces 56c of the three substrate support pins 56a and the isosceles triangle formed by connecting the tip surfaces 56d of the three substrate adhesive pins 56b overlap in the z direction. There is. The center point CP of the narrowed portion 31a is located in a region where these two isosceles triangles overlap in the z direction.

The wiring board 20 is provided in the sensor housing 50 so as to face each of these two isosceles triangles in the z direction. The portion of the wiring board 20 that faces the two isosceles triangles faces the two isosceles triangles for contact with the board support pin 56a and connection with the board adhesive pin 56b via the board adhesive 56e. The connection with the sensor casing 50 is more stable than that of a portion that does not. The first sensing section 21 and the second sensing section 22 are mounted on the wiring board 20 at a portion where the connection with the sensor housing 50 is stabilized.

When the wiring board 20 is mounted on the board support pins 56a and fixed to the board adhesive pins 56b via the board adhesive 56e, the opposing surface 20a of the wiring board 20 and the upper end surface 51e of the base 51 are aligned in the z direction. They are separated and facing each other. If there are no manufacturing errors, the distance between the opposing surface 20a and the upper end surface 51e is constant over the entire surface, and the two are in a parallel relationship.

As described above, the narrow portion 31a of the conductive bus bar 30 is insert-molded in the base portion 51. If there are no manufacturing errors, the distance between the surface 30a of the narrowed portion 31a and the upper end surface 51e of the base portion 51 is also constant over the entire surface, and the two are in a parallel relationship.

Due to the parallel relationship shown above, if there are no manufacturing errors, the distance between the opposing surface 20a of the wiring board 20 and the surface 30a of the narrowed portion 31a is constant over the entire surface, and the two are in a parallel relationship. .

By the way, as described above, the wiring board 20 is formed by laminating a plurality of resin layers and metal layers in the z direction. Therefore, the manufacturing error in the thickness of the wiring board 20 in the z direction becomes large. The manufacturing error in the thickness of the wiring board 20 in the z direction is the manufacturing error in the position in the z direction due to insert molding of the conductive bus bar 30 into the sensor housing 50, and the error in the placement of the wiring board 20 in the z direction with respect to the sensor housing 50. It is about twice that of the previous year.

On the other hand, as described above, the first sensing section 21 and the second sensing section 22 are provided on the surface 20a of the wiring board 20 facing the conductive bus bar 30. Therefore, the separation distance in the z-direction between the first sensing part 21 and the second sensing part 22 from the conductive bus bar 30 does not depend on the thickness of the wiring board 20 in the z-direction. Variations in the distances in the z-direction between the first sensing section 21, the second sensing section 22, and the conductive bus bar 30 due to manufacturing errors in the thickness of the wiring board 20 in the z-direction are suppressed.

Note that the number of substrate support pins 56a and substrate adhesive pins 56b is not limited to three. It is also possible to employ four or more as the number of substrate support pins 56a. The number of substrate adhesive pins 56b may be one, two, or four or more.

In addition, when the number of each of the board support pins 56a and the board adhesive pins 56b is three or more, a polygon formed by connecting the tip surfaces 56c of the three or more board support pins 56a and the number of the three or more board adhesive pins 56b are formed. It is preferable that the polygon formed by connecting the tip surfaces 56d overlap in the z direction. In this configuration, it is preferable to mount the first sensing section 21 and the second sensing section 22 in a region of the wiring board 20 that faces the two polygons in the z direction. As a result, positional displacement of the first sensing section 21 and the second sensing section 22 with respect to the sensor housing 50 is suppressed.

As indicated by the names board support pins 56a and board adhesion pins 56b, an example is shown in which these pins are columnar extending in the z direction. However, these shapes are not limited to columnar shapes. The shape is not particularly limited as long as the tip surface 56c of the substrate support pin 56a is farther from the upper end surface 51e than the tip surface 56d of the substrate adhesive pin 56b.

<Fixing form of the first shield to the sensor housing>
As shown in column (a) of FIG. 11 and column (a) of FIG. 14, a shield support pin 57a and a shield adhesive pin 57b that locally extend in the z direction are formed on the upper end surface 51e of the base 51. . A plurality of these shield support pins 57a and shield adhesive pins 57b are formed on the upper end surface 51e. Column (a) in FIG. 14 shows a perspective view of a sensor housing provided with a wiring board. The column (b) in FIG. 14 shows a perspective view of the sensor housing provided with the wiring board and the shield. In FIG. 14, in order to explain these pins, some symbols are omitted.

Each of the plurality of shield support pins 57a has a tip surface 57c facing the z direction. The positions of these plurality of tip surfaces 57c in the z direction are equal to each other. Similarly, each of the plurality of shield adhesive pins 57b has a tip surface 57d facing the z direction. The positions of these plurality of tip surfaces 57d in the z direction are equal to each other.

As shown in FIG. 15, each of the shield support pin 57a and the shield adhesive pin 57b has a longer length in the z direction than the board support pin 56a. More specifically, each of the shield support pin 57a and the shield adhesive pin 57b is longer in the z direction than the board support pin 56a by at least the thickness of the wiring board 20 in the z direction. Therefore, in the state where the wiring board 20 is mounted on the sensor housing 50 as described above, the tip surface 57c of the shield support pin 57a and the tip surface 57d of the shield adhesive pin 57b are both upper end surfaces than the back surface 20b of the wiring board 20. 51e in the z direction. Note that a configuration may also be adopted in which the difference in length in the z direction between the shield adhesive pin 57b and the board support pin 56a is shorter than the thickness of the wiring board 20 in the z direction.

As shown in FIG. 15, the length in the z direction between the tip end surface 57c and the upper end surface 51e of the shield support pin 57a is L3. The length in the z direction between the tip surface 57d and the upper end surface 51e of the shield adhesive pin 57b is L4. As clearly shown in the drawings, length L3 is longer than length L4.

Therefore, the tip surface 57c of the shield support pin 57a is further away from the upper end surface 51e in the z direction than the tip surface 57d of the shield adhesive pin 57b. The first shield 41 is mounted on the sensor housing 50 in such a manner that one surface 41a contacts the tip end surface 57c of the shield support pin 57a. The shield support pin 57a corresponds to a shield support portion. The tip surface 57c corresponds to a contact surface.

When mounted on the tip surface 57c of the shield support pin 57a, one surface 41a of the first shield 41 and the tip surface 57d of the shield adhesive pin 57b are separated in the z direction. A substrate adhesive 56e for adhesively fixing the first shield 41 and the shield adhesive pin 57b is provided between the first shield 41 and the shield adhesive pin 57b. The shield adhesive pin 57b corresponds to the shield adhesive part. The tip surface 57d corresponds to the installation surface.

When adhesively fixing the first shield 41 and the sensor housing 50 using the shield adhesive 57e, the temperature of the shield adhesive 57e is set higher than the environmental temperature where the first current sensor 11 is provided. The temperature of the shield adhesive 57e at this time can also be set to, for example, about 150°C. At this temperature, the shielding adhesive 57e has fluidity. A silicon adhesive can be used as the shield adhesive 57e.

A shield adhesive 57e having fluidity of about 150° C. is applied to the tip surface 57d of the shield adhesive pin 57b. The first shield 41 is provided in the sensor housing 50 so that the tip end surface 57c of the shield support pin 57a and the shield adhesive 57e are in contact with one surface 41a of the first shield 41. Thereafter, the shield adhesive 57e is cooled to room temperature and solidified.

As a result, residual stress that condenses toward the center of the shield adhesive 57e is generated in the shield adhesive 57e at the environmental temperature where the first current sensor 11 is provided. This residual stress brings the first shield 41 and the shield adhesive pin 57b closer to each other. The state of contact between the one surface 41a of the first shield 41 and the tip surface 57c of the shield support pin 57a is maintained.

As a result, the positional shift of the first shield 41 with respect to the sensor housing 50 does not depend on the shape variation of the shield adhesive 57e which has fluidity when being adhesively fixed. The positional deviation of the first shield 41 with respect to the sensor housing 50 results in a manufacturing error of the sensor housing 50. In other words, the positional deviation of the first shield 41 with respect to the wiring board 20 fixed to the sensor housing 50 results in a manufacturing error of the sensor housing 50.

In this embodiment, three shield support pins 57a are formed on the upper end surface 51e. One of these three shield support pins 57a is integrally connected to the left wall 53a. One of the remaining two shield support pins 57a is integrally connected to the right wall 53b. The remaining shield support pin 57a is integrally connected to the upper wall 53c. As a result, the tip surfaces 57c of the three shield support pins 57a form the vertices of a triangle.

A shield support pin 57a integrally connected to the left wall 53a and a shield support pin 57a integrally connected to the right wall 53b are lined up in the y direction. The space between these two shield support pins 57a and the shield support pin 57a integrally connected to the upper wall 53c are spaced apart in the x direction. The first sensing section 21 and the second sensing section 22 of the wiring board 20 are located in a triangular area formed by connecting the tip surfaces 57c of these three shield support pins 57a.

In this embodiment, three shield adhesive pins 57b are formed on the upper end surface 51e. One of these three shield adhesive pins 57b is integrally connected to the left wall 53a. One of the remaining two shield adhesive pins 57b is integrally connected to the right wall 53b. The remaining shield adhesive pin 57b is integrally connected to the upper wall 53c. As a result, the tip surfaces 57d of the three shield adhesive pins 57b form the vertices of a triangle.

The shield adhesive pin 57b integrally connected to the left wall 53a and the shield adhesive pin 57b integrally connected to the right wall 53b are lined up in the y direction. The space between these two shield adhesive pins 57b and the shield adhesive pin 57b integrally connected to the upper wall 53c are spaced apart in the x direction. A triangular region formed by connecting the tip surfaces 57d of these three shield adhesive pins 57b, the first sensing portion 21, and the second sensing portion 22 are lined up in the z direction.

Further, one shield support pin 57a and one shield adhesive pin 57b are arranged in each of the left wall 53a and the right wall 53b. One shield support pin 57a and one shield adhesive pin 57b are lined up on the upper wall 53c. A triangle formed by connecting the tip surfaces 57c of the three shield support pins 57a and a triangle formed by connecting the tip surfaces 57d of the three shield adhesive pins 57b overlap in the z direction. These overlapping regions in the z-direction and the center point CP of the narrowed portion 31a are aligned in the z-direction.

