Patent Publication Number: US-2022219526-A1

Title: Vehicle temperature adjustment system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2021-003818 filed on Jan. 13, 2021. 
     TECHNICAL FIELD 
     The present disclosure relates to a vehicle temperature adjustment system mounted on an electric vehicle or the like. 
     BACKGROUND ART 
     In related art, there has been known a vehicle including a rotary electric machine and an electric power conversion device, such as an electric vehicle. In general, since the rotary electric machine and the electric power conversion device generate heat during operation, a vehicle temperature adjustment system which adjusts a temperature of the rotary electric machine and the power conversion device is mounted on a vehicle including the rotary electric machine and the power conversion device. 
     For example JP-A-2001-238406 discloses a vehicle temperature adjustment system including a circulation path L through which oil circulates and which cools an electric motor M, a circulation path F through which cooling water circulates and which cools an inverter U, and a heat exchange unit (oil cooler C) which performs heat exchange between the cooling water flowing through the circulation path F and the oil flowing through the circulation path L. A radiator R is provided in the circulation path F, and the cooling water flowing through the circulation path F is cooled by the radiator R. The oil flowing through the circulation path L is cooled by the heat exchange between the cooling water flowing through the circulation path F and the oil flowing through the circulation path L in the heat exchange unit (oil cooler C). Therefore, in the vehicle temperature adjustment system in JP-A-2001-238406, a radiator for cooling the oil is not necessary, and the cooling water flowing through the circulation path F and the oil flowing through the circulation path L can be cooled by one radiator, thereby miniaturizing the vehicle temperature adjustment system. 
     JP-A-2019-103334 discloses a vehicle cooling device which cools oil by reducing a discharge amount of an electric water pump so that a temperature of the oil is increased when the temperature of the oil is lower than a predetermined value, and changing the discharge amount of the electric water pump in proportion to a vehicle speed so that the temperature of the oil is decreased when the temperature of the oil is equal to or higher than the predetermined value. 
     In order to prevent friction loss of a rotary electric machine such as an electric motor, it is desirable to keep the oil for lubricating the rotary electric machine at an appropriate temperature, but in the configuration in JP-A-2001-238406, heat exchange is always performed between the oil for cooling an electric motor M and the cooling water for cooling an inverter U. and thus there is a problem that it is difficult to adjust the temperature of the oil. 
     Further, in the configuration in JP-A-2019-103334, since a heat exchanger 12 and an inverter cooling circuit 10 for cooling the inverter 2 are connected in series, heat exchange always occurs between the inverter cooling circuit 10 and a T/M oil circuit 20 for cooling a first motor 3 and a second motor 4, and there is a problem that the efficiency of the first motor 3 and the second motor 4 is poor when the temperature is raised. Further, in the configuration in JP-A-2019-103334, since the cooling water is always supplied to the heat exchanger 12 at the same flow rate, there is a problem that the flow path resistance is increased and a pump having a large output is required. 
     SUMMARY 
     The present disclosure provides a vehicle temperature adjustment system which can prevent friction loss of a rotary electric machine. 
     According to an aspect of the present disclosure, there is provided a vehicle temperature adjustment system, including: 
     a first temperature adjustment circuit which is configured to adjust a temperature of a rotary electric machine and in which a first pump is provided; 
     a second temperature adjustment circuit which is configured to adjust a temperature of an electric power conversion device and in which a second pump is provided; and 
     a heat exchanger configured to perform heat exchange between a first temperature adjustment medium circulating through the first temperature adjustment circuit and a second temperature adjustment medium circulating through the second temperature adjustment circuit, in which: 
     the second temperature adjustment circuit includes:
         a first radiator configured to perform 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 configured to adjust a flow rate of the second temperature adjustment medium to the second branch flow path.       

     According to the present disclosure, friction loss of a rotary electric machine can be prevented. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram illustrating a vehicle temperature adjustment system according to an embodiment of the present disclosure. 
         FIG. 2  is a diagram illustrating an example of control of a valve device in accordance with an increase in a required output of an electric motor. 
         FIG. 3  is a flowchart illustrating an example of control of a rotation speed of a second pump based on a temperature detected by each temperature sensor. 
         FIG. 4  is a diagram illustrating an example of a front portion of a vehicle. 
         FIG. 5  is a flowchart illustrating an example of control of the valve device based on a vehicle speed. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an embodiment of a vehicle in which a vehicle temperature adjustment system according to the present disclosure is mounted will be described with reference to the accompanying drawings. It should be noted that the drawings are viewed in a direction of reference numerals. In the present specification and the like, in order to simplify and clarify the description, a front-rear direction, a left-right direction, and an upper-lower direction are respectively described in accordance with directions viewed from a driver of a vehicle. In the drawings, a front side of the vehicle is denoted by Fr, a rear side thereof is denoted by Rr, a left side thereof is denoted by L, a right side thereof is denoted by R, an upper side thereof is denoted by U. and a lower side thereof is denoted by D. 
     Embodiment 
     First, a vehicle temperature adjustment system  10  according to an embodiment of the present disclosure will be described with reference to  FIG. 1 . 
     As illustrated in  FIG. 1 , the vehicle temperature adjustment system  10  according to the present embodiment is mounted on a vehicle V, and includes an internal combustion engine ICE, a control device ECU, an electric motor  20 , a power generator  30 , a transmission device  40 , an electric power conversion device  50 , and a temperature adjustment circuit  60 . 
     The electric motor  20  is a rotary electric machine which outputs power for driving the vehicle V using electric power stored in an electric storage device (not illustrated) mounted on the vehicle V or electric power generated by the power generator  30 . When the vehicle V is braked, the electric motor  20  may generate electric power by kinetic energy of drive wheels of the vehicle V to charge the electric storage device described above. The electric motor  20  is provided with a third temperature sensor  20   a  which detects the temperature of the electric motor  20 . The third temperature sensor  20   a  outputs a detection value of the temperature of the electric motor  20  to the control device ECU. 
     The power generator  30  is a rotary electric machine which generates electric power by the power of the internal combustion engine ICE, charges the electric storage device described above, or supplies electric power to the electric motor  20 . 
     The transmission device  40  is a device, such as a gear-type power transmission device, reducing a speed of the power output from the electric motor  20  and transmitting the speed-reduced power to the drive wheels. 
