Battery warming system

Abstract

To provide a battery warming system that reduces heat loss generated by a rear-wheel drive device located at the rear of the vehicle and improves electricity consumption, among other benefits.SOLUTION: A battery warming system comprises: a rear wheel drive device 2 which has at least a motor transmitting driving rotational force to a travel system of a vehicle and a housing storing the motor and is arranged at the rear of a battery 3 supplying electric power to the motor; and a warming mechanism which transmits at least waste heat of the motor to the battery 3. The warming mechanism has a pump 53 which pumps cooling liquid distributed through the rear wheel drive device 2 and the battery 3 and valves 55 and 56 which are capable of creating a first state to circulate the cooling liquid through the rear wheel drive device 2 and the battery 3. The pump 53 and the valves 55 and 56 are arranged between the battery 3 and the rear wheel drive device 2.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a battery warm-up system. [Background technology]

[0002] Conventionally, there is known a cooling mechanism for cooling a motor that transmits drive torque to a vehicle's running system and a battery that supplies power to the motor (for example, Patent Document 1). This cooling mechanism stores at least a portion of the motor, battery, etc. in the same storage container, and cools the motor, battery, etc. by a common cooling mechanism provided in the storage container.

[0003] The cooling mechanism described in Patent Document 1 includes a flow path changing means capable of switching the circulation flow path of the cooling fluid, and switches the circulation flow path of the cooling fluid according to the temperature of the motor, the battery, etc. When cooling the battery, the cooling fluid delivered by the cooling mechanism provided at the front of the vehicle flows through the battery and the motor in that order, and then passes through a flow path that bypasses the battery before being returned to the cooling mechanism. When warming up the battery, the circulation flow path is switched so that the flow direction of the cooling fluid is reversed, and the cooling fluid delivered by the cooling mechanism passes through a flow path that bypasses the battery to cool the motor, warms up the battery, and is then returned to the cooling mechanism. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-105645 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the cooling system described in Patent Document 1, since the cooling mechanism is provided at the front of the vehicle, in order to utilize the heat generated by the motor located at the rear of the vehicle to warm up the battery, it was necessary to move the cooling fluid from the rear to the front of the vehicle and then circulate it to the battery. Therefore, the piping flow path from the motor to the battery was long, which caused heat loss. In addition, switching the circulation flow path to reverse the flow of the cooling fluid increased the load on the pump.

[0006] Therefore, there is a demand for a battery warm-up system having a cooling mechanism that can reduce heat loss due to heat radiation from piping. [Means for solving the problem]

[0007] The characteristic configuration of the battery warm-up system of the present invention is that it comprises a rear wheel drive device that includes at least a motor that transmits driving rotational force to the vehicle's running system and a housing that accommodates the motor, and is arranged rearward of a battery that supplies power to the motor, and a warm-up mechanism that transmits at least the waste heat of the motor to the battery, wherein the warm-up mechanism has a pump that pressurizes cooling fluid to be circulated through the rear wheel drive device and the battery, and a valve that is capable of creating a first state in which the cooling fluid circulates between the rear wheel drive device and the battery, and the pump and the valve are arranged between the battery and the rear wheel drive device.

[0008] In this configuration, the warm-up mechanism that transfers waste heat from the motor to the battery has a pump that pumps cooling fluid to the battery and a valve that can create a first state in which cooling fluid circulates between the rear wheel drive system and the battery, and warms up the battery in the first state. Here, the rear wheel drive system is disposed rearward of the battery, and the pump and valve are disposed between the battery and the rear wheel drive system. Therefore, compared to a case in which cooling fluid is circulated from the rear to the front of the vehicle and then the battery is warmed up, heat generated in the rear wheel drive system can be transferred to the battery through a short flow path, making it possible to reduce heat loss due to heat dissipation from piping. This makes it possible to improve electricity consumption and fuel efficiency (hereinafter sometimes referred to as "electricity consumption, etc.") when using heating in winter.

