JP4501456B2 - Cooling device for electric equipment mounted on vehicle - Google Patents

Description

  The present invention relates to a cooling device for an electric device mounted on a vehicle, and more particularly to a cooling device for an electric device such as a rotating electric machine such as a motor, a power unit such as an inverter, and a battery such as a power storage mechanism mounted on the vehicle.

  A motor or a generator mounted on a vehicle such as an automobile has a rotor (rotor) and a stator core that is disposed around the rotor and is wound with a stator coil. The motor energizes the stator coil to obtain a rotational force, and the generator extracts the current flowing through the stator coil by the rotation of the rotor. When a current flows through the stator coil during rotor rotation, the stator core and the stator coil generate heat. Such heat generation affects the magnetic flux penetrating the motor and the generator, and decreases the operation efficiency (rotation efficiency, power generation efficiency). In order to maintain the operation efficiency, it is necessary to cool the motor and the generator.

  In addition, PCUs (Power Control Units) including inverters that supply AC power to such motors, and batteries that supply DC power to inverters, etc., also generate heat due to chemical reactions associated with charging and discharging of the battery. It generates heat and needs to be cooled.

  The case where a motor and a generator are cooled in the electric equipment (a motor, a generator, PCU, and a battery) mounted in such a vehicle is demonstrated. The motor and the generator are mounted on the vehicle in a form covered with a housing. Therefore, for cooling the motor and the generator, a cooling medium passage is provided in the housing, and cooling with a refrigerant passing through the passage, that is, liquid cooling is often applied. At this time, since it is necessary to ensure insulation of the coil of the electric motor, cooling can be performed by a method of flowing cooling water through a refrigerant path provided in a portion that is not in contact with the coil in the housing, or in the vicinity of the heat generating portion. It is performed by a method of flowing or spraying an insulating machine oil or the like.

  In the method using an insulating refrigerant such as machine oil, it is not necessary to provide a refrigerant path in the housing while maintaining the insulating property. Therefore, the housing can be downsized and the refrigerant is supplied in the vicinity of the heat generating portion. Because it can, it is excellent in terms of large cooling capacity. A technique related to cooling for suppressing the heat generation of an electric motor mounted on such a vehicle is disclosed in the following publications.

  Japanese Patent Application Laid-Open No. 4-145801 (Patent Document 1) discloses an electric vehicle capable of traveling with a long charging distance while reducing power consumption. The electric vehicle includes a battery, an electric motor connected to the battery, wheels driven by the electric motor, and an oil supply pump motor that supplies oil for cooling the electric motor, and detects the temperature of the electric motor. And a control unit that controls the oil supply pump motor so as to limit the operation of the oil supply pump motor when the temperature of the electric motor is equal to or lower than a predetermined value.

According to this electric vehicle, the oil supply pump motor that supplies oil for cooling to the electric motor operates only when the temperature of the electric motor rises based on a signal from a temperature detection unit attached to the electric motor. For this reason, the oil supply pump motor does not operate in a traveling state in which the temperature of the electric motor does not increase. Therefore, power consumption can be reduced, energy saving can be realized, and one charge travel distance can be lengthened.
JP-A-4-145801

  However, in the electric vehicle disclosed in Patent Document 1 described above, even when the outside air temperature is low and the temperature of the motor is difficult to rise, when the temperature of the motor reaches a predetermined temperature, oil supply Operate the pump motor. That is, since there is a difference between the allowable temperature of the motor and the conditions for operating the oil supply pump motor, even if the outside air temperature is low and the oil supply pump motor is not operated, the temperature is below the allowable temperature. When the temperature of the electric motor exceeds a predetermined temperature, the oil supply pump motor starts operating. In such a state, there is a limit to lengthening one charging travel distance.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a cooling device capable of appropriately cooling an electric device mounted on a vehicle.

  According to a first aspect of the present invention, there is provided a cooling device for an electric device, a supply unit for supplying a cooling medium to the electric device, a unit for detecting the temperature of the electric device, a unit for detecting an air temperature, and the electric device. Control means for controlling the supply means on the basis of the temperature and the air temperature.

