JP7380384B2 - Vehicle drive device, hollow busbar, hollow busbar formation method - Google Patents

Description

The present disclosure relates to a vehicle drive device, a hollow bus bar, and a method for forming a hollow bus bar.

2. Description of the Related Art A bus bar is known that combines plate-like members to form a refrigerant flow path therein for flowing a liquid refrigerant.

Japanese Patent Application Publication No. 2014-11086

By the way, air cooling is insufficient for a bus bar that generates a relatively large amount of heat, and cooling using a liquid refrigerant as in the prior art described above is useful. However, in the above-mentioned conventional technology, since plate-like members are combined, productivity is not good, and the degree of freedom in the shape of the bus bar is relatively low, making it difficult to space-efficient wiring (layout).

Therefore, in one aspect, an object of the present disclosure is to enable cooling of a bus bar with a liquid refrigerant without reducing the degree of freedom in the shape of the bus bar.

In one aspect, a power converter;
a first bus bar that is electrically connected to the power converter, has a hollow pipe-like shape, and has a hollow interior that forms a refrigerant flow path;
A vehicle drive device is provided in which a liquid refrigerant is pumped into the refrigerant flow path.

In one aspect, according to the present disclosure, the bus bar can be cooled by a liquid refrigerant without reducing the degree of freedom in the shape of the bus bar.

FIG. 1 is a diagram showing an example of the overall configuration of an electric vehicle motor drive system. FIG. 2 is an explanatory diagram of an example of a mounting state of an inverter module. FIG. 2 is an explanatory diagram of a cooling system related to an inverter module. FIG. 3 is an explanatory diagram of a busbar configuration regarding a capacitor module. FIG. 3 is an explanatory diagram of a bus bar configuration between a traveling motor and an inverter. FIG. 3 is a perspective view showing a part of the busbar configuration. FIG. 2 is an explanatory diagram showing the arrangement of a busbar configuration. FIG. 3 is a perspective view of a hollow bus bar. It is a front view of a hollow bus bar. 10 is a cross-sectional view taken along line AA in FIG. 9. FIG. 11 is an enlarged view of section B in FIG. 10. FIG. It is a figure which shows an example of the pipe member for cooling water supply attached to a hollow bus bar. FIG. 2 is an explanatory diagram (part 1) of an example of a method for manufacturing a hollow bus bar. FIG. 2 is an explanatory diagram (part 2) of an example of a method for manufacturing a hollow bus bar. FIG. 3 is an explanatory diagram (part 3) of an example of a method for manufacturing a hollow bus bar. FIG. 4 is an explanatory diagram (Part 4) of an example of a method for manufacturing a hollow bus bar. FIG. 5 is an explanatory diagram (Part 5) of an example of a method for manufacturing a hollow bus bar. FIG. 6 is an explanatory diagram (part 6) of an example of a method for manufacturing a hollow bus bar. It is an explanatory view of another example of the manufacturing method of a hollow bus bar.

Hereinafter, each embodiment will be described in detail with reference to the accompanying drawings.

In the following, prior to explaining the power converter according to the present embodiment, first, a motor drive system 1 for an electric vehicle to which the power converter according to the present embodiment is preferably applied will be explained. In the description of FIG. 1 regarding the electric vehicle motor drive system 1, the term "connection" between various elements means "electrical connection" unless otherwise specified.

FIG. 1 is a diagram showing an example of the overall configuration of an electric vehicle motor drive system 1. As shown in FIG. The motor drive system 1 is a system that drives a vehicle by driving a travel motor 5 (an example of a rotating electric machine) using electric power from a high-voltage battery 2. Note that the details of the method and configuration of the electric vehicle are arbitrary as long as the electric vehicle is driven by driving the traveling motor 5 using electric power. Electric vehicles typically include a hybrid vehicle whose power source is an engine and a running motor 5, and an electric vehicle whose power source is only the running motor 5. Hereinafter, the term "vehicle" refers to a vehicle on which the motor drive system 1 is mounted, unless otherwise specified.

As shown in FIG. 1, the motor drive system 1 includes a high voltage battery 2, a smoothing capacitor 3, an inverter 4, a driving motor 5, and an inverter control device 6A.

The high-voltage battery 2 is any power storage device that stores power and outputs a DC voltage, and may include a capacitive element such as a nickel metal hydride battery, a lithium ion battery, or an electric double layer capacitor. The high voltage battery 2 is typically a battery with a rated voltage exceeding 100V, and the rated voltage is, for example, 288V.

The inverter 4 includes U-phase, V-phase, and W-phase arms arranged in parallel with each other between a positive electrode line and a negative electrode line. The U-phase arm includes a series connection of switching elements (IGBT: Insulated Gate Bipolar Transistor in this example) Q1 and Q2, the V-phase arm includes a series connection of switching elements (IGBT in this example) Q3 and Q4, and the W-phase arm includes a series connection of switching elements (IGBT in this example) Q3 and Q4. includes a series connection of switching elements (IGBT in this example) Q5 and Q6. Furthermore, diodes D11 to D16 are arranged between the collector and emitter of each of the switching elements Q1 to Q6, respectively, so that current flows from the emitter side to the collector side. Note that the switching elements Q1 to Q6 may be other switching elements other than IGBTs, such as MOSFETs (metal oxide semiconductor field-effect transistors).