     The electric power conversion device  50  includes a power drive unit (PDU) (not illustrated) which converts the electric power output from the electric storage device described above from a direct current to an alternating current to control input and output power of the electric motor  20  and the power generator  30 , and a voltage control unit (VCU) (not illustrated) which boosts the electric power output from the electric storage device described above as necessary. The VCU may step down the electric power generated by the electric motor  20  when the electric motor  20  generates the electric power in a case where the vehicle V is braked. The electric power conversion device  50  is provided with a fourth temperature sensor  50   a  which detects the temperature of the electric power conversion device  50 . The fourth temperature sensor  50   a  outputs a detection value of the temperature of the electric power conversion device  50  to the control device ECU. 
     The temperature adjustment circuit  60  includes a first temperature adjustment circuit  61  through which a non-conductive first temperature adjustment medium TCM 1  circulates and which adjusts temperature of the electric motor  20 , the power generator  30 , and the transmission device  40 ; a second temperature adjustment circuit  62  through which a conductive second temperature adjustment medium TCM 2  circulates and which adjusts a temperature of the electric power conversion device  50 ; and a heat exchanger  63  which performs heat exchange between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2 . The non-conductive first temperature adjustment medium TCM 1  is, for example, oil which is called automatic transmission fluid (ATF), can lubricate the electric motor  20 , the power generator  30 , and the transmission device  40 , and can adjust the temperature thereof. The conductive second temperature adjustment medium TCM 2  is, for example, cooling water which is called long life coolant (LLC). 
     The first temperature adjustment circuit  61  is provided with a first pump  611  and a storage unit  612 . The first pump  611  is a mechanical pump driven by the power of the internal combustion engine ICE and a rotational force of an axle (not illustrated) of the vehicle V. The storage unit  612  stores the first temperature adjustment medium TCM 1  circulating through the first temperature adjustment circuit  61 . The storage unit  612  is, for example, an oil pan provided at a bottom of a housing (not illustrated) in which the electric motor  20 , the power generator  30 , and the transmission device  40  are housed. The first temperature adjustment circuit  61  includes a branching portion  613 . The first temperature adjustment circuit  61  includes: a pressure feed flow path  610   a  in which the first pump  611  is provided, of which an upstream end portion is connected to the storage unit  612 , and of which a downstream end portion is connected to the branching portion  613  through the first pump  611 ; a first branch flow path  610   b   1  in which the electric motor  20  and the power generator  30  are provided, of which an upstream end portion is connected to the branching portion  613 , and of which a downstream end portion is connected to the storage unit  612  through the electric motor  20  and the power generator  30 ; and a second branch flow path  610   b   2  in which the transmission device  40  is provided, of which an upstream end portion is connected to the branching portion  613 , and of which a downstream end portion is connected to the storage unit  612  through the transmission device  40 . In the first temperature adjustment circuit  61 , the heat exchanger  63  is disposed upstream of the electric motor  20  and the power generator  30  in the first branch flow path  610   b   1 . 
     Therefore, in the first temperature adjustment circuit  61 , a flow path in which the first temperature adjustment medium TCM 1  pressure-fed from the first pump  611  is cooled by the heat exchange with the second temperature adjustment medium TCM 2  in the heat exchanger  63  through the first branch flow path  610   b   1  from the branching portion  613 , is supplied to the electric motor  20  and the power generator  30  to lubricate the electric motor  20  and the power generator  30  and adjust the temperature thereof, and then is stored in the storage unit  612 , and a flow path in which the first temperature adjustment medium TCM 1  pressure-fed from the first pump  611  is supplied to the transmission device  40  through the second branch flow path  610   b   2  from the branching portion  613  to lubricate the transmission device  40  and adjust the temperature thereof, and then is stored in the storage unit  612  are formed in parallel. The first temperature adjustment medium TCM 1  stored in the storage unit  612  flows through the pressure feed flow path  610   a  and is supplied to the first pump  611 , and the first temperature adjustment medium TCM 1  circulates through the first temperature adjustment circuit  61 . 
     In the present embodiment, the first branch flow path  610   b   1  and the second branch flow path  610   b   2  are formed such that a flow rate of the first temperature adjustment medium TCM 1  flowing through the first branch flow path  610   b   1  is larger than a flow rate of the first temperature adjustment medium TCM 1  flowing through the second branch flow path  610   b   2 . 
     The first temperature adjustment circuit  61  is provided with a first temperature sensor  61   a  which detects a temperature of the first temperature adjustment medium TCM 1  circulating through the first temperature adjustment circuit  61 . In the present embodiment, the first temperature sensor  61   a  is provided in the storage unit  612 , which is an oil pan, and detects the temperature of the first temperature adjustment medium TCM 1  stored in the storage unit  612 . 
     The first temperature sensor  61   a  outputs a detection value of the temperature of the first temperature adjustment medium TCM 1  stored in the storage unit  612  to the control device ECU. The first temperature adjustment circuit  61  further includes a pressure adjustment circuit  610   c  of which an upstream end portion is connected to the storage unit  612 , and of which a downstream end portion is connected to the pressure feeding flow path  610   a  on a downstream side of the first pump  611 . The pressure adjustment circuit  610   c  is provided with a pressure adjustment valve  619 . The pressure adjustment valve  619  may be a check valve or an electromagnetic valve such as a solenoid valve. When the liquid pressure of the first temperature adjustment medium TCM 1  pressure-fed from the first pump  611  is equal to or higher than a predetermined pressure, the pressure adjustment valve  619  is opened, and a part of the first temperature adjustment medium TCM 1  pressure-fed from the first pump  611  is returned to the storage unit  612 . Accordingly, the liquid pressure of the first temperature adjustment medium TCM 1  flowing through the first branch flow path  610   b   1  and the second branch flow path  610   b   2  is held to be equal to or lower than the predetermined pressure. 
     The second temperature adjustment circuit  62  is provided with a second pump  621 , a radiator  622 , and a storage tank  623 . The second pump  621  is, for example, an electric pump which is driven by the electric power stored in the electric storage device. The radiator  622  is disposed at a front portion of the vehicle V. and is a heat dissipation device which cools the second temperature adjustment medium TCM 2  by traveling wind when the vehicle V is traveling. The storage tank  623  is a tank in which the second temperature adjustment medium TCM 2  circulating through the second temperature adjustment circuit  62  is temporarily stored. Even when cavitation occurs in the second temperature adjustment medium TCM 2  circulating through the second temperature adjustment circuit  62 , the cavitation occurred in the second temperature adjustment medium TCM 2  disappears because the second temperature adjustment medium TCM 2  circulating through the second temperature adjustment circuit  62  is temporarily stored in the storage tank  623 . 
