JP2012165588A - Cooling system - Google Patents

Abstract

A plurality of power conversion circuits are cooled more appropriately according to the state of a vehicle.
According to the state of the vehicle, it is determined whether it is necessary to preferentially cool one of the inverter that drives the motor MG1, the inverter that drives the motor MG2, and the boost converter. S110 to S150), based on this determination, the first valve of the first heat exchange unit that cools the inverter for the motor MG1, the second valve of the second heat exchange unit that cools the inverter for the motor MG2, and the boost converter The open / close state of the third valve of the third heat exchanging section is set (S160 to S190). This increases the flow rate of the cooling medium in the heat exchanging section used for cooling prior to the temperature rise of either of the two inverters or boost converters that are predicted to generate heat according to the state of the vehicle, and suppresses the temperature rise. can do.
[Selection] Figure 3

Description

  The present invention relates to a cooling system, and more particularly, to a cooling system that cools a plurality of power conversion circuits including an inverter that converts power in order to drive an electric motor for traveling mounted on a vehicle.

  Conventionally, in this type of cooling system, a current command is generated based on the required output of the AC motor determined from the accelerator opening of the vehicle, and the inverter switching element is set so that the actual motor current matches the current command. In a cooling system that cools an inverter to be switched, a system that estimates a loss generated in an inverter based on an accelerator opening and sets a target flow rate of cooling water based on the estimated loss has been proposed (for example, a patent) Reference 1). In this cooling system, by setting the target flow rate of the cooling water and controlling the cooling water circulation pump as described above, both thermal protection of the inverter and power saving of the cooling system are achieved.

JP 2008-253098 A

  In a cooling system in a vehicle having a plurality of inverters for driving a plurality of motors, the loss generated in the inverters that drive all the motors does not change uniformly with respect to the accelerator opening, but at the time of acceleration or deceleration Since the loss generated in the inverter that drives each motor differs depending on the traveling state such as during high-speed cruise, the target flow rate of the cooling water cannot be set based only on the accelerator opening. Further, the target flow rate of the cooling water varies depending on how the cooling water flow paths are set for the plurality of inverters.

  The cooling system of the present invention is mainly intended to cool a plurality of power conversion circuits more appropriately according to the state of the vehicle.

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

The cooling system of the present invention comprises:
A cooling system that cools a plurality of power conversion circuits including an inverter that converts power to drive an electric motor for traveling on a vehicle,
A plurality of heat exchange units arranged in parallel in the circulation path of the cooling medium and cooling each of the plurality of power conversion circuits by heat exchange with the cooling medium;
A plurality of flow rate control valves for adjusting the flow rate of the cooling medium of each of the plurality of heat exchange units;
Relationship storage means for predetermining a relationship between a vehicle state and the opening / closing states of the plurality of flow control valves and storing the relationship as a valve opening / closing state setting relationship;
A valve that controls the opening and closing of the plurality of flow rate control valves so as to be in the open / closed state of the plurality of flow rate control valves obtained by applying the valve opening / closing state setting relationship stored in the relationship storage means to the vehicle state Opening and closing control means;
It is a summary to provide.

  In the cooling system of the present invention, a plurality of heat exchange units that cool each of the plurality of power conversion circuits by heat exchange with the cooling medium are arranged in parallel in the circulation passage of the cooling medium, and each of the plurality of heat exchange units A plurality of flow rate adjusting valves for adjusting the flow rate of the cooling medium are provided. Then, the relationship between the vehicle state and the opening / closing states of the plurality of flow control valves is determined in advance and stored as the valve opening / closing state setting relationship, and the valve opening / closing state setting relationship stored for the vehicle state is stored. The plurality of flow rate control valves are controlled to be opened and closed so that the plurality of flow rate control valves obtained by applying the above are opened and closed. Thereby, a some flow control valve can be made into a more suitable opening-and-closing state according to the state of a vehicle. As a result, the plurality of power conversion circuits can be more appropriately cooled according to the state of the vehicle.

