JP2012019590A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the insulation performance of an electric motor even when the atmospherical pressure is low.SOLUTION: When the atmospherical pressure is lower than a predetermined pressure, which is set as a pressure corresponding to the allowable lower limit of the insulation performance in a motor 30 under air environment, a valve 66, which is provided at a position where cooling oil is discharged from the motor 30, is closed. This action makes a space of the motor 30, in which a coil 46 is placed, oil tight. Thus, the insulation performance is secured in the motor 30 even when the atmospherical pressure is low.

Description

  The present invention relates to an electric vehicle, and more particularly, to an electric vehicle that travels using power from an electric motor that includes a rotor connected to a drive shaft connected to a drive wheel and a stator around which a coil is wound.

  Conventionally, as this type of technology, a rotating electrical machine in which a coil is wound around a stator is housed in a housing, and a coolant is supplied from above the coil end of the coil to the coil end. There has been proposed one provided with a guiding portion for guiding the coolant flowing along the outer peripheral surface of the coil end toward the axial end surface of the coil end (see, for example, Patent Document 1). In this technique, by providing such a guide portion, it is possible to actively flow the cooling liquid to the axial end surface of the coil end, and the cooling performance is improved by increasing the cooling area.

JP 2010-68640 A

  When the above-described technology is applied to an electric vehicle that travels using power from a motor as a rotating electric machine, in order to improve the cooling performance, the coolant flows without staying around the coil end. It is preferable. However, when the atmospheric pressure is low, such as when traveling on high altitudes, the insulation performance of the air is greatly reduced compared to the coolant, so the cooling oil flows without staying around the coil end, and the area around the coil is in the air environment. If it goes down, the insulation performance in an electric motor will become low.

  The main purpose of the electric vehicle of the present invention is to ensure the insulation performance of the electric motor even when the atmospheric pressure is low.

  The electric vehicle of the present invention employs the following means in order to achieve the main object described above.

The electric vehicle of the present invention is
An electric vehicle that travels using power from an electric motor including a rotor connected to a drive shaft coupled to a drive wheel and a stator wound with a coil,
A cooling liquid supply means for supplying a cooling liquid to a coil space in which the coil in the electric motor is disposed;
A valve provided at a cooling liquid discharge position from the coil space to the outside of the electric motor;
Atmospheric pressure detection means for detecting atmospheric pressure;
Control means for controlling the valve so that the valve is closed when the detected atmospheric pressure is lower than a predetermined pressure defined as a pressure corresponding to an allowable lower limit of insulation performance in the electric motor in a gaseous environment; ,
It is a summary to provide.

  In the electric vehicle of the present invention, when the atmospheric pressure is lower than a predetermined pressure determined as the pressure corresponding to the allowable lower limit of the insulation performance in the electric motor in the gas environment, the coil space that is a space in which the coil in the electric motor is arranged. The valve is controlled so that the valve provided at the discharge position of the cooling liquid from the motor to the outside of the motor is closed. It has been found that the insulation performance of an electric motor is lower in a gas environment than in a liquid environment and lower as the atmospheric pressure is lower. Therefore, when the atmospheric pressure is lower than the predetermined pressure, the insulation performance in the electric motor can be ensured by closing the valve and retaining the cooling medium in the coil space.

