Warm-up system

Abstract

To provide a warm-up system which uses waste heat of a brake oil for warming-up of a battery or heating of a passenger compartment.SOLUTION: A warm-up system A includes: a motor 1 which transmits driving rotational force to a traveling system of a vehicle; a battery 2 which supplies electric power to the motor 1; a braking mechanism 3 which brakes the vehicle with a fluid pressure of a brake oil stored in an oil tank; and a cooling passage which enables circulation of a cooling fluid to the battery 2 and the braking mechanism 3. The cooling fluid exchanges heat with the brake oil to use waste heat of the brake oil for warming-up of the battery 2 or heating of a passenger compartment.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a warm-up system that utilizes waste heat from brake oil to warm up or heat a battery. [Background technology]

[0002] Disc brakes used for braking vehicles apply braking by clamping a brake disc, which rotates together with the wheels, between brake pads using the hydraulic pressure of brake oil. When braking, the brake oil is heated by frictional heat between the brake disc and the brake pad. On the other hand, if the brake oil boils, air bubbles are generated in the brake piping, which may make it impossible to apply brake pressure. Therefore, in order to suppress this vapor lock phenomenon, a technique for cooling the brake oil is known (for example, Patent Document 1).

[0003] Patent Document 1 describes a cooling mechanism that provides a cooling flow path surrounding a brake oil flow path through which the brake oil flows, and cools the brake oil by heat exchange between the brake oil and a cooling fluid flowing through the cooling flow path. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-89162 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the cooling mechanism described in Patent Document 1, the brake oil is cooled by a cooling fluid, but the heat recovered by the cooling fluid is released into the outside air, so the waste heat of the brake oil cannot be utilized.

[0006] Therefore, there is a need for a warm-up system that cools the brake oil and utilizes the waste heat of the brake oil. [Means for solving the problem]

[0007] The warm-up system of the present invention is characterized by comprising a motor that transmits driving torque to the vehicle's running system, a battery that supplies power to the motor, a braking mechanism that brakes the vehicle using the hydraulic pressure of brake oil stored in an oil tank, and a cooling flow path that can circulate a cooling fluid between the battery and the braking mechanism, and the cooling fluid exchanges heat with the brake oil, thereby utilizing the waste heat of the brake oil to warm up the battery or heat the passenger compartment.

[0008] In automobiles equipped with a braking mechanism that brakes the vehicle using hydraulic pressure of brake oil, there is a risk of vapor lock occurring due to boiling of the brake oil. Therefore, according to this configuration, by performing heat exchange between the brake oil and the cooling fluid, it is possible to cool the brake oil and suppress the occurrence of the vapor lock phenomenon. Furthermore, the cooling fluid that has absorbed heat from the brake oil supplies the heat to the battery, thereby warming up the battery. In addition, when warming up of the battery is not necessary, the heat is used to heat the passenger compartment, making it possible to effectively utilize the waste heat of the brake oil. [Brief description of the drawings]

[0009] [Figure 1] 1 is a circuit configuration diagram of a warm-up system according to a first embodiment. FIG. [Diagram 2] FIG. 4 is a diagram showing a battery warm-up mode of the warm-up system according to the first embodiment. [Diagram 3] FIG. 4 is a diagram showing a heating mode of the warm-up system according to the first embodiment. [Figure 4] 3 is a schematic diagram of a cooling structure for a control mechanism according to the first embodiment; FIG. [Diagram 5] FIG. 6 is a circuit configuration diagram of a warm-up system according to a second embodiment. [Figure 6] FIG. 11 is a diagram showing a battery warm-up mode of the warm-up system according to the second embodiment. [Figure 7] FIG. 11 is a diagram showing a heating mode of the warm-up system according to the second embodiment. [Figure 8] FIG. 11 is a schematic diagram of a cooling structure for a control mechanism according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the 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.

[0011] First Embodiment 1 shows a circuit configuration diagram of a warm-up system A according to a first embodiment. The warm-up system A is mounted on an electric vehicle (such as a hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), battery electric vehicle (BEV), or fuel cell electric vehicle (FCEV)) equipped with a motor 1 that transmits drive torque to the vehicle's running system. Electric power is supplied to the motor 1 from a battery 2.