     The second temperature adjustment circuit  62  includes a branching portion  624  and a merging portion  625 . The second temperature adjustment circuit  62  includes a pressure feed flow path  620   a  in which the storage tank  623 , the second pump  621 , and the radiator  622  are provided in this order from an upstream side, of which an upstream end portion is connected to the merging portion  625 , and of which a downstream end portion is connected to the branching portion  624  through the storage tank  623 , the second pump  621 , and the radiator  622 . The second temperature adjustment medium TCM 2  stored in the storage tank  623  is pressure-fed by the second pump  621  through the pressure feed flow path  620   a , and is cooled by the radiator  622 . 
     The second temperature adjustment circuit  62  further includes: a first branch flow path  620   b   1  in which the electric power conversion device  50  is provided, of which an upstream end portion is connected to the branching portion  624 , and of which a downstream end portion is connected to the merging portion  625  through the electric power conversion device  50 ; and a second branch flow path  620   b   2  in which the heat exchanger  63  is provided, of which an upstream end portion is connected to the branching portion  624 , and of which a downstream end portion is connected to the merging portion  625  through the heat exchanger  63 . In the present embodiment, a valve device  626  is provided as a flow rate adjustment valve in a portion of the second branch flow path  620   b   2  upstream of the heat exchanger  63 . In the present embodiment, the valve device  626  may be an ON-OFF valve which switches the second branch flow path  620   b   2  between a fully open state and a fully closed state, or may be a variable flow rate valve which can adjust a flow rate of the second temperature adjustment medium TCM 2  flowing through the second branch flow path  620   b   2 . The valve device  626  is controlled by the control device ECU. 
     Therefore, the second temperature adjustment medium TCM 2  pressure-fed by the second pump  621  and cooled by the radiator  622  in the pressure-feed flow path  620   a  branches into the first branch flow path  620   b   1  and the second branch flow path  620   b   2  at the branching portion  624 . The second temperature adjustment medium TCM 2  flowing through the first branch flow path  620   b   1  cools the electric power conversion device  50  and is merged with the second branch flow path  620   b   2  and the pressure feeding flow path  620   a  at the merging portion  625 . The second temperature adjustment medium TCM 2  flowing through the second branch flow path  620   b   2  cools the first temperature adjustment medium TCM 1  by exchanging heat with the first temperature adjustment medium TCM 1  in the heat exchanger  63 , and is merged with the first branch flow path  620   b   1  and the pressure feed flow path  620   a  at the merging portion  625 . The second temperature adjustment medium TCM 2  flowing through the first branch flow path  620   b   1  and the second temperature adjustment medium TCM 2  flowing through the second branch flow path  620   b   2  are merged at the merging portion  625 , flow through the pressure feed flow path  620   a , and are temporarily stored in the storage tank  623 . Then, the second temperature adjustment medium TCM 2  stored in the storage tank  623  is supplied again to the second pump  621  through the pressure feed flow path  620   a , and the second temperature adjustment medium TCM 2  circulates through the second temperature adjustment circuit  62 . 
     In the present embodiment, the first branch flow path  620   b   1  and the second branch flow path  620   b   2  are formed such that the flow rate of the second temperature adjustment medium TCM 2  flowing through the first branch flow path  620   b   1  is larger than the flow rate of the second temperature adjustment medium TCM 2  flowing through the second branch flow path  620   b   2 . 
     The second temperature adjustment circuit  62  is provided with a second temperature sensor  62   a  which detects a temperature of the second temperature adjustment medium TCM 2  circulating through the second temperature adjustment circuit  62 . In the present embodiment, the second temperature sensor  62   a  is provided in the pressure feed flow path  620   a  between the radiator  622  and the branching portion  624 , and detects the temperature of the second temperature adjustment medium TCM 2  stored in the storage tank  623 . The second temperature sensor  62   a  outputs a detection value of the temperature of the second temperature adjustment medium TCM 2  discharged from the radiator  622  to the control device ECU. 
     In the first temperature adjustment circuit  61 , the temperature of the first temperature adjustment medium TCM 1  stored in the storage unit  612  after cooling the electric motor  20 , the power generator  30 , and the transmission device  40  is about 100 [° C.]. Therefore, the first temperature adjustment medium TCM 1  of about 100 [° C.] is supplied to the heat exchanger  63 . 
     Meanwhile, in the second temperature adjustment circuit  62 , a temperature of the second temperature adjustment medium TCM 2  cooled by the radiator  622  is about 40 [° C.]. 
     Since the second temperature adjustment medium TCM 2  supplied to the heat exchanger  63  does not pass through the electric power conversion device  50  which is a temperature-adjusted device, the second temperature adjustment medium TCM 2  of about 40 [° C.] is supplied to the heat exchanger  63 . 
     The heat exchanger  63  performs heat exchange between the first temperature adjustment medium TCM 1  of about 100 [° C.] and the second temperature adjustment medium TCM 2  of about 40 [° C.] which are supplied to the heat exchanger  63 . Then, the first temperature adjustment medium TCM 1  of about 80 [° C.] is discharged from the heat exchanger  63  to a downstream side of the first branch flow path  610   b   1  of the first temperature adjustment circuit  61 , and the second temperature adjustment medium TCM 2  of about 70 [° C.] is discharged from the heat exchanger  63  to a downstream side of the second branch flow path  620   b   2  of the second temperature adjustment circuit  62 . 
     In this way, since the first temperature adjustment medium TCM 1  is cooled in the heat exchanger  63 , the temperature adjustment circuit  60  can cool the first temperature adjustment medium TCM 1  without providing a radiator for cooling the first temperature adjustment medium TCM 1 . Therefore, since the temperature adjustment circuit  60  can cool the first temperature adjustment medium TCM 1  flowing through the first temperature adjustment circuit  61  and the second temperature adjustment medium TCM 2  flowing through the second temperature adjustment circuit  62  by one radiator  622 , the temperature adjustment circuit  60  can be miniaturized. 