  In such an electric vehicle of the present invention, the cooling liquid supply means is means for supplying cooling liquid by driving an electric pump, and the control means is configured to operate the electric motor when the detected atmospheric pressure is lower than the predetermined pressure. It may be a means for controlling the electric pump so that the electric pump is driven when the pump is stopped. An internal combustion engine capable of outputting driving power; and motoring means capable of motoring the internal combustion engine, wherein the cooling liquid supply means is a mechanical pump driven by rotation of the internal combustion engine. Means for supplying a cooling liquid by driving, wherein the control means is configured to cause the motor to rotate when the internal combustion engine is stopped when the detected atmospheric pressure is lower than the predetermined pressure. It can also be a means for controlling the ring means. In these cases, the cooling liquid can be supplied to the electric motor by driving the electric pump or the mechanical pump.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 as 1st Example of this invention. FIG. 3 is a configuration diagram showing an outline of the configuration of a motor 30 and a cooling mechanism 60. 2 is a configuration diagram showing an outline of a configuration around a stator 40 of a motor 30. FIG. 2 is a configuration diagram showing an outline of a configuration around a stator 40 of a motor 30. FIG. 3 is a flowchart showing an example of a cooling mechanism control routine executed by an electronic control unit 70. FIG. 3 is an explanatory diagram showing insulation performance in a motor 30. It is a block diagram which shows the outline of a structure of the hybrid vehicle 120 of 2nd Example. 3 is a flowchart showing an example of a cooling mechanism control routine executed by an electronic control unit 70. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of an electric vehicle 20 as a first embodiment of the present invention. As shown in the figure, an electric vehicle 20 according to the first embodiment includes, for example, a motor 30 that is configured as a synchronous generator motor and that inputs and outputs power to a drive shaft 22 that is connected to drive wheels 26a and 26b via a differential gear 24. , An inverter 56 that drives the motor 30, a battery 58 configured as, for example, a lithium ion secondary battery, a boost converter 57 that boosts power from the battery 58 and supplies the boosted power to the inverter 56, and cooling oil as a cooling liquid A cooling mechanism 60 that cools the motor 30 using the electronic control unit 70 that controls the entire vehicle is provided.

  FIG. 2 is a configuration diagram showing an outline of the configuration of the motor 30 and the cooling mechanism 60, and FIGS. 3 and 4 are configuration diagrams showing an outline of the configuration around the stator 40 of the motor 30. As shown in FIG. 2, the motor 30 includes a rotor 32 connected to the drive shaft 22 and a stator 40 around which a three-phase coil 46 is wound. Here, the rotor 32 includes a rotor core 34 formed by stacking a plurality of rotor members formed by punching a non-oriented electrical steel sheet, and permanent magnets 36 respectively inserted into a plurality of slots of the rotor core 34. . The stator 40 includes a stator core 42 formed by stacking a plurality of stator members formed by punching a non-oriented electrical steel sheet, and a coil 46 wound around each of the plurality of slots 44 of the stator core 42. Prepare. A lid member 48 is disposed on the inner peripheral side of the coils 46 in the plurality of slots 44 of the stator core 42 so as to close the openings of the plurality of slots 44 (see FIGS. 2 to 4). Further, the coil end 46 a (see FIGS. 3 and 4) of the coil 46 is covered with a cover 50. Therefore, the space in which the coil 46 is disposed, specifically, two spaces formed by the axial end of the stator core 42 and the cover 50 (two annular spaces around the coil end 46a (see FIG. 3)). ) And a plurality of spaces formed by the stator core 42 and the lid member 48 (a plurality of spaces around the portion of the coil 46 excluding the coil end 46a (see FIGS. 2 and 4)) serve as cooling oil flow paths. Can be used. Hereinafter, the former is referred to as an annular flow path 52 and the latter is referred to as an in-slot flow path 54. The annular flow path 52 and the in-slot flow path 54 communicate with each other (see FIG. 4).

  As shown in FIG. 2, the cooling mechanism 60 includes an oil pan 62 disposed below the motor 30 and cooling oil stored in the oil pan 62 at the top of the motor 30 (two annular flow paths 52 (FIG. 3 An electric pump 64 that is supplied to a cooling oil supply port (not shown) provided in at least one upper part of the motor 30 and a motor 30 in the lower part of the motor 30 (one lower part of the two annular channels 52). And a valve 66 provided at a position where the cooling oil is discharged from the inside to the outside of the motor 30. The cooling oil discharged to the outside of the motor 30 through the valve 66 returns to the oil pan 62.