The first shield 41 is provided in the sensor housing 50 so as to face each of these two triangles in the z direction. The portion of the first shield 41 that faces the two triangles is more likely to contact the shield support pin 57a and connect with the shield adhesive pin 57b via the shield adhesive 57e than the portion that does not face the two triangles. The connection with the sensor housing 50 is also stabilized.

The portions of the first shield 41 where the connection with the sensor housing 50 is stabilized are aligned with the first sensing portion 21 and the second sensing portion 22 of the wiring board 20 in the z direction. Specifically, the first central portion 41d of the first shield 41 is aligned with each of the first sensing section 21 and the second sensing section 22 in the z direction.

In a state where the first shield 41 is mounted on the shield support pin 57a and fixed to the shield adhesive pin 57b via the shield adhesive 57e, one surface 41a of the first shield 41 and the back surface 20b of the wiring board 20 are aligned in the z direction. They are facing away from each other. If there are no manufacturing errors, the distance between the first surface 41a and the rear surface 20b is constant over the entire surface, and the two are in a parallel relationship. Therefore, the distance between the facing surface 20a of the wiring board 20 and the one surface 41a of the first shield 41 is constant over the entire surface, and the two are in a parallel relationship.

As shown in column (a) of FIGS. 6 and 14, a notch 20g is provided at the end of the wiring board 20 for passing the shield support pin 57a and the shield adhesive pin 57b above the wiring board 20. is formed. The wiring board 20 is formed with a plurality of through holes 20h through which the other ends of the connection terminals 60 pass.

As shown in FIG. 6, the plurality of through holes 20h are arranged in the y direction. A portion of the wiring board 20 where the plurality of through holes 20h are formed and a portion where the first sensing portion 21 and the second sensing portion 22 are mounted are lined up in the x direction. Between these two portions of the wiring board 20 arranged in the x direction, there is a first groove for guiding the position of the wiring board 20 in the x direction with respect to the sensor housing 50 when the wiring board 20 is installed in the sensor housing 50. A notch 20i is formed. In addition, when the wiring board 20 is installed in the sensor housing 50, the position of the wiring board 20 in the y direction with respect to the sensor housing 50 is A second notch 20j is formed for guiding.

Correspondingly, as shown in column (a) of FIG. 11 and column (b) of FIG. A first convex portion 53e is formed. A second convex portion 53f is formed on each of the left wall 53a and the right wall 53b, and is arranged to face the second notch 20j in the y direction. The first notch 20i and the first convex portion 53e have similar shapes and extend in the y direction. The second notch 20j and the second convex portion 53f have similar shapes and extend in the x direction.

The number of shield support pins 57a and shield adhesive pins 57b described above is not limited to the above example. Four or more shield support pins 57a can be used. The number of shield adhesive pins 57b may be one, two, or four or more.

When the number of shield support pins 57a and shield adhesive pins 57b is three or more, a polygon formed by connecting the tip surfaces 57c of three or more shield support pins 57a and the tip surfaces of three or more shield adhesive pins 57b. It is preferable that the polygon formed by connecting 57d overlaps in the z direction. In this configuration, it is preferable that regions of the first shield 41 that face the two polygons in the z direction line up with each of the first sensing section 21 and the second sensing section 22 of the wiring board 20 in the z direction. This suppresses misalignment of the first shield 41 with respect to each of the first sensing section 21 and the second sensing section 22.

As indicated by the names shield support pin 57a and shield adhesive pin 57b, an example is shown in which these pins have a columnar shape extending in the z direction. However, these shapes are not limited to columnar shapes. The shape is not particularly limited as long as the tip surface 57c of the shield support pin 57a is farther from the upper end surface 51e than the tip surface 57d of the shield adhesive pin 57b.

<Fixing form of the second shield to the sensor housing>
As shown in column (b) of FIG. 11 and FIG. 15, a plurality of shield support pins 57a are also formed on the lower end surface 51f of the base 51.

Unlike the first shield 41, the wiring board 20 is not provided between the sensor housing 50 and the second shield 42. Therefore, the shield support pin 57a formed on the lower end surface 51f has a shorter length in the z direction than the shield support pin 57a formed on the upper end surface 51e. The positions of the tips of the plurality of substrate support pins 56a in the z direction are equal to each other. The second shield 42 is mounted on the sensor housing 50 in such a manner that one surface 42a contacts the tip end surface 57c of the shield support pin 57a.

When mounted on the tip end surface 57c of the shield support pin 57a, the one surface 42a of the second shield 42 is separated from the lower end surface 51f in the z direction. A shield adhesive 57e is provided between the second shield 42 and the lower end surface 51f.

When the second shield 42 and the sensor housing 50 are bonded and fixed using the shield adhesive 57e, the temperature of the shield adhesive 57e is also set higher than the environmental temperature where the first current sensor 11 is provided.

A fluid shielding adhesive 57e is applied to the lower end surface 51f. The second shield 42 is provided in the sensor housing 50 so that the tip end surface 57c of the shield support pin 57a and the shield adhesive 57e are in contact with one surface 42a of the second shield 42. Thereafter, the shield adhesive 57e is cooled to room temperature and solidified.

As a result, the shield adhesive 57e provided on the lower end surface 51f also generates residual stress that condenses toward its center at the environmental temperature where the first current sensor 11 is provided. This residual stress causes the second shield 42 and the shield adhesive pin 57b to approach each other. The state of contact between the one surface 42a of the second shield 42 and the tip surface 57c of the shield support pin 57a is maintained.

As a result, the positional shift of the second shield 42 with respect to the sensor housing 50 does not depend on the shape variation of the shield adhesive 57e which has fluidity at the time of adhesive fixation. The positional deviation of the second shield 42 with respect to the sensor housing 50 results in a manufacturing error of the sensor housing 50. In other words, the positional deviation of the second shield 42 with respect to the wiring board 20 fixed to the sensor housing 50 results in a manufacturing error of the sensor housing 50.

In this embodiment, four shield support pins 57a are formed on the lower end surface 51f. The tip surfaces 57c of the four shield support pins 57a form the vertices of a rectangle. The rectangle formed by connecting the tip surfaces 57c of these four shield support pins 57a and the center point CP of the narrowed portion 31a are aligned in the z direction. The shielding adhesive 57e is applied to a region of the lower end surface 51f facing this square.

The second shield 42 is provided in the sensor housing 50 in such a manner that it faces the above-mentioned quadrangle in the z direction. The portion of the second shield 42 that faces the square is in contact with the shield support pin 57a and is connected to the lower end surface 51f via the shield adhesive 57e, so that the portion of the second shield 42 that faces the square is more likely to be attached to the sensor casing than the portion that does not face the square. The connection with 50 is stable.

The portions of the second shield 42 where the connection with the sensor housing 50 is stabilized are aligned with the first sensing portion 21 and the second sensing portion 22 of the wiring board 20 in the z direction. Specifically, the second central portion 42d of the second shield 42 is aligned with each of the first sensing section 21 and the second sensing section 22 in the z direction.

Note that the number of shield support pins 57a formed on the lower end surface 51f is not limited to four. The number of shield support pins 57a may be three or more as appropriate.

When the number of shield support pins 57a is three or more, the region of the second shield 42 that faces the polygon formed by connecting the tip surfaces 57c of these three or more shield support pins 57a in the z direction is the first sensing portion. 21 and the second sensing section 22, respectively, in the z direction. This suppresses positional displacement of the second shield 42 with respect to each of the first sensing section 21 and the second sensing section 22.

As described above, each of the two end sides 42f of the second shield 42 aligned in the x direction is provided with an extending portion 42c extending in the z direction. Two groove portions 51g are formed in the lower end surface 51f for providing the extension portion 42c.

As shown in column (b) of FIG. 11 and FIG. 13, the two groove portions 51g are lined up in the x direction between the upper wall 54c and the lower wall 54d. The two groove portions 51g are each formed in the z direction from the lower end surface 51f toward the upper end surface 51e. A portion of one of the two groove portions 51g is formed by the upper wall 54c. A portion of the remaining groove 51g is formed by the lower wall 54d. The covering portion 31 is located between these two groove portions 51g. Therefore, the covering portion 31 is located between the two extending portions 42c of the second shield 42.

<Length of support pin and adhesive pin>
The upper end surface 51e of the base portion 51 is divided into a region where the other ends of the connection terminals 60 aligned in the x direction are exposed and a region that covers the narrowed portion 31a, using the first convex portion 53e as a boundary in the y direction. I can do it. The exposed portion of the other end of the connection terminal 60 on the upper end surface 51e is located closer to the lower end surface 51f in the z direction than the portion that covers the narrowed portion 31a. Therefore, the distance in the z direction between the exposed portion of the other end of the connection terminal 60 on the upper end surface 51 e and the opposing surface 20 a of the wiring board 20 is the same as the distance between the portion of the upper end surface 51 e that covers the narrowed portion 31 a and the opposing surface of the wiring board 20 . It is longer than the separation distance from the surface 20a in the z direction. This is to ensure a distance for inserting the other end of the connection terminal 60 into the through hole 20h of the wiring board 20.

In this way, the positions of the exposed portion of the other end of the connection terminal 60 on the upper end surface 51e and the portion that covers the narrowed portion 31a are different in the z direction. A substrate support pin 56a is formed at each of these two parts. Although the positions of the upper end surfaces 51e formed in this way differ in the z-direction, in this embodiment, the positions of the tip surfaces 56c of each of the plurality of substrate support pins 56a in the z-direction are the same. Therefore, the lengths of the plurality of substrate support pins 56a in the z direction are different.

The lengths of the plurality of substrate support pins 56a in the z direction are not uniformly the length L1 shown in FIG. 13. This length L1 indicates the length in the z direction of the substrate support pin 56a formed at a portion of the upper end surface 51e that covers the narrowed portion 31a. The length in the z direction of the board support pin 56a formed at the exposed part of the other end of the connection terminal 60 on the upper end surface 51e is longer than the length L1 in the z direction of the upper end surface 51e divided into the above two parts. It is longer by the difference in position.

As shown above, the length of the support pin in the z-direction may be different depending on the position of the formed surface in the z-direction. It is only necessary that the positions of the tip surfaces 56c of the plurality of substrate support pins 56a in the z direction are the same. This also applies to the plurality of shield support pins 57a.