  In such a cooling system of the present invention, the vehicle includes an internal combustion engine, a first electric motor that can also be driven as a generator, a first inverter for driving the first electric motor, and an output of the internal combustion engine. A planetary gear mechanism in which three rotating elements are connected to a shaft, a rotating shaft of the first electric motor, and a driving shaft connected to an axle; and a second generator that can also be driven as a generator that outputs power to the driving shaft. An electric motor, a second inverter for driving the second electric motor, a battery, and a boost converter that boosts the power of the battery and supplies the electric power to the first inverter and the second inverter. The plurality of power conversion circuits are the first inverter, the second inverter, and the boost converter, and the valve opening / closing state setting relationship is such that a vehicle state starts the internal combustion engine. When cranking is during cranking, the plurality of flow rate control valves reduce the flow rate of the cooling medium to the heat exchange unit that cools the second inverter and the boost converter, and heat that cools the first inverter. The plurality of flow rate control valves cool the second inverter and the boost converter when the flow rate of the cooling medium to the replacement unit becomes an open / closed state where the flow rate of the cooling medium increases and the vehicle is cruising at a high vehicle speed. The flow rate of the cooling medium to the heat exchanging portion that is reduced and the flow rate of the cooling medium to the heat exchanging portion that cools the first inverter is increased, and the vehicle state is accelerated at a low vehicle speed. When the vehicle speed is being accelerated, the plurality of flow rate control valves reduce the flow rate of the cooling medium to the heat exchange unit that cools the first inverter and the boost converter. The plurality of flow rate control valves are in an open / closed state in which the flow rate of the cooling medium to the heat exchanging section that cools the second inverter is increased and the vehicle is accelerating at a medium or high vehicle speed that is accelerating at a medium vehicle speed or higher. Is an open / closed state in which the flow rate of the cooling medium to the heat exchange unit that cools the first inverter and the second inverter decreases and the flow rate of the cooling medium to the heat exchange unit that cools the boost converter increases. When the vehicle is in a decelerating state, the plurality of flow rate control valves reduce the flow rate of the cooling medium to the heat exchange unit that cools the first inverter and the second inverter, and the boost converter It is also possible to have a relationship of being in an open / close state in which the flow rate of the cooling medium to the heat exchange unit that cools the air increases.

It is a block diagram which shows the outline of a structure of the hybrid vehicle 20 carrying the cooling system as one Example of this invention. 3 is a schematic configuration diagram schematically showing a schematic configuration of a heat exchange section 64. FIG. 5 is a flowchart showing an example of a valve opening / closing control routine executed by the hybrid electronic control unit 70.

  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 a hybrid vehicle 20 equipped with a cooling system as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22 that uses gasoline or light oil as fuel, an engine electronic control unit (hereinafter referred to as an engine ECU) 24 that controls the drive of the engine 22, and an engine 22. A planetary gear 30 in which a carrier is connected to the crankshaft 26 and a ring gear is connected to a drive shaft 36 connected to drive wheels 38a and 38b through a differential gear 37, and a rotor is configured as a planetary gear, for example, as a synchronous generator motor. A motor MG1 connected to 30 sun gears, a motor MG2 configured as a synchronous generator motor and having a rotor connected to the drive shaft 36, inverters 41 and 42 for driving the motors MG1 and MG2, and a battery 50 And boost the power from the battery 50 to The boost converter 46 charges the battery 50 by reducing the power obtained by supplying it to the motors 41, 42 and regeneratively controlling the motors MG1, MG2, and the switching elements (not shown) of the boost converter 46 and the inverters 41, 42 shown. A motor electronic control unit (hereinafter referred to as a motor ECU) 40 for controlling the driving of the motors MG1 and MG2 by switching control of the non-switching elements, a cooling system 60 for cooling the inverters 41 and 42, and the boost converter 46, and a shift Brake pedal position that detects the shift position from the shift position sensor 82 that detects the position of the lever, the accelerator opening from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal, and the depression amount of the brake pedal Comprising a brake position from the sensor 86, the hybrid electronic control unit 70 for controlling the entire vehicle to communicate with the engine ECU24 and motor ECU40 inputs the vehicle speed from the vehicle speed sensor 88, a.