     The control device ECU controls the internal combustion engine ICE, the electric power conversion device  50 , the second pump  621 , and the valve device  626 . A rotational speed sensor  621   a  which detects a rotational speed of the second pump  621  is attached to the second pump  621 . The rotational speed sensor  621   a  outputs a detection value of the rotational speed of the second pump  621  to the control device ECU. 
     Returning to  FIG. 1 , when the first temperature adjustment medium TCM 1  is ATF, a viscosity of the first temperature adjustment medium TCM 1  is increased as the temperature of the first temperature adjustment medium TCM 1  is decreased. Since the first temperature adjustment medium TCM 1  flows through the electric motor  20  and the power generator  30 , a friction loss generated in the electric motor  20  and the power generator  30  is increased, and output efficiencies of the electric motor  20  and the power generator  30  is decreased when the viscosity is increased. Therefore, when the electric motor  20  and the power generator  30  are not at a high temperature at the time of starting the electric motor  20  and the power generator  30  or the like, and the temperature of the first temperature adjustment medium TCM 1  is equal to or lower than a predetermined temperature, the first temperature adjustment medium TCM 1  does not need to be cooled and it is preferable that the first temperature adjustment medium TCM 1  is not cooled. 
     When the detection value of the temperature of the first temperature adjustment medium TCM 1  output from the first temperature sensor  61   a  is equal to or lower than the predetermined temperature, the control device ECU fully closes the valve device  626  and controls the valve device  626  so as to block the second temperature adjustment medium TCM 2  from flowing through the second branch flow path  620   b   2 . 
     When the second temperature adjustment medium TCM 2  is blocked from flowing through the second branch flow path  620   b   2 , the second temperature adjustment medium TCM 2  is not supplied to the heat exchanger  63 , and therefore, the heat exchange is not performed between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2 , and the first temperature adjustment medium TCM 1  is not cooled. Therefore, when the first temperature adjustment medium TCM 1  does not need to be cooled, the first temperature adjustment medium TCM 1  can be prevented from being cooled in the heat exchanger  63 . As a result, it is possible to prevent an increase in friction loss generated in the electric motor  20  and the power generator  30 . 
     As described above, the second temperature adjustment circuit  62  which adjusts the temperature of the electric power conversion device  50  includes the first branch flow path  620   b   1  of the second temperature adjustment medium TCM 2  which bypasses the heat exchanger  63 , the second branch flow path  620   b   2  of the second temperature adjustment medium TCM 2  which passes through the heat exchanger  63 , and the valve device  626  (flow rate adjustment valve) which adjusts the flow rate of the second temperature adjustment medium TCM 2  to the first branch flow path  620   b   1 . 
     Accordingly, since the inflow of the second temperature adjustment medium TCM 2  into the heat exchanger  63  can be adjusted, it is possible to prevent temperature decrease of the first temperature adjustment medium TCM 1  due to heat exchange between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2 , which are used for temperature adjustment of the electric motor  20  and the power generator  30  (rotary electric machine), and to prevent friction loss generated in the electric motor  20  and the power generator  30 . Therefore, it is possible to prevent a decrease in the output efficiency of the electric motor  20  and the power generator  30 . 
     For example, when the temperature detected by the first temperature sensor  61   a  which detects the temperature of the first temperature adjustment medium TCM 1  is equal to or less than a threshold value (predetermined value), the control device ECU controls the valve device  626  such that the flow rate of the second temperature adjustment medium TCM 2  to the second branch flow path  620   b   2  is smaller than a flow rate when the temperature detected by the first temperature sensor  61   a  exceeds the threshold value. 
     The control of the valve device  626  such that the flow rate of the second temperature adjustment medium TCM 2  to the second branch flow path  620   b   2  is small also includes fully closing the valve device  626  such that the second temperature adjustment medium TCM 2  does not flow to the second branch flow path  620   b   2 . For example, the control device ECU fully closes the valve device  626  when the temperature detected by the first temperature sensor  61   a  is equal to or lower than the threshold value, and fully opens the valve device  626  when the temperature detected by the first temperature sensor  61   a  exceeds the threshold value. 
     Accordingly, when the temperature of the first temperature adjustment medium TCM 1  is equal to or lower than the threshold value, the inflow of the second temperature adjustment medium TCM 2  into the heat exchanger  63  is limited, the heat exchange between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2  is prevented, and the temperature decrease of the first temperature adjustment medium TCM 1  can be prevented. The threshold value is, for example, a threshold value TH 0  to be described later. The control of the valve device  626  based on the comparison between the temperature of the first temperature adjustment medium TCM 1  and the threshold value TH 0  will be described later with reference to  FIG. 3 . 
     When the temperature detected by the third temperature sensor  20   a  which detects the temperature of the electric motor  20  is equal to or lower than the threshold value, the control device ECU may control the valve device  626  such that the flow rate of the second temperature adjustment medium TCM 2  to the second branch flow path  620   b   2  is smaller than the flow rate when the temperature detected by the third temperature sensor  20   a  exceeds the threshold value. 
     Accordingly, by limiting the inflow of the second temperature adjustment medium into the heat exchanger when the temperature of the electric motor  20  is equal to or lower than the threshold value, it is possible to prevent the heat exchange between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2  and prevent the temperature decrease of the first temperature adjustment medium TCM 1  in a state where cooling of the electric motor  20  is not required much. 
     The third temperature sensor  20   a  may be a sensor which detects the temperature of the power generator  30  instead of the electric motor  20 . Also in this case, when the temperature detected by the third temperature sensor  20   a  which detects the temperature of the power generator  30  is equal to or lower than the threshold value, the control device ECU may control the valve device  626  such that the flow rate of the second temperature adjustment medium TCM 2  to the second branch flow path  620   b   2  is smaller than the flow rate when the temperature detected by the third temperature sensor  20   a  exceeds the threshold value. 
     Accordingly, by limiting the inflow of the second temperature adjustment medium into the heat exchanger when the temperature of the power generator  30  is equal to or lower than the threshold value, it is possible to prevent the heat exchange between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2  and prevent the temperature decrease of the first temperature adjustment medium TCM 1  in a state where cooling of the power generator  30  is not required much. 
     The control of the valve device  626  in accordance with the increase in the required output of the electric motor  20  will be described with reference to  FIG. 2 . A temperature threshold characteristic  201  in  FIG. 2  is, for example, information stored in a memory accessible by the control device ECU, and indicates the temperature threshold value (predetermined value) for controlling the valve device  626  according to the required output of the electric motor  20  in the vehicle V. The required output is an output required for the electric motor  20 , and is, for example, information based on an accelerator pedal opening degree of the vehicle V, a vehicle speed of the vehicle V, or the like. 
