Cooling system

Abstract

A cooling system is provided. The cooling system includes: a motor; a power converter; a flow path through which a cooling fluid flows to the motor and the power converter; and a switching valve that switches a flow path through which the cooling fluid flows. The flow path includes a first flow path and a second flow path which are branched into two branches and merge again, the motor is disposed in the first flow path, and the power converter is disposed in the second flow path. The switching valve is disposed at a location where the flow path is branched into the first flow path and the second flow path, and is configured so as to be capable of switching the flow path through which the cooling fluid flows between the first flow path and the second flow path.

Description

Technical Field

[0001] The present disclosure relates to a cooling system. Background Art

[0002] In recent years, vehicles equipped with a motor as a driving power source for traveling (hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), battery electric vehicles (BEV), fuel cell electric vehicles (FCEV), etc.) have been becoming popular. These vehicles (hereinafter, collectively referred to as "electric vehicles") are equipped with a battery for driving the motor. For electric vehicles, there are many devices that need to be cooled, such as a motor (including an internal combustion engine such as an engine), a battery, an air conditioner, and an ECU. Therefore, a cooling circuit that circulates cooling water and a refrigerant is configured to cool these devices that need to be cooled. However, there are cases where the appropriate operating temperatures of these devices are different. In such a case, the temperature of the circulating cooling water and refrigerant is changed for each device with a different operating temperature. Therefore, heat exchange is performed through heat exchangers such as a cooler and a water-cooled condenser to control the temperature of the cooling water and refrigerant.

[0003] The cooling circuit disclosed in Patent Document 1 has a plurality of control modes that control a first pump, a second pump, a first switching valve, and a second switching valve, and change the flow mode of the cooling water in a first cooling water flow path, a second cooling water flow path, a third cooling water flow path, a fourth cooling water flow path, and a bypass flow path according to the outside air temperature or the battery water temperature. Among them, in the second cooling water flow path, an inverter cooling part and an electric generator cooling part are arranged in series in this order from the upstream side with respect to the flow direction of the cooling water.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-023059

[0005] In the second cooling water flow path of the cooling circuit disclosed in Patent Document 1, the cooling water is heated by heat exchange with the inverter and the electric generator. In this cooling circuit, an inverter cooling part is arranged on the upstream side in the flow direction of the cooling water in the second cooling water flow path, and an electric generator cooling part is arranged on the downstream side. Therefore, the cooling water first absorbs the heat of the inverter at the inverter cooling part and is heated, and then absorbs the heat of the electric generator at the electric generator cooling part and is heated. Therefore, the cooling water absorbs the heat of the electric generator after absorbing the heat of the inverter, resulting in a decrease in the amount of heat absorbed by the electric generator at the electric generator cooling part. Summary of the Invention

[0006] The present disclosure has been made in view of the above problems, and an object thereof is to provide a cooling system in which a cooling fluid can efficiently absorb heat generated by a motor.

[0007] One embodiment of the cooling system according to the present disclosure includes: a motor; a power converter; a flow path that allows a cooling fluid to flow through the motor and the power converter; and a switching valve that switches the flow path through which the cooling fluid flows. The flow path includes a first flow path and a second flow path that branch into two branches and then converge again. The motor is disposed in the first flow path, the power converter is disposed in the second flow path, and the switching valve is configured to be disposed at a position where the flow path branches into the first flow path and the second flow path, and can switch the flow path through which the cooling fluid flows between the first flow path and the second flow path.

[0008] In the cooling system of the present embodiment, the motor is disposed in the first flow path, the power converter is disposed in the second flow path, and a switching valve is disposed at a position where the flow path branches into the first flow path and the second flow path. The flow path through which the cooling fluid flows is switched between the first flow path and the second flow path by the switching valve. Thus, the motor and the power converter are arranged in parallel with respect to the flow path, and an adverse condition in which the amount of heat absorbed by the cooling fluid at the motor decreases because the cooling fluid absorbs the heat of the power converter and then absorbs the heat of the motor does not occur. Thus, a cooling system in which a cooling fluid can efficiently absorb heat generated by a motor can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural diagram showing a control example of the cooling system according to the present embodiment.

[0010] Figure 2 It is a flowchart showing the operation of the cooling system.

[0011] Figure 3 It is a structural diagram showing a control example of the cooling system according to the present embodiment.

[0012] Figure 4 It is a structural diagram showing a control example of the cooling system according to the present embodiment.

