JPH08116605A - Cooling device for electric automobile - Google Patents

Abstract

PURPOSE: To secure the safety actuation of a controller by surely preventing the temperature rise of the controller to an abnormal temperature even when the temperature of the cooling water is high at the time of cooling the running motor and controller of an electric automobile by circulating the cooling water. CONSTITUTION: A cooling water circulating passage 35 through which cooling water is successively circulated to a water pump 27, controller 9, motor 1, and radiator 28, by-pass passage 36 through which the cooling water is made to by-pass the motor 1, and temperature sensitive valve 37 which detects the temperature of the cooling water after the cooling water passes through the controller 9 and switches the flow passage of the cooling water to the motor 1 side of the circulating passage 35 or by-pass passage 36 are provided. By means of the valve 37, the cooling water is directed to the by-pass passage 36 and only circulated between the radiator 28 and controller 9 so that the controller 9 can be efficiently cooled in a concentrating state when the temperature of the water is higher than a prescribed value. Therefore, the temperature rise of the controller 9 to an abnormal temperature can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for an electric vehicle that travels by driving wheels by a traveling motor, and more particularly to a measure for stably cooling a controller that controls the traveling motor.

[0002]

2. Description of the Related Art Generally, an electric vehicle of this kind is provided with a controller for controlling the operation of the electric motor separately from a drive motor drivingly connected to the wheels. A field current of the motor is generated, and the rotor of the motor is rotated by the field current.

Since the capacity of the motor used in the electric vehicle is as large as 20 to 30 A, and the heat generation amount of the power transistor also increases accordingly, it is necessary to cool the heat generating portion of the controller together with the motor with the cooling liquid. Is being done. For example, JP-A-5-29
In the one disclosed in Japanese Patent No. 2703, a controller is integrated with a motor main body via a heat sink thereof, and a cooling liquid such as cooling water is caused to flow in the heat sink to cool a controller having lower heat resistance than a motor. The cooling liquid after the cooling is supplied to the motor main body to cool the motor main body.

[0004]

By the way, the above cooling liquid is supplied to the radiator through the cooling liquid passage after being heated to a high temperature by the cooling of the controller and the motor, and is cooled by exchanging heat with traveling wind or the like. When the temperature becomes low due to cooling, it is circulated so as to be supplied to the controller and the motor again. However, when the outside air temperature is high, such as during summer, the cooling liquid may not fall sufficiently to the target temperature even if it is cooled by the radiator, and the controller with low heat resistance will not be sufficiently cooled and the controller There is a possibility that the temperature rises to an abnormal temperature and the electronic element such as the transistor is thermally destroyed.

The present invention has been made in view of the above circumstances, and an object thereof is to improve the supply form of the cooling liquid to the motor and the controller so that the controller can be operated even when the temperature of the cooling liquid is high. Allows for preferential cooling to prevent the abnormal temperature from rising,
To ensure stable operation of the controller.

[0006]

In order to achieve the above object, in the invention of claim 1, the temperature of the cooling liquid after cooling the controller is not less than a predetermined value, paying attention to that the motor has a higher heat resistant temperature than the controller. When the temperature becomes high, the cooling liquid is bypassed to the motor so as to flow only between the controller and the radiator, and the controller is intensively cooled by the cooling liquid cooled by the radiator.

Specifically, the present invention is premised on a cooling device for an electric vehicle provided with a cooling means for cooling a traveling motor connected to drive wheels and a controller for controlling the operation of the traveling motor with a cooling liquid. is there.

The cooling means sucks and discharges the cooling liquid, a radiator for exchanging heat with the air outside the vehicle to cool the cooling liquid, and the cooling liquid discharged from the water pump in order. A cooling liquid circulation path that circulates the controller, the motor and the radiator so as to circulate back to the water pump, a bypass path that allows the cooling liquid to bypass the traveling motor, and a controller temperature representing the controller is lower than a predetermined value. In the case of, the cooling liquid is caused to flow to the motor side along the cooling liquid circulation path, while when the controller temperature is equal to or higher than a predetermined value, the cooling liquid is switched to flow along the bypass path. .