[0012] In an electric vehicle equipped with a motor 1, kinetic energy can be converted into electric power and recovered (regenerated), and the torque generated during the energy regeneration can be applied to the wheels as a braking force. Hereinafter, such a braking force is referred to as a regenerative brake. In addition to the regenerative brake, the wheels of the vehicle in this configuration are provided with a braking mechanism 3 that brakes the vehicle using the hydraulic pressure of brake oil stored in an oil tank 60 (see Figs. 4 and 8). The vehicle in this configuration is configured to brake the vehicle using both the regenerative brake and the braking mechanism 3, and when the braking force by the regenerative brake is insufficient, the braking mechanism is switched to braking by the braking mechanism 3. In addition, when the temperature of the battery 2 is below a predetermined temperature (for example, below 15°C) or when charging by the regenerative brake is impossible, a braking control unit (not shown) provided in the warm-up system A switches the braking of the vehicle from braking by the regenerative brake to braking by the braking mechanism 3.

[0013] The braking mechanism 3 is, for example, a disc brake, which applies braking by clamping a brake disc that rotates together with the wheel with brake pads 61 provided in a caliper. During braking, brake oil flows between the oil tank 60 and the brake pads 61, and the brake oil is heated by frictional heat between the brake disc and the brake pads 61, causing the temperature of the brake oil to rise. If the brake oil boils, air bubbles will form in the brake piping, and there is a risk that it will be impossible to apply brake pressure. Therefore, the warm-up system A is configured so that the cooling fluid can cool the brake oil.

[0014] 1, the warm-up system A is provided with a cooling flow path capable of circulating a cooling fluid to a battery 2 and a braking mechanism 3 through which brake oil flows. The cooling fluid in this configuration is a coolant, and the cooling flow path has a coolant flow path B through which the coolant circulates, and a refrigerant flow path C through which a refrigerant compressed by a compressor 9 circulates. The coolant is an antifreeze solution mainly composed of ethylene glycol or the like, a long-life coolant, or an insulating oil such as a paraffin-based oil, and the refrigerant is composed of a hydrofluorocarbon (HFC), a hydrofluoroolefin (HFO), or the like (same below).

[0015] First, the coolant flow path B will be described. The coolant flow path B is a flow path on the right side of the first heat exchanger 6 and the second heat exchanger 5 in FIG. 1. The coolant flow path B has a flow path 20, which is connected to a flow path 25 via a first switching valve 11 and to a flow path 21 via a second heat exchanger 5. A motor 1 is disposed in the middle of the flow path 20. The second heat exchanger 5 is, for example, a chiller, and the coolant transfers heat to a refrigerant in a low temperature state that flows in from a refrigerant path 30 (described later) in the second heat exchanger 5. When the first switching valve 11 connects the flow path 25 and the flow path 20, the coolant flows in the order of the flow path 25, the flow path 20, the motor 1, the flow path 20, the second heat exchanger 5, and the flow path 21. Hereinafter, the upstream side and downstream side of the flow direction of the coolant in the coolant flow path B are also simply referred to as the upstream side and the downstream side.

[0016] A flow path 22 branches off from the flow path 20 at a point downstream of the motor 1 via a second switching valve 12. The flow path 22 is connected to the flow path 21 downstream of the second heat exchanger 5. In other words, the flow path 22 is a flow path that bypasses the second heat exchanger 5.

[0017] The flow path 21 is connected to the flow path 25 via the first heat exchanger 6. The first heat exchanger 6 is, for example, a water-cooled condenser, and the coolant is heated in the first heat exchanger 6 by removing heat from the refrigerant in a high-temperature, high-pressure gas state that flows in from a refrigerant path 30 described later. The battery 2 and the radiator 4 are arranged in this order in the middle of the flow path 25. The third switching valve 13 is arranged upstream of the first heat exchanger 6 in the flow path 21 and downstream of the connection point with the flow path 22, and a flow path 24 branches off from the flow path 21 via the third switching valve 13. The flow path 24 is connected to the flow path 25 downstream of the battery 2. In other words, the flow path 24 is a flow path that bypasses the first heat exchanger 6 and the battery 2.

[0018] Further, a fourth switching valve 14 is disposed in the middle of the flow path 24, and a flow path 23 branches off from the flow path 24 via the fourth switching valve 14. The flow path 23 connects to a flow path 25 on the upstream side of the battery 2. That is, the flow path 23 is a flow path that bypasses the first heat exchanger 6. A first switching valve 11 is disposed in the flow path 25 on the downstream side of the radiator 4. The first switching valve 11 switches the flow path 25 to connect to the flow path 20 or the flow path 26. A braking mechanism 3 is disposed in the middle of the flow path 26, and the flow path 26 connects to the flow path 20 on the downstream side of the motor 1 and upstream of the second switching valve 12. The coolant flowing through the flow path 26 absorbs heat from the brake oil in the braking mechanism 3 and is heated.