  As shown in FIG. 1, the electronic control unit 70 is configured as a microprocessor centered on the CPU 72. In addition to the CPU 72, a ROM 74 that stores a processing program, a RAM 76 that temporarily stores data, and an unillustrated I / O port. The electronic control unit 70 includes signals necessary for driving and controlling the motor 30 (for example, a signal from a rotational position detection sensor that detects the rotational position of the rotor 32 of the motor 30) and an ignition signal from the ignition switch 80. , Shift position SP from the shift position sensor 82 that detects the operation position of the shift lever, accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal, and brake pedal position that detects the depression amount of the brake pedal The brake pedal position BP from the sensor 86, the vehicle speed V from the vehicle speed sensor 88, the atmospheric pressure Pa from the atmospheric pressure sensor 89 that detects the atmospheric pressure, and the like are input via the input port. Further, the electronic control unit 70 outputs a switching control signal to the switching element of the inverter 56, a driving signal to the electric pump 64, a driving signal to the valve 66, and the like through the output port.

  In the electric vehicle 20 of the first embodiment configured as described above, the cooling oil stored in the oil pan 62 is supplied to the supply port at the upper part of the motor 30 by driving the electric pump 64, and then the annular flow path 52 is moved downward. And flows in an in-slot flow path 54 communicating with the annular flow path 52 in the axial direction. When the valve 66 is opened at the lower part of the motor 30, it is discharged downward through the valve 66. The coil 46 of the motor 30 can be cooled by the flow of the cooling oil. When the valve 66 is closed, the cooling oil is not discharged outside the motor 30 but stays in the annular flow path 52 or the in-slot flow path 54.

  Next, the operation of the electric vehicle 20 of the first embodiment configured as described above, particularly, the operation of the cooling mechanism 60 will be described. FIG. 5 is a flowchart showing an example of a cooling mechanism control routine executed by the electronic control unit 70. This routine is executed repeatedly.

  When the cooling mechanism control routine is executed, the electronic control unit 70 first inputs the atmospheric pressure Pa from the atmospheric pressure sensor 89 (step S100), and compares the input atmospheric pressure Pa with the threshold value Paref (step S110). . Here, the threshold value Paref is a pressure corresponding to the allowable lower limit of the insulation performance of the motor 30 under a gas environment (air environment), and can be determined by experiments, analysis, or the like. As shown in FIG. 6, the insulation performance of the motor 30 is under an oil-tight environment (liquid environment) in which cooling oil stays in the motor 30 (the annular flow path 52 and the slot flow path 54). It has been found that the lower the pressure is, the lower the atmospheric pressure is. Therefore, in the first embodiment, the threshold value Paref is set based on this. That is, the process of step S110 is a process of determining whether or not there is a possibility that dielectric breakdown in the motor 30 occurs in an air environment.

  When the atmospheric pressure Pa is greater than or equal to the threshold value Paref, it is determined that there is no risk of dielectric breakdown in the motor 30 in an air environment, and the valve 66 is driven and controlled so that the valve 66 is opened when the valve 66 is closed. (Steps S120 and S130), a value 0 is set in the oil-tight flag F indicating whether or not the oil-tight state is set (step S140), and the electric pump 64 is driven as necessary based on the temperature of the coil 46 and the like. Thus, the electric pump 64 is driven and controlled (step S150), and this routine is finished. Note that the state of the valve 66 is maintained when it is already opened. Thus, by driving the electric pump 64 as necessary, the cooling oil can be supplied into the motor 30 (circulation flow path 52 or slot flow path 54) to cool the coil 46. In addition, by opening the valve 66, it is possible to suppress an increase in the temperature of the cooling oil due to the retention of the cooling oil in the motor 30 and to supply new cooling oil to the motor 30 by the electric pump 64. Therefore, the cooling oil can be circulated, and the cooling performance of the motor 30 can be improved.