The traveling motor 5 is, for example, a three-phase AC motor, and one ends of three coils of U, V, and W phases are commonly connected at a neutral point. The other end of the U-phase coil is connected to a midpoint M1 between switching elements Q1 and Q2, the other end of the V-phase coil is connected to a midpoint M2 of switching elements Q3 and Q4, and the other end of the W-phase coil is It is connected to a midpoint M3 between switching elements Q5 and Q6. A smoothing capacitor 3 is connected between the collector of the switching element Q1 and the negative line.

Various sensors such as a current sensor 6 that detects the current flowing through the travel motor 5 are connected to the inverter control device 6A. The inverter control device 6A controls the inverter 4 based on sensor information from various sensors. The inverter control device 6A includes, for example, a CPU, ROM, main memory (all not shown), etc., and various functions of the inverter control device 6A are executed by the CPU after a control program recorded in the ROM etc. is read out to the main memory. It is realized through execution. The control method for the inverter 4 is arbitrary, but basically, the two switching elements Q1 and Q2 related to the U phase are turned on and off in opposite phases, and the two switching elements Q3 and Q4 related to the V phase are turned on and off in opposite phases. They are turned on and off in opposite phases, and the two switching elements Q5 and Q6 related to the W phase are turned on and off in opposite phases.

In the example shown in FIG. 1, the motor drive system 1 includes a single traveling motor 5, but may include additional motors (including a generator). In this case, the additional motor(s) may be connected to the high voltage battery 2 in parallel relationship with the traction motor 5 and the inverter 4 together with a corresponding inverter. Further, in the example shown in FIG. 1, the motor drive system 1 does not include a DC/DC converter, but may include a DC/DC converter between the high voltage battery 2 and the inverter 4.

As shown in FIG. 1, a cutoff switch SW1 for cutting off power supply from the high voltage battery 2 is provided between the high voltage battery 2 and the smoothing capacitor 3. The cutoff switch SW1 may be composed of a semiconductor switch, a relay, or the like. The cutoff switch SW1 is normally on, and is turned off when a vehicle collision is detected, for example. Note that the on/off switching of the cutoff switch SW1 may be realized by the inverter control device 6A, or may be realized by another control device.

FIG. 2 is an explanatory diagram of an example of a mounting state of the inverter module 10. In FIG. 2, the Z direction (and the Z direction Z1 side and the Z direction Z2 side) is defined. Note that FIG. 2 is a schematic diagram, and other elements (such as the capacitor case 30) are illustrated separated in the Z direction in relation to the inverter module 10.

The inverter module 10 (an example of a power converter) is a module that includes switching elements Q1 to Q6 related to the inverter 4, diodes D11 to D16, and various bus bars (not shown).

For example, as shown in FIG. 2, the inverter module 10 may be supported on the Z1 side of the capacitor case 30 in the Z direction. Capacitor case 30 accommodates capacitor module 20. Note that the capacitor module 20 includes a plurality of capacitor elements that constitute the smoothing capacitor 3. Capacitor case 30 may be formed of, for example, a material with high thermal conductivity (eg, copper, aluminum, etc.). The condenser case 30 may integrally include a flow path forming part 38 that forms a refrigerant flow path. The flow path forming portion 38 is formed on the Z1 side of the capacitor case 30 in the Z direction. In this case, by supporting the inverter module 10 on the surface of the flow path forming portion 38 on the Z direction Z1 side, the inverter module 10 can be effectively cooled.

In the example shown in FIG. 2, the inverter module 10 may be configured as a unit integrated with the capacitor module 20 (module related to the smoothing capacitor 3) and the capacitor case 30.

For example, as shown in FIG. 2, a control board 40 may be arranged on the Z1 side of the inverter module 10 with a shield plate 50 interposed therebetween. The control board 40 may realize the inverter control device 6A. The inverter module 10 may be connected to the connector 42 on the control board 40 via the control wiring 13. That is, the control wiring 13 connects each switching element Q1 to Q6 and the inverter control device 6A.

FIG. 3 is an explanatory diagram of a cooling system related to the inverter module 10.

The cooling system related to the inverter module 10 includes a water pump 90 (an example of a pump), a radiator 92 (an example of a heat exchange section), and a circulation flow path 94.

The water pump 90 is a pump that circulates cooling water through the circulation channel 94. Note that the cooling water is an example of a liquid refrigerant, and is, for example, water containing antifreeze or LLC (Long Life Coolant). The water pump 90 is controlled by a control device 6B (an example of a control section). Note that part or all of the functions of the control device 6B may be realized by the inverter control device 6A.

The radiator 92 removes heat from the cooling water passing through the circulation flow path 94 and cools the cooling water. The radiator 92 may realize heat exchange between air (for example, air passing through when the vehicle is running) and cooling water.

The circulation flow path 94 returns the cooling water discharged from the water pump 90 to the water pump 90 via the radiator 92. The circulation flow path 94 is provided with a flow path forming section 38 and a busbar flow path section 900 (described later). That is, each flow path related to the flow path forming section 38 and the busbar flow path section 900 forms a part of the circulation flow path 94. Note that the radiator 92 may be provided at other positions, such as between the water pump 90 and the flow path forming section 38 or between the flow path forming section 38 and the bus bar flow path section 900. Further, when a cooling waterway is formed in the traveling motor 5, the cooling waterway may constitute a part of the circulation flow path 94.