  According to the first aspect of the invention, for example, when the temperature of the traveling motor mounted on the vehicle becomes high, the electric oil pump that is the supply means for supplying the cooling oil to the traveling motor is operated. The electric oil pump can be prevented from operating. That is, when it is considered that the outside air temperature is low and the temperature rise of the traveling motor is small, the electric oil pump is not operated. As a result, the frequency of operation of the electric oil pump can be reduced, and fuel efficiency can be improved, durability of the electric oil pump can be improved, and operating noise of the electric oil pump can be reduced. As a result, it is possible to provide a cooling device that can appropriately cool the electric device mounted on the vehicle.

  In the electrical apparatus cooling apparatus according to the second aspect of the invention, in addition to the configuration of the first aspect, the control means may be configured such that the air temperature is equal to or higher than the predetermined first temperature and the temperature of the electric equipment is previously set. Means for controlling the supply means to operate when the temperature is equal to or higher than the predetermined second temperature is included.

  According to the second invention, when the temperature is equal to or higher than the first temperature and the temperature of the traveling motor is equal to or higher than the second temperature, the electric oil pump is operated, and the temperature is less than the first temperature. If the temperature of the traveling motor is lower than the second temperature, the electric oil pump can be prevented from operating. The second temperature is set based on the allowable temperature of the traveling motor, and the first temperature is lower than the second temperature.

  In the cooling device for electric equipment according to the third invention, in addition to the configuration of the second invention, the second temperature is higher than the first temperature.

  According to the third invention, when the outside air temperature is equal to or higher than the first temperature and the temperature of the traveling motor is higher than the second temperature higher than the first temperature, the electric oil pump is operated to If the temperature is lower than the first temperature or the temperature of the traveling motor is lower than the second temperature, the electric oil pump can be prevented from operating.

  In the cooling device for electric equipment according to the fourth invention, in addition to the structure of the second or third invention, the second temperature is set based on the allowable temperature of the electric equipment.

  According to the fourth invention, since the second temperature is set based on the allowable temperature of the traveling motor, the traveling motor can be operated within the allowable temperature.

  In the cooling device for electric equipment according to the fifth invention, in addition to the configuration of the second or third invention, a plurality of second temperatures are set corresponding to the range of the air temperature.

  According to the fifth aspect of the invention, for example, the higher the temperature, the lower the second temperature at which the operation of the electric oil pump starts, and the lower the temperature, the higher the second temperature. Thereby, the operation of the electric oil pump can be accurately controlled according to the temperature.

  In the electrical apparatus cooling device according to the sixth invention, in addition to the configuration of any one of the second to fifth inventions, the control means is configured such that the temperature of the electrical apparatus is higher than the first temperature and the second temperature. Means for controlling to stop the operation of the supply means when the temperature becomes lower than the lower third temperature is further included.

  According to the sixth aspect of the invention, when the electric oil pump is operated and the temperature of the traveling motor becomes lower than the third temperature lower than the second temperature at which the operation of the electric oil pump starts, Since the operation is stopped, the operation time of the electric oil pump can be shortened, and a third temperature different from the second temperature is set, so that hunting in which the electric oil pump is operated or stopped can be prevented. .

  In the electrical device cooling device according to the seventh aspect of the invention, in addition to the configuration of any one of the first to sixth aspects, the electrical device is a rotating electrical machine for traveling of a vehicle.

  According to the seventh aspect of the invention, the electrical equipment mounted on the vehicle includes a traveling rotating electrical machine (electric motor, generator), PCU, and battery, but the traveling rotating electrical machine can be appropriately cooled.

  In the cooling device for an electric device according to the eighth invention, in addition to the configuration of any one of the first to seventh inventions, the cooling medium is a liquid.

  According to the eighth invention, there are liquid cooling and air cooling as the cooling method of the electric equipment mounted on the vehicle, but the running rotary electric machine (electric motor, generator), PCU and battery are appropriately cooled with the cooling oil. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
Hereinafter, a cooling system for a vehicle travel motor according to a first embodiment of the present invention will be described. In the following description, the cooling target is described as a vehicle travel motor, but the present invention is not limited to this. A PCU including an inverter unit and a DC / DC converter, or a large-capacity battery for traveling may be a cooling target.