In the second aspect of the invention, the controller temperature is the temperature of the cooling liquid after passing through the controller. Further, the adjusting means is a temperature sensitive valve that senses the temperature of the cooling liquid and selectively switches the cooling liquid flow path to the motor side or the bypass path.

According to the third aspect of the present invention, a heater core for exchanging heat with the air in the vehicle compartment is provided in the cooling liquid circulation path from the downstream end connection portion of the bypass path to the radiator.

According to the fourth aspect of the present invention, the cooling fan for blowing air to the motor and the radiator, and the rotational speed of at least one of the cooling fan and the water pump are increased stepwise in accordance with the controller temperature so that the controller temperature increases. A control means for controlling is provided.

[0012]

With the above structure, in the first aspect of the invention, the cooling liquid is switched by the adjusting means of the cooling means in accordance with the controller temperature representing the controller, and when the controller temperature is less than the predetermined value, the cooling liquid is Circulates by flowing along a coolant circuit. That is, the cooling liquid discharged from the water pump is supplied to the controller and then to the traveling motor, respectively, to cool them, and the temperature of the cooling liquid itself rises. The coolant whose temperature has risen is supplied to the radiator, cooled by heat exchange with the air outside the vehicle, and then sucked into the water pump.

On the other hand, when the controller temperature is equal to or higher than the predetermined value, the coolant circulates while bypassing the traveling motor. That is, the cooling liquid discharged from the water pump is supplied to the controller to cool it, and then is supplied to the radiator via the bypass path without passing through the traveling motor to be cooled, and then sucked into the water pump.
Therefore, when the controller temperature is high, the coolant circulates only between the radiator and the controller, so even if the temperature of the coolant is high, the controller is concentrated by the coolant that has become low in the radiator. It is possible to cool efficiently, and thus it is possible to reliably prevent the controller from rising to an abnormal temperature.

According to the second aspect of the present invention, the temperature sensing valve selectively switches the cooling liquid passage to the motor side or the bypass passage according to the temperature of the cooling liquid after passing through the controller, and the cooling liquid temperature is less than a predetermined value. In the case of, the cooling liquid flow path is on the motor side, but when it is a predetermined value or more, the cooling liquid flow path is a bypass path. Therefore, it is possible to obtain the same operational effect as that of the invention of claim 1, and to achieve the operational effect with a simple configuration of only the temperature sensitive valve and at low cost.

According to the third aspect of the present invention, at least the cooling liquid heated by cooling by the controller always exchanges heat with the air in the vehicle compartment through the heater core regardless of the flow path switching of the adjusting means (temperature sensitive valve). Therefore, the heating efficiency of the vehicle interior by the heater core can be improved.

According to the fourth aspect of the present invention, the control means controls the rotation speed of at least one of the cooling fan and the water pump for the motor and the radiator to increase stepwise in accordance with the increase in the controller temperature. . Therefore, the circulating amount of the cooling liquid or the cooling efficiency of the motor or the radiator by the cooling fan can be properly adjusted, and the power consumption of the power supply can be reduced.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows the overall construction of Embodiment 1 of the present invention, in which 1 is a traveling motor composed of a three-phase AC motor connected to driving wheels (not shown) in an automobile, and 9 is the traveling motor 1.
Is a motor controller that controls the operation of the motor, and 25 is a cooling device that cools the traveling motor 1 and the motor controller 9 with the circulating cooling water.

As shown in FIG. 7, the motor controller 9 includes a motor drive circuit 10 and this motor drive circuit 1.
And a motor control circuit 11 with a built-in CPU for controlling 0. The motor drive circuit 10 includes connection terminals 14a, 14 for positive and negative poles of a battery power source (not shown).
, which are connected in series in parallel with each other via b, and three smoothing capacitors 13, which are connected in parallel between the bipolar connection terminals 14a and 14b. , And the connecting portions of the power transistors 12, 12 of each pair are U, respectively.
It is connected to the U-phase, V-phase and W-phase of the traveling motor 1 via the pole, V-pole and W-pole connection terminals 15a to 15c. The motor control circuit 11 also receives an output signal of an accelerator opening sensor 23 that detects the opening degree (depression amount) of the accelerator pedal 22 in the vehicle. In the motor control circuit 11, the accelerator opening signal is output. In accordance with the above, each pair of power transistors 12, 1 of the motor drive circuit 10
2 by applying a control voltage to each pair of transistors 12, 12
By alternately turning on the transistors, the transistors 12, 1
A field current to the U-phase, V-phase and W-phase of the motor 1 is output from between the two connections.