Note that when mounting the wiring board 20 on the sensor housing 50, a fluid board adhesive 56e is applied to the tip surface 56d of the board adhesive pin 56b. The shape of the substrate adhesive 56e in the z direction is variable due to its fluidity. Therefore, the positions of the tip surfaces 56d of the plurality of substrate adhesive pins 56b in the z direction may be different. This also applies to the plurality of shield adhesive pins 57b.

<Second current sensor and third current sensor>
Next, the second current sensor 12 will be explained in detail. Note that the second current sensor 12 and the third current sensor 13 have substantially the same configuration. Therefore, description of the third current sensor 13 will be omitted.

Further, the second current sensor 12 has common components with the first current sensor 11. Therefore, in the following, the explanation of the same points as the first current sensor 11 will be omitted, and the different points will be mainly explained.

As described above, the second current sensor 12 is provided on the first energized bus bar 341 and the second energized bus bar 342. In order to detect the currents of the first energized bus bar 341 and the second energized bus bar 342, the second current sensor 12 includes two individual sensors 71 having the same function as the first current sensor 11. Further, the second current sensor 12 has a wiring case 72 that houses these two individual sensors 71.

One of the two individual sensors 71 detects the magnetic field generated from the alternating current flowing through the first energized bus bar 341 . The other of the two individual sensors 71 detects the magnetic field generated from the alternating current flowing through the second energized bus bar 342 .

Two individual sensors 71 are shown in FIG. In this way, the two individual sensors 71 have the same shape. The structural differences between this individual sensor 71 and the first current sensor 11 include the connection portion of the conductive bus bar 30 to the current-carrying bus bar, the shape of the connector portion 55 that covers the connection terminal 60, and the like. That is, the shapes of the first exposed portion 32 and the second exposed portion 33 of the conductive bus bar 30, the disappearance of the surrounding portion 55c, etc.

The reason for this structural difference between the individual sensor 71 and the first current sensor 11 is that they are connected to different objects. This is because the first current sensor 11 is connected to the energized bus bar 307 of the converter 310. This is because the second current sensor 12 is connected to the first energized bus bar 341 and the second energized bus bar 342 of the first inverter 320 . However, the internal structures of the individual sensor 71 and the first current sensor 11 are the same. Therefore, the individual sensor 71 has the same effect as the first current sensor 11.

The plurality of individual sensors 71 are housed in a wiring case 72 shown in FIG. As shown in FIG. 18, a plurality of individual sensors can be housed together in a wiring case 72. As shown in FIG. 19, the second current sensor 12 is configured by housing a plurality of individual sensors in a wiring case 72.

In addition, in the case of this arrangement, the first shield 41 and the second shield 42 of each individual sensor 71 are arranged alternately in the x direction. The detection directions of the magnetic field of the magnetoelectric converter 25 of the individual sensor 71 are the z direction and the y direction.

Further, six individual sensors 71 are housed in each of the wiring cases 72 shown in FIGS. 17 to 19 shown so far and the drawings shown below. The number of individual sensors 71 housed in this wiring case 72 is only an example. The wiring case 72 only needs to be able to accommodate at least two individual sensors 71.

Furthermore, the wiring case 72 of the second current sensor 12 may house a current sensor that detects the current of another vehicle-mounted device. Furthermore, the second current sensor 12 and the third current sensor 13 have a common wiring case 72, and the individual sensors each of the second current sensor 12 and the third current sensor 13 have in this common wiring case 72. It is also possible to adopt a configuration in which 71 is housed.

<Wiring case>
As shown in FIG. 17, the wiring case 72 includes an integrated housing 73, a terminal housing 74, and a current-carrying terminal 75. The integrated housing 73 and the terminal housing 74 are made of an insulating resin material. The integrated housing 73 and the terminal housing 74 are integrally connected. As shown in FIGS. 18 and 19, a plurality of individual sensors 71 are housed in an integrated housing 73. Therefore, the integrated housing 73 is larger than the sensor housing 50 of the individual sensor 71. A plurality of energizing terminals 75 are insert-molded in the terminal housing 74. As shown in FIGS. 20 to 23, one end and the other end of each of the plurality of current-carrying terminals 75 are exposed outside the terminal housing 74.

Column (a) in FIG. 20 shows a rear view of the wiring case. The column (b) in FIG. 20 shows a top view of the wiring case. Column (c) in FIG. 20 shows a bottom view of the wiring case. Column (a) in FIG. 21 shows a left side view of the wiring case. The column (b) in FIG. 21 shows a top view of the wiring case. Column (c) in FIG. 21 shows a right side view of the wiring case. Note that the same drawings are shown in column (b) of FIG. 20 and column (b) of FIG. 21.

Column (a) in FIG. 22 shows a front view of the second current sensor. The column (b) in FIG. 22 shows a top view of the second current sensor. Column (c) in FIG. 22 shows a bottom view of the second current sensor. Column (a) in FIG. 23 shows a side view of the second current sensor. The column (b) in FIG. 23 shows a top view of the second current sensor. Note that the same drawings are shown in the column (b) of FIG. 22 and the column (b) of FIG. 23.

As shown in column (c) of each of FIGS. 20 and 22, the wiring case 72 has an integrated wiring board 76. One end of the connection terminal 60 of the individual sensor 71 is connected to this integrated wiring board 76 . One end of the energizing terminal 75 is connected to the integrated wiring board 76 . Thereby, the individual sensor 71 and the energizing terminal 75 are electrically connected via the wiring pattern of the integrated wiring board 76. The other end of the energizing terminal 75 is electrically connected to the MGECU 802 via a wire harness or the like. As described above, the output of the individual sensor 71 is input to the MGECU 802 via the integrated wiring board 76, the energizing terminal 75, and the wire harness. The integrated wiring board 76 and the current-carrying terminal 75 correspond to input/output wiring.

As described above, the second current sensor 12 is provided on the first energized bus bar 341 and the second energized bus bar 342. These energizing bus bars are separated on the first inverter 320 side and the first motor 400 side. The current-carrying bus bar has a portion that connects the first inverter 320 and the second current sensor 12, and a portion that connects the second current sensor 12 and the first motor 400.

The portion of the current-carrying bus bar of this embodiment that connects the first inverter 320 and the second current sensor 12 is a conductive plate made of a metal material. The portion of the current-carrying bus bar that connects the second current sensor 12 and the first motor 400 is a wire. In the following, a portion of the current-carrying bus bar that connects the first inverter 320 and the second current sensor 12 will be simply referred to as a conductive plate. A portion of the current-carrying bus bar that connects the second current sensor 12 and the first motor 400 is simply referred to as a wire.

Note that the form of the current-carrying bus bar can be changed as appropriate depending on the respective shapes of the inverter and motor, and the manner in which they are mounted on the vehicle. Therefore, the specific form of the current-carrying bus bar is not limited to the above example. Depending on the form of these current-carrying bus bars, the form of each of the wiring case 72 and the conductive bus bar 30 of the individual sensor 71 can be changed as appropriate. In particular, the shape of the conductive bus bar 30 of the individual sensor 71 can be accommodated by simply changing the shapes of the first exposed portion 32 and the second exposed portion 33. Therefore, the internal shape of the individual sensor 71 does not need to be changed. This eliminates the need to change the manufacturing line for the individual sensors 71.

As shown in FIGS. 20 and 21, the integrated housing 73 has a bottom wall 77 and a peripheral wall 78. The bottom wall 77 faces the z direction. The planar shape of the bottom wall 77 is a rectangle whose longitudinal direction is in the x direction.

The peripheral wall 78 stands up in the z-direction from the inner bottom surface 77a of the bottom wall 77 facing in the z-direction. The peripheral wall 78 has a left wall 78a and a right wall 78b that are aligned in the x direction. The peripheral wall 78 has an upper wall 78c and a lower wall 78d arranged in the y direction. A left wall 78a, an upper wall 78c, a right wall 78b, and a lower wall 78d are connected in order in the circumferential direction around the z direction. As a result, the peripheral wall 78 has a cylindrical shape that opens in the z direction. A plurality of individual sensors 71 can be stored in the storage space formed by the bottom wall 77 and the peripheral wall 78.

As shown in FIG. 18, the individual sensor 71 is inserted into the storage space of the integrated housing 73 from the z direction. As shown in FIG. 19, a plurality of individual sensors 71 are arranged in the x direction in the storage space.

The plurality of individual sensors 71 have a first shield 41 and a second shield 42 similarly to the first current sensor 11 . The first shield 41 and the second shield 42 are spaced apart from each other in the x direction and face each other. Therefore, in the storage space, the first shields 41 and second shields 42 of the plurality of individual sensors are arranged alternately.

As shown in FIG. 16, a first exposed portion 32 and a second exposed portion 33 extend in the y direction from the sensor housing 50 of the individual sensor 71. A slit 78e is formed in the upper wall 78c of the integrated housing 73 for storing the sensor housing 50 of the individual sensor 71 in the storage space and arranging the tip of the first exposed portion 32 outside the storage space. There is. The slit 78e is formed along the z direction from the tip end face of the upper wall 78c toward the bottom wall 77.

When the individual sensor 71 is housed in the integrated housing 73, the tip of the first exposed portion 32 of the individual sensor 71 is located outside the storage space through the slit 78e. The tip of this first exposed portion 32 is electrically connected to the above-mentioned conductive plate by laser welding or the like.

Furthermore, a conductive terminal 79 is insert-molded in the bottom wall 77 of the integrated housing 73. As shown in column (b) of each of FIGS. 20 and 21, a portion of the conductive terminal 79 is exposed from the inner bottom surface 77a of the bottom wall 77.

In a state where the individual sensor 71 is housed in the integrated housing 73, the second exposed portion 33 of the individual sensor 71 is arranged to face the portion of the conductive terminal 79 exposed from the inner bottom surface 77a. This second exposed portion 33 and the conductive terminal 79 are electrically connected by laser welding or the like.

Further, the integrated housing 73 has a terminal block 80 for supporting the plurality of conductive terminals 79. The terminal block 80 is integrally formed on the bottom wall 77 side of the lower wall 78d. The terminal block 80 has a rectangular parallelepiped shape extending in the x direction. A plurality of conductive terminals 79 are also insert-molded in this terminal block 80. A portion of the plurality of conductive terminals 79 is exposed from this terminal block 80. The portion of the conductive terminal 79 exposed from the terminal block 80 extends in the z direction away from the terminal block 80. A portion of the conductive terminal 79 exposed from the terminal block 80 faces the lower wall 78d in the y direction. Portions of the plurality of conductive terminals 79 exposed from the terminal block 80 are spaced apart from each other in the x direction.

