JP7183921B2 - Vehicle fan motor controller - Google Patents

Description

The present invention relates to a device for controlling a fan motor for a vehicle.

While the vehicle is running and the engine is operating, the temperature in the engine room of the vehicle is cooled to some extent by the circulation of cooling water and the running wind. However, when the vehicle stops running, the cooling stops and the temperature in the engine room remains high for a while. At this time, if the outside air temperature is low, the body frame and harnesses routed inside and outside the engine room will be cooled, and the heat drawn from them will cause dew condensation on the equipment located in the engine room. May cause corrosion. Techniques for preventing such dew condensation are disclosed, for example, in Patent Documents 1 and 2.

JP-A-2005-29129 JP 2015-115984 A

However, the technique disclosed in Patent Document 1 uses an expensive humidity sensor to predict the amount of dew condensation that will occur and operates the air conditioner, which leads to an increase in cost. Further, in the technique disclosed in Patent Document 2, information on the temperature of the outside air is obtained and the electronic components are caused to self-heat so as not to cause dew condensation. In this case, it is necessary to take dew condensation measures for each component.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fan motor control device for a vehicle, which is low in cost and can collectively take countermeasures against dew condensation on components arranged in an engine room. to provide.

The vehicle fan motor control device according to claim 1 detects the temperature inside the device with a temperature sensor when controlling the drive of the fan motor that rotates the cooling fan arranged in the engine room, and the obtained engine The internal dew condensation state is estimated according to the difference between the ambient temperature in the room and the detected temperature. That is, when the temperature difference becomes large to some extent, dew condensation occurs at the interface with the temperature difference. Therefore, with this configuration, it is possible to estimate the dew condensation occurrence state inside the apparatus without using an expensive humidity sensor, and to take countermeasures as necessary.

Further, according to the vehicle fan motor control device of claim 1 , when the ignition switch of the vehicle is turned off, the ambient temperature in the engine room and the temperature inside the device are compared after the monitoring time has elapsed. If the temperature difference is greater than or equal to a predetermined value, the fan motor is rotated. That is, when the ignition switch is turned off, the atmospheric temperature in the engine room is high, and the high temperature is maintained for a relatively long time due to the large heat capacity.

On the other hand, the control device has a smaller heat capacity than the engine room. In addition, since the power line and the ground line connected to the battery are exposed to the outside of the device, they are cooled by the outside air, which facilitates a decrease in internal temperature. Therefore, it can be estimated that after a certain amount of time has passed since the ignition switch was turned off, dew condensation begins to occur inside the control device due to the temperature difference between the two due to the above factors. Therefore, by blowing air by rotating the fan motor, the occurrence of dew condensation can be prevented.

According to the vehicle fan motor control device of claim 2 , when the temperature difference between the two falls below a predetermined value, the rotation of the fan motor is stopped and the mode shifts to the standby mode, so unnecessary power consumption can be suppressed.

FIG. 1 is a diagram showing a model of a configuration arranged inside an engine room of a vehicle according to the first embodiment; Side view showing the configuration of the cooling fan motor unit with only the control device in cross section A plan view of the control device showing a part of the metal cover cut away. A diagram explaining how the control device is cooled when the ignition switch is turned off. Functional block diagram showing mainly the configuration of the cooling fan motor unit 4 is a flow chart showing the contents of processing by the control circuit of the control device; Timing chart corresponding to the processing contents shown in FIG. The top view of the control apparatus which is 2nd Embodiment and shows breaking a part of metal cover. A functional block diagram of the third embodiment, mainly showing the configuration of a cooling fan motor unit.

(First embodiment)
As shown in FIG. 1, in an engine room 2 of a vehicle 1, an engine 3, a cooling fan motor unit 4, a radiator 5, a condenser 6, and the like are arranged. As shown in FIG. 2, the cooling fan motor unit 4 has a control device 11, a fan motor 12 and a cooling fan 13. As shown in FIG. The cooling fan 13 blows air to the radiator 5 and the condenser 6 to cool them.

Inside the control device 11 , a printed circuit board 15 is fixed to a heat sink 14 with screws 16 . A heat dissipation material 30 is interposed between the heat sink 14 and the printed circuit board 15 . A temperature sensor 17 and other surface mount components 18 are mounted on the printed circuit board 15 . A metal cover 19 is attached to the heat sink 14 so as to cover the printed circuit board 15 . The printed board 15 corresponds to a circuit board. Also, the heat sink 14 and the metal cover 19 correspond to a housing.

A power supply line 21 and a ground line 22 are connected via a connector 20 to the upper part of the control device 11 in FIG. The power line 21 and the ground line 22 are connected to a battery 23 mounted on the vehicle 1 shown in FIG. 5 and supply power to the control device 11 . The fan motor 12 is attached to the outside of the heat sink 14, on the right side in FIG. The temperature sensor 17 is arranged near the area of the printed circuit board 15 where the terminals of the connector 20 are soldered.