  The cooling system 60 circulates a cooling medium 61 such as water, a pump 62 for circulating the cooling medium in the circulation path 61, and the cooling medium 60 is cooled by the outside air incorporated in the circulation path 61. A heat exchanger 63, a heat exchanging unit 64 which is incorporated in the circulation channel 61 and attached to the bases of the inverters 41 and 42 and the boost converter 46 and cools the inverters 41 and 42 and the boost converter 46 with a cooling medium by heat transfer; Is provided. As shown in FIG. 2, the heat exchanging unit 64 is configured to cool the inverter 42, the inflow channel 65 through which the cooling medium flows from the circulation channel 61, the first heat exchanging unit 66 a for cooling the inverter 41, and the like. The second heat exchanging part 66b, the third heat exchanging part 66c for cooling the step-up converter 46, the cooling flowing through the first heat exchanging part 66a, the second heat exchanging part 66b and the third heat exchanging part 66c. The first valve 67a, the second valve 67b, and the third valve 67c as three electromagnetic flow control valves for adjusting the flow rate of the medium, and the cooling medium that has flowed out of the first valve 67a, the second valve 67b, and the third valve 67c. And an outflow channel 68 for feeding the gas to the circulation channel 61. The pump 62, the first valve 67a, the second valve 67b, and the third valve 67c of the cooling system 60 are connected to the hybrid electronic control unit 70 through signal lines, and are subjected to drive control by the hybrid electronic control unit 70. Yes.

  The hybrid vehicle 20 of the embodiment thus configured calculates a required torque to be output to the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V corresponding to the amount of depression of the accelerator pedal by the driver, and this required torque. The engine 22, the motor MG 1, and the motor MG 2 are controlled for operation so that the required power corresponding to is output to the drive shaft 36. As the operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that the power corresponding to the required power is output from the engine 22, and all the power output from the engine 22 is transmitted to the planetary gear 30 and the motor. Torque conversion by the motor MG1 and the motor MG2 is converted into torque and output to the drive shaft 36. The torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 and the power required for the sum of the required power and the power required for charging and discharging the battery 50 Is controlled so that the engine 22 is output from the engine 22, and all or a part of the power output from the engine 22 with charging / discharging of the battery 50 is converted by the planetary gear 30, the motor MG1, and the motor MG2. So that the required power is output to the drive shaft 36. Charge-discharge drive mode for driving and controlling over data MG1 and the motor MG2, there is a motor operation mode in which operation control to output a power commensurate to stop the operation of the engine 22 to the required power from the motor MG2 to the drive shaft 36. Both the torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22 and the motors MG1, MG2 are controlled so that the required power is output to the drive shaft 36 with the operation of the engine 22. Since there is no difference in the control, both are hereinafter referred to as the engine operation mode.