The portion of the conductive terminal 79 exposed from the terminal block 80 has a flat shape with a thin thickness in the y direction. The portion of the conductive terminal 79 exposed from the terminal block 80 has a conductive surface 79a facing the y direction and a back surface 79b thereof. A bolt hole 79c is formed in the conductive terminal 79, passing through the current-carrying surface 79a and the back surface 79b in the y direction.

Further, a nut 81 that opens in the y direction is provided on the back surface 79b of the conductive terminal 79. The opening of this nut 81 and the opening of the bolt hole 79c are lined up in the y direction.

A wire terminal is provided on the current-carrying surface 79a of the conductive terminal 79. The terminal of this wire is also formed with a bolt hole penetrating in the y direction. The current-carrying surface 79a of the conductive terminal 79 faces the surface through which the bolt hole of the wire terminal passes. In this manner, the shafts of bolts (not shown) are passed through both bolt holes. Then, the tip of the shaft portion of this bolt is fastened to the nut 81. The bolt is fastened to the nut 81 from the tip of the bolt shaft toward the head. The conductive terminal 79 and the wire terminal are sandwiched between the head of the bolt and the nut 81. This brings the wire terminal and the conductive terminal 79 into contact, electrically and mechanically connecting them. As described above, the second exposed portion 33 of the individual sensor 71 and the wire terminal are electrically connected via the conductive terminal 79.

A connection terminal 60 extends from the sensor housing 50 of the individual sensor 71 in the z direction. An insertion hole is formed in the bottom wall 77 of the integrated housing 73 for arranging one end of the connection terminal 60 outside the storage space. This insertion hole passes through the inner bottom surface 77a of the bottom wall 77 and the outer bottom surface 77b on the back side thereof. One end of the connection terminal 60 projects outside the storage space through the insertion hole in a manner away from the outer bottom surface 77b. Note that the insertion hole is minute. For this reason, the insertion holes are not shown in the drawings.

The terminal housing 74 is aligned with the integrated housing 73 in the x direction. The terminal housing 74 is integrally connected to the left wall 78a of the integrated housing 73. The terminal housing 74 extends in the z direction. The terminal housing 74 has an upper surface 74a and a lower surface 74b that are aligned in the z direction.

A plurality of energizing terminals 75 insert-molded into this terminal housing 74 extend in the z direction. One end of the energizing terminal 75 protrudes from the lower surface 74b of the terminal housing 74. The other end of the energizing terminal 75 protrudes from the upper surface 74a of the terminal housing 74.

As shown in columns (a) and (c) of FIG. 20, the outer bottom surface 77b of the bottom wall 77 of the integrated housing 73 and the lower surface 74b of the terminal housing 74 are continuous in the x direction and the y direction. An integrated wiring board 76 is provided on this continuous outer bottom surface 77b and lower surface 74b.

The integrated wiring board 76 has a flat shape with a small thickness in the z direction. The integrated wiring board 76 has a mounting surface 76a facing the z direction and a back surface 76b. The integrated wiring board 76 is fixed to the integrated housing 73 and the terminal housing 74 in such a manner that the mounting surface 76a faces each of the outer bottom surface 77b and the lower surface 74b in the z direction.

As described above, one end of the current-carrying terminal 75 protrudes from the lower surface 74b. One end of the connection terminal 60 protrudes from the outer bottom surface 77b. On the other hand, the integrated wiring board 76 is formed with a first through hole 76c into which one end of the energizing terminal 75 is inserted. A second through hole 76d into which one end of the connection terminal 60 is inserted is formed in the integrated wiring board 76. The first through hole 76c and the second through hole 76d each penetrate the mounting surface 76a and the back surface 76b of the integrated wiring board 76 in the z direction. Further, a wiring pattern is formed on the integrated wiring board 76 to electrically connect the first through hole 76c and the second through hole 76d.

The integrated wiring board 76 is provided on the outer bottom surface 77b and the lower surface 74b so that one end of the current-carrying terminal 75 is inserted into the first through hole 76c. Then, the first through hole 76c and the current-carrying terminal 75 are electrically connected via solder or the like.

The individual sensor 71 is provided in the storage space so that one end of the connection terminal 60 is inserted into the insertion hole of the bottom wall 77 and the second through hole 76d. Then, the second through hole 76d and the connection terminal 60 are electrically connected via solder or the like. As described above, the connection terminal 60 of the individual sensor 71 is electrically connected to the current-carrying terminal 75 via the second through hole 76d, the wiring pattern of the integrated wiring board 76, and the first through hole 76c.

The wiring case 72 has a plurality of flanges 82 for mounting on a vehicle. A bolt hole 82a for bolting the second current sensor 12 to the vehicle is formed in each of these flanges 82.

The wiring case 72 of this embodiment has three flanges 82. One of the three flanges 82 is formed on the right wall 78b side of the bottom wall 77. One of the remaining two flanges 82 is formed on the lower wall 78d side of the terminal housing 74. This flange 82 is integrally connected to the terminal block 80. The remaining flange 82 is formed on the opposite side of the terminal housing 74 from the connection portion with the integrated housing 73.

As described above, two of the three flanges 82 are lined up in the x direction via the integrated housing 73 and the terminal housing 74. The remaining flange 82 is spaced apart from the two flanges 82 aligned in the x direction in the y direction. The three flanges 82 thus form the vertices of a triangle.

As described above, one end of the connection terminal 60 protrudes from the outer bottom surface 77b, and one end of the energizing terminal 75 protrudes from the lower surface 74b. An integrated wiring board 76 is provided on the outer bottom surface 77b and the lower surface 74b. In order to avoid contact between one end of the connection terminal 60, one end of the current-carrying terminal 75, and the integrated wiring board 76 with the vehicle, each of the three flanges 82 has a leg portion 83 extending in the z direction. The legs 83 separate one end of the connection terminal 60, one end of the current-carrying terminal 75, and the integrated wiring board 76 from the vehicle in the z direction when the second current sensor 12 is mounted on the vehicle.

<Effects of current sensor>
Next, the effects of the current sensor according to this embodiment will be explained. As described above, the first current sensor 11 and the individual sensors 71 of the second current sensor 12 and third current sensor 13 have the same configuration. Therefore, the same effect can be achieved. Therefore, in the following description, the first current sensor 11 and the individual sensor 71 will be simply referred to as current sensors without distinguishing between them in order to avoid complication. Various effects described below suppress a decrease in detection accuracy of the current to be measured.

<Magnetic saturation of shield>
As described above, the first end portions 41e of the first shield 41 are shorter in length in the x direction than the first central portion 41d. Therefore, it is difficult for the magnetic field to enter the first end portions 41e. A magnetic field can be transmitted from one of the two ends of the first end portion 41e to the other portion of the first center portion 41d that is directly connected to the first end portion 41e and lined up in the y direction (parallel portion). suppressed. As a result, magnetic saturation in the parallel portions of the first central portion 41d is suppressed. Electromagnetic noise is suppressed from leaking from the first central portion 41d.

In FIG. 24, regions that are likely to be magnetically saturated due to transmission of the magnetic field in the first shield 41 are schematically shown by hatching. Column (a) in FIG. 24 is a schematic diagram showing magnetic saturation occurring in a first shield without a notch as a comparative configuration. The column (b) in FIG. 24 is a schematic diagram showing the magnetically saturated region of the first shield 41 of this embodiment. The thick solid line arrow shown in FIG. 24 indicates the current flowing through the conductive bus bar 30.

As shown in this schematic diagram, the first shield without a notch tends to be uniformly magnetically saturated. On the other hand, in the first shield 41 in which the notch 41c is formed, even if magnetic saturation occurs in a region other than the parallel region of the first central portion 41d, magnetic saturation in the parallel region is suppressed.

FIG. 25 shows simulation results of the magnetic field distribution passing through the shield. Column (a) in FIG. 25 shows the magnetic field distribution in a cross section along the line XXVa-XXVa shown in FIG. 24. The column (b) in FIG. 25 shows the magnetic field distribution in the cross section along the line XXVb-XXVb shown in FIG.

However, column (a) in FIG. 25 shows the simulation results when the first shield 41 and the second shield 42 are each rectangular. The column (b) in FIG. 25 shows simulation results when the first shield 41 and the second shield 42 each have a notch 41c formed therein. The intensity of the magnetic field is shown by the density of hatching. The rougher the hatching, the weaker the magnetic field strength, and the denser the hatching, the higher the magnetic field strength.

As is clear from this simulation result, in the absence of the notch 41c, the magnetic field distributions of the first shield and the second shield are uniform. The overall magnetic field strength of each of the first shield and the second shield increases. On the other hand, when the notch 41c is formed, the overall magnetic field strength of each of the first shield and the second shield is reduced. In particular, the strength of the magnetic field distribution at the parallel portions of the first central portion 41d and the second central portion 42d becomes low. Therefore, leakage of electromagnetic noise from the first central portion 41d and the second central portion 42d due to magnetic saturation is suppressed.

Note that, as shown in FIG. 25, the magnetic field distribution strengths of the first shield 41 and the second shield 42 are different. This difference is due to the difference in the distance between the first shield 41 and the second shield 42 and the conductive bus bar 30. In both magnetic field distributions, the strength is low in the parallel regions, and the strength is high in regions other than the parallel regions.

This parallel portion of the first central portion 41d in which magnetic saturation is suppressed and the first sensing portion 21 and the second sensing portion 22 mounted on the wiring board 20 are lined up in the z direction. Therefore, the electromagnetic noise leaked due to the magnetic saturation of the first central portion 41d is suppressed from being input to the magnetoelectric conversion units 25 of the first sensing unit 21 and the second sensing unit 22.

<Shield misalignment>
The first shield 41 is mounted on a shield support pin 57a, and is fixed to a shield adhesive pin 57b via a shield adhesive 57e. The second shield 42 is mounted on a shield support pin 57a and fixed to the base 51 via a shield adhesive 57e.

As a result, the positional deviation of the first shield 41 and the second shield 42 with respect to the sensor housing 50 does not depend on the shape variation of the shield adhesive 57e which has fluidity at the time of adhesive fixation. The positional deviation of the first shield 41 and the second shield 42 with respect to the sensor housing 50 results in a manufacturing error of the sensor housing 50. The cause of the positional deviation of the first shield 41 and the second shield 42 with respect to the wiring board 20 fixed to the sensor housing 50 can be a manufacturing error of the sensor housing 50. As a result, the first shield 41 and the second shield 42 suppress the input of electromagnetic noise to the magnetoelectric converter 25 from decreasing.