[0019] Next, the refrigerant flow path C will be described. The refrigerant flow path C through which the refrigerant flows is a flow path on the left side of the first heat exchanger 6 and the second heat exchanger 5 in Fig. 1. The refrigerant flow path C has a refrigerant path 30, in which the second heat exchanger 5, the accumulator 10, the compressor 9, the first heat exchanger 6, and the first expansion valve 17 are arranged in this order. Hereinafter, the upstream side and downstream side of the refrigerant flow direction in the refrigerant flow path C are also simply referred to as the upstream side and the downstream side.

[0020] A fifth switching valve 15 is disposed downstream of the compressor 9 in the refrigerant passage 30 and upstream of the first heat exchanger 6, and a refrigerant passage 31 branches off from the refrigerant passage 30 via the fifth switching valve 15. The refrigerant passage 31 connects to the refrigerant passage 30 upstream of the first expansion valve 17. A condenser 7 is disposed in the middle of the refrigerant passage 31. A sixth switching valve 16 is disposed downstream of the connection point of the refrigerant passage 30 with the refrigerant passage 31 and upstream of the first expansion valve 17, and a refrigerant passage 32 branches off from the refrigerant passage 30 via the sixth switching valve 16. The refrigerant passage 32 connects to the refrigerant passage 30 downstream of the first expansion valve 17 in the refrigerant passage 30 and upstream of the second heat exchanger 5. A second expansion valve 18 and an evaporator 8 are disposed in this order in the middle of the refrigerant passage 32.

[0021] Next, the flow of the refrigerant in the refrigerant flow passage C will be described. When the fifth switching valve 15 and the sixth switching valve 16 do not cause a branch from the refrigerant flow passage 30, the refrigerant circulates through the refrigerant flow passage 30. The refrigerant that flows into the second heat exchanger 5 absorbs heat from the cooling liquid that flows in from the flow passage 20 and evaporates. When the evaporated refrigerant contains liquid, the liquid refrigerant is separated from the refrigerant that flows out of the second heat exchanger 5 in the accumulator 10. The refrigerant is then compressed by the compressor 9 to become a high-temperature, high-pressure gas, and is cooled by imparting heat to the cooling liquid that flows in from the flow passage 21 in the first heat exchanger 6. The refrigerant that flows out of the first heat exchanger 6 is expanded by the first expansion valve 17 to become a low-temperature, low-pressure mist, and then flows back to the second heat exchanger 5 (see FIG. 2).

[0022] When the fifth switching valve 15 connects the refrigerant path 30 and the refrigerant path 31, the refrigerant that has become a high-temperature, high-pressure gas in the compressor 9 flows into the condenser 7 and heats the air in the condenser 7 (cabin condenser). The heated air becomes hot air and is used to heat the vehicle interior. The refrigerant then flows through the refrigerant path 30 and is expanded by the first expansion valve 17 to become a low-temperature, low-pressure mist, and then flows back to the second heat exchanger 5 (see FIG. 3).

[0023] When the sixth switching valve 16 connects the refrigerant path 30 and the refrigerant path 32, the refrigerant flowing out of the first heat exchanger 6 or the refrigerant flowing out of the condenser 7 flows through the refrigerant path 32 via the sixth switching valve 16, is converted into a low-temperature, low-pressure mist by the second expansion valve 18, and then flows into the evaporator 8. The refrigerant that flows into the evaporator 8 absorbs heat from air introduced from the outside and evaporates. The air is cooled by the refrigerant absorbing heat, and is sent into the vehicle interior as cool air. The evaporated refrigerant flows into the refrigerant path 30 and is sent to the second heat exchanger 5.

[0024] Next, a usage mode of the warm-up system A while the vehicle is running will be described. A usage mode of the warm-up system A when the coolant flows into the braking mechanism 3 to remove heat from the brake oil and the heat is used to warm up the battery 2 (hereinafter referred to as the battery warm-up mode) will be described with reference to FIG.