[0009] In this way, the loss of heat generated in the rear wheel drive unit located at the rear of the vehicle can be reduced, resulting in a battery warm-up system that improves power consumption, etc. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of an electric vehicle equipped with a battery warm-up system. [Diagram 2] FIG. 2 is a circuit diagram of a battery warm-up system. [Diagram 3] 4A and 4B are diagrams illustrating a first mode of operation of the warm-up mechanism. [Figure 4] 11A and 11B are diagrams illustrating a second mode of operation of the warm-up mechanism. [Diagram 5] 13A and 13B are diagrams illustrating a third mode of operation of the warm-up mechanism. [Figure 6] FIG. 11 is a schematic diagram of a battery case according to a second embodiment. [Figure 7] FIG. 11 is a schematic view of a housing according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of a battery warm-up system according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment, and various modifications are possible without departing from the spirit and scope of the present invention.

[0012] First Embodiment FIG. 1 shows the configuration of an electric vehicle A equipped with a battery warm-up system 1 according to this embodiment. The battery warm-up system 1 includes a rear-wheel drive device 2, a battery 3, a power conversion module 4, and a warm-up mechanism 5. The rear-wheel drive device 2 generates driving force for rear wheels 13. The electric vehicle A according to this embodiment is an electric vehicle equipped with a motor as a driving source (such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a battery electric vehicle (BEV), or a fuel cell electric vehicle (FCEV)). In this embodiment, an example is shown in which the battery 3 is provided at the bottom center of the vehicle, and the rear-wheel drive device 2 is provided between a pair of rear wheels 13. Hereinafter, the positive direction of the X-axis in FIG. 1 may be referred to as the front, the negative direction as the rear, and the positive direction of the Y-axis as the up.

[0013] The rear-wheel drive device 2 is provided between a pair of rear wheels 13 of the electric vehicle A, and is disposed behind the battery 3. The rear-wheel drive device 2 has a motor 20 and a power transmission mechanism 24, each of which is accommodated in a housing 21 (see FIG. 7). The motor 20 is a known motor that generates a field magnet using a permanent magnet. The rear-wheel drive device 2 has an oil flow path (not shown) that circulates oil within the device. An oil pump and an oil cooler 23 are provided in the middle of the oil flow path, and the oil flow path supplies oil to the motor 20, the power transmission mechanism 24, etc., and circulates the oil in the rear-wheel drive device 2. The oil cooler 23 exchanges heat between the oil and a cooling fluid circulating in a cooling flow path 51 (described later), thereby cooling the rear-wheel drive device 2 and increasing the temperature of the cooling fluid (see FIG. 7). The cooling fluid is composed of an antifreeze liquid mainly composed of ethylene glycol or the like, a long-life coolant, an insulating oil such as paraffin-based, a hydrofluorocarbon (HFC), a hydrofluoroolefin (HFO), etc. (The same applies below.) In the following embodiment, an example is shown in which a cooling liquid such as an antifreeze liquid mainly composed of ethylene glycol or the like, a long-life coolant, or an insulating oil such as paraffin-based flows through the cooling flow path 51 as the cooling fluid.

[0014] The power conversion module 4 has an inverter and a power supply unit (not shown). The inverter has a motor drive board on which a switching element is mounted to control a drive current that drives the motor 20. The power conversion module 4 is supplied with power from the battery 3. In other words, the motor 20 is driven by the power supplied from the battery 3. The configuration of the inverter is well known, so a detailed description will be omitted.

[0015] The power supply unit of the power conversion module 4 is connected to the battery 3 and performs power conversion. The battery 3 is a high-voltage battery that drives the motor 20. The power supply unit has an OBC (On Board Charger) board (not shown) on which a power converter is mounted. The power converter includes at least an AC-DC converter that converts an externally input AC to a DC, and a DC-DC converter that converts the DC voltage into a DC voltage suitable for charging the battery 3. In this embodiment, the power conversion module 4 is disposed on the upper part of the battery case 30 via a cooling plate 40 (see Figs. 1 and 6). The cooling plate 40 is made of a metal with high thermal conductivity such as aluminum, and a cooling liquid flows through a space formed inside. The cooling liquid exchanges heat with the power conversion module 4 to lower the temperature of the power conversion module 4 and to raise the temperature of the cooling liquid.

[0016] The above-mentioned rear wheel drive device 2, battery 3, power conversion module 4, etc. each have an appropriate operating temperature. Therefore, the warm-up mechanism 5 adjusts the temperature of each device to an appropriate operating temperature by controlling the temperature of the coolant that cools each device. Also, an air conditioning unit 12 is provided to adjust the temperature inside the vehicle cabin.

