Vehicle temperature control system

Abstract

Provided is a vehicle temperature regulation system that can suppress an increase in friction loss of a rotating electric machine and a gear case. The vehicle temperature regulation system includes: a first temperature regulation circuit that performs temperature regulation of an electric motor and a transmission; a second temperature regulation circuit that performs temperature regulation of a power conversion device; a heat exchanger that performs heat exchange between a first temperature regulation medium and a second temperature regulation medium; and a control device. The second temperature regulation circuit includes a valve device that regulates the flow rate of the second temperature regulation medium to the heat exchanger, the power conversion device includes a PDU that supplies electric power to the electric motor, and the control device controls the carrier frequency of the PDU and the valve device based on the temperature of the first temperature regulation medium. In a case where the temperature of the first temperature regulation medium is lower than a prescribed value, the carrier frequency is reduced compared to a case where the temperature of the first temperature regulation medium is equal to or higher than the prescribed value, and the valve device is controlled to reduce the flow rate of the second temperature regulation medium to the heat exchanger.

Description

TECHNICAL FIELD

[0001] The present application relates to a temperature adjustment system for a vehicle. BACKGROUND

[0002] In recent years, as a specific countermeasure against global climate change, initiatives toward realization of a low-carbon society or a decarbonized society are very active. Also for vehicles, there is a strong demand for reduction in CO2 emissions, and electrification of drive sources is rapidly progressing. Specifically, development of vehicles (hereinafter also referred to as "electric vehicles") such as electric vehicles or hybrid electric vehicles, which have a motor (hereinafter also referred to as "rotary electric machine") as a drive source and a storage battery as a secondary battery capable of supplying electric power to the motor, is being promoted. In addition, such electric vehicles also have a power conversion device that performs conversion of electric power, a gear box that constitutes a transmission device, and the like. Furthermore, a temperature adjustment system for a vehicle that performs temperature adjustment of the rotary electric machine, the power conversion device, and the like is mounted in such an electric vehicle.

[0003] For example, in Patent Literature 1, a temperature adjustment system for a vehicle is disclosed, which has a circulation path L through which engine oil circulates to cool a motor M, a circulation path F through which cooling water circulates to cool an inverter U, and a heat exchange portion (oil cooler C) that performs heat exchange between the cooling water flowing in the circulation path F and the engine oil flowing in the circulation path L. In addition, in Patent Literature 2, a control technique is disclosed in which, in a case where the temperature of the engine oil is lower than a prescribed value, the discharge amount of an electric water pump is reduced to increase the temperature of the engine oil, and on the other hand, in a case where the temperature of the engine oil is equal to or higher than the prescribed value, the discharge amount of the electric water pump is changed in proportion to the vehicle speed to decrease the temperature of the engine oil.

[0004]

Prior Art Documents

[0005]

Patent Literature

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2001-238406

[0007] Patent Literature 2: Japanese Patent Application Publication No. 2019-103334 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] If the temperature of engine oil that lubricates the rotary electric machine and the gear box is low, the friction loss of the rotary electric machine and the gear box increases. Therefore, when the temperature of engine oil that lubricates the rotary electric machine and the gear box is relatively low, it is desirable to warm up the engine oil as early as possible, but in the related art, there is room for improvement in this regard.

[0010] Provided is a vehicle temperature regulation system capable of suppressing an increase in friction loss of a rotating electric machine and a gear box.

[0011] Means for solving the problem

[0012] Provided is a vehicle temperature regulation system including:

[0013] a first temperature regulation circuit provided with a first pump and configured to regulate the temperature of a rotating electric machine and a gear box included in a vehicle;

[0014] a second temperature regulation circuit provided with a second pump and configured to regulate the temperature of a power conversion device included in the vehicle;

[0015] a heat exchanger configured to perform heat exchange between a first temperature regulation medium circulating in the first temperature regulation circuit and a second temperature regulation medium circulating in the second temperature regulation circuit; and

[0016] a control device,

[0017] the first temperature regulation circuit includes a first temperature sensor configured to detect the temperature of the first temperature regulation medium,

[0018] the second temperature regulation circuit includes:

[0019] a radiator configured to perform heat exchange between the second temperature regulation medium and outside air;

[0020] a first branch flow path of the second temperature regulation medium that bypasses the heat exchanger;

[0021] a second branch flow path of the second temperature regulation medium that passes through the heat exchanger; and

[0022] a flow rate regulation valve configured to regulate the flow rate of the second temperature regulation medium to the second branch flow path;

[0023] the power conversion device is configured to include an inverter configured to supply electric power to the rotating electric machine, and is configured to be able to change the carrier frequency of the inverter according to the control of the control device,

[0024] the control device is configured to be able to control the carrier frequency and the flow rate regulation valve based on the temperature of the first temperature regulation medium detected by the first temperature sensor,

[0025] The control device reduces the carrier frequency and controls the flow rate adjustment valve to reduce the flow rate to the second branch flow path when the temperature of the first temperature regulating medium is lower than a prescribed value, as compared to when the temperature of the first temperature regulating medium is equal to or higher than the prescribed value.

[0026] Effects of Invention

[0027] According to the present application, an increase in frictional loss of the rotating electric machine and the gear box can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a block diagram of a vehicle equipped with the vehicle temperature regulating system of the present embodiment.

[0029] Figure 2 is a graph showing one example of a carrier frequency that the control device of the present embodiment can set.

[0030] Figure 3 is a flowchart showing one example of a process performed by the control device of the present embodiment.