The busbar flow path section 900 is formed by a hollow busbar 200 (described later), as described later. The busbar flow path section 900 will be described later.

FIG. 4 is an explanatory diagram of the bus bar configuration 80 related to the capacitor module 20, and is a perspective view showing the appearance of the capacitor case 30 with the capacitor module 20 (not visible in FIG. 4) built therein.

Capacitor module 20 includes bus bars 22 and 23. In FIG. 4, the bus bars 22 and 23 are provided as a pair and are connected to the inverter module 10 and the high voltage battery 2, respectively. Therefore, the pair of bus bars 22 and 23 form a terminal 221 (see FIG. 1) connected to the positive electrode side of the high-voltage battery 2 and a terminal 231 (see FIG. 1) connected to the negative electrode side of the high-voltage battery 2. . Note that the bus bars 22 and 23 may be directly connected to the terminals 14 and 15 (see FIG. 1) on the inverter 4 side, or may be connected via another bus bar.

FIG. 5 is an explanatory diagram of a bus bar configuration 80 between the traveling motor 5 and the inverter 4, and shows a three-sided view of the bus bar configuration 80. FIG. 6 is a perspective view showing a part of the busbar structure 80, and FIG. 7 is an explanatory diagram showing the arrangement of the busbar structure 80. A sensor unit 60 that accommodates the current sensor 6 is illustrated in FIG. 5 and the like.

The bus bar structure 80 forms the wiring section 70 between the traveling motor 5 and the inverter 4 shown in FIG. Note that, as shown in FIG. 1, the wiring section 70 includes a first wiring section 71 and a second wiring section 72, and the current sensor 6 is provided in the second wiring section 72. However, in a modified example, the current sensor 6 may be provided in the first wiring section 71.

Busbar configuration 80 includes a first busbar module 81 and a second busbar module 82, as shown in FIG.

The first busbar module 81 forms a first wiring section 71 (see FIG. 1). The first busbar module 81 may be arranged to be partially located within the space 51, for example, as shown in FIG. In the space 51, the driving motor 5 is arranged, and various gears (not shown) for transmitting driving force to the wheels may also be arranged.

The first busbar module 81 includes busbars 811, 812, and 813 (an example of a first busbar) for each of three phases (ie, U phase, V phase, and W phase). The first busbar module 81 has a resin part 810 that seals the busbars 811, 812, and 813, and the ends of the busbars 811, 812, and 813 are exposed from the resin part 810. Note that the resin portion 810 may be formed by pouring molten resin into a mold (not shown) in which the bus bars 811, 812, and 813 are set.

The second busbar module 82 forms the second wiring section 72 (see FIG. 1). The second busbar module 82 may be arranged within the space 52, as shown in FIG. 7, for example. In the space 52, the inverter module 10 and the control board 40 are arranged, and in addition, the capacitor case 30 and the like may be arranged.

The second busbar module 82 includes busbars 821, 822, and 823 (an example of second busbars) for each of three phases (ie, U phase, V phase, and W phase). The second busbar module 82 has a resin part 820 that seals the busbars 821, 822, and 823, and the ends of the busbars 821, 822, and 823 are exposed from the resin part 820 (see FIG. 6). Note that the resin portion 820 may be formed by pouring molten resin into a mold (not shown) in which the bus bars 821, 822, and 823 are set.

One end of the bus bars 821, 822, 823 is joined to one end of the bus bar 811, 812, 813 by, for example, a bolt 500. Thereby, bus bars 821, 822, and 823 are electrically connected to bus bars 811, 812, and 813 for each phase. The other ends of the bus bars 821, 822, 823 are joined to the bus bars of each phase on the inverter module 10 side (not shown, see terminals 16A, 17A, 18A in FIG. 1), and the ends of the bus bars 811, 812, 813 are The other end is connected to power lines of each phase from the traveling motor 5 (not shown, see terminals 16B, 17B, and 18B in FIG. 1). Note that such joining may involve tightening with bolts or the like.

Note that in this embodiment, as an example, the sensor unit 60 is provided in the second busbar module 82, as shown in FIG. 5, and therefore is arranged in the space 52 together with the second busbar module 82.

Next, the hollow bus bar 200 will be described with reference to FIGS. 8 to 12. The hollow bus bar 200 described below is preferably used as the above-mentioned various bus bars (bus bars 22, 23, bus bars 811, 812, 813, bus bars 821, 822, 823, etc.) connected to the inverter module 10. It is. This is because the bus bars 22, 23, the bus bars 811, 812, 813, and the bus bars 821, 822, 823 connected to the inverter module 10 tend to have a relatively high temperature because a relatively large current flows through them.

FIG. 8 is a perspective view of the hollow bus bar 200. 9 is a front view of the hollow bus bar 200, and FIG. 10 is a sectional view taken along line AA in FIG. FIG. 11 is an enlarged view of section B in FIG. 10. FIG. 12 is a diagram showing an example of cooling water supply pipe members 1200 and 1202 attached to the hollow bus bar 200. 8 and 12, the hollow interior 2011 of the hollow bus bar 200 is shown in perspective, and the hatched area is the hollow interior 2011.