As shown in FIG. 5, the control device 11 has a control circuit 24, a drive circuit 25, a smoothing circuit 26, and the like. The control circuit 24 is composed of a microcomputer or the like, and is connected to an engine ECU 27 that controls the engine 3 via a signal line 28 . The drive circuit 25 is, for example, a three-phase inverter circuit, and drives the fan motor 12 under switching control by the control circuit 24 . The smoothing circuit 26 is connected to the power supply line 21 , smoothes the power supply voltage supplied from the battery 23 , and supplies the smoothed power supply voltage to the drive circuit 25 .

The control circuit 24 communicates directly with the engine ECU 27 via a signal line 28, ie, a so-called Zika line or an in-vehicle LAN (Local Area Network). Thereby, the control circuit 24 acquires information such as the ON/OFF state of an ignition switch (not shown), the rotation speed of the engine 3, the ambient temperature in the engine room 2, and the like.

Next, the operation of this embodiment will be described. As shown in FIG. 6, the control circuit 24 of the control device 11 starts to operate when the ignition switch is turned on and power is supplied from the battery 23, and when initialization is performed (S1), it shifts to normal control ( S2). Then, while the ignition switch is turned on (S3; NO), normal control is executed. As shown in FIG. 7, the control device 11 drives the fan motor 12 to rotate the fan 13 in normal control, and controls the rotational speeds of the fans.

When the ignition switch is turned off (S3; YES), temperature information is obtained after the monitoring time has elapsed (S4). Here, the "monitoring time" is, for example, about 30 seconds to 1 minute, and the acquired "temperature information" is the ambient temperature TA in the engine room 2 and the temperature TB inside the control device 11 detected by the temperature sensor 17. be.

Next, the control circuit 24 determines whether or not the temperature difference (=TA-TB) is equal to or greater than the determination value (S5). Here, the "determination value" is, for example, about 3°C to 25°C. Immediately after the ignition switch is turned off and the engine 3 is stopped, the temperature inside the engine room 2 and the control device 11 is high, for example, about 100.degree. Since the engine 3 has a large heat capacity, the temperature in the engine room 2 does not drop immediately.

On the other hand, the control device 11 has a smaller heat capacity than the engine 3 . In addition, a power line 21 and a ground line 22 are connected to the control device 11, and as shown in FIGS. in a state. As a result, the inside of the control device 11 is "heated", so the temperature tends to drop. Due to these events, the temperature inside the control device 11 drops faster than the ambient temperature in the engine room 2 . Then, when the temperature difference between the two becomes large to some extent, dew condensation begins to occur inside the control device 11 on the low temperature side. Incidentally, in FIG. 3, a state in which dew condensation occurs inside the control device 11 is indicated by a broken line.

Therefore, if the temperature difference is greater than or equal to the judgment value (YES), the control circuit 24 continues the rotational speed control of the fan motor 12 to prevent condensation (S6). Then, after the monitoring time has elapsed again, the temperature information is acquired (S7), and it is determined whether or not the temperature difference is equal to or greater than the determination value (S8). If the temperature difference is equal to or greater than the judgment value (YES), the process returns to step S6.

If the temperature difference is less than the judgment value in step S8 (NO), it is determined that condensation inside the controller 11 has been avoided, and the control circuit 24 stops the fan motor 12 and the fan 13 (S9). Then, after the monitoring time has elapsed, the mode shifts to the standby mode (S10). Moreover, when it is judged as "NO" in step S5, it also transfers to step S9.

As described above, according to the present embodiment, the control device 11 detects the internal temperature using the temperature sensor 17 when controlling the driving of the fan motor 12 that rotates the cooling fan 13 arranged in the engine room 2. The internal dew condensation occurrence state is estimated according to the difference between the detected and acquired atmospheric temperature in the engine room 2 and the detected temperature. With this configuration, it is possible to estimate the state of condensation inside the control device 11 without using an expensive humidity sensor, and to take countermeasures as necessary.

When the ignition switch is turned off, the control device 11 compares the ambient temperature in the engine room 2 with the temperature in the device after the monitoring time has elapsed. Rotate 12. By rotating the fan 13 to blow air in this way, the occurrence of dew condensation can be prevented. Further, when the temperature difference between the two becomes less than a predetermined value, the control device 11 stops the rotation of the fan motor 12 and shifts to the standby mode, thereby suppressing unnecessary power consumption.