[0031] BRIEF DESCRIPTION OF REFERENCE NUMERALS

[0032] 10 vehicle temperature regulating system

[0033] 20 electric motor (rotating electric machine)

[0034] 40 speed changer (gear box)

[0035] 50 power conversion device

[0036] 51 PDU (inverter)

[0037] 61 first temperature regulating circuit

[0038] 61a first temperature sensor

[0039] 611 first pump

[0040] 62 second temperature regulating circuit

[0041] 62a second temperature sensor

[0042] 620b1 first branch flow path

[0043] 620b2 second branch flow path

[0044] 621 second pump

[0045] 622 radiator

[0046] 626 valve device (flow rate adjustment valve)

[0047] 63 heat exchanger

[0048] ECU control device

[0049] V vehicle DETAILED DESCRIPTION

[0050] Hereinafter, one embodiment of a vehicle equipped with a vehicle temperature adjustment system of the present application will be described based on the drawings. Note that the drawings are observed from the orientation of the symbols.

[0051]

Vehicle

[0052] First, the configuration of the vehicle of the present embodiment will be described with reference to Figure 1 The vehicle of the present embodiment will be described. As shown in Figure 1 The vehicle V of the present embodiment is provided with an internal combustion engine ICE, a control device ECU, a vehicle temperature adjustment system 10, an electric motor 20, a generator 30, a transmission device 40, a power conversion device 50, and a temperature adjustment circuit 60.

[0053] The electric motor 20 is a rotary electric motor that outputs power for driving the vehicle V by electric power accumulated in an electric storage device (not shown) mounted on the vehicle V or electric power generated by the generator 30. The electric motor 20 can also generate electric power by the kinetic energy of the drive wheels of the vehicle V at the time of braking of the vehicle V, and charge the aforementioned electric storage device. A third temperature sensor 20a that detects the temperature of the electric motor 20 is provided in the electric motor 20. The third temperature sensor 20a outputs the detected value of the temperature of the electric motor 20 to the control device ECU.

[0054] The generator 30 is a rotary electric motor that generates electric power by the power of the internal combustion engine ICE, and charges the aforementioned electric storage device, or supplies electric power to the electric motor 20.

[0055] The transmission device 40 is provided between the electric motor 20 and the drive wheels of the vehicle V, and is a power transmission device configured to be able to transmit power between the electric motor 20 and the drive wheels. For example, the transmission device 40 is a gear-type power transmission device that reduces the power output from the electric motor 20 and transmits the power to the drive wheels.

[0056] The electric power conversion device 50 is provided with a power drive unit (PDU) 51 that converts electric power output from the aforementioned electric storage device from direct current to alternating current and controls input and output electric power of the motor 20 and the generator 30, and a voltage control unit (VCU) not shown that steps up electric power output from the aforementioned electric storage device as necessary. Specifically, the PDU 51 is an inverter that can convert direct current output from the electric storage device to alternating current and supply it to the motor 20. Control of the PDU 51 by the control device ECU uses pulse width modulation (PWM) control.

[0057] The electric power conversion device 50 is configured to be able to change a carrier frequency of the PDU 51 (i.e., the inverter) in accordance with control by the control device ECU. In addition, the VCU can also step down electric power generated by the motor 20 in the case where the motor 20 generates electric power at the time of braking of the vehicle V. A fourth temperature sensor 50a that detects a temperature of the electric power conversion device 50 is provided in the electric power conversion device 50. The fourth temperature sensor 50a outputs a detected value of the temperature of the electric power conversion device 50 to the control device ECU.

[0058] The temperature regulation circuit 60 is provided with a first temperature regulation circuit 61 that circulates a first temperature regulation medium TCM1 that is non-conductive and performs temperature regulation of the motor 20, the generator 30, and the transmission device 40, a second temperature regulation circuit 62 that circulates a second temperature regulation medium TCM2 that is conductive and performs temperature regulation of the electric power conversion device 50, and a heat exchanger 63 that performs heat exchange between the first temperature regulation medium TCM1 and the second temperature regulation medium TCM2. The first temperature regulation medium TCM1 that is non-conductive is, for example, engine oil called automatic transmission fluid (ATF) that is able to perform lubrication and temperature regulation of the motor 20, the generator 30, and the transmission device 40. The second temperature regulation medium TCM2 that is conductive is, for example, cooling water called long life coolant (LLC).

[0059] The first pump (MOP) 611 is a mechanical pump that is driven by power of the internal combustion engine ICE and rotational force of a not-shown axle of the vehicle V. The reservoir 612 stores the first temperature regulation medium TCM1 that is circulated in the first temperature regulation circuit 61. The reservoir 612 is, for example, an oil pan that is provided to a bottom portion of a housing (not shown) that houses the motor 20, the generator 30, and the transmission device 40.

[0060] Further, the first temperature adjustment circuit 61 has a pressurized delivery flow path 610a provided with the first pump 611, a first branch flow path 610b1 provided with the motor 20 and the generator 30, a second branch flow path 610b2 provided with the transmission 40, and a branch portion 613 branching to the first branch flow path 610b1 or the second branch flow path 610b2.

[0061] The pressurized delivery flow path 610a passes through the first pump 611, and an end portion on an upstream side thereof is connected to the reservoir portion 612, and an end portion on a downstream side thereof is connected to the branch portion 613. The first branch flow path 610b1 passes through the motor 20 and the generator 30, and an end portion on an upstream side thereof is connected to the branch portion 613, and an end portion on a downstream side thereof is connected to the reservoir portion 612. The second branch flow path 610b2 passes through the transmission 40, and an end portion on an upstream side thereof is connected to the branch portion 613, and an end portion on a downstream side thereof is connected to the reservoir portion 612.