  In the engine operation mode, the hybrid electronic control unit 70 sets the required torque Tr * to be output to the drive shaft 36 based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88. The rotation speed Nr of the drive shaft 36 (for example, the rotation speed obtained by dividing the rotation speed Nm2 of the motor MG2 by the gear ratio of the reduction gear 35, or the vehicle speed V is obtained by multiplying the set required torque Tr * by the conversion factor. The travel power Pr * required for travel is calculated by multiplying the number of revolutions), and the charge / discharge required power Pb * of the battery 50 obtained based on the remaining capacity (SOC) of the battery 50 from the calculated travel power Pr *. The required power Pe * is set as the power to be output from the engine 22 by subtracting (a positive value when discharging from the battery 50). The target rotational speed Ne * of the engine 22 and the target are obtained by using an operation line (for example, a fuel efficiency optimum operation line) as a relation between the rotational speed Ne of the engine 22 and the torque Te that can output the power Pe * from the engine 22 efficiently. The torque Te * is set and output from the motor MG1 by the rotational speed feedback control so that the rotational speed Ne of the engine 22 becomes the target rotational speed Ne * within the range of the input / output limits Win and Wout of the battery 50. A torque command Tm1 * as a torque to be set is set, and when the motor MG1 is driven by the torque command Tm1 *, the torque acting on the drive shaft 36 via the planetary gear 30 is subtracted from the required torque Tr * to reduce the torque command of the motor MG2. Tm2 * is set and the engine ECU is set for the target rotational speed Ne * and the target torque Te *. Send to 4, the torque command Tm1 *, the Tm2 * is sent to the motor ECU 40. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * then controls the intake air amount control and fuel injection control of the engine 22 so that the engine 22 is operated by the target rotational speed Ne * and the target torque Te *. Perform ignition control. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  In the motor operation mode, the hybrid electronic control unit 70 sets the torque command Tm1 * of the motor MG1 to a value of 0 and outputs the required torque Tr * to the drive shaft 36 within the input / output limits Win and Wout of the battery 50. Then, torque command Tm2 * of motor MG2 is set and transmitted to motor ECU 40. Then, the motor ECU 40 that receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  Next, operation | movement of the cooling system 60 mounted in the hybrid vehicle 20 of an Example is demonstrated. FIG. 3 is a flowchart showing an example of a valve opening / closing control routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed every predetermined time.

  When the valve opening / closing control routine is executed, the hybrid electronic control unit 70 first inputs the state of the vehicle (step S100). Here, the vehicle state includes the shift position SP from the shift position sensor 82, the accelerator opening Acc from the accelerator pedal position sensor 84, the brake position BP from the brake pedal position sensor 86, the vehicle speed V from the vehicle speed sensor 88, The acceleration α calculated from the vehicle speed V by an acceleration calculation routine (not shown), the rotation speeds Nm1, Nm2 of the motors MG1, MG2 input by communication from the motor ECU 40, the rotation speed Ne of the engine 22 input by communication from the engine ECU 24, a drive (not shown) Required torque Tr *, required power Pe * from the control routine, target rotational speed Ne * of engine 22, target torque Te *, torque commands Tm1 * and Tm2 * of motors MG1 and MG2, start instruction and stop instruction of engine 22, etc. Is applicable.

  Subsequently, whether or not the input vehicle state is during cranking when cranking to start the engine 22 (step S110), or is during high-speed cruise that is cruising at a relatively high vehicle speed. No (step S120), whether it is a low-speed acceleration that is accelerating at a comparatively low vehicle speed (step S130), and whether it is a medium-high speed acceleration that is accelerating at a medium vehicle speed or a high vehicle speed (step S140). It is determined whether or not the vehicle is decelerating (step S150). Whether or not it is during cranking can be determined by whether or not torque is being output by the motor MG1 in a state where the engine 22 is instructed to start. Whether the vehicle is traveling at high speed or not is determined by determining whether the vehicle speed V is equal to or higher than a predetermined high speed determination vehicle speed (for example, 80 km / h or 90 km / h) in order to determine that the vehicle speed V is high. Whether or not the acceleration is within the cruise determination acceleration range set in advance as a relatively small range including 0, and in addition to this, changes in the accelerator opening Acc and changes in the brake position BP are relatively small including the value 0. It can be determined based on whether or not the change amount is equal to or less than a predetermined cruise determination change amount. As to whether or not the vehicle is accelerating at a low speed, the accelerator is opened in a state where the vehicle speed V is equal to or lower than a vehicle speed determination vehicle speed (for example, 20 km / h, 30 km / h, etc.) determined in advance to determine that the vehicle speed V is a low vehicle speed. Whether or not the degree Acc is greater than or equal to a predetermined acceleration determination opening (for example, 40%, 50%, etc.) to determine that acceleration is in progress, or the vehicle speed V is less than or equal to the low vehicle speed determination vehicle speed In this state, it is possible to determine whether or not the acceleration α is an acceleration determination acceleration determined in advance in order to determine that the acceleration α is during acceleration. As to whether or not the vehicle is accelerating at medium to high speed, whether or not the accelerator opening Acc is greater than or equal to the opening for acceleration determination in a state where the vehicle speed V is greater than the vehicle speed for low vehicle speed determination, or the vehicle speed V is determined to be low vehicle speed. The determination can be made based on whether or not the acceleration α is the acceleration determination acceleration in a state that is greater than the vehicle speed. Whether or not the vehicle is decelerating is determined whether or not the brake position BP is equal to or greater than a predetermined position for determining when decelerating in order to determine that the brake position BP is decelerating when the vehicle speed V is not zero. The determination can be made based on whether or not the acceleration α is equal to or less than a predetermined acceleration for deceleration determination in order to determine that the acceleration α is during deceleration when V is not 0.