The temperature of the shield adhesive 57e when each of the first shield 41 and the second shield 42 is adhesively fixed to the sensor housing 50 is set higher than the environmental temperature where the current sensor is provided. This shielding adhesive 57e is cooled to room temperature and solidified. Therefore, residual stress is generated in the shielding adhesive 57e that condenses toward its center at the environmental temperature where the current sensor is provided. This residual stress maintains the contact state between the first shield 41 and the shield support pin 57a, and the contact state between the second shield 42 and the shield support pin 57a.

This suppresses displacement of each of the first shield 41 and the second shield 42 in the z direction with respect to the sensor housing 50. In other words, displacement of the first shield 41 and the second shield 42 in the z direction with respect to the wiring board 20 fixed to the sensor housing 50 is suppressed. This suppresses a decrease in the suppression of input of electromagnetic noise to the magnetoelectric converter 25 by the first shield 41 and the second shield 42 .

<Misalignment of wiring board>
The wiring board 20 is mounted on board support pins 56a and fixed to board adhesive pins 56b via board adhesive 56e.

As a result, the positional deviation of the wiring board 20 with respect to the sensor housing 50 does not depend on the shape variation of the board adhesive 56e having fluidity when being bonded and fixed. Misalignment of the wiring board 20 with respect to the sensor housing 50 results in a manufacturing error of the sensor housing 50. The manufacturing error of the sensor housing 50 can be the cause of the misalignment of the wiring board 20 with respect to the conductive bus bar 30 fixed to the sensor housing 50 . As a result, fluctuations in the magnetic field to be measured that passes through the magnetoelectric conversion unit 25 mounted on the wiring board 20 are suppressed.

The temperature of the board adhesive 56e when adhesively fixing the wiring board 20 to the sensor housing 50 is set higher than the environmental temperature where the current sensor is provided. The substrate adhesive 56e is cooled to room temperature and solidified. Therefore, residual stress is generated in the substrate adhesive 56e that condenses toward its center at the environmental temperature where the current sensor is provided. This residual stress maintains the contact state between the wiring board 20 and the board support pins 56a.

This suppresses displacement of the wiring board 20 with respect to the sensor housing 50 in the z direction. In other words, displacement of the wiring board 20 in the z direction with respect to the conductive bus bar 30 fixed to the sensor housing 50 is suppressed. This suppresses fluctuations in the magnetic field to be measured that passes through the magnetoelectric converter 25 mounted on the wiring board 20.

<Manufacturing error of wiring board>
A first sensing section 21 and a second sensing section 22 are provided on a surface 20a of the wiring board 20 facing the conductive bus bar 30. As a result, the distance in the z direction between the first sensing part 21 and the second sensing part 22 and the conductive bus bar 30 does not depend on the thickness of the wiring board 20 in the z direction. Variations in the distance between the sensing portions and the conductive bus bars 30 in the z-direction due to manufacturing errors in the thickness of the wiring board 20 in the z-direction are suppressed.

<Separation of wiring case and individual sensor>
When a conductive bus bar is fixed to a casing made of an insulating resin material, the conductive bus bar may become misaligned with respect to the casing due to manufacturing errors in the casing or aging deterioration such as creep. The larger the size of the housing, the larger the positional shift becomes.

On the other hand, as described above, the second current sensor 12 and the third current sensor 13 have an integrated housing 73 that is larger in size than the sensor housing 50 of the current sensor (individual sensor 71). A current sensor is housed in this integrated housing 73. The conductive bus bar 30 is fixed not to the large integrated housing 73 but to the sensor housing 50. The magnetoelectric converter 25 detects the current flowing through the conductive bus bar 30.

According to this, relative positional deviation between the conductive bus bar 30 and the magnetoelectric conversion unit 25 is suppressed from occurring due to manufacturing errors of the casing or aging deterioration such as creep.

(Second embodiment)
Next, a second embodiment will be described based on FIGS. 26 and 27. The current sensors according to the embodiments described below have many features in common with those according to the embodiments described above. Therefore, in the following, explanations of common parts will be omitted and different parts will be explained with emphasis. Further, hereinafter, the same elements as those shown in the above-described embodiments are given the same reference numerals.

<Extended portions on both ends>
In the first embodiment, an example is shown in which the extension portions 42c extending in the z direction are formed on each of the second central portion 42d sides of the two end sides 42f of the second shield 42 aligned in the x direction. In contrast, in this embodiment, as shown in FIG. 26, extending portions 42c are formed on each of the second end portions 42e of the two end sides 42f of the second shield 42. Column (a) of FIG. 26 is a perspective view for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive bus bar. Column (b) of FIG. 26 is a side view for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive bus bar.

With this configuration, the magnetic field that has entered the second shield 42 is easily transmitted to the first shield 41 via the extending portions 42c formed on the second end portions 42e side. As schematically shown in FIG. 27, the transmission path of this magnetic field is on the first both ends 41e side of the first shield 41. Similarly, the transmission path of the magnetic field is on the second both end portions 42e side of the second shield 42.

Note that the thick solid line arrow shown in FIG. 27 indicates the current flowing through the conductive bus bar 30. A solid arrow indicates a magnetic field that passes through the first shield 41. The dashed arrow indicates the magnetic field passing through the second shield 42. A symbol with a dot in the center of a circle indicates a magnetic field directed from the second shield 42 to the first shield 41 in the z direction. A symbol with a cross inside a circle indicates a magnetic field directed from the first shield 41 to the second shield 42 in the z direction.

Therefore, electromagnetic noise that has entered the second shield 42 is less likely to flow to the first shield 41 via the second central portion 42d. Similarly, electromagnetic noise that has entered the first shield 41 is difficult to transmit to the second shield 42 via the first central portion 41d.

Therefore, the second central portion 42d and the first central portion 41d are difficult to be magnetically saturated. As a result, leakage of the magnetic field due to magnetic saturation from each of the second central portion 42d and the first central portion 41d is suppressed.

Further, as clearly shown in column (b) of FIG. 26, the magnetoelectric conversion sections 25 of the first sensing section 21 and the second sensing section 22 are located between the two extension sections 42c in the y direction. That is, the magnetoelectric converter 25 is located between the second central portion 42d and the first central portion 41d in the z direction. Therefore, input of the magnetic field leaked by the magnetic saturation of the second central portion 42d and the first central portion 41d to the magnetoelectric converter 25 is suppressed. As a result, deterioration in detection accuracy of the current to be measured is suppressed.

In this embodiment, an example has been shown in which the extending portions 42c are formed on the second both end portions 42e sides of the two end sides 42f of the second shield 42, respectively. However, for example, as shown in column (a) of FIG. 28, it is also possible to adopt a configuration in which extending portions 42c are also formed in the second central portions 42d of the two end sides 42f of the second shield 42. However, the length of the extending portion 42c formed in the second central portion 42d is shorter in the z direction than that of the extending portion 42c formed in the second both end portions 42e. This allows the magnetic field that has entered the shield 40 to more easily pass through the ends than the center.

Further, as shown in column (b) of FIG. 28, an extending portion 42c is formed on one second both ends 42e side of the two end sides 42f, and an extending portion 42c is formed on the other second both ends 42e and a second central portion. It is also possible to employ a configuration in which each of the extension portions 42d is formed with an extension portion 42c. However, the lengths in the z direction of the extension portions 42c formed at the other second end portions 42e of the two end sides 42f and the second central portion 42d are the same. This also allows the magnetic field that has entered the shield 40 to more easily pass through the ends than the center. Columns (a) and (b) in FIG. 28 are perspective views for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive bus bar, respectively.

Furthermore, as shown in column (a) of FIG. It is also possible to employ a configuration in which the extending portions 42c are formed on the other side of each of the two ends. The extending portion 42c formed on one of the two end sides 42f and the extending portion 42c formed on the other end are spaced apart from each other in the y direction and the x direction.

It is also possible to adopt a configuration in which not only the second shield 42 but also the first shield 41 is formed with the extending portion 42c. The first shield 41 has two opposing sides 41f arranged in the x direction. For example, as shown in column (b) of FIG. 29, a configuration may be adopted in which extending portions 42c are formed on each of the first end portions 41e of the two opposing sides 41f of the first shield 41. Columns (a) and (b) in FIG. 29 are perspective views for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive bus bar, respectively.

The form of the extending portion 42c that can be formed on the first shield 41 can be the same as the extending portion 42c formed on the second shield 42 shown above. The extended portion 42c formed on the first shield 41 corresponds to an extended portion.

Note that the current sensor according to this embodiment and the embodiments described below include the same components as the current sensor described in the first embodiment. Therefore, it goes without saying that the same effects can be achieved.

(Third embodiment)
Next, a third embodiment will be described based on FIGS. 30 to 32.

<Stress relaxation part>
In this embodiment, a stress relaxation section 34 is formed in the conductive bus bar 30 of the first current sensor 11. This stress relaxation part 34 is formed in each of the first exposed part 32 and the second exposed part 33 of the conductive bus bar 30.

As described above, the conductive bus bar 30 has the covering portion 31 that covers the sensor housing 50 . The first exposed portion 32 and the second exposed portion 33 are each exposed from the sensor housing 50 and are integrally connected to the covering portion 31. A bolt hole 30c is formed in each of the first exposed portion 32 and the second exposed portion 33 for electrically and mechanically connecting to the current-carrying bus bar 307 through which a bolt is passed. The stress relaxation part 34 is formed between the connection part of each of the first exposed part 32 and the second exposed part 33 with the covering part 31 and the part where the bolt hole 30c is formed.

As shown in FIG. 31, the stress relaxation portion 34 is locally curved from the back surface 30b of the conductive bus bar 30 toward the front surface 30a. Due to this curvature, the stress relaxation section 34 can be bent and elastically deformed in response to a force in the z direction applied to the conductive bus bar 30. In addition, in FIG. 31, the stress relaxation part 34 is curved so as to wave once, but the number of waves and the form of the curve are not limited to the above example.