[0062] In the first temperature adjustment circuit 61, the heat exchanger 63 is disposed at a position in the first branch flow path 610b1 that is more upstream than the motor 20 and the generator 30. Therefore, in the first temperature adjustment circuit 61, a first flow path and a second flow path are formed in parallel, in the first flow path, the first temperature adjustment medium TCM1 pressurized and delivered from the first pump 611 passes through the first branch flow path 610b1 from the branch portion 613, is cooled by heat exchange with the second temperature adjustment medium TCM2 in the heat exchanger 63, is supplied to the motor 20 and the generator 30 to lubricate and temperature-adjust the motor 20 and the generator 30, and is stored in the reservoir portion 612, in the second flow path, the first temperature adjustment medium TCM1 pressurized and delivered from the first pump 611 passes through the second branch flow path 610b2 from the branch portion 613, is supplied to the transmission 40 to lubricate and temperature-adjust the transmission 40, and is stored in the reservoir portion 612, in the first temperature adjustment circuit 61, the first temperature adjustment medium TCM1 stored in the reservoir portion 612 flows through the pressurized delivery flow path 610a to be supplied to the first pump 611, whereby the first temperature adjustment medium TCM1 circulates in the first temperature adjustment circuit 61.

[0063] In the present embodiment, the first branch flow path 610b1 and the second branch flow path 610b2 are formed such that the flow rate of the first temperature adjustment medium TCM1 flowing in the first branch flow path 610b1 is greater than the flow rate of the first temperature adjustment medium TCM1 flowing in the second branch flow path 610b2.

[0064] A first temperature sensor 61a that detects the temperature of the first temperature control medium TCM1 circulating in the first temperature control circuit 61 is provided in the first temperature control circuit 61. In the present embodiment, the first temperature sensor 61a is provided in the reservoir portion 612 that is an oil pan, and detects the temperature of the first temperature control medium TCM1 stored in the reservoir portion 612. The first temperature sensor 61a outputs the detected value of the temperature of the first temperature control medium TCM1 stored in the reservoir portion 612 to the control device ECU.

[0065] In addition, the first temperature control circuit 61 also has a pressure regulating circuit 610c provided with a pressure regulating valve 619. The end portion on the upstream side of the pressure regulating circuit 610c is connected to the reservoir portion 612, and the end portion on the downstream side is connected to the pressurized delivery flow path 610a at a position that is more downstream than the first pump 611. The pressure regulating valve 619 can be a check valve, or an electromagnetic valve such as a solenoid valve. When the hydraulic pressure of the first temperature control medium TCM1 pressurized and delivered from the first pump 611 is equal to or greater than a prescribed pressure, the pressure regulating valve 619 enters an open state, and a portion of the first temperature control medium TCM1 pressurized and delivered from the first pump 611 returns to the reservoir portion 612. Thereby, the hydraulic pressure of the first temperature control medium TCM1 flowing in the first branch flow path 610b1 and the second branch flow path 610b2 is maintained to be equal to or less than the prescribed pressure.

[0066] A second pump (EWP) 621, a radiator 622, and a reservoir tank 623 are provided in the second temperature control circuit 62. The second pump 621 is, for example, an electric pump that is driven by electric power accumulated in the above-described electric power storage device. In addition, a rotational speed sensor 621a that detects the rotational speed of the second pump 621 is attached to the second pump 621. The rotational speed sensor 621a outputs the detected value of the rotational speed of the second pump 621 to the control device ECU.

[0067] The radiator 622 is disposed in the front portion of the vehicle V, and is a heat sink device that cools the second temperature control medium TCM2 by the running wind when the vehicle V is running. The reservoir tank 623 is a tank that temporarily stores the second temperature control medium TCM2 circulating in the second temperature control circuit 62. Even in the case where cavitation occurs in the second temperature control medium TCM2 circulating in the second temperature control circuit 62, the cavitation occurring in the second temperature control medium TCM2 is eliminated by the second temperature control medium TCM2 circulating in the second temperature control circuit 62 being temporarily stored in the reservoir tank 623.

[0068] The second temperature adjustment circuit 62 has a branch portion 624 and a merging portion 625. The second temperature adjustment circuit 62 is provided with a storage tank 623, a second pump 621, and a radiator 622 in this order from the upstream side. In addition, the second temperature adjustment circuit 62 also has a pressurized delivery flow path 620a. The pressurized delivery flow path 620a passes through the storage tank 623, the second pump 621, and the radiator 622, and its upstream end is connected to the merging portion 625, and its downstream end is connected to the branch portion 624. The second temperature adjustment medium TCM2 stored in the storage tank 623 is pressurized and delivered by the second pump 621 through the pressurized delivery flow path 620a, and is cooled by the radiator 622.

[0069] In addition, the second temperature adjustment circuit 62 also has a first branch flow path 620b1 provided with the power conversion device 50 and a second branch flow path 620b2 provided with the heat exchanger 63. The first branch flow path 620b1 passes through the power conversion device 50, and its upstream end is connected to the branch portion 624, and its downstream end is connected to the merging portion 625. The second branch flow path 620b2 passes through the heat exchanger 63, and its upstream end is connected to the branch portion 624, and its downstream end is connected to the merging portion 625.

[0070] In the present embodiment, a valve device 626 as a flow rate adjustment valve is provided in a portion of the second branch flow path 620b2 that is upstream of the heat exchanger 63. The valve device 626 can be an ON-OFF valve that switches the second branch flow path 620b2 to either of a fully open state and a fully closed state, or can be a variable flow rate valve that can adjust the flow rate of the second temperature adjustment medium TCM2 flowing in the second branch flow path 620b2. The valve device 626 is controlled by the control device ECU.