Moreover, since the connector 20 to which the power line 21 and the ground line 22 are connected is provided, and the temperature sensor 17 is arranged near the terminals of the connector 20 connected to the printed circuit board 15, the power line 21 and the ground line 22 are connected. "Heat reduction" can detect the state of a portion where the temperature drops significantly. In addition, since the fan 13 for cooling the radiator 5 and the condenser 6 mounted on the vehicle 1 is used, there is no need to provide a separate fan for cooling the control device 11 .

(Second embodiment)
Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted, and different parts will be described. As shown in FIG. 8, the control device 11 has mounting portions 31L, 31R, and 31U extending outward from the heat sink 14 in order to fix the main body to the mechanical portion in the engine room 2. As shown in FIG. These mounting portions 31 are provided with holes for screwing, and the control device 11 is fixed to the above mechanism portion by screwing.

Although not shown, the mechanical portion to which the control device 11 is attached generally has a larger heat capacity than the control device 11. Therefore, heat is easily dissipated from the control device 11 via the attachment portion 31, and the temperature of the attachment portion 31 is lowered. easy. Therefore, in the second embodiment, the temperature sensor 17 is arranged on the mounting portion 31R, for example. Even when configured in this manner, the control device 11 can detect the state of the portion where the temperature drops significantly due to the "heat sink" of the mounting portion 31R.

(Third embodiment)
As shown in FIG. 9, the cooling fan motor unit 41 of the third embodiment includes a control circuit 42 that replaces the control circuit 24. As shown in FIG. The control device 43 has an input terminal TI, and a temperature sensor 44 for detecting the ambient temperature in the engine room 2 is connected to the input terminal TI. The input terminal TI corresponds to a dedicated terminal. The control circuit 42 directly acquires the ambient temperature in the engine room 2 detected by the temperature sensor 44 via the input terminal TI. With this configuration, the control circuit 42 can obtain the ambient temperature in the engine room 2 without communicating with the engine ECU 27 .

(Other embodiments)
The direction in which the fan motor is rotated may be set according to the type of vehicle. That is, it is possible to selectively set the case of rotating in the direction of intake into the room and the case of rotating in the direction of exhausting to the outside of the room, depending on the arrangement of each mechanism in the engine room.
A dedicated fan may be provided to cool the controller.
Specific numerical values of time and temperature may be appropriately changed according to individual designs.

Although the present disclosure has been described with reference to examples, it is understood that the present disclosure is not limited to such examples or structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and configurations, as well as other combinations and configurations, including single elements, more, or less, are within the scope and spirit of this disclosure.

In the drawings, 1 is a vehicle, 2 is an engine room, 3 is an engine, 4 is a cooling fan motor unit, 5 is a radiator, 6 is a condenser, 11 is a control device, 12 is a fan motor, 13 is a cooling fan, and 14 is a heat sink. , 15 is a printed circuit board, 17 is a temperature sensor, 19 is a metal cover, 20 is a connector, 21 is a power line, 22 is a ground line, and 23 is a battery.

Claims (8)

It acquires the ambient temperature information in the engine room (2) and controls the drive of the fan motor (12) that rotates the cooling fan (13) arranged in the engine room (2). a power line (21) and a ground line (22) that
A temperature sensor (17) that detects the temperature inside the device ,
estimating the dew condensation occurrence state in the inside according to the difference between the ambient temperature in the engine room and the temperature inside the device ;
Get the on/off information of the ignition switch of the vehicle,
When the ignition switch is turned off, the ambient temperature in the engine room and the temperature in the device are compared after a monitoring time has elapsed, and if the temperature difference between the two is equal to or greater than a predetermined value, the fan motor is rotated. Fan motor controller. 2. A vehicle fan motor controller according to claim 1 , wherein when the temperature difference between the two is less than a predetermined value, the fan motor stops rotating and shifts to a standby mode. 3. A vehicle fan motor control device according to claim 1 , wherein the direction of rotation of said fan motor is set according to the type of vehicle. A connector (20) to which the power line and the ground line are connected,
4. The vehicle fan motor control device according to claim 1, wherein the temperature sensor is arranged near a terminal of the connector connected to the circuit board. Equipped with a metal housing (14, 19),
The vehicle fan motor control device according to any one of claims 1 to 3 , wherein the temperature sensor is arranged in a mounting portion (31R) for fixing the housing in the engine room. 6. The vehicle fan motor control device according to any one of claims 1 to 5 , further comprising a dedicated terminal (TI) for acquiring ambient temperature information in the engine room. 7. The vehicle fan motor control device according to claim 6 , further comprising a temperature sensor (44) connected to the dedicated terminal and detecting an ambient temperature in the engine room. The vehicle fan motor control device according to any one of claims 1 to 7 , wherein the cooling fan is a fan for cooling a vehicle radiator (5) and a condenser (6).

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