  FIG. 1 shows an overall configuration diagram of the cooling system. The motor 100 is an electric motor for running the vehicle and is cooled by cooling oil. An oil pan 120 is formed in the lower part of the housing of the motor 100, and an electric oil pump 140 is connected from the oil pan 120 through an oil pipe 130. Cooling oil is supplied to the motor 100 from the electric oil pump 140 through the heat exchanger 200 and the oil pipe to the top of the housing. In other words, the cooling oil is circulated between the motor 100 and the heat exchanger 200 through the oil pipe 130 by the electric oil pump 140. In the present invention, the cooling medium is not limited to such a liquid. A gas such as air may be used. In this case, it becomes a fan instead of a pump.

  A motor temperature sensor 110 is attached to the stator coil of the motor 100. The motor temperature detected by the motor temperature sensor 110 is output to an ECU (Electronic Control Unit) 300. In addition, an outside air temperature sensor 400 that detects the outside air temperature of the vehicle is provided, and the outside air temperature sensor 400 detects the outside air temperature that is output to the ECU 300. In addition, ECU 300 outputs an operation command signal and an operation stop signal to electric oil pump 140.

  The housing of the motor 100 is provided with a cooling oil dropping portion that drops cooling oil on the stator core and the stator coil end at a position above the stator core and the stator coil end. The cooling oil dripping unit is configured by, for example, a nozzle that drops, sprays, and injects a cooling coil supplied from the electric oil pump 140 onto the stator core and the stator coil end. The stator core and the stator coil end are cooled by the cooling oil supplied from the cooling oil dropping portion to the stator core and the stator coil end. Alternatively, an oil passage may be provided inside the rotor, and cooling oil may be supplied from an oil passage provided at the center of the rotation shaft to an oil passage provided in the rotor to cool the rotor.

  Since the cooling oil as shown in FIG. 1 is circulated by the electric oil pump 140, the cooling oil that has cooled the stator core, the stator coil, the stator coil end, and the rotor is temporarily stored in an oil pan 120 provided below the housing. The cooling oil is circulated by the electric oil pump 140, and the temperature of the cooling oil in the high temperature state is lowered by the heat exchanger 200, and is supplied to the cooling oil dropping portion provided at the upper part of the housing.

  A control structure of a program executed by the ECU of FIG. 1 will be described with reference to FIG. In the following description, outside air temperature threshold value T (1) <motor temperature threshold value T (3) <motor temperature threshold value T (2).

  In step (hereinafter, step is abbreviated as S) 100, ECU 300 determines whether electric oil pump 140 is operating or not. This determination is made based on whether an operation command signal is output from ECU 300 to electric oil pump 140 or an operation stop signal is output. If electric oil pump 140 is operating (YES in S100), the process proceeds to S110. If not (NO in S100), the process proceeds to S130.

  In S110, ECU 300 determines whether or not the motor temperature is lower than motor temperature threshold value T (3). The motor temperature is detected based on a signal input to ECU 300 from motor temperature sensor 110 attached to the stator coil. If the motor temperature is lower than motor temperature threshold value T (3) (YES in S110), the process proceeds to S120. Otherwise (NO in S110), this process ends.

  In S120, ECU 300 outputs an operation stop signal to electric oil pump 140 to stop electric oil pump 140. Thereafter, the process ends.

  In S130, ECU 300 determines whether or not the outside air temperature is lower than outside air temperature threshold value T (1). ECU 300 detects the outside air temperature based on the signal input from outside air temperature sensor 400. If the outside air temperature is lower than outside air temperature threshold value T (1) (YES at S130), this process ends. If not (NO in S130), the process proceeds to S140.

  In S140, ECU 300 determines whether or not the motor temperature is lower than motor temperature threshold value T (2). If the motor temperature is lower than motor temperature threshold value T (2) (YES in S140), this process ends. If not (NO in S140), the process proceeds to S150.

  In S150, ECU 300 outputs an operation command signal to electric oil pump 140 to operate the electric oil pump. Thereafter, the process ends.

  The operation of the cooling system according to the present embodiment based on the above-described structure and flowchart will be described.

  If electric oil pump 140 is not in operation (NO in S100), if the outside air temperature is lower than outside air temperature threshold value T (1), the operation command signal is not output to electric oil pump 140, and the electric oil pump 140 is electrically operated. The oil pump 140 is not activated. Even if the outside air temperature is equal to or higher than the outside air temperature threshold value T (1) (NO in S130), the motor oil is also used when the motor temperature is lower than the motor temperature threshold value T (2) (YES in S140). The operation command signal is not output to the pump 140, and the electric oil pump 140 is not operated.