[0071] The second temperature adjustment medium TCM2, which is pressurized and conveyed in the pressurized-conveyance flow path 620a by the second pump 621 and is cooled by the radiator 622, is branched to the first branched flow path 620bl and the second branched flow path 620b2 at the branch portion 624. The second temperature adjustment medium TCM2 flowing in the first branched flow path 620bl cools the power conversion device 50 and merges with the second branched flow path 620b2 and the pressurized-conveyance flow path 620a at the merging portion 625. The second temperature adjustment medium TCM2 flowing in the second branched flow path 620b2 cools the first temperature adjustment medium TCM1 by exchanging heat with the first temperature adjustment medium TCM1 in the heat exchanger 63 and merges with the first branched flow path 620bl and the pressurized-conveyance flow path 620a at the merging portion 625. The second temperature adjustment medium TCM2 flowing in the first branched flow path 620bl merges with the second temperature adjustment medium TCM2 flowing in the second branched flow path 620b2 at the merging portion 625, flows in the pressurized-conveyance flow path 620a, and is temporarily stored in the storage tank 623. Also, the second temperature adjustment medium TCM2 stored in the storage tank 623 is supplied again to the second pump 621 through the pressurized-conveyance flow path 620a, whereby the second temperature adjustment medium TCM2 circulates in the second temperature adjustment circuit 62.

[0072] In the present embodiment, the first branched flow path 620bl and the second branched flow path 620b2 are formed so that the flow rate of the second temperature adjustment medium TCM2 flowing in the first branched flow path 620bl is larger than the flow rate of the second temperature adjustment medium TCM2 flowing in the second branched flow path 620b2.

[0073] The second temperature adjustment circuit 62 is provided with a second temperature sensor 62a that detects the temperature of the second temperature adjustment medium TCM2 circulating in the second temperature adjustment circuit 62. In the present embodiment, the second temperature sensor 62a is provided in the pressurized-conveyance flow path 620a between the radiator 622 and the branch portion 624 and detects the temperature of the second temperature adjustment medium TCM2 discharged from the radiator 622. The second temperature sensor 62a outputs the detected value of the temperature of the second temperature adjustment medium TCM2 discharged from the radiator 622 to the control device ECU.

[0074] In the first temperature adjustment circuit 61, if the temperature of the first temperature adjustment medium TCM1 stored in the storage portion 612 after the motor 20, the generator 30, and the transmission 40 are cooled is about 100 [°C], the first temperature adjustment medium TCM1 at about 100 [°C] is supplied to the heat exchanger 63.

[0075] On the other hand, in the second temperature adjustment circuit 62, if the temperature of the second temperature adjustment medium TCM2 cooled by the radiator 622 is about 40 [°C], since the second temperature adjustment medium TCM2 supplied to the heat exchanger 63 does not pass through the electric power conversion device 50 as the temperature adjustment device, the second temperature adjustment medium TCM2 at about 40 [°C] is supplied to the heat exchanger 63.

[0076] In this case, the heat exchanger 63 performs heat exchange between the first temperature adjustment medium TCM1 at about 100 [°C] supplied to the heat exchanger 63 and the second temperature adjustment medium TCM2 at about 40 [°C]. Then, the first temperature adjustment medium TCM1 at about 80 [°C] is discharged from the heat exchanger 63 to the downstream side of the first branch flow path 610b1 of the first temperature adjustment circuit 61, and the second temperature adjustment medium TCM2 at about 70 [°C] is discharged to the downstream side of the second branch flow path 620b2 of the second temperature adjustment circuit 62.

[0077] Thus, the first temperature adjustment medium TCM1 is cooled in the heat exchanger 63, and therefore the temperature adjustment circuit 60 can cool the first temperature adjustment medium TCM1 without providing a radiator for cooling the first temperature adjustment medium TCM1. Therefore, the temperature adjustment circuit 60 can cool the first temperature adjustment medium TCM1 flowing in the first temperature adjustment circuit 61 and the second temperature adjustment medium TCM2 flowing in the second temperature adjustment circuit 62 with one radiator 622, and thus can be downsized.

[0078] The control device ECU is realized by, for example, an electronic control unit (ECU) provided with a processor that performs various kinds of operation, a storage device that stores various kinds of information, an input / output device that controls input and output of data to and from the inside and outside of the control device ECU, and the like, and performs unified control of the vehicle V as a whole. The control device ECU can be realized by one ECU or by a plurality of ECUs. The control device ECU controls, for example, the internal combustion engine ICE, the electric power conversion device 50, the second pump 621, the valve device 626, and the like.

[0079] Generally, the first temperature adjustment medium TCM1 has a higher viscosity when the temperature thereof is lower. Also, if the viscosity of the first temperature adjustment medium TCM1 is higher, the friction loss generated in the electric motor 20 and the transmission device 40 increases, and the output efficiency of the electric motor 20 and the transmission device 40 decreases. Therefore, for example, in a case where the first temperature adjustment medium TCM1 is at a low temperature (for example, the temperature of the first temperature adjustment medium TCM1 is lower than a predetermined value) immediately after the electric motor 20 and the generator 30 are started, it is preferable that the first temperature adjustment medium TCM1 is not cooled (that is, the first temperature adjustment medium TCM1 is warmed up).