The cooling device 25 is arranged, for example, in the front part of the automobile and a water pump 27 which sucks and discharges the cooling water by the operation of the pump motor 26, and cools the cooling water by exchanging heat with the air outside the vehicle. The radiator 28, the heater core 29 arranged in the vehicle compartment for exchanging heat between the cooling water and the air in the vehicle compartment, and the electric motor 30 are operated to drive the traveling motor 1.
A cooling fan 31 for the motor that blows air to the fan to cool it,
Similarly, it is provided with a radiator cooling fan 33 that blows air to the radiator 28 by the operation of the electric motor 32 to cool it. The water pump 27, the motor controller 9, the traveling motor 1, the heater core 29, and the radiator 28 are connected in series by a cooling water circulation path 35, and the cooling water discharged from the water pump 27 is sequentially operated by the operation of the water pump 27. Motor controller 9, travel motor 1, heater core 29, and radiator 28
Then, the water is circulated along the cooling water circulation path 35 so as to be returned to the water pump 27.

The flow passage of the cooling water in the traveling motor 1 will be described. As shown in FIGS. 5 and 6, in the housing 2 of the traveling motor 1, one of the lower left and right sides of the side surfaces facing in the axial direction of the output shaft 1a is located. A cooling water inlet 3 and a cooling water outlet 4 are opened on both sides, and these cooling water inlets and outlets 3 and 4 are connected through cooling water passages 6 formed inside the housing 2 and inside a connecting pipe 5 outside the housing 2, respectively. Has been done. The cooling water passage 6 extends from the cooling water inlet 3 to the other side surface of the housing 2 along the output shaft 1a and then bends by 180 °, returns to the side surface on the inlet 3 side of the housing 2 and is connected to the communication pipe 5. After repeating the reciprocating path four times around the output shaft 1a along the outer circumference of the housing 2, the path is communicated with the cooling water outlet 4. 7a to 7c in FIG.
Are input terminals connected to the U-pole, V-pole, and W-pole connection terminals 15a to 15c of the motor controller 9, respectively.

On the other hand, the flow passage of the cooling water in the motor controller 9 will be described. As shown in FIGS. 2 to 4, the housing 17 of the motor controller 9 has a cooling water inlet 18 on one of the opposite side surfaces and the other side surface. Cooling water outlet 1
9 are opened respectively, and these cooling water inlets and outlets 18, 1
9 is connected inside the housing 17 via a cooling water passage 20. As shown in FIG. 3 and FIG. 4, this cooling water passage 20 is provided from the cooling water inlet 18 to the outlet 1 of the housing 17.
After extending to the side surface on the 9 side, bend 180 ° and enter 1
After returning to the side surface on the 8th side and then bending again by 180 ° and extending to the side surface on the outlet 19 side, it is communicated with the cooling water outlet 19.

Further, as a feature of the present invention, a portion of the cooling water circulation passage 35 from the downstream end connecting portion (cooling water outlet 19) of the motor controller 9 to the upstream end connecting portion (cooling water inlet 3) of the traveling motor 1 is provided. A short-circuit connection is made by a bypass path 36 between the downstream end connection portion (cooling water outlet 4) of the traveling motor 1 and the portion reaching the heater core 29. As a result, the heater core 29 is removed from the bypass passage 36.
It is arranged in the cooling water circulation path 35 extending from the downstream end connection part to the radiator 28, and the cooling water discharged from the motor controller 9 is caused to bypass the motor 1 by the bypass path 36 and flow to the heater core 29.