[0017] 2 is a circuit diagram through which coolant for the warm-up mechanism 5 flows. The warm-up mechanism 5 is roughly composed of a cooling flow path 51 and a refrigerant flow path 52. Coolant such as antifreeze containing ethylene glycol or the like as a main component, long-life coolant, and paraffin-based insulating oil flows through the cooling flow path 51, while refrigerant such as hydrofluorocarbon (HFC) or hydrofluoroolefin (HFO) flows through the refrigerant flow path 52. The warm-up mechanism 5 cools the rear wheel drive device 2 and warms up the battery 3 through the cooling flow path 51.

[0018] First, the cooling flow passage 51 will be described. The cooling flow passage 51 has a flow passage 511, which is connected to a flow passage 512 or a flow passage 514 via a first changeover valve 55 (an example of a valve). The first changeover valve 55 is a four-way valve, and includes, for example, two L-shaped passages that are not connected to each other. A first pump 53 is disposed in the middle of the flow passage 511. When the first changeover valve 55 connects the flow passages 511 and 512, the cooling liquid that has circulated through the rear wheel drive device 2 passes through the flow passage 511, is pressurized by the first pump 53, and then circulates through the flow passage 512 (see FIG. 3). The first pump 53 and the first changeover valve 55 are disposed between the rear wheel drive device 2 and the battery 3. That is, a part of the warm-up mechanism 5 is provided at the rear of the electric vehicle A.

[0019] The power conversion module 4 (not shown) and the battery 3 are disposed in the middle of the flow path 512. In this embodiment, the power conversion module 4 is disposed above the battery case 30 and is in contact with the battery case 30 via the cooling plate 40 (see FIG. 6). The cooling plate 40 constitutes a part of the flow path 512, and the coolant flowing through the flow path 512 exchanges heat between the battery 3 and the power conversion module 4. The flow path 512 is connected to the flow path 513 or the flow path 516 via a second switching valve 56 (an example of a valve) on the downstream side of the power conversion module 4 and the battery 3. Hereinafter, the upstream side and the downstream side with respect to the flow direction of the coolant in the cooling flow path 51 are also simply referred to as the upstream side and the downstream side. The second switching valve 56 is a four-way valve like the first switching valve 55. When the second switching valve 56 connects the flow path 512 and the flow path 513, the coolant flows in the order of the flow path 512, the power conversion module 4, the battery 3, the flow path 513, and the rear wheel drive device 2 (see FIG. 3). The second switching valve 56 is disposed between the rear wheel drive device 2 and the battery 3, similar to the first switching valve 55.

[0020] When the first switching valve 55 connects the flow path 511 and the flow path 514, the coolant flows through the flow path 511, is pressurized by the first pump 53, and then flows through the flow path 514 (see FIG. 4). The third switching valve 57 and the radiator 7 are disposed in the middle of the flow path 514. The radiator 7 is disposed in front of the electric vehicle A as shown in FIG. 1, and cools the coolant by exchanging heat with the outside air. The flow path 514 is connected to the flow path 513 or the flow path 516 via the second switching valve 56 on the downstream side. When the flow path 514 is connected to the flow path 513 via the second switching valve 56, the coolant flows through the rear wheel drive device 2, the flow path 511, the flow path 514, the radiator 7, and the flow path 513 in this order. Note that a three-way valve is provided as the third switching valve 57 on the upstream side of the radiator 7, and the flow path 514 is connected to the flow path 515 via the third switching valve 57. The flow path 515 is connected to the flow path 514 downstream of the radiator 7. In other words, the flow path 515 is a flow path that bypasses the radiator 7, and the coolant can be prevented from flowing through the radiator 7 by operating the third switching valve 57.

[0021] When the second switching valve 56 connects the flow path 514 and the flow path 516, the coolant flows through the flow path 514, and is then pressurized by the second pump 54 and flows through the flow path 516 (see FIG. 5). The flow path 516 is connected to the chiller 6 (heat exchanger), and the coolant is cooled by exchanging heat with a refrigerant described later in the chiller 6. The coolant that has flowed through the chiller 6 passes through the flow path 517 and is connected to the flow path 512 via the first switching valve 55. That is, when the first switching valve 55 connects the flow path 511 and the flow path 514 and also connects the flow path 517 and the flow path 512, and the second switching valve 56 connects the flow path 514 and the flow path 516 and also connects the flow path 512 and the flow path 513, the coolant circulates through the cooling flow path 51 in the order of the rear wheel drive device 2, the flow path 511, the flow path 514, the radiator 7, the flow path 516, the chiller 6, the flow path 517, the flow path 512, and the flow path 513.