[0080] Thus, the control device ECU controls the valve device 626 based on the first temperature detected by the first temperature sensor 61a so as to adjust the temperature of the first temperature regulating medium TCM1. The control device ECU adjusts the flow rate of the second temperature regulating medium TCM2 to the second branch flow path 620b2 provided with the heat exchanger 63 through the valve device 626, and can control the heat exchange of the first temperature regulating medium TCM1 and the second temperature regulating medium TCM2 via the heat exchanger 63.

[0081] Specifically, the control device ECU controls the valve device 626 so that the flow rate of the second temperature regulating medium TCM2 to the second branch flow path 620b2 is smaller than when the temperature of the first temperature regulating medium TCM1 is equal to or higher than the prescribed value, when the temperature of the first temperature regulating medium TCM1 is lower than the prescribed value (e.g., 50 [°C]). In other words, the control device ECU controls the valve device 626 so that the flow rate of the second temperature regulating medium TCM2 to the first branch flow path 620b1 is larger than when the temperature of the first temperature regulating medium TCM1 is equal to or higher than the prescribed value, when the temperature of the first temperature regulating medium TCM1 is lower than the prescribed value. Note that the prescribed value is, for example, set in advance by the manufacturer of the control device ECU or the like.

[0082] Thus, when the temperature of the first temperature regulating medium TCM1 is lower than the prescribed value, the heat exchange of the first temperature regulating medium TCM1 and the second temperature regulating medium TCM2 via the heat exchanger 63 is suppressed by reducing the flow rate of the second temperature regulating medium TCM2 to the second branch flow path 620b2 provided with the heat exchanger 63. Thereby, the heat of the first temperature regulating medium TCM1 is prevented from being transferred to the second temperature regulating medium TCM2, and the temperature decrease of the first temperature regulating medium TCM1 is suppressed. Therefore, the increase in the friction loss of the motor 20 and the transmission device 40 caused by the low temperature of the first temperature regulating medium TCM1 is suppressed.

[0083] Also, the control device ECU controls the carrier frequency of the PDU 51 (i.e., the inverter) based on the temperature of the first temperature regulating medium TCM1 detected by the first temperature sensor 61a. Specifically, the control device ECU reduces the carrier frequency of the PDU 51 when the temperature of the first temperature regulating medium TCM1 is lower than the prescribed value, compared to when the temperature of the first temperature regulating medium TCM1 is equal to or higher than the prescribed value.

[0084] Thus, in the case where the temperature of the first temperature control medium TCM1 is lower than the prescribed value, by reducing the carrier frequency of the PDU 51, the loss of the electric motor 20 can be increased, and the amount of heat generated by the electric motor 20 along with the loss can be increased. Therefore, by the heat of the electric motor 20, the first temperature control medium TCM1 can be rapidly warmed up, and the increase in the frictional loss of the electric motor 20 and the transmission 40 due to the low temperature of the first temperature control medium TCM1 can be suppressed.

[0085] Also, the control device ECU can control the second pump 621 based on the temperature of the first temperature control medium TCM1 detected by the first temperature sensor 61a. Specifically, the control device ECU can reduce the flow rate of the second pump 621 in the case where the temperature of the first temperature control medium TCM1 is lower than the prescribed value, as compared with the case where the temperature of the first temperature control medium TCM1 is the prescribed value or more.

[0086] That is, when the carrier frequency of the PDU 51 is low, the amount of heat generated by the PDU 51 also becomes small, and therefore even if the flow rate of the second pump 621 is reduced, the temperature of the second temperature control medium TCM2 does not easily rise. Therefore, in the case where the temperature of the first temperature control medium TCM1 is lower than the prescribed value, by reducing the flow rate of the second pump 621, the energy (for example, electric power) required for driving the second pump 621 can be reduced while suppressing the rise in the temperature of the second temperature control medium TCM2.

[0087]

Control Device Control Example of Valve Device, Carrier Frequency, and Second Pump

[0088] Next, a specific control example of the control device ECU on the valve device 626, the carrier frequency of the PDU 51, and the second pump 621 will be described with reference to Figure 2 , and Figure 3 .

[0089] First, one example of the carrier frequency of the PDU 51 that the control device ECU can set will be described. In the present embodiment, the control device ECU is configured to be able to set fa [Hz], fb [Hz], and fc [Hz] shown in Figure 2 as the carrier frequency of the PDU 51. These carrier frequencies are higher in the order of fa [Hz] < fb [Hz] < fc [Hz].

[0090] As described above, the lower the carrier frequency of the PDU 51, the greater the loss of the motor 20, and thus the lower the efficiency of the motor 20. In other words, the higher the carrier frequency of the PDU 51, the higher the efficiency of the motor 20. For example, let the efficiency of the motor 20 when the carrier frequency is fa [Hz] be EMa, the efficiency of the motor 20 when the carrier frequency is fb [Hz] be EMb, and the efficiency of the motor 20 when the carrier frequency is fc [Hz] be EMc, then EMa < EMb < EMc.

[0091] On the other hand, the lower the carrier frequency of the PDU 51, the higher the efficiency of the PDU 51. For example, let the efficiency of the PDU 51 when the carrier frequency is fa [Hz] be EPa, the efficiency of the PDU 51 when the carrier frequency is fb [Hz] be EPb, and the efficiency of the PDU 51 when the carrier frequency is fc [Hz] be EPc, then EPa > EPb > EPc.