The hollow bus bar 200 has a hollow pipe shape and has a hollow interior 2011, as shown in FIGS. 8 to 10. Cooling water is circulated in the hollow interior 2011. That is, the refrigerant flow path formed by the hollow interior 2011 forms the busbar flow path section 900 shown in FIG. 3 . Thereby, the hollow bus bar 200 can be effectively cooled by the cooling water.

The hollow bus bar 200 preferably has a main body portion 201 made of a hollow pipe. The main body portion 201 may be formed from a pipe with a circular cross section, or may be formed from a pipe with a cross section of another shape. Note that the pipe for forming the hollow bus bar 200 is made of a conductive material such as aluminum, copper, or iron. In this embodiment, as an example, the main body portion 201 has a rectangular cross section.

When the main body 201 is made of a hollow pipe, the degree of freedom in the shape of the main body 201 is increased. That is, since the pipe can be relatively easily bent into various shapes by press working or the like, the degree of freedom in the shape of the main body portion 201 can be increased.

For example, in the example shown in FIGS. 8-10, body portion 201 includes a bent portion 2014 that is bent and formed, and a closed end portion 2016.

The bent portion 2014 can be easily formed by bending a pipe. The bending direction of the bent portion 2014 may be a direction in which the long side of the rectangular shape is bent, a direction in which the short side of the rectangular shape is bent, or a combination thereof. . The bent portions 2014 may be set at multiple locations as appropriate.

The end portion 2016 can be easily formed by crushing the end of the pipe (so-called tube end crushing). The end portion 2016 functions as a joint portion with other bus bars, power lines, and the like. Furthermore, the end portion 2016 has a function of preventing cooling water from leaking from the main body portion 201 by liquid-tightly closing the hollow interior 2011. For this purpose, the collapsing of the end of the pipe is preferably realized in such a way that no cooling water leaks from the end 2016.

Note that a bolt hole 2017 may be formed in the end portion 2016 for tightening a bolt (see bolt 500 in FIG. 5) when connecting to another bus bar or power line.

As shown in FIG. 11, the main body portion 201 preferably has a coating layer 2018 of a coating material on the hollow interior 2011 side in order to improve corrosion resistance. In this case, even if the material of the pipe is corrosive to water, the main body portion 201 can be protected. That is, the corrosion resistance of the main body portion 201 can be improved.

The coating layer 2018 may be formed over the entire hollow interior 2011 side of the main body portion 201 . That is, the coating layer 2018 may also be formed on the pipe portion that will become the end portion 2016 before the end portion of the pipe is crushed. In this case, the coating layer 2018 is subjected to pressure during molding to crush the end of the pipe. Thereby, the coating layer 2018 can function as a sealing layer, and the liquid tightness (sealability) of the end portion 2016 can be improved.

The main body portion 201 has an inlet hole 2019 and an outlet hole 2020 for cooling water. The inlet hole 2019 may be formed near one end of the main body 201 , and the outlet hole 2020 may be formed near the other end of the main body 201 . Note that a plurality of inlet holes 2019 and/or outlet holes 2020 may be provided for one main body portion 201.

As schematically shown in FIG. 12, a pipe member 1200 is connected to the inlet hole 2019 in a fluid-tight manner. The tubular member 1200 forms part of the circulation flow path 94 described above with reference to FIG. Cooling water pumped from the water pump 90 is supplied to the pipe member 1200 (see arrow R12), and the cooling water is introduced into the hollow interior 2011 of the hollow bus bar 200 via the inlet hole 2019. In addition, in the example shown in FIG. 12, the pipe member 1200 (the same applies to the pipe member 1202 described later) has three bus bar connection parts 1200A, 1200B, and 1200C. In this case, for example, busbars related to each of the U phase, V phase, and W phase, such as the above-mentioned busbars 811, 812, and 813, are realized by the hollow busbar 200, and the busbar connection portions 1200A, 1200B are attached to each busbar. , 1200C can be connected.

In addition, when the above-mentioned bus bars 811, 812, 813 are constituted by the hollow bus bar 200 and the pipe member 1200 is connected to each hollow bus bar 200, the pipe member 1200 is each hollow bus bar 200 related to the bus bar 811, 812, 813. At the same time, the resin portion 810 may be used for sealing. In this case, the sealing properties of the busbar connection parts 1200A, 1200B, and 1200C of the tube member 1200 and the connection parts with each hollow busbar 200 can be improved. However, even in this case, a sealing member such as an O-ring may be provided at the connection portion between the busbar connection portions 1200A, 1200B, and 1200C and each hollow busbar 200. This also applies to the pipe member 1202 described later.

As schematically shown in FIG. 12, the pipe member 1202 is connected to the outlet hole 2020 in a liquid-tight manner. Tube member 1202 forms part of circulation flow path 94 described above with reference to FIG. Cooling water that has been pressure-fed from the water pump 90 and passed through the hollow interior 2011 of the hollow bus bar 200 is returned to the pipe member 1202 to the water pump 90 (see arrow R13). That is, the cooling water used to cool the hollow bus bar 200 is discharged from the inside of the hollow bus bar 200 to the pipe member 1202 .