[0013] Figure 5 It is a structural diagram showing a control example of the cooling system according to the present embodiment. DETAILED DESCRIPTION

[0014] Hereinafter, embodiments of the cooling system according to the present disclosure will be described in detail with reference to the drawings. In addition, the embodiments described below are examples for explaining the present disclosure, and the present disclosure is not limited only to these embodiments. Therefore, the present disclosure can be implemented in various forms without departing from its gist.

[0015] 〔Structure of Cooling System〕

[0016] The cooling system A according to this embodiment is used for an automobile (such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a battery electric vehicle (BEV), a fuel cell electric vehicle (FCEV), etc.) that has a motor as a driving power source. Hereinafter, these automobiles are collectively referred to as electric vehicles. As Figure 1 shown, the cooling system A is configured to include: a motor cooling circuit 1 through which a cooling fluid circulates, a battery cooling circuit 2, and a four-way valve 3. The four-way valve 3 switches between a connection state in which the motor cooling circuit 1 is connected to the battery cooling circuit 2 and an independent state in which the motor cooling circuit 1 is separated from the battery cooling circuit 2. Figure 1 The four-way valve 3 shown represents an independent state in which the motor cooling circuit 1 is separated from the battery cooling circuit 2, Figures 3 to 5 The four-way valve 3 shown represents a connection state in which the motor cooling circuit 1 is connected to the battery cooling circuit 2.

[0017] The motor cooling circuit 1 includes: a motor pump 11 composed of a water pump or the like that pumps the cooling fluid, a motor 12 that is a driving power source of the electric vehicle, an inverter 13 (an example of a power converter) that supplies power to the motor 12, a radiator 14 that cools the cooling fluid, a motor flow path 16 (an example of a flow path) through which the cooling fluid circulates in the above components, and a switching valve 15 that switches the motor flow path 16. In addition, the cooling fluid is cooling water such as long-life coolant (LLC), insulating oil such as paraffin-based, or a refrigerant such as hydrofluorocarbon (HFC) or hydrofluoroolefin (HFO). In this embodiment, it is preferable to use cooling water such as long-life coolant (LLC) or a liquid with high electrical insulation such as fluorine-based inert liquid, and it may also be a coolant composed of cooling water or insulating oil. In addition, the power converter includes, for example, a DC-DC converter, an OBC (On Board Charger), etc.

[0018] The motor flow path 16 includes a first motor flow path 16a (an example of a first flow path) and a second motor flow path 16b (an example of a second flow path) that branch into two branches and then converge again. The motor 12 is cooled by the cooling fluid flowing in the first motor flow path 16a, and the inverter 13 is cooled by the cooling fluid flowing in the second motor flow path 16b. The switching valve 15 is arranged at the part where the motor flow path 16 branches into the first motor flow path 16a and the second motor flow path 16b. The switching valve 15 is configured such that, by the switching valve body, it can switch between four flow modes: a case where the cooling fluid flows only in the first motor flow path 16a, a case where the cooling fluid flows only in the second motor flow path 16b, a case where the cooling fluid flows in both the first motor flow path 16a and the second motor flow path 16b, and a case where the cooling fluid does not flow in either the first motor flow path 16a or the second motor flow path 16b. Additionally, the switching valve 15 may be configured to eliminate the case where the cooling fluid does not flow in either the first motor flow path 16a or the second motor flow path 16b and be able to switch between three flow modes.

[0019] Next, the operation of the motor cooling circuit 1 when the motor cooling circuit 1 and the battery cooling circuit 2 are in an independent state by the four-way valve 3 will be described. The independent state can be formed by rotating the valve body 90 degrees from the state of the four-way valve 3 shown in Figure 3 to the state shown in Figure 1 . The cooling fluid pumped by the motor pump 11 flows in the motor flow path 16 and flows into the switching valve 15. Since the motor pump 11 is operating, the switching valve 15 switches to any one of the cases where the cooling fluid flows only in the first motor flow path 16a, the case where the cooling fluid flows only in the second motor flow path 16b, and the case where the cooling fluid flows in both the first motor flow path 16a and the second motor flow path 16b. Figure 1 The switching valve 15 shown in