  When it is determined that the vehicle is in the cranking state, the motor MG1 has a small rotation speed Nm1 but a large value is set in the torque command Tm1 * of the motor MG1, so that the inverter 41 that drives the motor MG1 generates heat. In order to increase the flow rate of the cooling medium in the first heat exchange section 66a for cooling the inverter 41, the inverter 41 should be cooled in preference to the inverter 42 and the boost converter 46. The first valve 67a is opened, the second valve 67b and the third valve 67c are closed (step S160), and this routine is terminated. By such valve operation, the flow rate of the cooling medium in the first heat exchanging portion 66a that cools the inverter 41 prior to the temperature rise of the inverter 41 can be quickly increased. Can do.

  When it is determined that the vehicle is in a high-speed cruise state, a small value is set in the torque command Tm1 * of the motor MG1, but the motor 41 generates heat at the inverter 41 that drives the motor MG1 because the motor MG1 has a large rotation speed Nm1. In order to increase the flow rate of the cooling medium in the first heat exchange section 66a for cooling the inverter 41, the inverter 41 should be cooled in preference to the inverter 42 and the boost converter 46. The first valve 67a is opened, the second valve 67b and the third valve 67c are closed (step S160), and this routine is terminated. By such valve operation, the flow rate of the cooling medium in the first heat exchanging portion 66a that cools the inverter 41 prior to the temperature rise of the inverter 41 can be increased, so that the temperature rise due to heat generation of the inverter 41 can be suppressed. .

  When it is determined that the state of the vehicle is at the time of low speed acceleration, since the rotational speed Nm2 of the motor MG2 is small but a large value is set in the torque command Tm2 * of the motor MG2, the inverter 42 that drives the motor MG2 generates heat. In order to increase the flow rate of the cooling medium in the second heat exchange section 66b for cooling the inverter 42, it is determined that the inverter 42 should be cooled in preference to the inverter 41 and the boost converter 46. The second valve 67b is opened and the first valve 67a and the third valve 67c are closed (step S170), and this routine is terminated. By such valve operation, the flow rate of the cooling medium in the second heat exchange unit 66b that cools the inverter 42 prior to the temperature rise of the inverter 42 can be increased, so that the temperature rise due to heat generation of the inverter 42 can be suppressed. .

  When it is determined that the vehicle is in the middle / high speed acceleration state, the current IB output from the battery 50 is increased, so that heat generation in the boost converter 46 is expected, and the boost converter 46 is connected to the inverters 41 and 42. In order to increase the cooling medium flow rate in the third heat exchanging section 66c for cooling the boost converter 46, the third valve 67c is opened and the first valve 67a and the first valve 67a 2 The valve 67b is closed (step S180), and this routine is finished. By such valve operation, the flow rate of the cooling medium in the third heat exchanging portion 66c that cools the boost converter 46 prior to the temperature rise of the boost converter 46 can be increased. be able to.