As described above, the conductive bus bar 30 is bolted to the current carrying bus bar 307. The energizing bus bar 307 of this embodiment corresponds to the first terminal block 307a and the second terminal block 307b shown in FIG. 32. The conductive bus bar 30 is bolted to the first terminal block 307a and the second terminal block 307b. As a result, the first terminal block 307a and the second terminal block 307b are bridged by the current-carrying bus bar 307. The first terminal block 307a and the second terminal block 307b are electrically connected via the current-carrying bus bar 307. Note that in the following, as shown in FIG. 32, the bolt passed through the bolt hole 30c of the conductive bus bar 30 is designated by the reference numeral 307c. The first terminal block 307a and the second terminal block 307b correspond to an external current-carrying section.

The first terminal block 307a has a first mounting surface 307d facing the z direction. Similarly, the second terminal block 307b has a second mounting surface 307e facing the z direction. A fastening hole 307f for fastening the shaft portion of the bolt 307c is formed in the first mounting surface 307d and the second mounting surface 307e. The fastening hole 307f is open to the first mounting surface 307d and the second mounting surface 307e. The fastening hole 307f extends in the z direction. Column (a) in FIG. 32 shows a case where the positions of the first mounting surface and the second mounting surface in the z direction match. The column (b) in FIG. 32 shows a case where the positions of the first mounting surface and the second mounting surface in the z direction do not match.

The back surface 30b of the first exposed portion 32 faces the first mounting surface 307d in the z direction. The back surface 30b of the second exposed portion 33 faces the second mounting surface 307e in the z direction. In this manner, the first current sensor 11 is provided on the first terminal block 307a and the second terminal block 307b.

As shown in column (a) of FIG. 32, when the positions of the first mounting surface 307d and the second mounting surface 307e in the z direction match, the back surface of the first exposed portion 32 is placed on the first mounting surface 307d. 30b contacts, and the back surface 30b of the second exposed portion 33 also contacts the second mounting surface 307e. In this contact state, the tip of the shaft portion of the bolt 307c is inserted from the z direction into the bolt hole 30c of the conductive bus bar 30 and the fastening hole 307f of the terminal block. Then, the bolt 307c is fastened to the terminal block so that the head of the bolt 307c approaches the first mounting surface 307d (second mounting surface 307e). The first exposed portion 32 and the second exposed portion 33 are held between the head of the bolt 307c and the terminal block. This mechanically and electrically connects the first current sensor 11 to the terminal block.

On the other hand, as shown in column (b) of FIG. 32, when the positions of the first mounting surface 307d and the second mounting surface 307e in the z direction do not match, the When the back surface 30b of the exposed portion 32 contacts, the back surface 30b of the second exposed portion 33 does not contact the second mounting surface 307e. The second mounting surface 307e and the back surface 30b of the second exposed portion 33 are spaced apart in the z direction, and a gap is formed between them.

When the shaft portion of the bolt 307c is passed through the bolt hole 30c and the fastening hole 307f in this separated state, and the head of the bolt 307c contacts the surface 30a of the second exposed portion 33, a force is applied to the second exposed portion 33 in the z direction. acts.

As described above, in order to strengthen the intensity of the magnetic field to be measured that passes through the magnetoelectric conversion section 25, the covering section 31 is locally formed with a narrowed section 31a having a short length in the x direction. Since the narrowed portion 31a has a short length in the x direction, its rigidity is lower than other portions. Therefore, the narrowed portion 31a is easily deformed.

Therefore, when the force in the z direction when the bolt 307c is fastened acts on the second exposed portion 33 as described above, there is a possibility that the narrowed portion 31a may be deformed. There is a possibility that the position of the narrowed portion 31a within the sensor housing 50 may be displaced. Of course, even if the narrow portion 31a is not formed in the covering portion 31, there is a possibility that the position of the covering portion 31 within the sensor housing 50 may be displaced. This may change the distribution of the magnetic field to be measured that passes through the magnetoelectric converter 25.

On the other hand, as described above, stress relaxation parts 34 are formed in each of the first exposed part 32 and the second exposed part 33. Therefore, even if there is a gap between the second mounting surface 307e and the back surface 30b of the second exposed portion 33 due to the difference in the positions of the first mounting surface 307d and the second mounting surface 307e in the z direction, , the stress relaxation portion 34 is elastically deformed in response to the force of the bolt 307c in the z direction. This suppresses deformation of the narrowed portion 31a. Displacement of the narrowed portion 31a within the sensor housing 50 is suppressed. As a result, changes in the distribution of the magnetic field to be measured passing through the magnetoelectric converter 25 are suppressed. Decrease in detection accuracy of the current to be measured is suppressed.

Note that the length (thickness) between the front surface 30a and the back surface 30b of the stress relaxation section 34 is equal to the thickness of each of the covering section 31, the first exposed section 32, and the second exposed section 33. . As a result, unlike a structure in which the thickness of the stress relaxation part is locally thinner than that of the covered part or the exposed part, for example, the stress relaxation part 34 is suppressed from locally generating heat due to the application of current. As a result, reduction in the life of the conductive bus bar 30 is suppressed.

(Fourth embodiment)
Next, a fourth embodiment will be described based on FIGS. 33 to 35. Column (a) in FIG. 33 shows a top view of the conductive bus bar. The column (b) in FIG. 33 shows a side view of the conductive bus bar. Column (a) in FIG. 34 shows the positions of the wiring board 20 and the conductive bus bar 30 on which the magnetoelectric conversion sections 25 of the first sensing section 21 and the second sensing section 22 are mounted, respectively. The column (b) in FIG. 34 shows the displacement of the wiring board 20 with respect to the conductive bus bar 30. Column (c) in FIG. 34 shows the magnetic fields that pass through the magnetoelectric converters 25 of the first sensing section 21 and the second sensing section 22.

<Difference cancellation>
In the first embodiment, an example is shown in which the magnetoelectric conversion units 25 of the first sensing unit 21 and the second sensing unit 22 are arranged in the y direction. On the other hand, in this embodiment, the magnetoelectric conversion sections 25 of the first sensing section 21 and the second sensing section 22 are arranged in the x direction, as shown by broken lines in FIG. 33. The magnetoelectric conversion section 25 of the first sensing section 21 corresponds to a first magnetoelectric conversion section. The magnetoelectric conversion section 25 of the second sensing section 22 corresponds to a second magnetoelectric conversion section.

The two magnetoelectric converters 25 are arranged symmetrically with respect to the axis of symmetry AS. The positions of the two magnetoelectric converters 25 in the y direction and the position of the axis of symmetry AS (center point CP) in the y direction are the same. Therefore, the two magnetoelectric converters 25 are arranged in the x direction with the center point CP interposed therebetween.

Furthermore, the distances in the z direction between the two magnetoelectric conversion sections 25 and the covering section 31 are the same. The covering portion 31 and the narrowing portion 31a have a line-symmetrical shape with respect to the axis of symmetry AS. As described above, although the z-direction components are different, the magnetic fields to be measured with the same x-direction components are transmitted through the two magnetoelectric conversion units 25 . Therefore, the absolute values of the electric signals output from the two magnetoelectric converters 25 are equal.

As described above, the covering portion 31 covers the base 51 of the sensor housing 50. The wiring board 20 on which the two magnetoelectric converters 25 are mounted is mounted on board support pins 56a formed in the sensor housing 50. Therefore, displacement of the wiring board 20 in the z direction is regulated by the board support pins 56a.

However, the wiring board 20 is fixed to the board adhesive pins 56b via the board adhesive 56e. The substrate adhesive 56e expands due to changes in environmental temperature and deteriorates over time such as creep. For this reason, there is a possibility that the wiring board 20 may be displaced relative to the covering portion 31 in the x direction and the y direction.

When the wiring board 20 is displaced in the y direction, due to the symmetrical arrangement of the two magnetoelectric converters 25 in the x direction, the x direction component of the magnetic field to be measured that passes through both does not change. However, as shown in FIG. 34, when the wiring board 20 is displaced in the x direction, the x direction component of the magnetic field to be measured that passes through both changes. As a result, the absolute values of the electric signals output from the two magnetoelectric converters 25 are no longer equal.

The broken lines shown in FIG. 34 indicate the arrangement positions of the two magnetoelectric conversion units 25 with respect to the conductive bus bar 30. The one-dot chain line indicates the axis of symmetry AS passing through the center point CP of the conductive bus bar 30. The two-dot chain line indicates the position where the two magnetoelectric conversion units 25 are displaced with respect to the conductive bus bar 30. The white arrows indicate the direction in which the wiring board 20 on which the two magnetoelectric transducers 25 are mounted is displaced with respect to the conductive bus bar 30 by the board adhesive 56e. The solid line arrows shown in columns (a) and (b) of FIG. 34 indicate the magnetic field passing through the magnetoelectric converter 25. The solid arrow shown in column (c) of FIG. 34 indicates the direction of change in the magnetic field passing through the magnetoelectric conversion section 25.

However, as described above, both the two magnetoelectric conversion units 25 are mounted on the wiring board 20. Therefore, even if the relative position of the wiring board 20 and the covering part 31 in the x direction changes due to the deformation of the board adhesive 56e as described above, the relative distance between the two magnetoelectric converters 25 mounted on the wiring board 20 does not change. Therefore, when the relative position between the wiring board 20 and the covering part 31 changes in the x direction due to deformation of the board adhesive 56e, one of the two magnetoelectric transducers 25 approaches the symmetry axis AS, and the other moves away from the symmetry axis AS. . Their far and near distances are the same. In column (b) of FIG. 34, this distance is indicated by Δ.

Therefore, as shown in column (c) of FIG. 34, the magnetic field to be measured that passes through one of the two magnetoelectric converters 25 decreases, and the magnetic field to be measured that passes through the other increases. It is expected that the amount of decrease and the amount of increase in the measured magnetic field passing through the two magnetoelectric converters 25 will be the same. In column (b) of FIG. 34, the amount of change in the magnetic field to be measured is indicated as ΔB.

Therefore, in this embodiment, the polarities of the electric signals output from the two magnetoelectric conversion sections 25 are reversed. In order to reverse the polarity in this manner, for example, as shown in FIG. 35, the arrangement of the first magnetoresistive element 25a and the second magnetoresistive element 25b is reversed between the two magnetoelectric converters 25. Alternatively, more simply, the polarities of the two electrical signals are reversed by reversing the inverting input terminal and the non-inverting input terminal of the differential amplifier 25c shown in FIG. 7 between the first sensing section 21 and the second sensing section 22. be able to.