     In the temperature threshold characteristic  201 , the higher the required output of the electric motor  20  is, the lower the temperature threshold value is. The control device ECU may acquire a threshold value corresponding to the required output of the electric motor  20  in accordance with the temperature threshold value characteristic  201 , and may control the valve device  626  based on the temperature using the acquired threshold value. 
     That is, as described above, the control device ECU compares the temperature detected by the first temperature sensor  61   a  or the third temperature sensor  20   a  with the threshold value. The control device ECU controls the valve device  626  such that when the temperature is equal to or lower than the threshold value, the flow rate of the second temperature adjustment medium TCM 2  to the second branch flow path  620   b   2  is smaller than the flow rate when the temperature exceeds the threshold value. Then, the control device ECU decreases the threshold value in accordance with the increase in the required output of the electric motor  20 . 
     In this way, the control device ECU may decrease the temperature threshold value (predetermined value) for controlling the valve device  626  in accordance with the increase in the required output of the electric motor  20 . For example, in a situation where the temperatures of the first temperature adjustment medium TCM 1  and the electric motor  20  are low and the valve device  626  is closed and the heat exchange between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2  is not performed, the threshold value is decreased when the required output of the electric motor  20  is increased. Accordingly, before the temperature of the electric motor  20  is actually raised, the valve device  626  is opened to start the heat exchange between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2 , and the first temperature adjustment medium TCM 1  can be cooled, so that the temperature raising of the electric motor  20  can be prevented. 
     The control device ECU may adjust a temperature threshold value (predetermined value) for controlling the valve device  626  based on a traveling mode of the vehicle V. The traveling mode is a traveling mode of the vehicle V in which the presence or absence of use of the electric motor  20  and the form thereof are different. 
     For example, when the traveling mode of the vehicle V is a traction traveling mode in which a high load is applied to the electric motor  20 , the control device ECU sets the temperature threshold value for controlling the valve device  626  to be relatively low. As a result, it is possible to prevent the temperature raising of the electric motor  20  by advancing a timing at which the valve device  626  is opened to cool the first temperature adjustment medium TCM 1 . 
     When the traveling mode of the vehicle V is a lock-up traveling mode (engine direct connection mode) in which the load of the electric motor  20  is low, the control device ECU sets the temperature threshold value for controlling the valve device  626  to be relatively high. Accordingly, by delaying the timing at which the valve device  626  is opened to cool the first temperature adjustment medium TCM 1 , it is possible to prevent the temperature decrease of the first temperature adjustment medium TCM 1 . 
     In this way, the temperature of the electric motor  20  can be appropriately adjusted by controlling the valve device  626  to change the timing of cooling the first temperature adjustment medium TCM 1  based on the traveling mode of the vehicle V. 
     The control device ECU may control the rotation speed of the second pump  621  based on the temperature detected by each temperature sensor. The control of the rotational speed of the second pump  621  by the control device ECU will be described with reference to  FIG. 3 . For example, when an ignition power source of the vehicle V is turned on, the control device ECU executes the process illustrated in  FIG. 3 . As an initial state, it is assumed that the valve device  626  is fully opened. 
     First, the control device ECU starts driving the second pump  621  (step S 301 ). Specifically, the control device ECU starts driving the second pump  621  by inputting a drive signal of a predetermined duty ratio to the second pump  621 . 
     The second pump  621  operates at a rotation speed corresponding to the duty ratio of the drive signal input from the control device ECU, thereby pressure-feeding the second temperature adjustment medium TCM 2 . Here, it is assumed that there are three rotational speeds of Low, Mid, and Hi as the required rotational speed for the second pump  621 . Low is the lowest rotational speed, and Hi is the highest rotational speed. 
     Next, the control device ECU executes the processes in steps S 302  to S 310  and the processes in steps S 311  to S 317 . These processes may be executed in parallel or sequentially. 
     In step S 302 , the control device ECU acquires the temperature of the first temperature adjustment medium TCM 1  detected by the first temperature sensor  61   a  (step S 302 ). Next, the control device ECU determines whether the temperature acquired in step S 302  is equal to or higher than the threshold value TH 0  (step S 303 ). The threshold value TH 0  is a minimum temperature of the first temperature adjustment medium TCM 1  to such an extent that friction loss generated in the electric motor  20  and the power generator  30  does not cause a problem, and may be, for example, 65 [° C.]. 
     In step S 303 , when the temperature acquired in step S 302  is not equal to or higher than the threshold value TH 0  (step S 303 : No), the control device ECU closes the valve device  626  (step S 304 ), and proceeds to step S 318 . In this case, a temperature raising mode is set in which the heat exchange between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2  in the heat exchanger  63  is not performed. In the temperature raising mode, since the first temperature adjustment medium TCM 1  is not cooled by the heat exchange with the second temperature adjustment medium TCM 2 , the temperature of the first temperature adjustment medium TCM 1  is raised, and as a result, the temperature of the electric motor  20 , the power generator  30 , and the transmission device  40  are also raised. 
     When the temperature acquired in step S 302  is equal to or higher than the threshold value TH 0  (step S 303 : Yes), the control device ECU determines whether the temperature acquired in step S 302  is equal to or higher than a first threshold value TH 1  (step S 305 ). The first threshold value TH 1  is a value higher than the threshold value TH 0 , and may be, for example, 70 [° C.]. 
     In step S 305 , when the temperature acquired in step S 302  is not equal to or higher than the first threshold value TH 1  (step S 305 : No), the control device ECU sets the required rotation speed of the second pump  621  to Low (step S 306 ), and proceeds to step S 318 . 
     In step S 305 , when the temperature acquired in step S 302  is equal to or higher than the first threshold value TH 1  (step S 305 : Yes), the control device ECU acquires the temperature of the electric motor  20  detected by the third temperature sensor  20   a  (step S 307 ). 
     Next, the control device ECU determines whether the temperature acquired in step S 307  is equal to or higher than a third threshold value TH 3  (step S 308 ). The third threshold value TH 3  is a value higher than the first threshold value TH 1 , and may be, for example, 80 [° C.]. 