Such a hollow bus bar 200 can be easily formed from a pipe and has a high degree of freedom in shape. Moreover, since the hollow bus bar 200 can circulate cooling water in the hollow interior 2011, direct heat exchange between the hollow bus bar 200 and the cooling water is possible. Thereby, the performance of the hollow bus bar 200 by cooling water can be effectively improved. In particular, unlike a simple flow of air, cooling water has a high cooling capacity and its flow rate can be adjusted. That is, as described above with reference to FIG. 3, the cooling water radiated via the radiator 92 is force-fed by the water pump 90 to the circulation flow path 94 in which the busbar flow path section 900 is provided, and the flow rate of the cooling water is increased. can be adjusted depending on the operating state of the water pump 90. Thereby, the hollow bus bar 200 can be cooled more effectively and efficiently than in the case of air cooling.

Next, an example of a method for manufacturing the hollow bus bar 200 will be described with reference to FIGS. 13A to 13F.

13A to 13F are explanatory diagrams of an example of a method for manufacturing the hollow bus bar 200. 13A-13F show cross-sectional views of pipe 1300 during each manufacturing step. Also, in FIGS. 13A to 13F, except for FIG. 13C, a side view showing the end of the pipe 1300 is shown on the left side of the cross-sectional view of the pipe 1300.

The method for manufacturing the hollow bus bar 200 first includes the step of preparing a hollow pipe 1300 having a circular cross section, as shown in FIG. 13A. Note that the pipe 1300 will eventually form the main body portion 201 of the hollow bus bar 200 by this manufacturing method.

Next, in the method for manufacturing the hollow bus bar 200, a coating material is put into the hollow portion 1301 of the pipe 1300, as a layer 1302 of coating material is schematically shown by a two-dot chain line in FIG. 13B. The coating material may be in liquid form and may be introduced into the hollow portion 1301 of the pipe 1300 in any manner. For example, the coating material may be introduced into the hollow portion 1301 of the pipe 1300 by immersing the pipe 1300 in a tank containing the coating material. Alternatively, the coating material may be applied (or sprayed) only to a part of the hollow part 1301 of the pipe 1300 (for example, only to the end on the side where a spherical object 1304 described below is introduced). In either case, a layer 1302 (schematically illustrated by a two-dot chain line) of coating material is formed on the inner circumferential surface of the pipe 1300 by this step.

Next, the method for manufacturing the hollow bus bar 200 includes a step of passing a spherical object 1304 through the hollow portion 1301 of the pipe 1300 from one end of the pipe 1300 to the other end, as shown in FIG. 13C. In FIG. 13C, three positions P1 to P3 in the movement process of the spherical object 1304 are shown together with an arrow R1300 indicating the direction of movement. The spherical object 1304 may be fed under pressure from one end of the pipe 1300 to the other end using, for example, compressed air. The sphere 1304 may be spherical with a radius slightly smaller than the inner diameter of the pipe 1300.

When the spherical object 1304 is passed from one end of the pipe 1300 to the other end in this manner, the coating material can be applied over the entire inner peripheral surface of the pipe 1300. That is, the spherical material 1304 has the function of uniformizing the coating material so that it is distributed over the entire inner peripheral surface of the pipe 1300 by being passed through the hollow part 1301 of the pipe 1300 from one end side to the other end side of the pipe 1300. have Through this process, the thickness of the coating material layer on the inner peripheral surface of the pipe 1300 is made uniform. Note that the spherical object 1304 may be passed from one end of the pipe 1300 to the other end, and then passed from the other end of the pipe 1300 to one end. That is, the sphere 1304 may be passed through the pipe 1300 in a reciprocating manner. Alternatively, the spherical object 1304 may be passed from one end of the pipe 1300 to the other end, and then passed from one end of the pipe 1300 to the other end.

Next, the method for manufacturing hollow bus bar 200 includes a step of bending and forming pipe 1300, as shown in FIG. 13D. Note that this type of bending is performed at locations depending on the final shape of the hollow bus bar 200. In the example shown in FIG. 13D, bent portions 1306 and 1308 are formed at two locations in this step.

Next, the method for manufacturing the hollow bus bar 200 includes the step of closing the hollow portion 1301 of the pipe 1300 with the end of the pipe 1300 by crushing the end of the pipe 1300, as shown in FIG. 13E. The ends of the pipe 1300 that are crushed in this step are the ends on both sides of the pipe 1300. In FIG. 13E, the collapsed closed ends 1310, 1312 are shown. Note that the ends 1310 and 1312 form the end 2016 of the main body 201 of the hollow bus bar 200 described above.

Here, in this embodiment, as described above, since the coating material coating process (see FIGS. 13B and 13C) is included, the ends 1310 and 1312 are coated on the inner circumferential surface like the other parts of the pipe 1300. has a layer of coating material on it. Thus, at the ends 1310, 1312 that are collapsed as described above, the layer of coating material becomes the sealing layer for the ends 1310, 1312. For example, the layers of coating material may be firmly bonded together by pressure and/or heat when the end of the pipe 1300 is collapsed. For example, depending on the properties of the coating material, layers of coating material may be integrated by welding. In this case, the layer of coating material on the ends 1310, 1312 can effectively function as a sealing layer.