As a result of the above, the two magnetoelectric conversion units 25 output electrical signals in which the absolute values of the increase amount and the decrease amount are equal and have different polarities. Two electrical signals generated by the first current sensor 11 are input to the battery ECU 801. Two electrical signals generated by each of the second current sensor 12 and the third current sensor 13 are input to the MGECU 802 .

Battery ECU 801 and MGECU 802 take the difference between the two electrical signals. In this difference processing, B+ΔB−(−(B− It can be expressed as ΔB))=2B. Alternatively, it can be expressed as B−ΔB−(−(B+ΔB))=2B. The plus sign corresponds to one of the first polarity and the second polarity, and the minus sign corresponds to the other of the first polarity and the second polarity.

By performing the differential processing in this manner, the decrease and increase in the electrical signal due to the change in the relative position between the wiring board 20 and the covering portion 31 due to the deformation of the substrate adhesive 56e described above is canceled. Battery ECU 801 and MGECU 802 correspond to the difference section.

Note that, for example, as shown in FIG. 36, a configuration in which a difference circuit 29 that takes the difference between the outputs of two magnetoelectric converters 25 is mounted on the wiring board 20 can also be adopted. A first output wiring 20d and a second output wiring 20e are connected to an inverting input terminal and a non-inverting input terminal of the difference circuit 29. In this case, the differential circuit 29 corresponds to a differential section.

The change in the relative position of the wiring board 20 and the covering part 31 in the x direction is caused not only by the deformation of the board adhesive 56e but also by, for example, external stress acting on the vehicle or vibrations caused by the drive of the engine 600. obtain. However, even if the relative position of the wiring board 20 and the covering section 31 in the x direction changes due to these factors, the difference between the two electrical signals output from the two magnetoelectric conversion sections 25 is calculated as described above. By doing so, decreases and increases in the electrical signal due to changes in the relative position between the wiring board 20 and the covering portion 31 are canceled. As described above, the detection accuracy of the magnetic field to be measured is prevented from decreasing.

(Fifth embodiment)
Next, a fifth embodiment will be described based on FIGS. 37 and 38.

<Anisotropy of magnetic permeability>
In the first embodiment, an example was shown in which the first shield 41 and the second shield 42 are each manufactured by compressing a plurality of flat plates made of a soft magnetic material. In contrast, in this embodiment, the first shield 41 and the second shield 42 are each manufactured by rolling electromagnetic steel.

By specifying the rolling direction of the electromagnetic steel as described in the first embodiment, the magnetic permeability of the shield can be made anisotropic. In this embodiment, the rolling direction of the first shield 41 and the second shield 42 is along the z direction. This gives anisotropy to the magnetic permeability of the first shield 41 and the second shield 42. Note that the method for manufacturing the first shield 41 and the second shield 42 is not limited to the above example, and they may be manufactured using a material that has anisotropy in magnetic permeability. Further, one of the first shield 41 and the second shield 42 may have magnetic permeability anisotropy.

As shown in FIG. 37, in each of the second current sensor 12 and the third current sensor 13, individual sensors 71 are arranged side by side in the x direction. The first shield 41 and the second shield 42 of each individual sensor 71 are arranged alternately in the x direction. In this configuration, the directions in which the magnetic field of the magnetoelectric converter 25 of the individual sensor 71 is detected are in the z direction and the y direction. Note that in this configuration, a configuration may be adopted in which the first shield 41 of one of the two individual sensors 71 arranged in the x direction and the second shield 42 of the other are combined into one.

In such a configuration in which a plurality of individual sensors 71 are arranged in the x direction, the magnetic field to be measured emitted from the conductive bus bar 30 of one individual sensor 71 becomes external noise for other individual sensors 71. This external noise is formed in a ring shape in a plane defined by the x direction and the z direction, with the conductive bus bar 30 as the center. Therefore, the external noise has components along the x direction and the z direction. In this way, the environment is such that external noise along the x direction and the z direction easily passes through the individual sensor 71.

In FIG. 37, two individual sensors 71 are shown. Of the two individual sensors 71, the current to be measured flows through the conductive bus bar 30 that is marked with a cross in the circle. The magnetic field to be measured is emitted from here. For the adjacent individual sensor 71, the magnetic field to be measured emitted from the conductive bus bar 30 marked with a cross in this circle becomes electromagnetic noise. In FIG. 37, magnetic fields are indicated by arrows.

As described above, each of the first shield 41 and the second shield 42 has anisotropy in the z direction. Therefore, components of external noise along the z direction try to enter the first shield 41 and the second shield 42, respectively. On the other hand, the component of external noise along the x direction no longer depends on the anisotropy of the first shield 41 and the second shield 42. Therefore, the component along this x direction tends to pass through the magnetoelectric conversion section 25.

For example, when a magnetic field indicated by a broken line arrow in FIG. 37 attempts to pass through the magnetoelectric conversion unit 25, a component of this magnetic field along the z direction actively tries to pass through each of the first shield 41 and the second shield 42. However, some component of this magnetic field in the x direction remains. Therefore, the x-direction component of this magnetic field tends to pass through the magnetoelectric converter 25.

On the other hand, the detection directions of the magnetic field to be measured by the magnetoelectric converter 25 are the z direction and the y direction. The magnetoelectric converter 25 does not detect the magnetic field in the x direction. Therefore, even if the x-direction component of the electromagnetic noise described above passes through the magnetoelectric converter 25, the detection accuracy of the magnetic field to be measured is prevented from being degraded thereby.

The arrangement of the individual sensors 71 is not limited to the above example. For example, as shown in FIG. 38, a configuration in which individual sensors 71 are arranged side by side in the x direction is also conceivable. In this configuration, the first shields 41, the second shields 42, and the magnetoelectric converters 25 of the individual sensors 71 are aligned in the x direction. The detection directions of the magnetic field of the magnetoelectric converter 25 of the individual sensor 71 are the x direction and the y direction. In this configuration, it is also possible to adopt a configuration in which the first shields 41 of each of the plurality of individual sensors 71 arranged in the x direction are combined into one. Similarly, it is also possible to adopt a configuration in which the second shields 42 of the plurality of individual sensors 71 are combined into one.

Two individual sensors 71 are also shown in FIG. The current to be measured flows through the conductive bus bar 30 of the two individual sensors 71, which is marked with a cross in the circle. Also in FIG. 38, magnetic fields are indicated by arrows. The magnetic field has components along the x and z directions. Therefore, the environment is such that external noise along the x direction and the z direction easily passes through the individual sensor 71.

In this configuration, the magnetic permeability of the first shield 41 and the second shield 42 is higher in the x direction than in the y direction. Therefore, components of external noise along the x direction try to enter the first shield 41 and the second shield 42, respectively. On the other hand, the component of external noise along the z direction no longer depends on the anisotropy of the first shield 41 and the second shield 42. Therefore, the component along the z direction tends to pass through the magnetoelectric conversion section 25.

For example, when a magnetic field indicated by a broken line arrow in FIG. 38 attempts to pass through the magnetoelectric conversion unit 25, a component of this magnetic field along the x direction actively tries to pass through each of the first shield 41 and the second shield 42. However, some component of this magnetic field in the z direction remains. Therefore, the z-direction component of this magnetic field tends to pass through the magnetoelectric converter 25.

On the other hand, the detection directions of the magnetic field to be measured by the magnetoelectric converter 25 are the x direction and the y direction. The magnetoelectric converter 25 does not detect the magnetic field in the z direction. Therefore, even if the z-direction component of the electromagnetic noise described above passes through the magnetoelectric converter 25, the detection accuracy of the magnetic field to be measured is prevented from being degraded thereby.

Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and can be implemented with various modifications without departing from the gist of the present disclosure. It is.

(First modification)
In the first embodiment, an example was shown in which notches 41c were formed at the four corners of the first shield 41. This shows an example in which the first end portions 41e of the first shield 41 are shorter in length in the x direction than the first central portion 41d. An example is shown in which the second shield 42 is provided with an extended portion 42c.

On the other hand, as shown in FIG. 39, a configuration in which cutouts 41c are formed at each of the four corners of the first shield 41 and the second shield 42 can also be adopted. As a result, the length of the second end portions 42e in the x direction is shorter than that of the second center portion 42d. As shown in column (b) of FIG. 39, the magnetoelectric conversion unit 25 of the first sensing unit 21 and the second sensing unit 22 mounted on the wiring board 20 is located between the first central portion 41d and the second central portion 42d. is located. Column (a) in FIG. 39 is a perspective view for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive bus bar. Column (b) in FIG. 39 is a side view for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive bus bar.

Further, as shown in column (a) of FIG. 40, the extending portion 42c and the notch 41c may not be formed in the second shield 42. As shown in column (b) of FIG. 40, a configuration in which notches 41c are formed at two of the four corners of the first shield 41 can also be adopted. Note that in column (b) of FIG. 40, two notches 41c are lined up in the x direction. Columns (a) and (b) in FIG. 40 are perspective views for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive bus bar, respectively. As shown above, it is only necessary that the first end portions 41e of the first shield 41 have a shorter length in the x direction than the first central portion 41d, and the position where the notch 41c is formed is not particularly limited.

(Second modification)
In the first embodiment, an example was shown in which the integrated housing 73 has a bottom wall 77 and a peripheral wall 78, and a plurality of individual sensors 71 are stored in a storage space formed by these. However, as shown in FIGS. 41 to 43, the integrated housing 73 may not have the peripheral wall 78. In this case, the individual sensors 71 are rotated by 90 degrees with respect to the bottom wall 77. Thereby, the front surface 30a and the back surface 30b of the conductive bus bar 30 of the individual sensor 71 each face the z direction. One surface 41a and back surface 41b of the first shield 41 each face in the z direction. Similarly, the one surface 42a and the back surface 42b of the second shield 42 each face the z direction. The detection directions of the magnetoelectric transducer 25 of the individual sensor 71 are the x direction and the y direction.

As a result, as shown in FIG. 38, the first shields 41 of the plurality of individual sensors 71 are arranged in the x direction. The second shields 42 of each of the plurality of individual sensors 71 are arranged in the x direction. The magnetoelectric conversion units 25 of each of the plurality of individual sensors 71 are arranged in the x direction.

Note that column (a) in FIG. 42 shows a top view of the second current sensor. The column (b) in FIG. 42 shows a front view of the second current sensor. Column (c) in FIG. 42 shows a bottom view of the second current sensor. Column (a) in FIG. 43 shows a side view of the second current sensor. The column (b) in FIG. 43 shows a front view of the second current sensor. The same drawings are shown in column (b) of FIG. 42 and column (b) of FIG. 43.