  On the other hand, when the atmospheric pressure Pa is lower than the threshold value Paref in step S110, it is determined that there is a risk of dielectric breakdown in the motor 30 in an air environment, and the value of the oil tight flag F is examined (step S160). When the oil tight flag F is 0, that is, when the inside of the motor 30 (annular flow path 52 or slot flow path 54) is not in an oil tight state, it is determined whether the valve 66 is open or closed. (Step S170), when the valve 66 is opened, the drive of the valve 66 is controlled so that the valve 66 is closed (Step S180), and when the valve 66 is already closed, the state is maintained. Then, it is determined whether or not the electric pump 64 is stopped (step S190). When the electric pump 64 is stopped, the electric pump 64 starts to be driven (step S200), and the electric pump 64 is already driven. If it is, the drive is continued, waits for the inside of the motor 30 to be in an oil-tight state (step S210), a value 1 is set in the oil-tight flag F (step S220), and the electric pump 64 is driven. Stop (step S230) and end the routine. Here, whether or not the inside of the motor 30 is in an oil-tight state is determined based on, for example, the amount of cooling oil that can stay in the motor 30 (the annular passage 52 or the slot passage 54) and the driving state of the electric pump 64 ( For example, based on a signal from a sensor that detects that the motor 30 is in an oil-tight state. Thus, by ensuring that the interior of the motor 30 (the annular flow path 52 and the in-slot flow path 54) is in an oil-tight state, the insulation performance of the motor 30 can be ensured even when the atmospheric pressure Pa is low, such as when traveling on high altitudes. Can do. Generally, when the insulation performance of the motor 30 is low, in order to suppress dielectric breakdown, the upper limit of the torque output from the motor 30 is largely limited, or the voltage after boosting by the boost converter 57 (voltage on the inverter 56 side) is lowered. In the first embodiment, since the insulation performance in the motor 30 can be ensured even when the atmospheric pressure Pa is low, the voltage after the boosting by the boosting converter 57 is made relatively high or the motor Thus, a relatively large torque can be output from the vehicle 30, and a decrease in the operating performance of the vehicle can be suppressed. When the inside of the motor 30 is in an oil-tight state in this way, when the atmospheric pressure Pa is lower than the threshold value Paref next time in step S110, it is determined in step S160 that the oil-tight flag F is a value 1, and this routine is ended as it is.

  According to the electric vehicle 20 of the first embodiment described above, when the atmospheric pressure Pa is lower than the threshold value Paref determined as the pressure corresponding to the allowable lower limit of the insulation performance in the motor 30 in the air environment, the inside of the motor 30 Since the valve 66 provided at the position where the cooling oil is discharged to the outside of the motor 30 is closed, the space (the annular flow path 52 and the in-slot flow path 54) in which the coil 46 in the motor 30 is disposed is oil-tight. Insulation performance in the motor 30 can be ensured even when the atmospheric pressure Pa is low.

  In the electric vehicle 20 according to the first embodiment, the cooling oil stored in the oil pan 62 by the electric pump 64 is supplied to the motor 30, but instead of or in addition to the electric pump 64, The cooling oil may be supplied to the motor 30 by rotation of a gear in which the part is immersed (for example, the differential gear 24 or the like).

  In the first embodiment, the present invention is applied to the electric vehicle 20 including the motor 30 that inputs and outputs power to the drive shaft 22. However, the present invention may be applied to a vehicle including an engine in addition to the motor 30. In this case, the cooling mechanism may include a mechanical pump that is attached to the crankshaft of the engine and driven by the rotation of the engine instead of or in addition to the electric pump (see FIGS. 1 to 3).

  FIG. 7 is a configuration diagram showing an outline of the configuration of the hybrid vehicle 120 of the second embodiment. The hybrid vehicle 120 according to the second embodiment includes, for example, a motor 30 that is configured as a synchronous generator motor and that inputs and outputs power to a drive shaft 22 that is connected to drive wheels 26 a and 26 b via a differential gear 24. A planetary gear 124 to which a ring gear is connected, an engine 122 that is connected to a carrier of the planetary gear 124 and outputs power using gasoline or light oil as a fuel, and a motor 130 that is configured as a synchronous generator motor and connected to the sun gear of the planetary gear 124, for example. , Inverters 56 and 156 for driving the motors 30 and 130, a battery 58 configured as, for example, a lithium ion secondary battery, a boost converter 57 that boosts power from the battery 58 and supplies the boosted power to the inverters 56 and 156, and cooling With cooling oil as liquid Includes a cooling mechanism 160 for cooling the over data 30 and the motor 130, the electronic control unit 70 that controls the whole vehicle, the. Of the hardware configuration of the hybrid vehicle 120 of the second embodiment, the same hardware configuration as that of the electric vehicle 20 of the first embodiment is denoted by the same reference numeral, and detailed description thereof is omitted. The motor 130 and the inverter 156 are configured in the same manner as the motor 30 (see FIGS. 1 to 4) and the inverter 56.