[0020] represents a state where the cooling fluid flows in both the first motor flow path 16a and the second motor flow path 16b. Figure 4 In the case where the switching valve 15 switches to the state where the cooling fluid flows only into the first motor flow path 16a, the cooling fluid flowing into the switching valve 15 flows only into the first motor flow path 16a, absorbs the heat generated by the motor 12, and is heated (refer to Figure 5 ). In the case where the switching valve 15 switches to the state where the cooling fluid flows only into the second motor flow path 16b, the cooling fluid flowing into the switching valve 15 flows only into the second motor flow path 16b, absorbs the heat generated by the inverter 13, and is heated (refer to Figure 5 ). In the case where the switching valve 15 switches to the state where the cooling fluid flows into both the first motor flow path 16a and the second motor flow path 16b, the cooling fluid flowing into the switching valve 15 flows into both the first motor flow path 16a and the second motor flow path 16b, absorbs the heat generated by the motor 12 and the inverter 13, and is heated (refer toFigure 1 , Figure 3 )。 In any case, the cooling fluid heated to a higher water temperature circulates in the motor flow path 16 and flows into the radiator 14, is cooled by the radiator 14, and then returns to the motor pump 11.

[0021] Next, the battery cooling circuit 2 will be described. The battery cooling circuit 2 includes: a battery pump 21 composed of a water pump or the like for pumping the cooling fluid, a battery 22 for supplying power to the inverter 13, a cooler 24 for cooling the cooling fluid, and a battery flow path 26 (an example of a flow path) for allowing the cooling fluid to circulate among these components. The battery flow path 26 of the battery cooling circuit 2 is configured to be freely switched between a connected state and an independent state with the motor flow path 16 of the motor cooling circuit 1 by switching the four-way valve 3.

[0022] Next, the operation of the battery cooling circuit 2 when the motor cooling circuit 1 and the battery cooling circuit 2 are in an independent state by the four-way valve 3 will be described. The cooling fluid pumped by the battery pump 21 circulates in the battery flow path 26 and flows into the battery 22. The cooling fluid absorbs the heat generated by the battery 22 and is heated. The heated cooling fluid with a higher water temperature circulates in the battery flow path 26 and flows into the cooler 24, is cooled by the cooler 24, and then returns to the battery pump 21.

[0023] 〔Operation of the cooling system〕

[0024] Next, based on Figure 2 the operation of the cooling system A will be described. In the present embodiment, Figure 2 the temperature settings of T1 (first temperature) to T4 (fourth temperature) shown are set such that T1 < T2 < T4 < T3. In the following description, the operations of the motor pump 11, the motor 12, the inverter 13, the radiator 14, the switching valve 15, the battery pump 21, the battery 22, and the cooler 24 are controlled by an ECU (Electronic Control Unit) not shown. In addition, the temperatures of the motor 12, the inverter 13, and the battery 22 are measured by temperature sensors not shown, and the measurement results are configured to be input to the ECU. Alternatively, the temperatures of the motor 12, the inverter 13, and the battery 22 can be estimated based on the temperatures of the cooling fluid flowing through them respectively.

[0025] If the power switch of the stopped electric vehicle is pressed to start the motor 12 (step S1), the temperature sensor measures the temperature of the battery 22. When the temperature of the battery 22 exceeds the fourth temperature T4 (for example, 35 degrees) (Yes in step S3), the four-way valve 3 is switched to make the motor cooling circuit 1 and the battery cooling circuit 2 independent. Also, the switching valve 15 is switched to allow the cooling fluid to flow through both the first motor flow path 16a and the second motor flow path 16b, and the cooler 24 operates (step S17, refer to Figure 1 ). The temperature of the motor 12 and the inverter 13 just after startup is substantially the same as the temperature of the battery 22. When the temperature of the battery 22 exceeds the fourth temperature T4, it is necessary to cool the motor 12, the inverter 13, and the battery 22, and the state is switched to make the motor cooling circuit 1 and the battery cooling circuit 2 independent in a way that maximally cools them. That is, in the motor cooling circuit 1, the cooling fluid flows through both the first motor flow path 16a and the second motor flow path 16b, is heated by cooling the motor 12 and the inverter 13, and then is cooled by the radiator 14. In addition, in the battery cooling circuit 2, the cooling fluid cools the battery 22 and is heated, and then is cooled by the cooler 24. The state of step S17 continues until the power switch of the electric vehicle is pressed again to stop the motor 12 (step S19).