In this modification, the same number of bolt holes as the individual sensors 71 are formed in the terminal block 80 along the z direction. A bolt hole 30c is formed in the second exposed portion 33 of the individual sensor 71. Bolts are passed through the bolt hole of this terminal block 80, the bolt hole 30c of the second exposed portion 33, and the bolt hole formed in the terminal of the wire. A nut is then fastened to the tip of the bolt. Tighten the nut to the bolt from the tip of the bolt shaft toward the head. The second exposed portion 33 and the wire terminal are sandwiched between the bolt head and the terminal block 80. As a result, the second exposed portion 33 and the wire terminal come into contact, and the two are electrically and mechanically connected.

(Third modification)
As shown in the first embodiment, the rib 52a is formed on the sensor housing 50 of the first current sensor 11. Similarly, ribs 52a may be formed on the sensor housing 50 of the individual sensor 71 as shown in FIG. 44. A guide portion 72a for inserting the individual sensor 71 into the wiring case 72 may be formed on the bottom wall 77 of the integrated housing 73. The guide portion 72a constitutes a hollow groove having a similar shape to the rib 52a. The guide portion 72a is open in the z direction. The rib 52a is passed through the opening into the hollow of the guide portion 72a. This facilitates assembly of the individual sensors 71 into the integrated housing 73. In the modification shown in FIG. 44, a groove 77c is formed in the bottom wall 77 to provide a protruding end portion of the connecting terminal 60 of the individual sensor 71.

(Fourth modification)
As schematically shown in column (a) of FIG. 45, each embodiment shows an example in which individual sensors 71 are provided in the U-phase stator coil and the V-phase stator coil of the motor. An example has been shown in which these individual sensors 71 have a first sensing section 21 and a second sensing section 22.

However, as schematically shown in column (b) of FIG. 45, it is also possible to adopt a configuration in which individual sensors 71 are provided for each of the U-phase stator coil, V-phase stator coil, and W-phase stator coil of the motor. . These individual sensors 71 can adopt a configuration having only the first sensing section 21.

As described above, the remaining one current can be detected based on the currents flowing through two of the three-phase stator coils. Therefore, the current in the remaining one stator coil can be detected based on the outputs of two of the first sensing sections 21 of the three individual sensors 71 provided in the three-phase stator coil. Further, the current in the remaining one stator coil can be detected by the first sensing section 21 of the individual sensor 71 provided in the remaining one stator coil. By comparing these two detected currents, it can be determined whether an abnormality has occurred in either one.

(Other variations)
In each embodiment, an example is shown in which a current sensor is applied to the in-vehicle system 100 that constitutes a hybrid system. However, the in-vehicle system to which the current sensor is applied is not limited to the above example. For example, the current sensor may be applied to an in-vehicle system for an electric vehicle or an engine vehicle. There are no particular limitations on the system to which the current sensor is applied.

DESCRIPTION OF SYMBOLS 11... First current sensor, 12... Second current sensor, 13... Third current sensor, 20... Wiring board, 20a... Opposing surface, 20b... Back surface, 21... First sensing section, 22... Second sensing section, 25 ... Magnetoelectric conversion section, 29... Differential circuit, 30... Conductive bus bar, 30a... Front surface, 30b... Back surface, 30c... Bolt hole, 31... Covering section, 31a... Narrowing section, 32... First exposed section, 33... Second exposed section Part, 34... Stress relaxation part, 40... Shield, 41... First shield, 41a... One surface, 41c... Notch, 41d... First central part, 41e... First both ends, 41f... Opposing side, 42... Second Shield, 42a...one surface, 42c...extended portion, 42d...second central portion, 42e...second both ends, 42f...edge, 50...sensor housing, 51...base, 51f...lower end surface, 56a...substrate support Pin, 56b...Substrate adhesive pin, 56c...Tip surface, 56d...Tip surface, 56e...Substrate adhesive, 57a...Shield support pin, 57b...Shield adhesive pin, 57c...Tip surface, 57d...Tip surface, 57e...Shield adhesive agent, 71... individual sensor, 72... wiring case, 73... integrated housing, 75... energizing terminal, 76... integrated wiring board, 100... in-vehicle system, 307... energizing bus bar, 307a... first terminal block, 307b... second Terminal block, 341... First energized bus bar, 342... Second energized bus bar, 343... Third energized bus bar, 344... Fourth energized bus bar, 345... Fifth energized bus bar, 346... Sixth energized bus bar, 801... Battery ECU, 802...MGECU, AS...axis of symmetry, CP...center point

Claims (5)

a conductive member (30) through which the current to be measured flows;
a first magnetoelectric conversion unit (21, 25) that converts a magnetic field to be measured generated by the flow of the current to be measured into an electric signal of a first polarity; a wiring board (20) on which a second magnetoelectric conversion unit (22, 25) for converting into an electric signal is mounted;
a difference unit (29, 801, 802) that takes a difference between the electrical signal of the first magnetoelectric conversion unit and the electrical signal of the second magnetoelectric conversion unit;
a sensor housing (50) housing each of the conductive member and the wiring board in such a manner that the wiring board faces the conductive member;
a substrate adhesive (56e) for bonding a surface (20a) of the wiring board facing the conductive member to the sensor housing;
Assuming that the three directions that are orthogonal to each other are the x direction, y direction, and z direction,
A center point (CP) of the conductive member, the first magnetoelectric conversion unit, and the second magnetoelectric conversion unit exist on one plane perpendicular to the y direction, which is the extension direction of the conductive member, The first magnetoelectric conversion section and the second magnetoelectric conversion section are connected to each other such that the first magnetoelectric conversion section and the second magnetoelectric conversion section are aligned in the x direction via the center point (CP) of the conductive member. arranged on the opposing surface or the back side of the opposing surface ,
Each of the first magnetoelectric conversion unit and the second magnetoelectric conversion unit has a resistance value depending on a component of the magnetic field passing through the unit along the y direction and a component along the x direction, which is a lateral direction of the conductive member. A current sensor having a plurality of variable magnetoresistive elements (25a, 25b). The current sensor according to claim 1, wherein the magnetoresistive element has a resistance value that does not change depending on a component of the transmitted magnetic field along the z direction. Each of the first magnetoelectric conversion section and the second magnetoelectric conversion section includes a first magnetoresistive element (25a) and a second magnetoresistive element, which are provided as the magnetoresistive element so that increases and decreases in resistance values are reversed. It has an effect element (25b),
The first magnetoresistive element and the second magnetoresistive element are connected in series between a power supply potential and a reference potential to form a half-bridge circuit,
By reversing the arrangement of the first magnetoresistive element and the second magnetoresistive element in the half-bridge circuit of the first magneto-electric conversion section and the half-bridge circuit of the second magneto-electric conversion section, The current sensor according to claim 1 or 2, wherein the polarity of the electric signal outputted by the first magnetoelectric conversion section and the polarity of the electric signal outputted by the second magnetoelectric conversion section are different. Each of the first magnetoelectric conversion section and the second magnetoelectric conversion section includes a first magnetoresistive element (25a) and a second magnetoresistive element, which are provided as the magnetoresistive element so that increases and decreases in resistance values are reversed. It has an effect element (25b) and a differential amplifier (25c),
The first magnetoelectric conversion section and the second magnetoelectric conversion section include a half-bridge circuit in which the first magnetoresistive element and the second magnetoresistive element are connected in series between a power supply potential and a reference potential. They each have two,
In each of the first magnetoelectric conversion section and the second magnetoelectric conversion section, the midpoint potential of one of the half-bridge circuits is inputted to one of the input terminals of the differential amplifier, and the midpoint potential of one of the half-bridge circuits is inputted to one of the input terminals of the differential amplifier. A midpoint potential is input to another input terminal of the differential amplifier,
The arrangement of the first magnetoresistive element and the second magnetoresistive element is the same in one of the half-bridge circuits of the first magnetoelectric conversion section and one of the half-bridge circuits of the second magnetoelectric conversion section. The other one of the half-bridge circuits of the first magneto-electric conversion unit and the other one of the half-bridge circuits of the second magneto-electric conversion unit are connected to the first magnetoresistive element and the second magnetoresistive element. The arrangement of elements is the same,
By reversing the input terminals of the differential amplifier in the half-bridge circuit of the first magneto-electric conversion unit and the half-bridge circuit of the second magneto-electric conversion unit, which are arranged the same, the first magneto-electric conversion is performed. The current sensor according to claim 1 or 2, wherein the polarity of the electric signal outputted by the second magnetoelectric conversion unit is different from the polarity of the electric signal outputted by the second magnetoelectric conversion unit. a conductive member (30) through which the current to be measured flows;
a first magnetoelectric conversion unit (21, 25) that converts a magnetic field to be measured generated by the flow of the current to be measured into an electric signal of a first polarity; a wiring board (20) on which a second magnetoelectric conversion unit (22, 25) for converting into an electric signal is mounted;
a difference unit (29, 801, 802) that takes a difference between the electrical signal of the first magnetoelectric conversion unit and the electrical signal of the second magnetoelectric conversion unit;
a sensor housing (50) housing each of the conductive member and the wiring board in such a manner that the wiring board faces the conductive member;
a substrate adhesive (56e) for bonding a surface (20a) of the wiring board facing the conductive member to the sensor housing;
Assuming that the three directions that are orthogonal to each other are the x direction, y direction, and z direction,
A center point (CP) of the conductive member, the first magnetoelectric conversion unit, and the second magnetoelectric conversion unit exist on one plane perpendicular to the y direction, which is the extension direction of the conductive member, The first magnetoelectric conversion section and the second magnetoelectric conversion section are connected to each other such that the first magnetoelectric conversion section and the second magnetoelectric conversion section are aligned in the x direction via the center point (CP) of the conductive member. arranged on the opposing surface or the back side of the opposing surface ,
The sensor housing includes a board support part (56a) that supports the wiring board, and a board adhesive part (56b) on which the board adhesive is provided,
A mounting surface (56d) on which the board adhesive (56e) is provided in the board bonding part is further away from the wiring board than a support surface (56c) of the wiring board in the board support part,
A current sensor, wherein the wiring board is mounted on the support surface of the board support part, and the board adhesive is provided between the mounting surface of the board adhesive part and the wiring board.

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