  The cooling mechanism 160 is the same as the cooling mechanism 60 of the first embodiment except that a mechanical pump 164 is provided instead of the electric pump 64, and an oil pan 162 disposed below the motor 30 and the motor 130, A mechanical pump 164 attached to the output shaft of the engine 122 and driven by the rotation of the engine 122 to supply the cooling oil stored in the oil pan 162 to the cooling oil supply port provided on the motor 30 or the motor 130. A valve 166 provided at a position where the cooling oil is discharged from the inside of the motor 30 below the motor 30 to the outside of the motor 30, and a position where the cooling oil is discharged from the inside of the motor 130 below the motor 130 to the outside of the motor 130. Provided with a valve 167.

  The electronic control unit 70 of the second embodiment includes a signal necessary for controlling the operation of the engine 122, a signal necessary for driving and controlling the motors 30 and 130, an ignition signal from the ignition switch 80, a shift lever The shift position SP from the shift position sensor 82 for detecting the operation position, the accelerator opening Acc from the accelerator pedal position sensor 84 for detecting the depression amount of the accelerator pedal, and the brake pedal position sensor 86 for detecting the depression amount of the brake pedal. The brake pedal position BP, the vehicle speed V from the vehicle speed sensor 88, the atmospheric pressure Pa from the atmospheric pressure sensor 89 that detects the atmospheric pressure, and the like are input via the input port. The electronic control unit 70 outputs a signal for controlling the operation of the engine 122, a switching control signal to the switching elements of the inverters 56 and 156, a driving signal to the valves 166 and 167, and the like through the output port. Has been.

  In the hybrid vehicle 120 of the second embodiment thus configured, the required torque to be output to the drive shaft 22 is calculated based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal by the driver, and the engine The engine 122 and the motors 30 and 130 are controlled so that the required torque is output to the drive shaft 22 with the intermittent operation 122. Hereinafter, a control mode for controlling the engine 122 and the motors 30 and 130 so that the required torque is output with the operation of the engine 122 is referred to as a hybrid travel mode, and the drive shaft 22 is driven from the motor 30 while the engine 122 is stopped. A control mode in which the engine and the motors 30 and 130 are controlled so that the required torque is output is called an electric travel mode.

  In the hybrid vehicle 120 of the second embodiment, the cooling mechanism control routine of FIG. 8 is executed instead of the cooling mechanism control routine of FIG. In the cooling mechanism control routine of FIG. 8, the atmospheric pressure Pa from the atmospheric pressure sensor 89 is input (step S300), and the input atmospheric pressure Pa is used as the insulation performance in the motor 30 and the motor 130 in a gas environment (air environment). Is compared with the threshold value Paref2 as a pressure corresponding to the allowable lower limit (step S310), and when the atmospheric pressure Pa is equal to or higher than the threshold value Paref2, it is determined that there is no risk of dielectric breakdown in the motor 30 or the motor 130 in an air environment. Of the valves 166 and 167, the corresponding valve is driven and controlled so that the closed valve is opened, and the state of the already opened valve is maintained (steps S320 and S330). A value 0 is set in the oil-tight flag F2 indicating whether or not both are in an oil-tight state. S340), it is determined whether or not the mechanical pump 164 is stopped by determining whether or not the vehicle is traveling in the electric travel mode (step S342). It is determined that the pump 164 is stopped, and the motor 130 is driven and controlled so that the mechanical pump 164 is driven by the motoring of the engine 122 by the motor 130 as required based on the temperature of the coil 46 ( Step S350), this routine is finished. When the vehicle is not traveling in the electric travel mode, that is, when traveling in the hybrid travel mode, it is determined that the mechanical pump 164 is being driven, and this routine is immediately terminated. By such control, the cooling performance of the motor 30 and the motor 130 can be ensured as in the first embodiment.