[0022] As described above, the first switching valve 55 and the second switching valve 56 include two L-shaped passages that are not connected to each other. Therefore, by operating the first switching valve 55, it is possible to switch between a state in which the flow path 511 and the flow path 512 are connected and the flow path 514 and the flow path 517 are connected, and a state in which the flow path 511 and the flow path 514 are connected and the flow path 517 and the flow path 512 are connected. Similarly, by operating the second switching valve 56, it is possible to switch between a state in which the flow path 512 and the flow path 513 are connected and the flow path 514 and the flow path 516 are connected, and a state in which the flow path 513 and the flow path 514 are connected and the flow path 512 and the flow path 516 are connected. In this way, by switching the first switching valve 55 and the second switching valve 56, respectively, it is possible to switch between a state in which the flow paths 511, 512, and 513 communicate (first state), a state in which the flow paths 511, 514, and 513 communicate and the flow paths 512, 516, and 517 communicate (second state), and a state in which the flow paths 511, 514, 516, 517, 512, and 513 communicate (third state (also a form of the second state)). Therefore, by setting the cooling flow path 51 to the first state when warming up the battery 3, it is possible to circulate the coolant in a short flow path, thereby reducing waste heat loss from the rear wheel drive device 2 and efficiently warming up the battery 3.

[0023] The warm-up mechanism 5 includes a control unit (not shown) capable of controlling the first pump 53, the second pump 54, the first switching valve 55, the second switching valve 56, and the third switching valve 57 arranged in the cooling flow path 51. The control unit controls the operation of the first switching valve 55, the second switching valve 56, and the third switching valve 57 based on the temperature of the battery 3 and the temperature of the coolant circulating through the cooling flow path 51. Specifically, the control is performed based on the temperature of the battery 3 and the outlet temperature of the rear wheel drive device 2 of the coolant circulating through the cooling flow path 51. The temperature of the battery 3 is detected by, for example, a temperature sensor (not shown) arranged in the battery 3. The outlet temperature of the rear wheel drive device 2 of the coolant circulating through the cooling flow path 51 is detected by, for example, a temperature sensor (not shown) arranged near the outlet of the rear wheel drive device 2 in the cooling flow path 51.

[0024] The control unit switches the cooling flow path 51 to the first state, the second state, or the third state based on the temperature of the battery 3 and the temperature of the coolant circulating through the cooling flow path 51. Therefore, it is possible to efficiently control the temperature of each device.

[0025] Next, the refrigerant flow path 52 will be described. The refrigerant flow path 52 is a flow path on the left side of the chiller 6 in FIG. 2, and a refrigerant flows through the refrigerant flow path 52. The refrigerant flow path 52 has a refrigerant passage 521 on the downstream side of the flow direction of the refrigerant with respect to the chiller 6 (hereinafter, the upstream side and downstream side with respect to the flow direction of the refrigerant in the refrigerant flow path 52 are also simply referred to as the upstream side and downstream side). In the middle of the refrigerant passage 521, an accumulator 9, a compressor 10, a first valve 15, and an indoor condenser 8 are arranged in this order. The refrigerant passage 521 is connected to a refrigerant passage 522 on the downstream side. The refrigerant passage 522 is connected to the chiller 6 via a first expansion valve 58 arranged in the middle. That is, the chiller 6 is attached to the refrigerant passage 522 at a position downstream with respect to the flow direction of the refrigerant compressed at high temperature by the compressor 10.

[0026] A refrigerant path 524 branches off from the refrigerant path 521 downstream of the compressor 10 and upstream of the first valve 15. A second valve 16 and an outdoor condenser 14 are arranged in this order in the middle of the refrigerant path 524. The refrigerant path 524 is connected to the refrigerant path 522 on the downstream side.