  When it is determined that the vehicle is decelerating, the current IB charging the battery 50 is increased, so that heat generation is expected in the boost converter 46. The boost converter 46 is given priority over the inverters 41 and 42. In order to increase the flow rate of the cooling medium in the third heat exchange section 66c for cooling the boost converter 46, the third valve 67c is opened and the first valve 67a and the second valve 67b are determined to be cooled. Is closed (step S180), and this routine is terminated. By such valve operation, the flow rate of the cooling medium in the third heat exchanging portion 66c that cools the boost converter 46 prior to the temperature rise of the boost converter 46 can be increased. be able to.

  When the vehicle is not cranking, high-speed cruising, low-speed accelerating, medium-high-speed accelerating, or decelerating, that is, when cruising or stopping at low or medium vehicle speed, It is determined that it is not necessary to cool any of the converters 46 with priority over the other, and the cooling medium flows through the first heat exchange unit 66a, the second heat exchange unit 66b, and the third heat exchange unit 66c. As described above, all of the first valve 67a, the second valve 67b, and the third valve 67c are opened (step S190), and this routine is finished.

  According to the cooling system of the embodiment described above, it is determined whether or not it is necessary to cool one of the inverters 41 and 42 and the boost converter 46 with priority over the other according to the state of the vehicle. Based on this determination, the opening and closing states of the first valve 67a, the second valve 67b, and the third valve 67c are determined and operated, so that the inverters 41, 42, The flow rate of the cooling medium in the first heat exchange unit 66a, the second heat exchange unit 66b, and the third heat exchange unit 66c that cools the boost converter 46 can be increased. Therefore, temperature rise due to heat generation of inverters 41, 42 and boost converter 46 can be suppressed as compared with a case where valve operation is performed after detecting temperature rise of inverters 41, 42 and boost converter 46.

  In the cooling system of the embodiment, when it is determined that it is necessary to preferentially cool any one of the inverters 41 and 42 and the boost converter 46 in accordance with the state of the vehicle, it is necessary to preferentially cool. The valve attached to the heat exchanger determined to be open and the other valves closed, but the coolant flow rate to the heat exchanger determined to be preferentially cooled Therefore, the valve attached to the heat exchange unit determined to be preferentially cooled is fully opened and the other valve is 1/3 of the flow rate to the other heat exchange unit. It is good also as what is set as the state of an opening degree, a 1/4 opening degree, or a 1/5 opening degree.

  In the cooling system of the embodiment, the first valve 67a, the second valve 67b, and the third valve 67c are attached to the outflow side of the first heat exchange unit 66a, the second heat exchange unit 66b, and the third heat exchange unit 66c. However, the first valve 67a, the second valve 67b, and the third valve 67c may be attached to the inflow side of the first heat exchange unit 66a, the second heat exchange unit 66b, and the third heat exchange unit 66c.

  In the cooling system of the embodiment, the planetary gear 30 in which the engine 22, the motor MG1, the crankshaft 26 of the engine 22, the rotating shaft of the motor MG1, the drive shaft 36, the carrier that is three rotating elements, the sun gear, and the ring gear are connected. And a motor MG2 attached to the drive shaft 36, a battery 50, and a boost converter 46 that boosts the electric power of the battery 50 and supplies it to inverters 41 and 42 for driving the motors MG1 and MG2. However, as long as the vehicle is equipped with a plurality of power conversion circuits such as an inverter and a boost converter, it may be mounted on a vehicle having any configuration. In this case, assuming a heat generation state of a plurality of power conversion circuits such as an inverter and a boost converter mounted from the state of the vehicle, the heat exchange unit is configured so that cooling of the power conversion circuit that is predicted to generate heat is given priority. The valve operation may be performed.

  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 embodiment, the inverters 41 and 42 and the boost converter 46 correspond to “a plurality of power conversion circuits”, and the first heat exchange unit 66a, the second heat exchange unit 66b, and the third heat exchange unit 66c are “a plurality of heat conversion circuits”. The first valve 67a, the second valve 67b, and the third valve 67c correspond to “a plurality of flow control valves”, and the hybrid electronic control unit 70 that stores the valve opening / closing control routine of FIG. The hybrid electronic control unit 70 that corresponds to “relation storage means” and executes the valve opening / closing control routine of FIG. 3 corresponds to “valve opening / closing control means”.