     In step S 308 , when the acquired temperature is not equal to or higher than the third threshold value TH 3  (step S 308 : No), the control device ECU sets the requested rotation speed of the second pump  621  to Mid (step S 309 ), and proceeds to step S 318 . When the acquired temperature is equal to or higher than the third threshold value TH 3  (step S 308 : Yes), the control device ECU sets the required rotation speed of the second pump  621  to Hi (step S 310 ), and proceeds to step S 318 . 
     In step S 311 , the control device ECU acquires the temperature of the second temperature adjustment medium TCM 2  detected by the second temperature sensor  62   a  (step S 311 ). Next, the control device ECU determines whether the temperature acquired in step S 311  is equal to or higher than a second threshold TH 2  (step S 312 ). The second threshold value TH 2  is, for example, the same value as the first threshold value TH 1  for comparison with the temperature of the first temperature adjustment medium TCM 1 , and may be, for example, 70 [° C.]. However, since the temperature of the second temperature adjustment medium TCM 2  is normally lower than that of the first temperature adjustment medium TCM 1 , the second threshold value TH 2  may be set to a value lower than the first threshold value TH 1 . 
     In step S 312 , when the temperature acquired in step S 311  is not equal to or higher than the second threshold value TH 2  (step S 312 : No), the control device ECU sets the required rotation speed of the second pump  621  to Low (step S 313 ), and proceeds to step S 318 . 
     In step S 312 , when the temperature acquired in step S 311  is equal to or higher than the second threshold TH 2  (step S 312 : Yes), the control device ECU acquires the temperature of the electric power conversion device  50  detected by the fourth temperature sensor  50   a  (step S 314 ). 
     Next, the control device ECU determines whether the temperature acquired in step S 314  is equal to or higher than a fourth threshold value TH 4  (step S 315 ). The fourth threshold value TH 4  is, for example, the same value as the third threshold value TH 3  for comparison with the temperature of the electric motor  20 , and may be, for example, 80 [° C.]. However, since the temperature of the electric power conversion device  50  is normally lower than that of the electric motor  20 , the fourth threshold value TH 4  may be set to a value lower than the third threshold value TH 3 . 
     In step S 315 , when the acquired temperature is not equal to or higher than the fourth threshold value TH 4  (step S 315 : No), the control device ECU sets the requested rotation speed of the second pump  621  to Mid (step S 316 ), and proceeds to step S 318 . When the acquired temperature is equal to or higher than the fourth threshold value TH 4  (step S 315 : Yes), the control device ECU sets the required rotation speed of the second pump  621  to Hi (step S 317 ), and proceeds to step S 318 . 
     In step S 318 , the control device ECU derives the maximum required rotation speed among the required rotation speed of the second pump  621  set in any one of steps S 306 , S 309 , and S 310  and the required rotation speed of the second pump  621  set in any one of steps S 313 . S 316 , and S 317  as the rotation speed to be set in the second pump  621  (step S 318 ). However, when the valve device  626  is closed in step S 304 , the control device ECU derives the required rotation speed of the second pump  621  set in any one of steps S 313 , S 316 , and S 317  as the rotation speed to be set in the second pump  621 . 
     Next, the control device ECU controls the second pump  621  so as to operate at the rotation speed derived in step S 318  (step S 319 ), and ends the series of processes. Specifically, the control device ECU generates a drive signal in which the duty ratio is adjusted such that the second pump  621  operates at the rotation speed derived in step S 318 , and inputs the generated drive signal to the second pump  621 . 
     The control device ECU may repeatedly execute the process illustrated in  FIG. 3 . In this case, the control device ECU omits step S 301  in the second and subsequent processes. In this case, the control device ECU performs control to open (for example, fully open) the valve device  626  when it is determined in step S 303  that the temperature of the first temperature adjustment medium TCM 1  is equal to or higher than the threshold value TH 0  and the valve device  626  is in a closed state. 
     In this way, the control device ECU controls the rotation speed of the second pump  621  based on the first temperature detected by the first temperature sensor  61   a  which detects the temperature of the first temperature adjustment medium TCM 1  and the second temperature detected by the second temperature sensor  62   a  which detects the temperature of the second temperature adjustment medium TCM 2 . Accordingly, it is possible to perform cooling when the temperature of the first temperature adjustment medium TCM 1  or the second temperature adjustment medium TCM 2  is high while preventing the power consumption of the second pump  621 . 
     Specifically, in a case where the first temperature is equal to or higher than the first threshold value TH 1  or the second temperature is equal to or higher than the second threshold value TH 2  (including a case where the first temperature is equal to or higher than the first threshold value TH 1  and the second temperature is equal to or higher than the second threshold value TH 2 ), the control device ECU controls the rotational speed of the second pump  621  to be higher (to be Mid or Hi) than the rotational speed in a case where the first temperature is lower than the first threshold value TH 1  and the second temperature is lower than the second threshold value TH 2 . Thus, when the temperature of at least one of the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2  is high, the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2  can be cooled. 
     The control device ECU may control the rotation speed of the second pump  621  based on, in addition to the first temperature and the second temperature, a third temperature detected by the third temperature sensor  20   a  which detects the temperature of the electric motor  20  or a fourth temperature detected by the fourth temperature sensor  50   a  which detects the temperature of the electric power conversion device  50 . 
     Accordingly, for example, even when the first temperature of the first temperature adjustment medium TCM 1  is equal to or higher than the first threshold value TH 1 , the requested rotation speed of the second pump  621  is set to Mid lower than Hi, and the power consumption of the second pump  621  can be prevented as long as the third temperature of the electric motor  20  to be cooled by the first temperature adjustment medium TCM 1  is lower than the third threshold value TH 3 . Further, even when the second temperature of the second temperature adjustment medium TCM 2  is equal to or higher than the second threshold value TH 2 , the requested rotation speed of the second pump  621  is set to Mid lower than Hi, and the power consumption of the second pump  621  can be prevented as long as the fourth temperature of the electric power conversion device  50  to be cooled by the second temperature adjustment medium TCM 2  is lower than the fourth threshold value TH 4 . 
     As illustrated in  FIG. 4 , a fan  401  is provided in a front portion of the vehicle V behind the radiator  622 . The fan  401  blows air from the front side (Fr) to the rear side (Rr) of the vehicle V to introduce outside air into the radiator  622 . 