A temperature sensitive valve 37 (thermostat) is arranged in the cooling water circulation passage 35 at the connection with the upstream end of the bypass passage 36. The temperature-sensitive valve 37 automatically connects the cooling water passage to the traveling motor 1 side or the bypass passage 36 according to the temperature of the cooling water after passing through the motor controller 9 (controller temperature representing the motor controller 9). Alternatively, when the temperature of the cooling water is lower than a predetermined value (for example, 65 ° C.), the cooling water is caused to flow to the motor 1 side along the cooling water circulation path 35, and when the temperature is equal to or higher than the predetermined value, the cooling water is bypassed. It is designed to flow along 36.

Next, the operation of the above embodiment will be described. During operation of the electric vehicle, the traveling motor 1 is operated and controlled by the motor controller 9 according to the opening degree (depression amount) of the accelerator pedal 22 detected by the accelerator opening sensor 23, and the driving wheel is driven by the rotation output of the traveling motor 1. Rotates and the car runs. At this time, the electric motor 3
The motor cooling fan 31 and the radiator cooling fan 33 are rotated by the operation of 0 and 32, and the cooling fan 3
1, 33 to the traveling motor 1 and the radiator 28, respectively
Are blown to cool them.

Further, the cooling water circulates through the cooling water circulation path 35 or the bypass path 36 by the operation of the water pump 27 by the pump motor 26, and the motor controller 9 or the traveling motor 1 is cooled by this cooling water. That is, in the cooling water circulation path 35, the temperature sensitive valve 37 is switched to operate depending on the temperature of the cooling water after passing through the motor controller 9, and the cooling water flow path is selectively switched to the motor 1 side or the bypass path 36 to cool the cooling water flow path. When the water temperature is lower than a predetermined value (65 ° C), the temperature sensing valve 3 is arranged so that the cooling water flow path is on the motor 1 side.
7 is switched, and the cooling water flows along the cooling water circulation path 35 to circulate it. Specifically, the water pump 2
The cooling water discharged from 7 is the motor controller 9 first.
To cool it, and then to the traction motor 1 to cool it. As the motor controller 9 and the traveling motor 1 are cooled, the temperature of the cooling water itself rises. The heated cooling water is supplied to the heater core 29, where it heats the air in the vehicle compartment to cool itself, and then is supplied to the radiator 28 to be further cooled by heat exchange with the air outside the vehicle. It is sucked into the water pump 27.

On the other hand, when the cooling water temperature is equal to or higher than the predetermined value (65 ° C.), the temperature sensitive valve 37 is switched so that the cooling water flow path is on the side of the bypass path 36, and the cooling water bypasses the traveling motor 1. Circulate. That is, the cooling water discharged from the water pump 27 is supplied to the motor controller 9 to cool it, and then the motor controller 9
Is supplied to the heater core 29 and the radiator 28 through the bypass path 36 without passing through the traveling motor 1, cooled there, and then sucked into the water pump 27.

As described above, when the temperature of the cooling water discharged from the motor controller 9 is high, the cooling water is supplied to the traveling motor 1
Since it circulates only between the radiator 28 and the motor controller 9 without passing through it, even if the temperature of the cooling water is high, the cooling water cooled by the radiator 28 is concentrated and supplied to the motor controller 9. Can be efficiently cooled, and the rise of the motor controller 9 to an abnormal temperature can be reliably prevented. At this time, the circulation of the cooling water to the traveling motor 1 is cut off and the cooling becomes insufficient. However, the traveling motor 1 has a high inherent heat resistance temperature, and moreover, it is blown by the motor cooling fan 31. Since the cooling is ensured, its operation is not adversely affected.

Further, in this embodiment, since the temperature sensing valve 37 which switches according to the temperature of the cooling water is arranged at the branch connection portion at the upstream end of the bypass 36 of the cooling water circulation path 35, the above-mentioned constitution is adopted. The effect can be obtained with a simple structure and at low cost.