  If the outside air temperature is equal to or greater than the outside air temperature threshold T (1) (NO in S130) and the motor temperature is equal to or greater than the motor temperature threshold T (2) (NO in S140), electric oil pump 140 Is activated (S150).

  FIG. 3A shows the time change of the motor temperature when the outside air temperature is high, and FIG. 3B shows the time change of the motor temperature when the outside air temperature is low.

  As shown in FIG. 3A, when the outside air temperature is high (NO in S130), electric oil pump 140 is a motor in both the cooling system according to the embodiment of the present invention and the conventional cooling system. If temperature is equal to or higher than motor temperature threshold value T (2) (NO in S140), the operation is performed.

  On the other hand, when the outside air temperature is low as shown in FIG. 3B, the motor temperature is equal to or higher than motor temperature threshold value T (2) (NO in S140), and the outside temperature is the outside air temperature threshold value. If lower than T (1) (YES in S130), electric oil pump 140 is maintained in a non-operating state. That is, as shown by the solid line in FIG. 3B, when the outside air temperature is low, the motor temperature at the start of operation of the motor 100 is lower and the outside air temperature is lower than when the outside air temperature is high. This is because it is considered that the motor temperature does not reach the allowable temperature even if the electric oil pump 140 is not operated.

  As described above, according to the cooling system according to the present embodiment, the operation / non-operation of the electric oil pump is based on the motor temperature and the outside air temperature, compared to the case where the control is based on the motor temperature and the temperature of the cooling medium. Since the operation is controlled, when the outside air temperature is low and the motor temperature does not reach the permissible temperature, the electric oil pump is not operated even when the electric oil pump exceeds the operating temperature. The state can be maintained and the operation time of the electric oil pump can be reduced. As a result, it is possible to improve fuel efficiency, improve the durability of the electric oil pump, and reduce the operating noise of the electric oil pump.

<Second Embodiment>
Hereinafter, a cooling system according to a second embodiment of the present invention will be described. The structure of the cooling system according to the present embodiment is the same as the structure of the cooling system according to the first embodiment described above. Therefore, description of the structure described in FIG. 1 will not be repeated here. The cooling system according to the present embodiment differs from the cooling system according to the first embodiment described above in the control structure of a program executed in ECU 300.

  With reference to FIG. 4, a control structure of a program executed by ECU 300 of the cooling system according to the present embodiment will be described. In the flowchart shown in FIG. 4, the same steps as those in the flowchart shown in FIG. 2 are given the same step numbers. The processing for them is the same. Therefore, detailed description thereof will not be repeated here.

  In addition, the temperature threshold value used in the following description is demonstrated. {Outside air temperature threshold T (1A), T (1B), T (1C)} <Motor temperature threshold T (3) <{Motor temperature threshold T (2A), T (2B), T ( 2C), T (2D)}. Further, the outside air temperature threshold value T (1C) <the outside air temperature threshold value T (1B) <the outside air temperature threshold value T (1A). Further, motor temperature threshold value T (2A) <motor temperature threshold value T (2B) <motor temperature threshold value T (2C) <motor temperature threshold value T (2D).

  The motor temperature threshold T (2A) is a motor temperature when the electric oil pump 140 is operated when the outside air temperature is equal to or higher than the outside air temperature threshold T (1A). The motor temperature threshold value T (2B) is a motor temperature at which the operation of the electric oil pump 140 is started when the outside air temperature is between the outside air temperature threshold value T (1B) and the outside air temperature threshold value T (1A). Motor temperature threshold value T (2C) is a motor temperature at which operation of electric oil pump 140 is started when the outside air temperature is between outside air temperature threshold value T (1C) and outside air temperature threshold value T (1B). The motor temperature threshold T (2D) is a motor temperature at which the operation of the electric oil pump 140 is started regardless of the outside air temperature.

  In S200, ECU 300 determines whether or not the outside air temperature is higher than outside air temperature threshold value T (1A). If the outside air temperature is higher than outside air temperature threshold value T (1A) (YES in S200), the process proceeds to S230. If not (NO in S200), the process proceeds to S210.