  On the other hand, when the atmospheric pressure Pa is lower than the threshold value Paref2 in step S310, it is determined that there is a risk of dielectric breakdown in the motor 30 or the motor 130 in the air environment, and the value of the oil tight flag F2 is examined (step S360). When the oil tight flag F2 is 0, that is, when at least one of the motor 30 and the motor 130 is not in an oil tight state, the opened valve of the valves 166 and 167 is closed. Whether or not the mechanical pump 164 has been stopped by determining whether or not it is traveling in the electric travel mode while controlling the driving of the corresponding valve and maintaining the state of the valve already closed (step S380). (Step S390), when the vehicle is traveling in the electric travel mode, it is determined that the mechanical pump 164 is stopped, and the mechanical pump 164 is driven by the motoring of the engine 122 by the motor 130. Start (step S400) and not travel in the electric travel mode, that is, travel in the hybrid travel mode. When you are, it is determined that the mechanical pump 164 has already been driven to continue the driving. After waiting for both the motor 30 and the motor 130 to become oil-tight (step S410), the oil-tight flag F2 is set to 1 (step S420), and when traveling in the electric travel mode. By terminating the motoring of the engine 122 by the motor 130, the driving of the mechanical pump 164 is stopped (steps S422 and S430), and this routine is terminated. Thus, by making the inside of the motor 30 and the inside of the motor 130 oil-tight, the insulation performance in the motor 30 and the motor 130 can be ensured even when the atmospheric pressure Pa is low, such as when traveling on high altitudes. When the inside of the motor 30 and the motor 130 are in an oil-tight state in this way, when the atmospheric pressure Pa is lower than the threshold value Paref2 in step S310 next time, it is determined in step S360 that the oil-tight flag F2 is a value 1, and this routine is directly executed. finish.

  According to the hybrid vehicle 120 of the second embodiment described above, similarly to the first embodiment, the atmospheric pressure Pa is determined as a pressure corresponding to the allowable lower limit of the insulation performance in the motor 30 or the motor 130 in the air environment. When the value is lower than the threshold value Paref2, the valve 166 provided at the cooling oil discharge position from the motor 30 to the outside of the motor 30 and the valve 167 provided at the cooling oil discharge position from the motor 130 to the outside of the motor 130 are closed. Therefore, the space in which the coils in the motors 30 and 130 are disposed can be made oil-tight, and insulation performance in the motor 30 and the motor 130 can be ensured even when the atmospheric pressure Pa is low.

  In the hybrid vehicle 120 of the second embodiment, when it is necessary to drive the mechanical pump 164 while traveling in the electric travel mode, the mechanical pump 164 is driven by motoring of the engine 122 by the motor 130. However, the engine 122 may be motored by the motor 130 and started, and the mechanical pump 164 may be driven by the autonomous operation of the engine 122.

  In the hybrid vehicle 120 of the second embodiment, a motor 30 that inputs and outputs power to the drive shaft 22 connected to the drive wheels 26a and 26b via a differential gear 24, and a planetary gear 124 that has a ring gear connected to the drive shaft 22; The engine 122 connected to the carrier of the planetary gear 124 and the motor 130 connected to the sun gear of the planetary gear 124 are provided. However, as illustrated in the hybrid vehicle 220 of the modified example of FIG. The present invention may be applied to a so-called series-type hybrid vehicle 220 having a power generation motor 230 and a traveling motor 30.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the first embodiment, the motor 30 corresponds to “electric motor”, the electric pump 64 corresponds to “cooling liquid supply means”, the valve 66 corresponds to “valve”, and the atmospheric pressure sensor 89 corresponds to “atmospheric pressure detection means”. When the atmospheric pressure Pa is lower than a threshold value Paref determined as a pressure corresponding to the allowable lower limit of the insulation performance of the motor 30 in an air environment, the cooling mechanism control routine of FIG. The electronic control unit 70 to be executed corresponds to “control means”. In the second embodiment, the motor 30 corresponds to “electric motor”, the mechanical pump 164 attached to the output shaft of the engine 122 corresponds to “cooling liquid supply means”, and the valve 166 corresponds to “valve”. When the atmospheric pressure sensor 89 corresponds to “atmospheric pressure detecting means” and the atmospheric pressure Pa is lower than the threshold value Paref2, the electronic control unit 70 that executes the cooling mechanism control routine of FIG. It corresponds to “means”.