  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 can be used in the manufacturing industry of in-vehicle cooling systems.

  20 hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 40 motor electronic control unit (motor ECU), 41, 42 Inverter, 46 Boost converter, 50 Battery, 60 Cooling system, 61 Circulation flow path, 62 Pump, 63 Heat exchanger, 64 Heat exchange section, 65 Inflow flow path, 66a First heat exchange section, 66b Second heat Exchange part, 66c 3rd heat exchange part, 67a 1st valve, 67b 2nd valve, 67c 3rd valve, 68 Outflow flow path, 70 Hybrid electronic control unit, 82 Shift position sensor, 84 Accelerator pedal position sensor, 86 Brake Pedal positive Sensor, 88 vehicle speed sensor, MG1, MG2 motor.

Claims (2)

A cooling system that cools a plurality of power conversion circuits including an inverter that converts power to drive an electric motor for traveling on a vehicle,
A plurality of heat exchange units arranged in parallel in the circulation path of the cooling medium and cooling each of the plurality of power conversion circuits by heat exchange with the cooling medium;
A plurality of flow rate control valves for adjusting the flow rate of the cooling medium of each of the plurality of heat exchange units;
Relationship storage means for predetermining a relationship between a vehicle state and the opening / closing states of the plurality of flow control valves and storing the relationship as a valve opening / closing state setting relationship;
A valve that controls the opening and closing of the plurality of flow rate control valves so as to be in the open / closed state of the plurality of flow rate control valves obtained by applying the valve opening / closing state setting relationship stored in the relationship storage means to the vehicle state Opening and closing control means;
With cooling system. The cooling system of claim 1,
The vehicle includes an internal combustion engine, a first electric motor that can also be driven as a generator, a first inverter for driving the first electric motor, an output shaft of the internal combustion engine, and the first electric motor. A planetary gear mechanism in which three rotating elements are connected to a rotating shaft and a driving shaft connected to an axle; a second electric motor that can also be driven as a generator that outputs power to the driving shaft; A second inverter for driving the electric motor, a battery, and a boost converter that boosts the power of the battery and supplies the boosted power to the first inverter and the second inverter,
The plurality of power conversion circuits are the first inverter, the second inverter, and the boost converter,
The valve open / close state setting relationship is such that when the vehicle state is cranking for cranking to start the internal combustion engine, the plurality of flow rate control valves heat the second inverter and the boost converter. During high-speed cruising where the flow rate of the cooling medium to the exchange unit decreases and the flow rate of the cooling medium to the heat exchange unit that cools the first inverter increases and the vehicle is cruising at a high vehicle speed. The plurality of flow rate control valves reduce the flow rate of the cooling medium to the heat exchange unit that cools the second inverter and the boost converter, and the cooling medium to the heat exchange unit that cools the first inverter. When the vehicle is accelerating at a low vehicle speed when the vehicle is accelerating at a low vehicle speed, the plurality of flow control valves are connected to the first inverter. An opening / closing state in which the flow rate of the cooling medium to the heat exchanging unit for cooling the boost converter is reduced and the flow rate of the cooling medium to the heat exchanging unit for cooling the second inverter is increased, and the vehicle state is higher than the medium vehicle speed. When the vehicle is accelerating at medium to high vehicle speed, the plurality of flow rate control valves reduce the flow rate of the cooling medium to the heat exchange unit that cools the first inverter and the second inverter, and When the vehicle is in a decelerating state where the flow rate of the cooling medium to the heat exchanging unit to be cooled is increased and the vehicle is decelerating, the plurality of flow rate control valves connect the first inverter and the second inverter. The relationship is such that the flow rate of the cooling medium to the heat exchanging portion to be cooled is reduced and the flow rate of the cooling medium to the heat exchanging portion to cool the boost converter is increased or closed.
Cooling system.

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