[0026] When the temperature of the battery 22 just after the motor 12 starts is below the fourth temperature T4 (No in step S3) and exceeds the first temperature T1 (for example, 5 degrees, an example of the first predetermined temperature) (Yes in step S5), the four-way valve 3 is switched to make the motor cooling circuit 1 and the battery cooling circuit 2 connected. Then, the switching valve 15 is maintained to allow the cooling fluid to flow through both the first motor flow path 16a and the second motor flow path 16b, and the cooler 24 stops (step S15, refer to Figure 3 ). If the motor cooling circuit 1 and the battery cooling circuit 2 are connected, the cooling fluid flowing in the part after the first motor flow path 16a and the second motor flow path 16b converge in the motor flow path 16 flows into the battery pump 21 arranged in the battery flow path 26 of the battery cooling circuit 2. Also, the cooling fluid flowing in the battery flow path 26 on the downstream side of the cooler 24 flows into the radiator 14 of the motor cooling circuit 1. In addition, "stopping the cooler 24" means that the cooling fluid is not cooled at the cooler 24. For example, it is achieved by switching to a bypass flow path that bypasses the cooler 24.

[0027] When the temperature of the battery 22 exceeds the first temperature T1 and is below the fourth temperature T4, control is performed to cool the motor 12 and the inverter 13 and preheat the battery 22. That is, in the motor cooling circuit 1, the cooling fluid is heated by flowing through both the first motor flow path 16a and the second motor flow path 16b to cool the motor 12 and the inverter 13. The heated cooling fluid flows into the battery cooling circuit 2 to preheat the battery 22. The cooling fluid cooled by preheating the battery 22 is not further cooled by the cooler 24 but is only cooled by the radiator 14. Thus, the cooling fluid is not overcooled, and therefore, the motor 12 and the inverter 13 can be cooled and the battery 22 can be preheated. The state of step S15 continues until the battery 22 is preheated to the fourth temperature T4. Moreover, when the battery 22 exceeds the fourth temperature T4 (Yes in step S3), the motor cooling circuit 1 and the battery cooling circuit 2 are switched to the state of step S17.

[0028] When the temperature of the battery 22 is below the first temperature T1 immediately after the motor 12 starts (No in step S5), the four-way valve 3 is switched to connect the motor cooling circuit 1 and the battery cooling circuit 2. Moreover, the switching valve 15 is switched so that the cooling fluid only flows through the first motor flow path 16a and the cooler 24 stops (step S7, refer to Figure 4 ).

[0029] When the temperature of the battery 22 is below the first temperature T1, control is performed to cool the motor 12 and preheat the battery 22. That is, in the motor cooling circuit 1, the cooling fluid is heated by flowing only through the first motor flow path 16a to cool the motor 12. A state where the cooling fluid stagnates is formed in the second motor flow path 16b, so the inverter 13 is not cooled and self-heats. The cooling fluid heated by the motor 12 flows into the battery cooling circuit 2 to preheat the battery 22. The cooling fluid cooled by preheating the battery 22 is not further cooled by the cooler 24 but is only cooled by the radiator 14. Thereby, the cooling fluid is not overcooled, and therefore, the motor 12 can be cooled and the battery 22 can be preheated. In addition, the self-heat of the motor 12 with a large heat capacity is used to heat the cooling fluid, so the temperature rise of the battery 22 can be quickly achieved and preheating can be promoted.

[0030] As described above, when the temperature of the battery 22 is equal to or lower than the first temperature T1, the cooling fluid does not flow through the inverter 13. Therefore, if the motor 12 is continuously driven, the temperature of the inverter 13 rises. When the temperature of the inverter 13 is equal to or lower than the third temperature T3 (for example, 40 degrees, an example of the third predetermined temperature) (No in step S9), the process returns to step S5, and the temperature sensor measures the temperature of the battery 22. Moreover, as long as the temperature of the battery 22 is equal to or lower than the first temperature T1 and the temperature of the inverter 13 is equal to or lower than the third temperature T3, the state of step S7 continues. If the temperature of the inverter 13 exceeds the third temperature T3 (Yes in step S9), the switching valve 15 is switched so that the cooling fluid flows only through the second motor flow path 16b (step S11, refer to Figure 5 ). That is, the cooling fluid in the first motor flow path 16a becomes a stagnant state. At this time, the motor cooling circuit 1 and the battery cooling circuit 2 are in a connected state, and the cooler 24 stops.