Further, since the heater core 29 is arranged in the cooling water circulation passage 35 extending from the downstream end connecting portion of the bypass passage 36 to the radiator 28, the temperature sensing valve 3 is arranged as described above.
Even if the cooling water flow path is switched by 7, the cooling water whose temperature has been raised by at least the motor controller 9 always passes through the heater core 29, so that the heating efficiency of the vehicle interior by the heater core 29 can be improved.

(Second Embodiment) FIGS. 8 to 10 show a second embodiment of the present invention (note that the same parts as those in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted). 1, the temperature sensitive valve 37 is used for switching the flow path of the cooling water, whereas the three-way switching valve is used for electrically switching control, and at the same time, controlling the operation of the water pump 27. It is the one.

That is, in this embodiment, as shown in FIG. 8, at the connection portion of the cooling water circulation passage 35 with the upstream end of the bypass passage 36, the cooling water passage is provided on the traveling motor 1 side or the bypass passage 36. A control valve 39 including a three-way switching valve that selectively switches is arranged. The control valve 39 includes the pump motor 26 of the water pump 27 and the motor cooling fan 3.
1 and each electric motor 3 of the radiator cooling fan 33
It is controlled by a cooling controller 41 as a control means together with 0, 32 and a warning device 40 which lights up and displays an abnormality. Also, this control valve 3
A water temperature sensor 42 that detects a temperature tw of the cooling water after passing through the motor controller 9 (a controller temperature representing the motor controller 9) is provided in the cooling water circulation path 35 on the upstream side of the motor controller 9 and on the downstream side of the motor controller 9. , The output signal of the water temperature sensor 42 is the cooling controller 41.
Has been entered in. The cooling controller 41 is connected to the motor controller 9 so that signals can be exchanged.

The control operation of the water pump 27, the cooling fans 31 and 33 for motors and radiators, the control valve 39, and the warning device 40 in the cooling controller 41 will be described with reference to FIGS. 9 and 10.
First, in step S1, data or the like from the water temperature sensor 42 is input, and in step S2 it is determined whether an ignition key switch (not shown) of the vehicle is in an ON state, that is, whether the vehicle is in a driving state. When the determination is NO in "Ignition key switch OFF", the process proceeds to step S3, it is determined whether or not the cooling water temperature tw is equal to or higher than the second set value tw2 (for example, 65 ° C), and the determination is YES in tw≥tw2. In case of, in step S4, the water pump 27 and the cooling fans 31, 33 are rotated for a predetermined time, and then the process returns. On the other hand, if the determination in step S3 is NO for tw <tw2, the process ends. With such control, when the vehicle is in a stopped state such as immediately after traveling and the cooling water temperature tw is high,
Even if the ignition key switch is off,
The water pump 27 circulates the cooling water and rotates the cooling fans 31 and 33 to forcibly cool the motor controller 9 and the traveling motor 1.

If it is determined that "Ignition key switch ON" is YES in step S2, step S5
11. As shown in FIG. 11, the cooling water temperature tw is lower than the second setting value tw2 by the first set value tw1 (for example, tw1).
= 50 ° C. <tw2) It is determined whether or not it is in the region I. If this determination is YES at tw <tw1, the process returns after stopping the rotation of the water pump 27 in step S6.

Further, the determination in step S5 is tw ≧ tw1.
If NO in step S7, the process proceeds to step S7, and it is determined whether or not the cooling water temperature tw is in the region II (see FIG. 11) lower than the second set value tw2. This judgment is tw
<YES in tw2, the water pump 27 is rotated at the first rotation speed N1 in step S8, and
After switching the control valve 39 so that the cooling water flow path is on the traveling motor 1 side, the process returns.

If the determination in step S7 is tw ≧ tw2 NO
If it is, the process proceeds to step S9, and this time, the region II in which the cooling water temperature tw is less than the third set value tw3 (for example, tw3 = 67 ° C.> tw2) higher than the second set value tw2.
I (see FIG. 11). When this determination is YES at tw <tw3, the process proceeds to step S10, the water pump 27 is rotated at a second rotation speed N2 (> N1) higher than the first rotation speed N1, and then at step S11, the cooling water temperature is increased. It is determined whether tw was in the area III last time. When the determination is NO, the process directly returns, but when the determination is YES, the control valve 39 is switched so that the cooling water flow path is on the bypass 36 side in step S12, and then the process proceeds to step S19.