[0027] A refrigerant path 523 branches off from the refrigerant path 522 upstream of the first expansion valve 58 in the refrigerant path 522. A second expansion valve 59, an evaporator 11, and a check valve (not shown) are arranged in this order in the middle of the refrigerant path 523. The refrigerant path 523 is connected to the refrigerant path 521 on the downstream side.

[0028] Next, the flow of the refrigerant in the refrigerant flow passage 52 will be described. The refrigerant compressed by the compressor 10 into a high-temperature compressed gas flows through the refrigerant passage 521 when the first valve 15 is open, and heats the air in the interior condenser 8. The heated air becomes hot air and is used to heat the vehicle interior. When the heating is not used, the second valve 16 is open, and the refrigerant flows into the refrigerant passage 524 and is cooled in the exterior condenser 14. The refrigerant flowing out of the interior condenser 8 or the exterior condenser 14 flows through the refrigerant passage 522, is expanded by the first expansion valve 58, and is turned into a low-temperature, low-pressure mist, and is then sent to the chiller 6. The mist refrigerant absorbs heat from the cooling liquid flowing in from the flow passage 516 in the chiller 6 and evaporates. The refrigerant flowing out of the chiller 6 flows through the refrigerant passage 521, and in the accumulator 9, if the vaporized refrigerant contains liquid, the liquid refrigerant is separated. Since a check valve is provided in the refrigerant passage 523, the refrigerant does not flow into the evaporator 11. Thereafter, the vaporized refrigerant flows out of the accumulator 9 and flows back to the compressor 10, where it is compressed again to become a high-temperature, high-pressure gas.

[0029] On the other hand, when cooling the vehicle interior, the refrigerant flowing out from the exterior condenser 14 is expanded by the second expansion valve 59 to be turned into a low-temperature, low-pressure mist, and then flows into the evaporator 11. The refrigerant flowing into the evaporator 11 absorbs heat from the air introduced from the outside and evaporates. The air is cooled by the refrigerant absorbing heat, and is sent into the vehicle interior as cold air. The evaporated refrigerant flows through a check valve (not shown) arranged in the refrigerant passage 523 and flows into the refrigerant passage 521. The evaporated refrigerant then flows through the refrigerant passage 521 and is sent to the accumulator 9. In the accumulator 9, if the evaporated refrigerant contains liquid, the liquid is separated from the evaporated refrigerant. The evaporated refrigerant then flows back to the compressor 10 and is compressed again to become a high-temperature compressed gas.

[0030] An air conditioning system (HVAC system) that performs heating, ventilation, and air conditioning for the interior of a vehicle is performed by an air conditioning unit 12 shown in Fig. 1. The air conditioning unit 12 has an air conditioning case (not shown) and is disposed, for example, in a dashboard panel.

[0031] The air conditioning unit 12 is equipped with a blower fan (not shown). The blower fan has an inside / outside air switching door (a door for switching between recirculated air and fresh air), an outside air inlet, and an inside air inlet. The inside / outside air switching door is appropriately switched to introduce air outside the vehicle (outside air) into the air conditioning unit 12 through the outside air inlet, or to introduce air inside the vehicle cabin (inside air) into the air conditioning unit 12 through the inside air inlet.

[0032] Depending on the rotation speed of the drive motor, the blower fan draws outside air from the outside air inlet or inside air from the inside air inlet as an airflow toward the evaporator 11. The evaporator 11 cools the airflow sucked in from the blower fan with a refrigerant.

[0033] Next, a description will be given of a usage mode of the warm-up mechanism 5 while the electric vehicle A is traveling. A usage mode of the warm-up mechanism 5 when warming up the battery 3 (hereinafter referred to as a first mode) will be described with reference to FIG.

[0034] The first mode is a mode of use immediately after the electric vehicle A is driven after the battery 3 has been warmed up to a certain degree when the outside air temperature is low (for example, 0° C. or lower), or when the electric vehicle A is driven when the outside air temperature is 0° C. or higher and lower than 40° C., and the battery 3 is in the middle of being warmed up or has been warmed up. At this time, it is necessary to supply cooled coolant to the rear wheel drive device 2. On the other hand, when the battery 3 is at 0° C. or lower, it is necessary to supply heated coolant to the battery 3 to warm up the battery 3. Also, since the battery 3 operates properly at a temperature range of, for example, 25° C. or higher and lower than 40° C., it may be warmed up if the temperature is lower than 40° C. Then, the first switching valve 55 and the second switching valve 56 are switched by the control unit to a first state in which the rear wheel drive device 2 and the battery 3 are communicated with each other, and the flow paths 511, 512, and 513 are communicated with each other. In the first mode shown in FIG. 3, the coolant flows through the flow paths indicated by the thick solid lines.