[0031] The cooling fluid cools the inverter 13 by flowing through the inverter 13, and the temperature of the inverter 13 is reduced to below the third temperature T3. The state of step S11 continues until the temperature of the inverter 13 becomes less than the second temperature T2 (for example, 30 degrees, an example of the second predetermined temperature) (No in step S13). Moreover, if the temperature of the inverter 13 is less than the second temperature T2 (Yes in step S13), the process returns to step S5, and the temperature of the battery 22 is measured. As Figure 4 shown, when the temperature of the battery 22 is still equal to or lower than the first temperature T1 (No in step S5), the switching valve 15 is switched again so that the cooling fluid flows only through the first motor flow path 16a, and step S7 is executed. The above series of steps are repeated until the temperature of the battery 22 exceeds the first temperature T1. Moreover, when the temperature of the battery 22 exceeds the first temperature T1 (Yes in step S5), as Figure 3 shown, the motor cooling circuit 1 and the battery cooling circuit 2 are switched to the state of step S15.

[0032] Thus, in the cooling system A according to this embodiment, the motor 12 is arranged in the first motor flow path 16a, the inverter 13 is arranged in the second motor flow path 16b, and a switching valve 15 is arranged at the part where the motor flow path 16 branches into the first motor flow path 16a and the second motor flow path 16b. The motor flow path 16 through which the cooling fluid flows can be switched between the first motor flow path 16a and the second motor flow path 16b by the switching valve 15. Thus, the motor 12 and the inverter 13 are arranged in parallel with respect to the motor flow path 16, and there is no such bad situation that the amount of heat absorbed by the cooling fluid at the motor 12 is reduced because the cooling fluid absorbs the heat of the inverter 13 first and then absorbs the heat of the motor 12. In addition, when preheating the battery 22, the cooling fluid is made to flow only through the first motor flow path 16a. Thus, the self-heat generation of the motor 12 with a large heat capacity is used to heat the cooling fluid, and the temperature rise of the battery 22 can be achieved quickly.

[0033] In addition, the switching valve 15 of the cooling system A switches the motor flow path 16 through which the cooling fluid flows between the first motor flow path 16a and the second motor flow path 16b based on the condition that the temperature of the battery 22 is below the first temperature T1 (e.g., 5 degrees) and the temperature of the inverter 13 exceeds the third temperature T3 (e.g., 40 degrees). Therefore, the temperatures of the battery 22 and the inverter 13 can be appropriately controlled, and the cooling fluid can efficiently absorb the heat generated by the motor 12. In particular, when a CPU is built in the inverter 13, the CPU is not heat-resistant, so it is important to appropriately control the temperature of the inverter 13.

[0034] Moreover, in the cooling system A, when the temperature of the battery 22 is below the first temperature T1 (e.g., 5 degrees) and the temperature of the inverter 13 is less than the second temperature T2 (e.g., 30 degrees), it is necessary to preheat the battery 22. Therefore, the switching valve 15 is switched so that the cooling fluid flows only in the first motor flow path 16a. Thus, the heat of the motor 12 with a large heat capacity can be efficiently absorbed to heat the cooling water, and the battery 22 can be efficiently preheated. In addition, in this state, the cooling fluid does not flow through the second motor flow path 16b, so the inverter 13 is not cooled and self-heats. If the inverter 13 becomes high temperature, there may be a risk of failure. Therefore, when the temperature of the inverter 13 exceeds the third temperature T3 (e.g., 40 degrees), the switching valve 15 is switched so that the cooling fluid flows only through the second motor flow path 16b. Thus, the failure of the inverter 13 can be prevented, and the battery 22 can be efficiently preheated.

[0035] Moreover, when the temperature of the battery 22 exceeds the first temperature T1 (e.g., 5 degrees), the switching valve 15 of the cooling system A is switched so that the cooling fluid flows through both the first motor flow path 16a and the second motor flow path 16b. Therefore, the cooling of the motor 12 and the inverter 13 can be given priority over the preheating of the battery 22.

[0036] [Other Embodiments]

[0037] (1) In the above-described embodiment, the switching valve 15 is controlled based on the temperature of the inverter 13, but it is also possible to control the switching valve 15 based on the temperature of the motor 12.

[0038] (2) In the above-described embodiment, the cooler 24 is stopped in order to prioritize the preheating of the battery 22, but in the case where heat exchange is required in the refrigerant circuit (e.g., a heat pump system) that exchanges heat with the cooler 24 at the cooler 24, the cooler 24 can also be operated.