Next, as shown in FIG. 13F, the method for manufacturing the hollow bus bar 200 includes forming holes 1314 and 1320 for the bolt holes 2017 (see FIG. 8) in the pipe 1300, holes 1316 for the inlet hole 2019 (see FIG. 8), and drilling hole 1318 for exit hole 2020 (see FIG. 8). The holes 1314 and 1320 for the bolt holes 2017, the hole 1316 for the inlet hole 2019, and the hole 1318 for the outlet hole 2020 can be formed by press working in the same process, so that efficient manufacturing can be achieved.

Next, although not shown, the method for manufacturing the hollow bus bar 200 may include a step of pressing a portion that will become the main body portion 201 so that the cross section has a rectangular shape (see FIG. 8, etc.). Note that if the cross section is used as it is circular, this step may be omitted.

According to the example shown in FIGS. 13A to 13F, the hollow bus bar 200 can be easily manufactured from the pipe 1300. In particular, the spheres 1304 can be used to spread the coating material over the entire inner peripheral surface of the pipe 1300, increasing the reliability of the layer of coating material. As a result, excellent corrosion resistance can be achieved. Further, by having the ends 1310 and 1312 of the pipe 1300 with a layer of coating material, sealing performance can be improved.

FIG. 14 is an explanatory diagram of another example of the method for manufacturing the hollow bus bar 200.

The example shown in FIG. 14 differs from the examples shown in FIGS. 13A to 13F in the method of applying the coating material. In the example shown in FIG. 14, after the various forming steps of the pipe 1300 are completed, the coating material and air are introduced through the hole 1316 for the inlet hole 2019 (see FIG. 8) (see arrow R140). The air introduced through the hole 1316 for the inlet hole 2019 (see FIG. 8) is discharged from the hole 1318 for the outlet hole 2020 (see FIG. 8) (see arrow R142), so that the coating material is inside the pipe 1300. It can flow along the circumferential surface towards hole 1318 (see arrow R141). In this way, the coating material can be made uniform so that it is spread over the entire inner circumferential surface of the pipe 1300 with the air.
Also by the manufacturing method shown in FIG. 14, the hollow bus bar 200 can be easily manufactured from the pipe 1300. In particular, air can be used to spread the coating material over the entire inner peripheral surface of the pipe 1300, increasing the reliability of the layer of coating material. As a result, excellent corrosion resistance can be achieved. Further, by using air to bring the coating material to the ends 1310 and 1312 of the pipe 1300, it is also possible to improve the sealing performance. Furthermore, since the manufacturing method shown in FIG. 14 allows the coating material to be introduced after completing various forming processes for the pipe 1300, the coating material can be applied even when the hollow bus bar 200 has a more complicated shape (for example, when complicated molding is involved). It becomes possible to apply the material.

According to the present embodiment described above, particularly the following excellent effects can be achieved.

According to this embodiment, as described above, at least one of the various bus bars connected to the inverter module 10, such as the bus bars 22, 23, the bus bars 811, 812, 813, and the bus bars 821, 822, 823, This is realized by the hollow bus bar 200. Thereby, the bus bar can be cooled by cooling water (an example of a liquid refrigerant) without reducing the degree of freedom in the shape of the bus bar.

In particular, the hollow bus bar 200 can be easily manufactured using the pipe 1300 and has a high degree of freedom in shape. Therefore, even in spaces where wiring space is limited, such as the space 51, the space 52, the space inside the capacitor case 30, etc., the hollow bus bar 200 can be effectively routed (layout).

Further, when the refrigerant passing through the hollow interior 2011 of the hollow bus bar 200 is cooling water, it is useful to consider corrosion of the hollow bus bar 200, but the hollow bus bar 200 can be easily manufactured in a corrosion-resistant manner. can. That is, the hollow bus bar 200 with excellent corrosion resistance can be easily manufactured by simply applying a layer of coating material to the pipe 1300 before bending. In particular, as mentioned above, the reliability of the layer of coating material can be increased when spherical objects 1304 are utilized. Note that if the refrigerant passing through the hollow interior 2011 of the hollow bus bar 200 is oil, it is possible to omit the layer of coating material. In this case, the oil passing through the hollow bus bar 200 may drip into the space 51 where the travel motor 5 is arranged. Therefore, the oil passing through the hollow bus bar 200 can be used for cooling and/or lubricating the travel motor 5. Furthermore, in this case, even if oil leaks from the hollow bus bar 200, it only drips into the space 51 and does not cause any significant harm. Therefore, in this case, it is also possible to reduce the requirements regarding the sealing performance of the hollow bus bar 200.

Further, according to this embodiment, as described above, the flow rate of cooling water passing through the hollow interior 2011 of the hollow bus bar 200 can be easily adjusted by controlling the operation of the water pump 90, for example. Thereby, efficient cooling can be achieved in a manner that takes into account the state of the hollow bus bar 200.

By the way, the various bus bars connected to the inverter module 10, such as the bus bars 22, 23, the bus bars 811, 812, 813, and the bus bars 821, 822, 823, are used to flow a relatively large current from the high voltage battery 2. Therefore, the amount of heat generated is also relatively large. Moreover, when the temperature of various bus bars connected to the inverter module 10 rises, the temperature of the surrounding atmosphere also rises accordingly. Therefore, it may be necessary to take measures such as increasing the heat resistance of peripheral components or reducing the output of the travel motor 5. For example, when the temperature of the atmosphere within the space 52 becomes high, the heat resistance of the current sensor 6 within the space 52 tends to become a problem.