Furthermore, the determination in step S9 is tw ≧
When NO in tw3, it is determined that the cooling water temperature tw is in the region IV (see FIG. 11), the process proceeds to step S13, the water pump 27 is rotated at the second rotation speed N2, and the control valve 39 is set to the cooling water flow. The road is switched to the bypass 36 side. Next, in step S14, it is determined whether the cooling water temperature tw was in the region IV last time. When the determination is NO, the count value m of the first timer is set to m = 0 in step S15, while when the determination is YES, the process directly proceeds to step S16. In this step S16, the count value m of the first timer is incremented by "1", and in the next step S17 it is determined whether or not the count value m has become equal to or greater than the set value m0. When this determination is NO, the routine returns, but when YES, that is, m ≧ m0, in step S18, the current suppression control for the traveling motor 1 is performed. That is, this current suppression control is, as shown in FIG. 12, intended to keep the current command value for the traveling motor 1 at the upper limit value max even if the accelerator opening is increased. The output of No. 1 is limited to reduce the amount of heat generation, and the motor abnormality is avoided.

After step S18, the above step S
In step S19, the cooling water temperature tw
It was determined whether the previous was in Region III or Region IV. If this determination is NO, after the count value n of the second timer is set to n = 0 in step S20,
On the other hand, when the determination is YES, the process directly proceeds to step S21. In this step S21, the count value n of the second timer is incremented by "1", and in the next step S22 it is determined whether or not the count value n has become equal to or greater than the set value n0. If this determination is NO, the process returns, but if n ≧ n0, YES, step S2.
3, the warning device 40 is turned on, and in the next step S24, the water pump 27 is rotated at, for example, the second rotation speed N2, and the control valve 39 is switched so that the cooling water flow path is on the traveling motor 1 side. , Return. That is, in the above steps S19 to S24, the cooling water temperature t is kept until the second timer counts up.
Seeing that w did not fall from the region III or the region IV, it was judged that this was due to the abnormality of the water temperature sensor 42, and the warning device 40 warned the driver of the abnormality, and as a safety side, cooling was performed. Water channel to motor 1
To the motor controller 9 and the traveling motor 1
Are cooled together, and a decrease in cooling performance of the motor controller 9 due to the cooling is dealt with by an increase in the rotation speed of the water pump 27.

Therefore, in the case of this embodiment, the temperature tw of the cooling water that has passed through the motor controller 9 while the vehicle is operating with the ignition key switch in the ON state.
Is detected by the water temperature sensor 42, and this cooling water temperature tw
Accordingly, the operation of the water pump 27 and the switching of the cooling water flow paths are controlled. First, the cooling water temperature tw is the first set value t
When in the region I lower than w1, the control valve 39 holds the flow path of the cooling water on the traveling motor 1 side, for example, and the water pump 27 and the cooling fans 31 and 33 are stopped and held. The motor controller 9 and the traveling motor 1 are not cooled by water.

When the cooling water temperature tw is in the region II above the first set value tw1 and lower than the second set value tw2, the control valve 3
The flow passage of the cooling water is switched and held by the traveling motor 1 side by 9, and the water pump 27 is rotated at the first rotation speed N1, and the cooling fans 31 and 33 are also rotated at a predetermined rotation speed. As a result, the motor controller 9 using the cooling water
And the traveling motor 1 is cooled.

Further, the cooling water temperature tw is the second set value tw2.
As described above, when the area III is lower than the third set value tw3,
During a predetermined time, the rotation speed of the water pump 27 is the above first
The second rotation speed N2 is higher than the rotation speed N1. Then, after that, when the cooling water temperature tw does not change from the region III, the control valve 39 causes the cooling water flow passage to change to the bypass passage 3.
It is switched to the 6 side. By this switching, the motor controller 9 is preferentially cooled by the cooling water.