  Here, the “motor” is not limited to the motor 30 configured as a synchronous generator motor, and a rotor and a coil connected to a drive shaft connected to a drive wheel such as an induction motor are wound. Any type of electric motor may be used as long as the electric motor includes a stator. The “cooling liquid supply means” is not limited to the electric pump 64 or the mechanical pump 164 attached to the output shaft of the engine 122, but a gear partially immersed in the oil pan 62 (for example, a differential As long as the cooling liquid is supplied to the coil space in which the coil in the electric motor is disposed, such as the gear 24, etc., any device may be used. The “valve” is not limited to the valve 66, and any type of valve may be used as long as it is provided at a position where the cooling liquid is discharged from the coil space to the outside of the electric motor. The “atmospheric pressure detecting means” is not limited to the atmospheric pressure sensor 89, and any means that detects atmospheric pressure may be used. The “control means” is not limited to the one that closes the valve 66 and the valves 166 and 167 when the atmospheric pressure Pa is lower than the threshold value Paref or when the atmospheric pressure Pa is lower than the threshold value Paref2, and the atmospheric pressure is Any valve may be used as long as the valve is controlled to be closed when the pressure is lower than a predetermined pressure defined as a pressure corresponding to the allowable lower limit of the insulation performance in the electric motor in a gas environment.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention is applicable to the manufacturing industry of electric vehicles.

  20 electric vehicle, 22 drive shaft, 24 differential gear, 26a, 26b drive wheel, 30 motor, 32 rotor, 34 rotor core, 36 permanent magnet, 40 stator, 42 stator core, 44 slot, 46 coil, 46a coil end, 48 lid member , 50 cover, 52 annular channel, 54 channel in slot, 56 inverter, 58 battery, 60 cooling mechanism, 62 oil pan, 64 electric pump, 66 valve, 70 electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 82 shift position sensor, 84 accelerator pedal position sensor, 86 brake pedal position sensor, 88 vehicle speed sensor, 89 atmospheric pressure sensor, 120 hybrid vehicle, 122 engine, 12 4 planetary gear, 130 motor, 156 inverter, 160 cooling mechanism, 162 oil pan, 164 mechanical pump, 166, 167 valve, 220 hybrid vehicle, 222 engine, 230 motor.

Claims (3)

An electric vehicle that travels using power from an electric motor including a rotor connected to a drive shaft coupled to a drive wheel and a stator wound with a coil,
A cooling liquid supply means for supplying a cooling liquid to a coil space in which the coil in the electric motor is disposed;
A valve provided at a cooling liquid discharge position from the coil space to the outside of the electric motor;
Atmospheric pressure detection means for detecting atmospheric pressure;
Control means for controlling the valve so that the valve is closed when the detected atmospheric pressure is lower than a predetermined pressure defined as a pressure corresponding to an allowable lower limit of insulation performance in the electric motor in a gaseous environment; ,
Electric car with The electric vehicle according to claim 1,
The cooling liquid supply means is means for supplying a cooling liquid by driving an electric pump,
The control means is means for controlling the electric pump so that the electric pump is driven when the electric pump is stopped when the detected atmospheric pressure is lower than the predetermined pressure.
Electric car. The electric vehicle according to claim 1,
An internal combustion engine capable of outputting driving power;
Motoring means capable of motoring the internal combustion engine;
With
The cooling liquid supply means is means for supplying a cooling liquid by driving a mechanical pump driven by rotation of the internal combustion engine,
The control means is means for controlling the motoring means so that the internal combustion engine rotates when the detected internal atmospheric pressure is lower than the predetermined pressure and the internal combustion engine is stopped.
Electric car.

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