[0092] With the relationship of the efficiencies of the motor 20 and the PDU 51 with respect to the carrier frequency of the PDU 51 as described above, in the present embodiment, even if the carrier frequency of the PDU 51 is set to any one of fa [Hz], fb [Hz], and fc [Hz], the total efficiency of both the motor 20 and the PDU 51 is substantially constant as shown in FIG. 6. In other words, fa [Hz], fb [Hz], and fc [Hz], at which the total efficiency of both the motor 20 and the PDU 51 is substantially constant, are stored in advance in the control device ECU as the carrier frequencies that can be set by the control device ECU. Also, in the control device ECU, information indicating the flow rate of the second pump 621 to be set when set to each of the carrier frequencies is stored in advance in correspondence with each of the carrier frequencies. Figure 2

[0093] Next, one example of the process performed by the control device ECU will be described. For example, the control device ECU sets fc [Hz] as the initial value of the carrier frequency when the ignition power of the vehicle V is turned on, and starts the drive of the PDU 51 (i.e., the power conversion device 50) and the drive of the second pump 621 in a manner such that the flow rate of the second pump 621 becomes the flow rate corresponding to fc [Hz]. Then, the control device ECU performs the process shown in FIG. 7. Figure 3

[0094] In the process shown in FIG. 7, the control device ECU first determines whether the carrier frequency of the PDU 51 is fc [Hz] (step S101). If the carrier frequency is not fc [Hz] (NO in step S101), the control device ECU determines whether the carrier frequency is fb [Hz] (step S102). If the carrier frequency is not fb [Hz] (NO in step S102), the control device ECU determines whether the carrier frequency is fa [Hz] (step S103). If the carrier frequency is not fa [Hz] (NO in step S103), the control device ECU determines that the carrier frequency is not any one of fa [Hz], fb [Hz], and fc [Hz] (step S104), and ends the process. Figure 3 ​​In this case, the control device ECU first acquires the temperature of the first temperature control medium TCM1 detected by the first temperature sensor 61a (step S301), and determines whether the temperature of the first temperature control medium TCM1 is lower than 50 [°C] (step S302). If the control device ECU determines that the temperature of the first temperature control medium TCM1 is lower than 50 [°C] (step S302: YES), it closes the valve device 626 (step S303), and proceeds to step S304. By closing the valve device 626, the flow rate of the second temperature control medium TCM2 to the second branch flow passage 620b2 provided with the heat exchanger 63 can be reduced, and the heat exchange between the first temperature control medium TCM1 and the second temperature control medium TCM2 via the heat exchanger 63 can be suppressed. Therefore, the heat of the first temperature control medium TCM1 can be prevented from being transferred to the second temperature control medium TCM2, and the temperature decrease of the first temperature control medium TCM1 can be suppressed.

[0095] Next, the control device ECU determines whether the internal combustion engine ICE is being driven (step S304). If the control device ECU determines that the internal combustion engine ICE is being driven (step S304: YES), it sets the carrier frequency of the PDU 51 to fa [Hz] (i.e., the minimum value among the settable carrier frequencies), drives the PDU 51, and drives the second pump 621 so that the flow rate of the second pump 621 becomes the flow rate corresponding to fa [Hz] (step S305), and then returns to step S301. Here, the flow rate of the second pump 621 corresponding to fa [Hz] is smaller than the flow rates of the second pump 621 corresponding to fb [Hz] and fc [Hz], respectively.

[0096] That is, the control device ECU, in the case where the temperature of the first temperature control medium TCM1 is lower than 50 [°C] and the internal combustion engine ICE is being driven, reduces the carrier frequency of the PDU 51 as much as possible, makes the PCU 50 operate at high efficiency, and on the other hand, makes the electric motor 20 operate at low efficiency. Thereby, the decrease in the total efficiency of both the electric motor 20 and the PDU 51 can be suppressed, and the loss of the electric motor 20 (i.e., the heat generation of the electric motor 20) can be increased, and the first temperature control medium TCM1 can be warmed up by the heat of the electric motor 20. In addition, the control device ECU, when the carrier frequency of the PDU 51 is reduced like this and the PCU 50 operates at high efficiency, i.e., when the heat generation of the PCU 50 is small, reduces the flow rate of the second pump 621, and thereby the energy (e.g., electric power) required for driving the second pump 621 can be reduced while suppressing the temperature increase of the second temperature control medium TCM2.

[0097] On the other hand, in step S304, if the control device ECU determines that the internal combustion engine ICE is not driven (step S304: No), the carrier frequency of the PDU 51 is set to fb [Hz] (i.e., the middle value among the settable carrier frequencies) to drive the PDU 51, and the second pump 621 is driven in such a manner that the flow rate of the second pump 621 becomes the flow rate corresponding to fb [Hz] (step S306), after which the routine returns to step S301. Here, the flow rate of the second pump 621 corresponding to fb [Hz] is larger than the flow rate of the second pump 621 corresponding to fa [Hz] and smaller than the flow rate of the second pump 621 corresponding to fc [Hz].

[0098] That is, the control device ECU needs to ensure the driving force of the vehicle V by the electric motor 20 alone in the case where the temperature of the first temperature control medium TCM1 is lower than 50 [°C] and the internal combustion engine ICE is not driven (e.g., during EV running of the vehicle V), and thus the carrier frequency of the PDU 51 is not reduced to the carrier frequency applied when the process of step S305 is executed, although the carrier frequency of the PDU 51 is reduced.