Further, the cooling water temperature tw is the third set value tw.
When the region IV of 3 or more is reached, the rotation speed of the water pump 27 is maintained at the higher second rotation speed N2, and the control valve 39 switches the flow path of the cooling water to the bypass path 36 side. Then, after the switching of the cooling water flow path to the bypass path 36, the count value m of the first timer is m ≧.
If a state in which cooling water does not flow to the traveling motor 1 side continues for a predetermined time until reaching m0, the current command value for the traveling motor 1 with respect to the traveling motor 1 will be the upper limit value max even if the accelerator opening is increased. The current suppression control that is maintained at is performed. As a result, the output of the traveling motor 1 is limited, the amount of heat generated is suppressed, and the traveling motor 1 can be prevented from entering an abnormal state. The cooling water temperature tw associated with the above control
FIG. 13 shows an example of the change of

On the other hand, when the cooling water temperature tw is equal to or higher than the second set value tw2 when the vehicle is stopped with the ignition key switch in the OFF state, the cooling water temperature tw is still high, for example, immediately after the vehicle is running. The water pump 27 and the cooling fans 31 and 33 are rotated for a predetermined time. By this control, the cooling water is circulated, the traveling motor 1 and the radiator 28 are cooled, and the motor controller 9 and the traveling motor 1 are forcibly cooled.

Therefore, also in this embodiment, the same operational effect as that of the above-mentioned first embodiment can be obtained. In particular, in this embodiment, the rotation speed of the water pump 27 is increased between the first and second rotation speeds N1 and N2 so as to increase as the cooling water temperature tw increases.
Since it is controlled in stages, the circulating amount of cooling water can be adjusted appropriately,
The power consumption of the battery power supply can be reduced.

As in the second embodiment, the rotation speed of the water pump 27 is set to 2 between the first and second rotation speeds N1 and N2.
In addition to switching to the stage, each cooling fan 31, 3
The number of rotations of 3 may be switched in a plurality of stages according to the cooling water temperature tw. By doing so, it is possible to properly adjust the cooling efficiency of the cooling fans 31 and 33 for the motor 1 and the radiator 28, and to further reduce the power consumption of the battery power supply.

In the second embodiment, the cooling water temperature tw
The rotation speeds of the control valve 39 and the water pump 27 are switched in accordance with the above, but the temperature sensing valve 37 shown in the first embodiment is used in place of the control valve 39, and the switching temperature is set to the water pump 27 (or The temperature of the cooling fans 31, 33 is changed, that is, the flow path of the cooling water is changed by the temperature sensitive valve 37, and the temperature of the temperature sensitive valve 37 is matched to the temperature of the water pump 27 (or the cooling fan 31). , 33) can be switched.

Further, in the second embodiment, for example, when the traveling motor 1 is made to function as a generator to regenerate a current in the battery when the automobile is being braked, the regenerative current is directly returned to the water pump 27 without being returned to the battery. It may be supplied as driving power. In this way, regeneration can be performed with higher efficiency than returning to the battery.

[0047]

As described above, according to the invention of claim 1, when the traveling motor and the controller thereof in the electric vehicle are cooled by circulating the cooling liquid, the cooling liquid is supplied to the water pump, the controller, the motor and the radiator. A circulation path that circulates in sequence and a bypass path that allows the cooling fluid to bypass the motor are provided, and the adjustment means causes the cooling fluid to flow along the circulation path to the motor side when the temperature of the controller is less than a predetermined value. When the controller temperature is equal to or higher than the specified value, the cooling liquid is made to flow along the bypass path, so that even when the controller temperature is high, the cooling liquid is circulated only between the radiator and the controller, and the low temperature from the radiator is circulated. The controller's cooling liquid can cool the controller intensively and efficiently. Controller is reliably prevented from rising to an abnormal temperature, it is possible to secure the stable operation.

According to the invention of claim 2, the adjusting means senses the temperature of the cooling liquid after passing through the controller to selectively switch the cooling liquid flow path to the motor side or the bypass path. As a result, the effect of the invention of claim 1 can be obtained with a simple configuration including only the temperature sensitive valve and at low cost.