[0035] In the cooling flow path 51, the first pump 53 is operating, and the coolant pumped by the first pump 53 heats the battery 3. This makes it possible to heat and warm up the battery 3 by utilizing waste heat from the rear wheel drive device 2 in the cooling flow path 51. Note that if the heat quantity of the coolant is insufficient, an electric heater for heating the coolant may be provided upstream of the battery 3.

[0036] As described above, in the first state, the coolant does not flow through the radiator 7 provided in front of the electric vehicle A, and transfers heat from the rear wheel drive device 2 to the battery 3 through a short flow path, thereby suppressing heat loss due to piping radiation. Therefore, the waste heat from the rear wheel drive device 2 can be efficiently transferred to the battery 3. As a result, the warm-up mechanism 5 can quickly heat the battery 3 using the waste heat from the rear wheel drive device 2. Furthermore, suppressing heat loss makes it possible to improve electricity efficiency, etc.

[0037] Next, a usage mode (hereinafter, referred to as a second mode) of the warm-up mechanism 5 when only the rear wheel drive device 2 is cooled will be described with reference to FIG.

[0038] The second mode is, for example, a mode of use in a state where the electric vehicle A is driven and warming up is completed. In this case, it is necessary to supply cooled coolant to the rear wheel drive device 2. On the other hand, it is not necessary to supply heated coolant to the battery 3. Therefore, in the second mode, unlike the first mode, the first switching valve 55 and the second switching valve 56 are switched to the second state, the flow paths 511, 514, and 513 are connected, and the flow paths 512, 516, and 517 are connected. As a result, the coolant is cooled by the radiator 7, and the rear wheel drive device 2 can be cooled. In the second mode shown in FIG. 4, the coolant flows through the flow paths indicated by the thick solid lines. Note that, when it is not necessary for the coolant to be cooled by the radiator 7, the third switching valve 57 may be switched to allow the coolant to flow through the flow path 515. When the coolant is also supplied to the battery 3, the second pump 54 may be driven to circulate the coolant through the flow paths 512, 516, and 517. In this case, heat exchange may take place in the chiller 6 between the cooling liquid and the refrigerant.

[0039] Next, a usage mode (hereinafter, referred to as a third mode) of the warm-up mechanism 5 when cooling the battery 3 and the rear wheel drive device 2 will be described with reference to FIG.

[0040] The third mode is, for example, a mode of use when the electric vehicle A is driven for a long time under an environment in which the rear wheel drive device 2 requires high torque. In this case, it is necessary to supply cooled coolant to the rear wheel drive device 2. It is also necessary to supply coolant to the battery 3 to cool it. Therefore, in the third mode, the first switching valve 55 and the second switching valve 56 are switched to the third state, and the flow paths 511, 514, 516, 517, 512, and 513 are in a state of communication. As a result, the coolant heated by the waste heat of the rear wheel drive device 2 and the like in the cooling flow path 51 is cooled by the radiator 7. In the third mode shown in FIG. 5, the coolant flows through the flow path indicated by the thick solid line. Note that, during heating use, the third switching valve 57 connects the flow path 514 and the flow path 515 to bypass the radiator 7. Then, the refrigerant flows through the refrigerant paths 521 and 522, whereby the heat of the coolant is removed in the chiller 6, and the waste heat of the rear wheel drive device 2 and the like is used for heating.

[0041] Second Embodiment In the first embodiment, an example has been described in which the first pump 53, the first switching valve 55, and the second switching valve 56 are provided between the rear wheel drive device 2 and the battery 3. Alternatively, the first pump 53, the first switching valve 55, and the second switching valve 56 may be integrated into the battery case 30 that houses the battery 3 as shown in FIG. 6. Specifically, the first pump 53 and the first switching valve 55 are arranged on a side surface of the battery case 30 as shown in FIG. 6. The second switching valve 56 is arranged on the opposite side to the side surface on which the first switching valve 55 is arranged. The power conversion module 4 is arranged on the upper part of the battery case 30 via the cooling plate 40, and the cooling plate 40 constitutes a part of the flow path 512. The other configurations are the same as those of the first embodiment, so detailed description of the same configurations as those of the first embodiment will be omitted.