Note that air circulation cannot be expected in a relatively highly closed space such as the space 52. Therefore, in a comparative example in which air is used as a refrigerant passing through the hollow interior 2011 of the hollow bus bar 200, it is difficult to effectively cool the hollow bus bar 200 in such a relatively highly closed space. As a result, in this comparative example, the need for measures to increase the heat resistance of the current sensor 6 increases.

In this regard, according to this embodiment, as described above, the refrigerant passing through the hollow interior 2011 of the hollow bus bar 200 is a liquid (for example, cooling water) that has a relatively high heat exchange ability, unlike air. In particular, in this embodiment, the cooling water circulating through the circulation channel 94 via the radiator 92 is used to cool the hollow bus bar 200 . Thereby, the temperature rise of the hollow bus bar 200 can be effectively suppressed. As a result, the rise in temperature of the surrounding atmosphere can be effectively reduced, and the need for measures such as increasing the heat resistance of peripheral components or reducing the output of the traveling motor 5 can be reduced.

In this way, according to this embodiment, even in a relatively highly closed space where air circulation cannot be expected, the hollow bus bar 200 can be operated using circulating cooling water without using air. Can be cooled effectively.

Although each embodiment has been described in detail above, it is not limited to a specific embodiment, and various modifications and changes can be made within the scope of the claims. It is also possible to combine all or a plurality of the components of the embodiments described above.

For example, in the embodiments described above, cooling water is used as the refrigerant, but the refrigerant need not be air and may be any liquid such as oil. In addition, when the refrigerant is oil, the oil may also be used for lubricating and cooling the traveling motor 5. Also, unlike cooling water, oil is less likely to cause corrosion. Therefore, in this case, the application of the coating material described above may be omitted.

<Additional notes>
Regarding the above embodiments, the following will be further disclosed. Note that, among the effects described below, effects related to each form additional to one form are additional effects resulting from each additional form.

(1) One form includes a power converter (10);
a first bus bar (811, 812, 813) that is electrically connected to the power converter, has a hollow pipe-like shape, and has a hollow interior (2011) forming a refrigerant flow path (94, 900);
In the vehicle drive device, liquid refrigerant is pumped into the refrigerant flow path.

According to this embodiment, the bus bar can be cooled by the liquid refrigerant without reducing the degree of freedom in the shape of the bus bar electrically connected to the power converter. Note that the bus bar electrically connected to the power converter generates a relatively large amount of heat, and cooling with a liquid refrigerant is effective. Thereby, it is possible to effectively reduce the rise in ambient temperature around the bus bar due to the rise in temperature of the bus bar.

(2) Also, in this embodiment, preferably a pump (90) that pumps liquid refrigerant to the refrigerant flow path;
further comprising a control unit (6B) that controls the pump,
The refrigerant flow path is a part of a circulation flow path (94) in which the refrigerant circulates, and the circulation flow path includes a heat exchange section (92) that removes heat from the refrigerant.

In this case, since the liquid refrigerant circulates through the heat exchange section, the bus bar can be effectively cooled.

(3) In this embodiment, preferably, a second bus bar (821, 822, 823) whose one end is coupled to the first bus bar and whose other end is electrically connected to the power converter;
further comprising a current sensor (6, 60) provided on the first bus bar or the second bus bar,
One end of the first bus bar is electrically connected to the rotating electrical machine (5), and the other end is coupled to the second bus bar.

In this case, a configuration in which the current sensor is provided on the first bus bar or the second bus bar can be established without excessively increasing the heat resistance of the current sensor. Further, since the supply of current to the rotating electrical machine can be realized using the first bus bar having excellent cooling performance, it is possible to prevent the ambient temperature around the rotating electrical machine from rising excessively.

(4) Also, in this embodiment, preferably, the first bus bar has a main body (201) made of a hollow pipe (1300),
The body portion includes a bent portion (2014) and a closed end portion (2016).

In this case, the first bus bar can be efficiently routed (layout) using the bent portion while improving the liquid tightness of the first bus bar.

(5) Also, in this embodiment, preferably, the main body portion has a coating layer (2018) of a coating material over the entire inner circumferential surface, and the end portion (2016) is closed.

In this case, the coating layer of the coating material can improve the sealing performance at the end while increasing the corrosion resistance. Therefore, the first bus bar can be used even for refrigerants that can corrode metals, such as cooling water.

(6) Another form is a hollow bus bar electrically connected to the power converter (10),
It has a main body (201) made of a hollow pipe (1300),
The main body is a hollow bus bar (200) whose hollow interior (2011) forms a refrigerant flow path (94, 900) for a liquid refrigerant.

In this case, a hollow bus bar whose hollow interior forms a refrigerant flow path for a liquid refrigerant can be constructed from a hollow pipe. Therefore, the bus bar can be cooled by the liquid refrigerant without reducing the degree of freedom in the shape of the bus bar electrically connected to the power converter.

(7) Also, in this embodiment, preferably, the main body portion has a coating layer (2018) of a coating material over the entire inner circumferential surface, and the end portion (2016) is closed.

In this case, the coating layer of the coating material can improve the sealing performance at the end while increasing the corrosion resistance. In this case, the hollow bus bar is also suitable for refrigerants that can corrode metals, such as cooling water.