  In S210, ECU 300 determines whether or not the outside air temperature is higher than outside air temperature threshold value T (1B). If the outside air temperature is higher than outside air temperature threshold value T (1B) (YES in S210), the process proceeds to S240. If not (NO in S210), the process proceeds to S220.

  In S220, ECU 300 determines whether or not the outside air temperature is higher than outside air temperature threshold value T (1C). If the outside air temperature is higher than outside air temperature threshold value T (1C) (YES in S220), the process proceeds to S250. If not (NO in S220), the process proceeds to S260.

  In S230, ECU 300 substitutes motor temperature threshold value T (2A) for motor temperature threshold value T (2). In S240, ECU 300 substitutes motor temperature threshold value T (2B) for motor temperature threshold value T (2). In S250, ECU 300 substitutes motor temperature threshold value T (2C) for motor temperature threshold value T (2). In S260, ECU 300 substitutes motor temperature threshold value T (2D) for motor temperature threshold value T (2).

  The operation of the cooling system according to the present embodiment based on the above-described structure and flowchart will be described.

  When electric oil pump 140 is not operating (NO in S100), if the outside air temperature is higher than outside air temperature threshold value T (1A), the motor temperature is set to motor temperature threshold value T (2). The threshold value T (2A) is substituted. The motor temperature threshold value T (2A) is the lowest temperature among the motor temperature threshold values that are the operating conditions of the electric oil pump 140.

  When the outside air temperature is outside air temperature threshold value T (1B) to outside air temperature threshold value T (1A) (NO in S200, YES in S210), the motor temperature is set to motor temperature threshold value T (2). The threshold value T (2B) is substituted (S240). When the outside air temperature is outside air temperature threshold value T (1C) to outside air temperature threshold value T (1B) (NO in S200, NO in S210, YES in S220), motor temperature threshold T ( The motor temperature threshold value T (2C) is substituted into 2) (S250).

  If the outside air temperature does not satisfy any of the above conditions (NO in S220), motor temperature threshold value T (2D) is substituted for motor temperature threshold value T (2) (S260). The motor temperature threshold value T (2D) is the highest temperature among the motor temperature threshold values that are the operating conditions of the electric oil pump 140.

  That is, the motor temperature threshold value T (2) is set in correspondence with the outside air temperature range. When the motor temperature becomes equal to or higher than the set motor temperature threshold value T (2) (NO in S140), an operation command signal is output to electric oil pump 140 (S150).

  As described above, according to the cooling system according to the present embodiment, the operation / non-operation of the electric oil pump can be controlled more finely than the first embodiment described above, and the electric oil pump is not operated. The state may be maintained for a long time, and the operation frequency of the electric oil pump can be further reduced.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a control block diagram of the cooling system which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the control structure of the program performed by ECU of the cooling system which concerns on the 1st Embodiment of this invention. It is a figure which shows the temperature rise state in the cooling system which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the control structure of the program performed by ECU of the cooling system which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Motor, 110 Motor temperature sensor, 120 Oil pan, 130 Oil piping, 140 Electric oil pump, 200 Heat exchanger, 300 ECU, 400 Outside temperature sensor.

Claims (7)

A cooling device for electric equipment mounted on a vehicle,
Supply means for supplying a cooling medium to the electrical equipment;
Means for detecting the temperature of the electrical equipment;
A means to detect the temperature;
Based on the temperature and the air temperature of the electrical device, seen including a control means for controlling said supplying means,
The control means controls to operate the supply means when the air temperature is equal to or higher than a predetermined first temperature and the temperature of the electric device is equal to or higher than a predetermined second temperature. A cooling device comprising means for The cooling device according to claim 1 , wherein the second temperature is higher than the first temperature. The cooling device according to claim 1 or 2 , wherein the second temperature is set based on an allowable temperature of the electric device. The cooling device according to claim 1 or 2 , wherein a plurality of the second temperatures are set corresponding to the range of the air temperature. The control means controls to stop the operation of the supply means when the temperature of the electrical device becomes lower than a third temperature higher than the first temperature and lower than the second temperature. The cooling device according to any one of claims 1 to 4 , further comprising: The electric device is a traveling electric rotating machine of the vehicle, the cooling device according to any one of claims 1-5. The cooling medium is a liquid, the cooling device according to any one of claims 1-6.

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