[0042] As in the present embodiment, by integrating a part of the warm-up mechanism 5 with the battery case 30, the overall size of the device can be reduced, which makes it possible to expand the vehicle mounting space. In addition, the amount of piping required for the warm-up mechanism 5 can be reduced.

[0043] Third Embodiment In the first embodiment, an example has been described in which the power conversion module 4 is provided so as to be in contact with the upper part of the battery case 30 via the cooling plate 40. Alternatively, as shown in FIG. 7, the power conversion module 4 may be housed in the housing 21 that houses the motor 20. Specifically, as shown in FIG. 7, the first pump 53 and the first switching valve 55 are arranged on a side of the housing 21, and the second switching valve 56 is arranged on the opposite side. The rear wheel drive device 2 (the motor 20 and the power transmission mechanism 24 such as gears) is arranged below the housing 21, and the space inside the housing 21 is divided by a partition wall. In the upper space of the housing 21, the oil cooler 23 that cools the oil, the cooling plate 40 provided above the oil cooler 23, and the power conversion module 4 provided above the cooling plate 40 are arranged. The cooling plate 40 is in contact with the oil cooler 23 and the power conversion module 4, and constitutes a part of the flow path 513. Since the other configurations are the same as those of the first embodiment, detailed description of the same configurations as those of the first embodiment will be omitted.

[0044] In this embodiment, the power conversion module 4 is disposed in the housing 21, and a part of the warm-up mechanism 5 is integrated with the housing 21, thereby making it possible to reduce the size of the entire device, thereby enabling the in-vehicle space to be expanded. In addition, the amount of piping required for the warm-up mechanism 5 can be reduced.

[0045] In the above-described embodiment, the following configurations are envisaged. (1) A battery warm-up system 1 comprising: a rear wheel drive device 2 including at least a motor 20 that transmits driving torque to a vehicle's running system and a housing 21 that accommodates the motor 20, and arranged rearward of a battery 3 that supplies power to the motor 20; and a warm-up mechanism 5 that transfers at least the waste heat of the motor 20 to the battery 3, wherein the warm-up mechanism 5 has a pump (first pump 53) that pressurizes a cooling fluid to be circulated through the rear wheel drive device 2 and the battery 3, and valves (first switching valve 55 and second switching valve 56) that are capable of creating a first state in which the cooling fluid circulates through the rear wheel drive device 2 and the battery 3, and the pump (first pump 53) and the valves (first switching valve 55 and second switching valve 56) are arranged between the battery 3 and the rear wheel drive device 2.

[0046] In this configuration, the warm-up mechanism 5 that transfers waste heat from the motor 20 to the battery 3 includes a first pump 53 that pumps cooling fluid to the battery 3, and a first switching valve 55 and a second switching valve 56 that can switch the flow path of the cooling fluid. The warm-up mechanism 5 warms up the battery 3 in a first state in which the cooling fluid is circulated to the rear wheel drive device 2 and the battery 3. Here, the rear wheel drive device 2 is disposed rearward of the battery 3, and the first pump 53, the first switching valve 55, and the second switching valve 56 are disposed between the battery 3 and the rear wheel drive device 2. Therefore, compared to a case in which the cooling fluid is circulated from the rear side to the front side of the vehicle and then the battery 3 is warmed up, the heat generated in the rear wheel drive device 2 can be transferred to the battery 3 through a short flow path, and heat loss due to piping heat radiation can be reduced. This can improve the electricity consumption, etc.

[0047] (2) In the battery warm-up system 1 of (1), it is preferable that the valves (first switching valve 55 and second switching valve 56) are switching valves that can be switched between a first state and a second state in which cooling fluid is circulated to the rear wheel drive device 2 and the radiator 7.

[0048] The first switching valve 55 and the second switching valve 56 switch the cooling flow path 51 for the cooling fluid between a first state for warming up the battery 3 and a second state for circulating the cooling fluid to the rear wheel drive device 2 and the radiator 7 to cool the rear wheel drive device 2. This makes it possible to reduce the load on the first pump 53 that pumps the cooling fluid, since there is no need to reverse the cooling fluid in the first state when cooling the rear wheel drive device 2.