[0039] (3) The control for switching between the motor 12 and the inverter 13 constituted by the parallel flow paths (the first motor flow path 16a and the second motor flow path 16b) by the switching valve 15 as in the above-described embodiment is not limited to the above-described embodiment. For example, it may be that when the temperature of the battery 22 is equal to or lower than the first temperature T1 (e.g., 5 degrees), the switching valve 15 is switched so that the cooling fluid flows only in the second motor flow path 16b, and the battery 22 is preheated using the self-heat generation of the inverter 13.

[0040] In the above-described embodiment, the following structure is considered.

[0041] <1> One form of the cooling system (A) includes: a motor (12); a power converter (13); flow paths (16, 16a, 16b) that allow a cooling fluid to flow to the motor (12) and the power converter (13); and a switching valve (15) that switches the flow paths (16a, 16b) through which the cooling fluid flows. The flow paths include a first flow path (16a) and a second flow path (16b) that branch into two branches and then converge again. The motor (12) is disposed in the first flow path (16a), the power converter (13) is disposed in the second flow path (16b), and the switching valve (15) is configured to be disposed at the portion where the flow path (16) branches into the first flow path (16a) and the second flow path (16b), and is capable of switching the flow path through which the cooling fluid flows between the first flow path (16a) and the second flow path (16b).

[0042] In this method, the motor (12) is arranged in the first flow path (16a), the power converter (13) is arranged in the second flow path (16b), a switching valve (15) is arranged at the part where the flow path (16) branches into the first flow path (16a) and the second flow path (16b), and it is configured that the flow path (16) through which the cooling fluid flows can be switched between the first flow path (16a) and the second flow path (16b) by the switching valve (15). Thus, the motor (12) and the power converter (13) are arranged in parallel with respect to the flow paths (16a, 16b), and the cooling fluid absorbs the heat of the power converter (13) and then absorbs the heat of the motor (12). Thus, an abnormal condition such as a decrease in the amount of heat absorbed by the cooling fluid at the motor (12) does not occur. Thus, a cooling system (A) in which the cooling fluid can efficiently absorb the heat generated by the motor (12) can be provided.

[0043] <2> Preferably, in the cooling system (A) of <1>, a battery (22) used for driving the motor (12) is further provided, and the switching valve (15) switches the flow path through which the cooling fluid flows between the first flow path (16a) and the second flow path (16b) based on the temperature of the battery (22).

[0044] Accordingly, the cooling system (A) further includes a battery (22) used for driving the motor. The switching valve (15) switches the flow path through which the cooling fluid flows between the first flow path (16a) and the second flow path (16b) based on the temperature of the battery (22). Therefore, the temperature of the battery (22) can be appropriately controlled, and the cooling fluid can efficiently absorb the heat generated by the motor (12). In addition, when preheating the battery (22), the cooling fluid is made to flow only through the first flow path (16a). Thus, the self-heat of the motor (12) with a large heat capacity can be used to heat the cooling fluid, and the temperature rise of the battery (22) can be achieved quickly.

[0045] <3> Preferably, in the cooling system (A) of <2>, a battery flow path (26) is provided. The battery flow path (26) can be connected to the part where the first flow path (16a) and the second flow path (16b) in the flow path (16) converge, and the battery (22) is connected to the battery flow path (26).

[0046] Accordingly, the cooling system (A) includes a battery flow path (26). The battery flow path (26) can be connected to the part where the first flow path (16a) and the second flow path (16b) in the flow path (16) converge, and the battery (22) is connected to the battery flow path (26). Thus, the cooling fluid is made to flow only through the first flow path (16a), and the self-heat of the motor (12) with a large heat capacity is used to heat the cooling fluid. Then, the cooling fluid is made to flow from the flow path (16) to the battery flow path (26). Thus, the temperature rise of the battery (22) can be achieved quickly.

[0047] <4> Preferably, in the cooling system (A) described in <3>, the switching valve (15) switches the flow path through which the cooling fluid flows between the first flow path (16a) and the second flow path (16b) based on the temperature of the power converter (13).

[0048] Accordingly, the switching valve (15) switches the flow path through which the cooling fluid flows between the first flow path (16a) and the second flow path (16b) based on the temperature of the power converter (13). Therefore, the temperature of the power converter (13) can be appropriately controlled, and the cooling fluid can efficiently absorb the heat generated by the motor (12). Especially when a CPU is built in the power converter (13), the CPU is not heat-resistant, so it is important to appropriately control the temperature of the power converter (13).