According to the third aspect of the present invention, the heater core for exchanging heat with the air in the passenger compartment is provided in the circulation path from the downstream end connection portion of the bypass path to the radiator, so that the coolant from the controller is supplied. The heater core can always be passed through regardless of the switching of the flow path of the cooling liquid, and the heating efficiency of the vehicle interior by the heater core can be improved.

According to the fourth aspect of the present invention, the rotational speed of at least one of the cooling fan and the water pump for blowing air to the motor and the radiator is increased stepwise in accordance with the increase in the controller temperature.
It is possible to reduce the power consumption of the power supply by properly adjusting the circulating amount of the cooling liquid or the cooling efficiency of the cooling fan to the motor and the radiator.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a cooling device according to a first embodiment of the present invention.

FIG. 2 is a front view showing a cooling water flow path of a motor controller.

FIG. 3 is a side view showing a cooling water flow path of the motor controller.

FIG. 4 is a plan view schematically showing a cooling water flow path of a motor controller.

FIG. 5 is a front view showing a cooling water passage of the traveling motor.

FIG. 6 is a side view showing a cooling water passage of the traveling motor.

FIG. 7 is a circuit diagram showing a configuration of a motor controller.

FIG. 8 is a view corresponding to FIG. 1 and showing a second embodiment of the present invention.

FIG. 9 is a flowchart showing one half of a control operation performed in the cooling controller according to the second embodiment.

FIG. 10 is a flowchart showing the other half of the control operation performed in the cooling controller.

FIG. 11 is a diagram showing a control region according to a cooling water temperature.

FIG. 12 is a diagram showing a current characteristic with respect to an accelerator opening degree in current suppression control.

FIG. 13 is a time chart showing a change characteristic of cooling water temperature.

[Explanation of symbols]

 1 Traveling Motor 9 Motor Controller 25 Cooling Device 27 Water Pump 28 Radiator 29 Heater Core 31 Motor Cooling Fan 33 Radiator Cooling Fan 35 Cooling Water Circulation Path 36 Bypass Path 37 Temperature Sensing Valve (Adjusting Means) 39 Control Valve (Adjusting Means) 41 Cooling Controller (control means) 42 Water temperature sensor tw Cooling water temperature

Claims (4)

[Claims] 1. A cooling device for an electric vehicle, comprising: a traveling motor connected to driving wheels; and a controller for cooling the traveling motor with a controller for controlling the operation of the traveling motor. A water pump that draws in and discharges it, a radiator that cools the cooling liquid by exchanging heat with the air outside the vehicle, and a cooling liquid that has been discharged from the water pump, which in turn flows to the controller, motor, and radiator, and then returns to the water pump. A cooling liquid circulation passage for circulating the cooling liquid, a bypass passage for flowing the cooling liquid by-passing the traveling motor, and a cooling liquid circulation motor along the cooling liquid circulation passage when the controller temperature representing the controller is lower than a predetermined value. On the other hand, when the controller temperature is equal to or higher than a predetermined value, the cooling liquid is caused to flow along the bypass passage. Cooling apparatus for an electric vehicle, characterized in that shall become and a cut switched adjusting means. 2. The cooling device for an electric vehicle according to claim 1, wherein the controller temperature is a temperature of the cooling liquid after passing through the controller, and the adjusting means senses the temperature of the cooling liquid to cool the cooling liquid. A cooling device for an electric vehicle, which is a temperature-sensitive valve that selectively switches a flow path to a motor side or a bypass path. 3. A cooling device for an electric vehicle according to claim 1 or 2, wherein a heater core for exchanging heat between the cooling liquid and the air in the vehicle compartment is provided in the cooling liquid circulation path from the downstream end connection part of the bypass path to the radiator. A cooling device for an electric vehicle, which is characterized in that 4. The cooling device for an electric vehicle according to claim 1, wherein the rotational speed of at least one of the cooling fan and the cooling fan that blows air to the motor and the radiator is increased as the controller temperature increases. As described above, the cooling device for an electric vehicle is provided with control means for performing stepwise control according to the controller temperature.