[0099] In addition, generally, if the carrier frequency of the PDU 51 is reduced to drive the electric motor 20, the driving sound of the electric motor 20 becomes large. Therefore, it is assumed that, in the case where the internal combustion engine ICE is not driven (e.g., during EV running of the vehicle V), if the carrier frequency of the PDU 51 is reduced to fa [Hz], the noise and vibration (NV) characteristics of the vehicle V deteriorate due to the driving sound of the electric motor 20, and the marketability of the vehicle V can decrease. Therefore, in the present embodiment, as described above, in the case where the temperature of the first temperature control medium TCM1 is lower than 50 [°C] and the internal combustion engine ICE is driven, the carrier frequency of the PDU 51 is reduced and the flow rate of the second pump 621 is reduced as compared with the case where the temperature of the first temperature control medium TCM1 is lower than 50 [°C] and the internal combustion engine ICE is stopped (i.e., not driven). Thus, it is possible to suppress the deterioration of the NV characteristics of the vehicle V due to the driving sound of the electric motor 20, and it is possible to promote the temperature increase of the first temperature control medium TCM1 using the heat of the electric motor 20.

[0100] In addition, if the control device ECU determines that the temperature of the first temperature control medium TCM1 is not lower than 50 [°C] in step S302 (step S302: No), the valve device 626 is opened (step S307). Then, the control device ECU drives the PDU 51 with the carrier frequency of the PDU 51 set to fc [Hz] (i.e., the maximum value among the settable carrier frequencies), and drives the second pump 621 in such a manner that the flow rate of the second pump 621 becomes the flow rate corresponding to fc [Hz] (step S308), after which the routine returns to step S301.

[0101] That is, the control device ECU increases the flow rate of the second temperature regulating medium TCM2 to the second branch flow path 620b2 provided with the heat exchanger 63 by opening the valve device 626 when the temperature of the first temperature regulating medium TCM1 is 50 [°C] or higher. Thereby, heat exchange between the first temperature regulating medium TCM1 and the second temperature regulating medium TCM2 via the heat exchanger 63 is promoted, and the temperature increase of the first temperature regulating medium TCM1 can be suppressed. Also, the control device ECU can reduce the heat generation amount of the motor 20 by operating the motor 20 at a high efficiency by increasing the carrier frequency of the PDU 51. Thereby, the temperature increase of the first temperature regulating medium TCM1 can be suppressed. In addition, increasing the carrier frequency of the PDU 51 increases the heat generation amount of the PDU 51, but the control device ECU can suppress the temperature increase of the second temperature regulating medium TCM2 by increasing the flow rate of the second pump 621 at this time.

[0102] As explained above, according to the present embodiment, when the temperature of the first temperature regulating medium TCM1 is lower than the prescribed value, the carrier frequency of the PDU 51 is reduced, and the valve device 626 is controlled to reduce the flow rate of the second temperature regulating medium TCM2 to the second branch flow path 620b2 provided with the heat exchanger 63, whereby the first temperature regulating medium TCM1 can be warmed up quickly, and the increase in the friction loss of the motor 20 and the transmission 40 caused by the low temperature of the first temperature regulating medium TCM1 can be suppressed.

[0103] The above describes one embodiment of the present application with reference to the drawings, but the present application is of course not limited to this embodiment. It is obvious that a person skilled in the art can conceive various modifications or corrections within the scope of the technical solution, and it should be understood that these modifications and corrections also belong to the technical scope of the present application. In addition, the constituent elements in the above embodiments can be arbitrarily combined within the scope of the gist of the present application.

[0104] For example, the structure in which the vehicle V is provided with the internal combustion engine ICE is described, but the vehicle V can also be an electric vehicle not provided with the internal combustion engine ICE.

[0105] In addition, the structure in which the power conversion device 50 and the heat exchanger 63 are arranged in parallel is described, but the structure in which the power conversion device 50 and the heat exchanger 63 are arranged in series can also be adopted. For example, the structure can be adopted in which the power conversion device 50 is arranged between the radiator 622 and the branch portion 624.

[0106] In addition, a grille shutter that adjusts the amount of outside air that comes into contact with the radiator 622 can be provided in front of the radiator 622. Thus, the ECU can control the cooling of the second temperature control medium TCM2 by the radiator 622 by opening and closing the grille shutter.

[0107] In the present specification, the following matters are described at least. In parentheses, corresponding constituent elements and the like in the above-described embodiments are shown as an example, but the present application is not limited thereto.

[0108] (1) A temperature control system for a vehicle (temperature control system for a vehicle 10) includes:

[0109] a first temperature control circuit (first temperature control circuit 61) that is provided with a first pump (first pump 611) and that controls the temperature of a rotating electric machine (electric motor 20) and a gear box (transmission 40) provided in a vehicle (vehicle V);

[0110] a second temperature control circuit (second temperature control circuit 62) that is provided with a second pump (second pump 621) and that controls the temperature of a power conversion device (power conversion device 50) provided in the vehicle;

[0111] a heat exchanger (heat exchanger 63) that performs heat exchange between a first temperature control medium circulating in the first temperature control circuit and a second temperature control medium circulating in the second temperature control circuit; and

[0112] a control device (control device ECU) that controls the first temperature control circuit and the second temperature control circuit,

[0113] the first temperature control circuit includes a first temperature sensor (first temperature sensor 61a) that detects the temperature of the first temperature control medium,

[0114] the second temperature control circuit includes:

[0115] a radiator (radiator 622) that performs heat exchange between the second temperature control medium and outside air;

[0116] a first branch flow path (first branch flow path 620b1) of the second temperature control medium that bypasses the heat exchanger;

[0117] a second branch flow path (second branch flow path 620b2) of the second temperature control medium that passes through the heat exchanger; and

[0118] a flow rate adjustment valve (valve device 626) that adjusts the flow rate of the second temperature control medium to the second branch flow path,

[0119] The electric power conversion device is configured to include an inverter (PDU 51) that supplies electric power to the rotary electric machine, and is configured to be able to change a carrier frequency of the inverter in accordance with control by the control device,

[0120] The control device is configured to be able to control the carrier frequency and the flow rate adjustment valve based on a temperature of the first temperature adjustment medium detected by the first temperature sensor,

[0121] The control device reduces the carrier frequency in a case where the temperature of the first temperature adjustment medium is lower than a prescribed value, as compared with a case where the temperature of the first temperature adjustment medium is the prescribed value or more, and controls the flow rate adjustment valve to reduce the flow rate to the second branch flow path.