(8) Another form is to form a bus bar (22, 23, 811, 812, 813, etc.) from a hollow pipe (1300) whose hollow interior (2011) forms a refrigerant flow path (94, 900). A method for forming a hollow busbar, the method comprising:
Putting a coating material into the hollow part (1301) of the pipe;
The method for forming a hollow bus bar includes the step of, after putting the coating material into the hollow part, passing a spherical object (1304) through the hollow part from one end of the pipe to the other end.

According to this embodiment, it becomes easy to uniformly apply a layer of the coating material on the inner circumferential surface of the pipe. Thereby, the reliability of the layer of coating material can be increased, and the function of the layer of coating material (the function of increasing corrosion resistance) can be effectively realized. Therefore, it is possible to obtain a hollow bus bar that is less susceptible to corrosion even when a liquid refrigerant is passed through the refrigerant flow path.

(9) Also, in this embodiment, preferably, after passing the spherical object, the pipe further includes a processing step of crushing the ends (1310, 1312) of the pipe to close the hollow part.

In this case, a layer of coating material can be used to improve the sealing of the end of the pipe. Therefore, it is possible to obtain a hollow bus bar in which refrigerant does not easily leak at the ends even when liquid refrigerant is passed through the refrigerant flow path.

(10) Another form is to form a bus bar (22, 23, 811, 812, 813, etc.) from a hollow pipe (1300) whose hollow interior (2011) forms a refrigerant flow path (94, 900). A method for forming a hollow busbar, the method comprising:
forming a layer (1302) of coating material on the inner peripheral surface of the pipe;
further comprising a processing step of crushing and closing the ends (1310, 1312) of the pipe after forming the layer of coating material;
The end of the pipe has a layer of the coating material.

According to this embodiment, it is possible to improve the sealing performance of the end of the pipe by using the layer of the coating material while increasing the corrosion resistance by the layer of the coating material. Thereby, a hollow bus bar suitable for passing liquid refrigerant through the hollow interior can be obtained.

1 Motor drive system 2 High voltage battery 3 Smoothing capacitor 4 Inverter 5 Traveling motor 6 Current sensor 6A Inverter control device 6B Control device 10 Inverter module 13 Control wiring 20 Capacitor modules 22, 23 Bus bar 30 Capacitor case 38 Flow path forming part 40 Control board 42 Connector 50 Shield plates 51, 52 Space 60 Sensor unit 70 Wiring section 71 First wiring section 72 Second wiring section 80 Bus bar configuration 81 First bus bar module 810 Resin sections 811, 812, 813 Bus bar 82 Second bus bar module 820 Resin section 821, 822, 823 Busbar 90 Water pump 92 Radiator 94 Circulation channel 900 Busbar channel section 200 Hollow busbar 201 Main body section 2011 Hollow interior 2014 Bend section 2016 End section 2017 Bolt hole 2018 Coating layer 2019 Inlet hole 2020 Outlet hole 221 Terminal 231 Terminal 500 Bolt 1200 Tube member 1200A Busbar connection part 1200B Busbar connection part 1200C Busbar connection part 1202 Tube member 1300 Pipe 1301 Hollow part 1304 Spherical object 1306 Bend part 1308 Bend part 1310 End part 1312 End part

Claims (5)

a power converter;
a first bus bar that is electrically connected to the power converter, has a hollow pipe-like shape, and has a hollow interior that forms a refrigerant flow path ;
a pump that pumps refrigerant to the refrigerant flow path;
a control unit that controls the pump;
a second bus bar having one end coupled to the first bus bar and the other end electrically connected to the power converter;
a current sensor provided on the first bus bar or the second bus bar ,
The refrigerant flow path is a part of a circulation flow path in which the refrigerant circulates, and the circulation flow path has a heat exchange part that removes heat from the refrigerant.
The first bus bar is a vehicle drive device in which one end is electrically connected to the rotating electric machine and the other end is coupled to the second bus bar . a power converter;
a first bus bar that is electrically connected to the power converter, has a hollow pipe-like shape, and has a hollow interior that forms a refrigerant flow path;
A liquid refrigerant is pumped into the refrigerant flow path,
The first bus bar has a main body made of a hollow pipe,
The main body portion includes a bent portion formed by bending and a closed end portion,
In the vehicle drive device, the main body has a coating layer of a coating material over the entire inner circumferential surface, and the end portion is closed in such a manner that the coating layers are in close contact with each other. a pump that pumps the refrigerant into the refrigerant flow path;
further comprising a control unit that controls the pump,
The vehicle drive device according to claim 2, wherein the refrigerant flow path is a part of a circulation flow path through which the refrigerant circulates, and the circulation flow path includes a heat exchange section that removes heat from the refrigerant. a second bus bar having one end coupled to the first bus bar and the other end electrically connected to the power converter;
further comprising a current sensor provided on the first bus bar or the second bus bar,
The vehicle drive device according to claim 3, wherein the first bus bar has one end electrically connected to a rotating electrical machine and the other end coupled to the second bus bar. A hollow bus bar electrically connected to a power converter,
The main body is made of a hollow pipe and has a hollow interior that forms a refrigerant flow path for a liquid refrigerant ,
The main body portion includes a bent portion formed by bending and a closed end portion,
The main body portion has a coating layer of a coating material over the entire inner circumferential surface, and the end portions are closed in such a manner that the coating layers are in close contact with each other.