[0049] (3) In the battery warm-up system 1 of (1) or (2), it is preferable that the pump (first pump 53) and the valves (first switching valve 55 and second switching valve 56) are integrated into the battery case 30 that houses the battery 3.

[0050] In this configuration, the first pump 53, the first switching valve 55, and the second switching valve 56 are integrated into the battery case 30 that houses the battery 3, so that the overall device can be made more compact than when the battery case 30, the first pump 53, the first switching valve 55, and the second switching valve 56 are arranged separately from the battery case 30. This makes it possible to expand the loading space of the vehicle. In addition, the amount of piping for the warm-up mechanism 5 can be reduced.

[0051] (4) In the battery warm-up system 1 of (1) or (2), the rear wheel drive device 2 further has a power conversion module 4 including an electronic circuit that drives the motor 20, and it is preferable that the pump (first pump 53) and the valves (first switching valve 55 and second switching valve 56) are integrated into the housing 21, and the power conversion module 4 is accommodated in the housing 21.

[0052] In this configuration, the first pump 53, the first switching valve 55, and the second switching valve 56 are integrated into the housing 21 that accommodates the motor 20, and the power conversion module 4 including an electronic circuit for driving the motor 20 is accommodated in the housing 21, so that the overall size of the device can be reduced compared to a case in which these and the housing 21 are arranged separately. This makes it possible to increase the loading space of the electric vehicle A. In addition, the waste heat of the power conversion module 4 can also be utilized to warm up the battery 3, so that it is possible to further improve the electricity consumption, etc. Furthermore, the amount of piping for the warm-up mechanism 5 can be reduced.

[0053] Other embodiments (1) In the above-described embodiment, the second pump 54 may be integrated into the battery case 30. This makes it possible to reduce the size of the entire device compared to a case in which the second pump 54 and the battery case 30 are disposed separately.

[0054] (2) In the above-described embodiment, the cooling flow path 51 and the refrigerant flow path 52 may have a water-cooled condenser (heat exchanger). The water-cooled condenser may be provided in a flow path that branches off from the flow path 513, bypasses the rear wheel drive device 2, and connects to the flow path 511. In the refrigerant flow path 52, the water-cooled condenser may be provided in place of the exterior condenser 14. The water-cooled condenser heats the coolant by removing heat from the refrigerant in a high-temperature compressed gas state. Therefore, when the coolant is at a low temperature, the battery 3 can be efficiently warmed up by performing heat exchange in the water-cooled condenser.

[0055] (3) In the above-described embodiment, a front-wheel drive unit may be provided in addition to the rear-wheel drive unit 2 to form a four-wheel drive vehicle. [Industrial Applicability]

[0056] The present invention can be used in a battery warm-up system. [Explanation of symbols]

[0057] 1: battery warm-up system, 2: rear wheel drive device, 3: battery, 4: power conversion module, 5: warm-up mechanism, 20: motor, 21: housing, 30: battery case, 53: first pump (pump), 55: first switching valve (valve), 56: second switching valve (valve), 7: radiator

Claims

1. a rear wheel drive device including at least a motor that transmits a drive torque to a running system of a vehicle and a housing that accommodates the motor, the rear wheel drive device being disposed rearward of a battery that supplies power to the motor; a warm-up mechanism that transfers at least waste heat from the motor to the battery, the warm-up mechanism includes a pump that pumps a cooling fluid to be circulated through the rear wheel drive device and the battery, and a valve that can create a first state in which the cooling fluid is circulated through the rear wheel drive device and the battery, The pump and the valve are disposed between the battery and the rear wheel drive system.

2. 2. The battery warm-up system according to claim 1, wherein the valve is a switching valve that is switchable between the first state and a second state in which the cooling fluid is circulated to the rear wheel drive device and a radiator.

3. 3. The battery warm-up system according to claim 1, wherein the pump and the valve are integrated into a battery case that houses the battery.

4. the rear wheel drive device further comprises a power conversion module including an electronic circuit for driving the motor; 3. The battery warm-up system according to claim 1, wherein the pump, the valve and the power conversion module are integrated into the housing, and the power conversion module is accommodated in the housing.

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