     An air conditioner condenser  402  is a condenser of an air conditioner of the vehicle V, and is located, for example, in front of the fan  401  and above the radiator  622 . A first radiator  403  is a radiator for cooling the internal combustion engine ICE, and is located, for example, in front of the fan  401  and behind the radiator  622 . 
     The control of the valve device  626  based on the vehicle speed will be described with reference to  FIG. 5 . First, the control device ECU acquires the vehicle speed of the vehicle V detected by a vehicle speed sensor provided in the vehicle V (step S 501 ). Next, the control device ECU determines whether the vehicle speed acquired in step S 501  is equal to or less than a threshold value TH 5  (step S 502 ). The threshold value TH 5  may be, for example, 10 km/hour. 
     In step S 502 , when the acquired vehicle speed is equal to or less than the threshold value TH 5  (step S 502 : Yes), the control device ECU closes the valve device  626  (step S 503 ), and returns to step S 501 . In this case, the heat exchange is not performed between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2  in the heat exchanger  63 . Therefore, it is possible to prevent the heat of the electric motor  20  and the power generator  30  from being transferred to the radiator  622 . 
     In step S 502 , when the acquired vehicle speed is not equal to or less than the threshold value TH 5  (step S 502 : No), the control device ECU opens the valve device  626  (step S 504 ), and returns to step S 501 . In this case, the heat exchange is performed between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2  in the heat exchanger  63 . Therefore, the heat of the electric motor  20  and the power generator  30  is transferred to the radiator  622 , and the electric motor  20  and the power generator  30  can be cooled. 
     As described above, the control device ECU prevents the heat exchange between the first temperature adjustment medium TCM 1  and the second temperature adjustment medium TCM 2  and prevents heat of the electric motor  20  and the power generator  30  (rotary electric machine) from being transferred to the radiator  622  (first radiator) while the vehicle V is stopped or running at a low speed, thereby preventing temperature raising of the outside air due to temperature exchange between the radiator  622  and the outside air and preventing the heat exchange in other heat exchangers such as the air conditioner condenser  402  and the first radiator  403  (second radiator) from being hindered. 
     Since the electric power conversion device  50  is disposed in the first branch flow path  620   b   1 , the electric power conversion device  50  and the heat exchanger  63  are arranged in parallel. Accordingly, it is possible to reduce the resistance of the second temperature adjustment circuit  62  when the valve device  626  is opened to cool the electric motor  20 , and it is possible to use a low output pump as the second pump  621 . 
     Although one embodiment of the present invention has been described above with reference to the accompanying drawings, it is needless to say that the present invention is not limited to such an embodiment. It is apparent to those skilled in the art that various changes and modifications can be conceived within the scope of the claims, and it is also understood that the various changes and modifications belong to the technical scope of the present invention. The components in the embodiments described above may be combined freely within a range not departing from the spirit of the invention. 
     For example, although the configuration in which the vehicle V includes the internal combustion engine ICE has been described, the vehicle V may be an electric vehicle which does not include the internal combustion engine ICE. 
     In addition, although the configuration in which the third temperature sensor  20   a  is provided in the electric motor  20  and the temperature of the electric motor  20  is measured by the third temperature sensor  20   a  has been described, a configuration in which the third temperature sensor  20   a  is provided in the power generator  30  and the temperature of the power generator  30  is measured by the third temperature sensor  20   a  may be adopted. 
     Although the configuration in which the electric power conversion device  50  and the heat exchanger  63  are arranged in parallel has been described, the electric power conversion device  50  and the heat exchanger  63  may be arranged in series. For example, the electric power conversion device  50  may be arranged between the radiator  622  and the branching portion  624 . 
     In the present specification, at least the following matters are described. In the parentheses, the corresponding constituent elements and the like in the above-described embodiment are illustrated as an example, and the present invention is not limited thereto. 
     (1) A vehicle temperature adjustment system (vehicle temperature adjustment system  10 ) including: 
     a first temperature adjustment circuit (first temperature adjustment circuit  61 ) which is configured to adjust a temperature of a rotary electric machine (electric motor  20 , power generator  30 ) and in which a first pump (first pump  611 ) is provided: 
     a second temperature adjustment circuit (second temperature adjustment circuit  62 ) which is configured to adjust a temperature of a electric power conversion device (electric power conversion device  50 ) and in which a second pump (second pump  621 ) is provided; and 
     a heat exchanger (heat exchanger  63 ) configured to perform heat exchange between a first temperature adjustment medium (first temperature adjustment medium TCM 1 ) circulating through the first temperature adjustment circuit and a second temperature adjustment medium (second temperature adjustment medium TCM 2 ) circulating through the second temperature adjustment circuit, in which: 
     the second temperature adjustment circuit includes.
         a first radiator (first radiator  403 ) configured to perform heat exchange between the second temperature adjustment medium and outside air;   a first branch flow path (first branch flow path  620   b   1 ) of the second temperature adjustment medium bypassing the heat exchanger;   a second branch flow path (second branch flow path  620   b   2 ) of the second temperature adjustment medium passing through the heat exchanger; and   a flow rate adjustment valve (valve device  626 ) configured to adjust a flow rate of the second temperature adjustment medium to the second branch flow path.       

     According to (1), since the second temperature adjustment circuit which adjusts the temperature of the electric power conversion device includes the first branch flow path of the second temperature adjustment medium bypassing the heat exchanger, the second branch flow path of the second temperature adjustment medium passing through the heat exchanger, and the flow rate adjustment valve which adjusts the flow rate of the second temperature adjustment medium to the second branch flow path, it is possible to limit the inflow of the second temperature adjustment medium to the heat exchanger, and thus it is possible to prevent the temperature decrease of the first temperature adjustment medium due to the heat exchange between the first temperature adjustment medium used for the temperature adjustment of the rotary electric machine such as the electric motor and the second temperature adjustment medium, and to prevent the friction loss due to the first temperature adjustment medium. 
     (2) The vehicle temperature adjustment system according to (1), in which: the first temperature adjustment circuit includes a first temperature sensor (first temperature sensor) which is configured to detect a temperature of the first temperature adjustment medium; and 
     a control device (control device ECU) configured to control the flow rate adjustment valve such that when the temperature detected by the first temperature sensor is equal to or lower than a predetermined value (TH 0 ), the flow rate of the second temperature adjustment medium to the second branch flow path is smaller than a flow rate when the temperature detected by the first temperature sensor exceeds the predetermined value is provided. 