[0049] <5> Preferably, in the cooling system (A) described in <4>, when the temperature of the battery (22) is below the first predetermined temperature (T1) and the temperature of the power converter (13) is less than the second predetermined temperature (T2), the switching valve (15) switches to make the cooling fluid flow only in the first flow path (16a). When the temperature of the battery (22) is below the first predetermined temperature (T1) and the temperature of the power converter (13) exceeds the third predetermined temperature (T3) higher than the second predetermined temperature (T2), the switching valve (15) switches to make the cooling fluid flow only in the second flow path (16b).

[0050] Accordingly, when the temperature of the battery (22) is below the first predetermined temperature (T1) and the temperature of the power converter (13) is less than the second predetermined temperature (T2), the battery (22) needs to be preheated. Therefore, the switching valve (15) switches to make the cooling fluid flow only in the first flow path (16a). Thus, the heat of the motor (12) can be efficiently absorbed to heat the cooling fluid, and the battery (22) can be efficiently preheated. In addition, in this state, the cooling fluid does not flow into the second flow path (16b), so the power converter (13) is not cooled and self-heats. If the power converter (13) becomes high temperature due to heat generation, a failure may occur. Therefore, when the temperature of the power converter (13) exceeds the third predetermined temperature (T3) higher than the second predetermined temperature (T2), the switching valve (15) switches to make the cooling fluid flow only in the second flow path (16b). Thus, the failure of the power converter (13) can be prevented, and the battery (22) can be efficiently preheated.

[0051] <6> Preferably, in the cooling system (A) described in <4>, when the temperature of the battery (22) exceeds the first predetermined temperature (T1), the switching valve (15) switches to make the cooling fluid flow in both the first flow path (16a) and the second flow path (16b).

[0052] Accordingly, when the temperature of the battery (22) exceeds the first predetermined temperature (T1), the switching valve (15) switches to allow the cooling fluid to flow through both the first flow path (16a) and the second flow path (16b). Therefore, it is possible to cool the motor (12) and the power converter (13) preferentially over preheating the battery (22).

[0053] Industrial applicability

[0054] The present disclosure can be utilized in a cooling system.

[0055] Description of reference numerals

[0056] 12... motor; 13... inverter (power converter); 15... switching valve; 16... motor flow path (flow path); 16a... first motor flow path (first flow path, flow path); 16b... second motor flow path (second flow path, flow path); 22... battery; 26... battery flow path (flow path); A... cooling system; T1... first temperature (first predetermined temperature); T2... second temperature (second predetermined temperature); T3... third temperature (third predetermined temperature).

Claims

1. A cooling system, It is characterized in that have: motor; Power converters; a flow path that allows a cooling fluid to flow toward the motor and the power converter; and a switching valve for switching the flow path through which the cooling fluid flows, The flow path includes a first flow path that branches into two branches and merges again with a second flow path, The motor is arranged in the first flow path. The power converter is arranged in the second flow path, The switching valve is disposed at a portion where the flow path branches into the first flow path and the second flow path, and is configured to be capable of switching the flow path through which the cooling fluid flows between the first flow path and the second flow path.

2. The cooling system according to claim 1, It is characterized in that A battery is also provided for driving the motor. The switching valve switches the flow path through which the cooling fluid flows between the first flow path and the second flow path based on the temperature of the battery.

3. The cooling system according to claim 2, It is characterized in that A battery flow path is provided, wherein the battery flow path can be connected to a portion of the flow path where the first flow path and the second flow path merge, The battery is connected to the battery flow path.

4. The cooling system according to claim 3, It is characterized in that The switching valve switches the flow path through which the cooling fluid flows between the first flow path and the second flow path based on the temperature of the power converter.

5. The cooling system according to claim 4, It is characterized in that When the temperature of the battery is below a first predetermined temperature and the temperature of the power converter is lower than a second predetermined temperature, the switching valve is switched so that the cooling fluid flows only in the first flow path; and when the temperature of the battery is below the first predetermined temperature and the temperature of the power converter exceeds a third predetermined temperature higher than the second predetermined temperature, the switching valve is switched so that the cooling fluid flows only in the second flow path.

6. The cooling system according to claim 4, It is characterized in that The switching valve switches so that the cooling fluid flows through both the first flow path and the second flow path when the temperature of the battery exceeds a first predetermined temperature.

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