[0122] According to (1), in a case where the temperature of the first temperature adjustment medium is lower than a prescribed value, the control device reduces the carrier frequency of the inverter that supplies electric power to the rotary electric machine, as compared with a case where the temperature of the first temperature adjustment medium is the prescribed value or more. Thereby, it is possible to increase the amount of heat generation that accompanies loss of the rotary electric machine in a case where the temperature of the first temperature adjustment medium is lower than the prescribed value. Also, in a case where the temperature of the first temperature adjustment medium is lower than the prescribed value, the control device controls the flow rate adjustment valve so that the flow rate of the second temperature adjustment medium to the second branch flow path through the heat exchanger is smaller than in a case where the temperature of the first temperature adjustment medium is the prescribed value or more, thereby it is possible to suppress heat exchange of the first temperature adjustment medium and the second temperature adjustment medium via the heat exchanger, that is, it is possible to suppress escape of heat of the first temperature adjustment medium to the second temperature adjustment medium. Therefore, it is possible to rapidly warm up the first temperature adjustment medium using heat of the rotary electric machine, and thereby it is possible to suppress an increase in frictional loss of the rotary electric machine and the gear case due to the temperature of the first temperature adjustment medium being low.

[0123] (2) The temperature adjustment system for a vehicle according to (1), wherein

[0124] The second pump is configured to be able to change the flow rate in accordance with control by the control device,

[0125] The control device also reduces the flow rate of the second pump in a case where the temperature of the first temperature adjustment medium is lower than the prescribed value, as compared with a case where the temperature of the first temperature adjustment medium is the prescribed value or more.

[0126] When the carrier frequency is low, the amount of heat generated by the inverter decreases, so the temperature of the second temperature regulating medium is unlikely to rise even if the flow rate of the second pump is reduced. According to (2), the control device reduces the flow rate of the second pump when the temperature of the first temperature regulating medium is lower than the prescribed value, compared to when the temperature of the first temperature regulating medium is equal to or higher than the prescribed value, so it is possible to reduce the energy required to drive the second pump while suppressing an increase in the temperature of the second temperature regulating medium.

[0127] (3) The temperature regulating system for a vehicle according to (1) or (2), wherein

[0128] The vehicle further includes an internal combustion engine (internal combustion engine ICE),

[0129] The control device reduces the carrier frequency and controls the flow rate adjusting valve to reduce the flow rate to the second branch flow path when the temperature of the first temperature regulating medium is lower than the prescribed value and the internal combustion engine is in operation, compared to when the temperature of the first temperature regulating medium is lower than the prescribed value and the internal combustion engine is stopped.

[0130] According to (3), it is possible to suppress deterioration of the NV (Noise and Vibration) characteristics of the vehicle caused by the driving sound of the rotary electric machine, and it is possible to promote warming of the first temperature regulating medium using the heat of the rotary electric machine.

Claims

1. A temperature adjustment system for a vehicle, comprising: a first temperature adjustment circuit provided with a first pump and adjusting the temperature of a rotating electric machine and a gear box provided in the vehicle; a second temperature adjustment circuit provided with a second pump and adjusting the temperature of a power conversion device provided in the vehicle; a heat exchanger performing heat exchange between a first temperature adjustment medium circulating in the first temperature adjustment circuit and a second temperature adjustment medium circulating in the second temperature adjustment circuit; and a control device, wherein the first temperature adjustment circuit is provided with a first temperature sensor detecting the temperature of the first temperature adjustment medium, the second temperature adjustment circuit is provided with: a radiator performing heat exchange between the second temperature adjustment medium and outside air; a first branch flow path of the second temperature adjustment medium bypassing the heat exchanger; a second branch flow path of the second temperature adjustment medium passing through the heat exchanger; and a flow rate adjustment valve adjusting the flow rate of the second temperature adjustment medium to the second branch flow path, the power conversion device is configured to include an inverter supplying electric power to the rotating electric machine and is configured to be able to change a carrier frequency of the inverter according to control by the control device, the control device is configured to be able to control the carrier frequency and the flow rate adjustment valve based on the temperature of the first temperature adjustment medium detected by the first temperature sensor, the control device reduces the carrier frequency and controls the flow rate adjustment valve to reduce the flow rate to the second branch flow path in a case where the temperature of the first temperature adjustment medium is lower than a prescribed value, as compared to a case where the temperature of the first temperature adjustment medium is the prescribed value or more.

2. The temperature adjustment system for a vehicle according to claim 1, wherein the second pump is configured to be able to change the flow rate according to control by the control device, and the control device further reduces the flow rate of the second pump in a case where the temperature of the first temperature adjustment medium is lower than the prescribed value, as compared to a case where the temperature of the first temperature adjustment medium is the prescribed value or more.

3. The temperature adjustment system for a vehicle according to claim 1 or 2, wherein the vehicle is further provided with an internal combustion engine, and the control device reduces the carrier frequency and controls the flow rate adjustment valve to reduce the flow rate to the second branch flow path in a case where the temperature of the first temperature adjustment medium is lower than the prescribed value and the internal combustion engine is in driving, as compared to a case where the temperature of the first temperature adjustment medium is lower than the prescribed value and the internal combustion engine is in stopping. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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