     According to (2), by limiting the inflow of the second temperature adjustment medium into the heat exchanger when the temperature of the first temperature adjustment medium is equal to or lower than the predetermined value, it is possible to prevent the heat exchange between the first temperature adjustment medium and the second temperature adjustment medium and to prevent the temperature decrease of the first temperature adjustment medium. 
     (3) The vehicle temperature adjustment system according to (1) or (2), in which: 
     the first temperature adjustment circuit includes a third temperature sensor (third temperature sensor  20   a ) configured to detect a temperature of the rotary electric machine; and 
     a control device configured to control the flow rate adjustment valve such that when the temperature detected by the third temperature sensor is equal to or lower than a predetermined value, a flow rate of the second temperature adjustment medium to the second branch flow path is smaller than a flow rate when the temperature detected by the third temperature sensor exceeds the predetermined value is provided. 
     According to (3), by limiting the inflow of the second temperature adjustment medium into the heat exchanger when the temperature of the rotary electric machine is equal to or lower than the predetermined value, it is possible to prevent the heat exchange between the first temperature adjustment medium and the second temperature adjustment medium, and prevent the temperature decrease of the first temperature adjustment medium in a state where cooling of the rotary electric machine is not required so much. 
     (4) The vehicle temperature adjustment system according to (2) or (3), in which: 
     the rotary electric machine includes an electric motor (electric motor  20 ); and 
     the control device is configured to decrease the predetermined value in accordance with an increase in a required output of the electric motor. 
     According to (4), by decreasing the reference temperature for limiting the inflow of the second temperature adjustment medium into the heat exchanger in accordance with the increase in the required output of the electric motor, the heat exchange between the first temperature adjustment medium and the second temperature adjustment medium can be started and the first temperature adjustment medium can be cooled before the temperature of the electric motor is actually raised, so that the temperature raising of the electric motor can be prevented. 
     (5) The vehicle temperature adjustment system according to any one of (2) to (4), which is mounted on an electric vehicle (vehicle V) which travels using the rotary electric machine, in which: 
     the control device is configured to adjust the predetermined value based on a traveling mode of the electric vehicle. 
     According to (5), the temperature of the rotary electric machine can be appropriately adjusted by changing the reference temperature for limiting the inflow of the second temperature adjustment medium into the heat exchanger based on the traveling mode of the electric vehicle, thereby changing the timing for cooling the first temperature adjustment medium TCM 1  by controlling the flow rate adjustment valve. 
     (6) The vehicle temperature adjustment system according to any one of (1) to (5), in which: 
     the second pump is an electric pump; 
     the first temperature adjustment circuit includes a first temperature sensor (first temperature sensor  61   a ) configured to detect a temperature of the first temperature adjustment medium: 
     the second temperature adjustment circuit includes a second temperature sensor (second temperature sensor  62   a ) configured to detect a temperature of the second temperature adjustment medium; and 
     a control device configured to control a rotation speed of the electric pump based on a first temperature detected by the first temperature sensor and a second temperature detected by the second temperature sensor is provided. 
     According to (6), by controlling the rotation speed of the electric pump based on the each temperature of the first temperature adjustment medium and the second temperature adjustment medium, it is possible to perform cooling when the temperature of the first temperature adjustment medium or the second temperature adjustment medium is high while preventing the power consumption of the electric pump. 
     (7) The vehicle temperature adjustment system according to (6), in which: the control device controls the rotational speed of the electric pump to be higher in a case where the first temperature is equal to or higher than a first threshold value or when the second temperature is equal to or higher than a second threshold value than in a case where the first temperature is lower than the first threshold value (first threshold value TH 1 ) and the second temperature is lower than the second threshold value (second threshold value TH 2 ). 
     According to (7), when the temperature of at least one of the first temperature adjustment medium and the second temperature adjustment medium is high, it is possible to cool the first temperature adjustment medium and the second temperature adjustment medium. 
     (8) The vehicle temperature adjustment system according to (6) or (7), in which: the first temperature adjustment circuit includes a third temperature sensor (third temperature sensor) configured to detect a temperature of the rotary electric machine; and the control device is configured to control a rotation speed of the electric pump based on the first temperature, the second temperature, and a third temperature detected by the third temperature sensor. 
     According to (8), even when the temperature of the first temperature adjustment medium is high, the rotation speed of the electric pump is set to be relatively low when the temperature of the rotary electric machine to be cooled by the first temperature adjustment medium is not high, and the power consumption of the electric pump can be prevented. 
     (9) The vehicle temperature adjustment system according to any one of (6) to (8), in which: 
     the second temperature adjustment circuit includes a fourth temperature sensor (fourth temperature sensor  50   a ) configured to detect a temperature of the electric power conversion device; and 
     the control device is configured to control a rotation speed of the electric pump based on the first temperature, the second temperature, and a fourth temperature detected by the fourth temperature sensor. 
     According to (9), even when the temperature of the second temperature adjustment medium is high, the rotation speed of the electric pump is set to be relatively low when the temperature of the electric power conversion device to be cooled by the first temperature adjustment medium is not high, and the power consumption of the electric pump can be prevented. 
     (10) The vehicle temperature adjustment system according to any one of (1) to (9), which is mounted on an electric vehicle which travels using the rotary electric machine, in which: 
     a control device configured to control the flow rate adjustment valve such that when a vehicle speed of the electric vehicle is equal to or less than a predetermined value, a flow rate of the second temperature adjustment medium to the second branch flow path is smaller than a flow rate when the vehicle speed exceeds the predetermined value is provided. 
     According to (10), while the electric vehicle is stopped or running at a low speed, the heat exchange between the first temperature adjustment medium and the second temperature adjustment medium is prevented to prevent the heat of the rotary electric machine from being transferred to the first radiator, so that the temperature raising of the outside air due to the temperature exchange between the first radiator and the outside air can be prevented, and the heat exchange in other heat exchangers such as the air conditioner condenser and the second radiator can be prevented from being hindered. 
     (11) The vehicle temperature adjustment system according to any one of (1) to (10), in which the electric power conversion device is disposed in the first branch flow path. 
     According to (11), the electric power conversion device and the heat exchanger are in a parallel relationship, so that it is possible to reduce the resistance of the second temperature adjustment circuit when the flow rate adjustment valve is opened to cool the electric motor, and it is possible to use a low output pump as the second pump.