[0025] When the battery 2 is at a predetermined temperature (for example, 15°C) or lower, the braking of the vehicle is switched from regenerative braking to braking by the braking mechanism 3 by a braking control unit (not shown). When the vehicle is braked by the braking mechanism 3, the brake oil is heated by frictional heat between the brake disc and the brake pad 61. When the brake oil reaches a predetermined temperature (for example, 40°C) or higher, the warm-up system A enters a battery warm-up mode in which the first heat exchanger 6 and the braking mechanism 3 communicate with each other. That is, the battery warm-up mode is a usage mode in which the battery 2 is at a predetermined temperature or lower and the brake oil is at a predetermined temperature or higher. At this time, the waste heat of the brake oil is used to warm up the battery 2. The temperature of the battery 2 and the temperature of the brake oil can be measured by a thermometer provided on the battery 2 or the oil tank 60, respectively. The braking control unit may switch the braking of the vehicle to braking by the braking mechanism 3 when the braking force by the regenerative brake is insufficient or charging by the regenerative brake is impossible.

[0026] In the battery warm-up mode, as shown in FIG. 2, the first switching valve 11 connects the flow path 25 and the flow path 26, and the second switching valve 12 connects the flow path 20 and the second heat exchanger 5. The third switching valve 13 connects the flow path 21 and the first heat exchanger 6, and the fifth switching valve 15 connects the refrigerant path 30 and the first heat exchanger 6, so that the first heat exchanger 6 communicates with the braking mechanism 3. The sixth switching valve 16 does not cause a branch from the refrigerant path 30. The switching of such switching valves is performed by a control unit (not shown) provided in the warm-up system A or a system higher than the warm-up system A. The control unit performs control based on the temperature detected by a thermometer provided in the oil tank 60. In this case, the coolant circulates through the flow paths 26, 20, 21, and 25, and the refrigerant circulates through the refrigerant path 30. In the battery warm-up mode shown in FIG. 2, the coolant flows through the flow paths indicated by the thick solid lines, and the refrigerant flows through the flow paths indicated by the thick dashed lines.

[0027] In the flow path 26, the coolant flowing into the brake mechanism 3 absorbs heat from the brake oil and cools the brake oil. The coolant that absorbed heat from the brake oil flows into the second heat exchanger 5 and transfers heat to the refrigerant. The refrigerant that has received heat from the coolant passes through the accumulator 10 and is compressed in the compressor 9 to become a high-temperature, high-pressure gas, and transfers heat to the coolant in the first heat exchanger 6. The coolant that has absorbed heat from the refrigerant in the first heat exchanger 6 flows into the battery 2 and warms up the battery 2. Therefore, the waste heat of the brake oil is once transferred to the refrigerant and heated in the compressor 9, and then transferred again to the coolant and used to warm up the battery 2. The coolant that flows out of the battery 2 is cooled in the radiator 4 and then flows back into the brake mechanism 3.

[0028] In addition, when the coolant flowing out from the braking mechanism 3 is sufficiently heated, the second switching valve 12 may connect the flow path 20 to the flow path 22, the third switching valve 13 may connect the flow path 21 to the flow path 24, and the fourth switching valve 14 may connect the flow path 24 to the flow path 23. In this case, the coolant does not flow into the second heat exchanger 5 and the first heat exchanger 6, so that the waste heat of the brake oil can be directly transferred to the battery 2.

[0029] Next, the usage mode of the warm-up system A when the waste heat of the brake oil is used to heat the vehicle interior (hereinafter referred to as the heating mode) will be described with reference to Fig. 3. When the temperature of the brake oil is higher than a predetermined temperature during heating, the warm-up system A is switched to the heating mode in which the first heat exchanger 6 and the braking mechanism 3 are not in communication with each other.

[0030] In the heating mode, the first switching valve 11 connects the flow path 25 and the flow path 26, and the second switching valve 12 connects the flow path 20 and the second heat exchanger 5. The third switching valve 13 connects the flow path 21 and the flow path 24, and the fifth switching valve 15 connects the refrigerant path 30 and the refrigerant path 31, so that the first heat exchanger 6 and the braking mechanism 3 are not connected to each other. The fourth switching valve 14 connects the flow path 24 and the flow path 25, and the sixth switching valve 16 does not cause a branch from the refrigerant path 30. Therefore, the coolant circulates through the flow paths 26, 20, 21, 24, and 25, and the refrigerant circulates through the refrigerant paths 30 and 31. In the heating mode shown in FIG. 3, the coolant flows through the flow paths indicated by the thick solid lines, and the refrigerant flows through the flow paths indicated by the thick dashed lines.

[0031] In the heating mode, the coolant transfers the waste heat of the brake oil to the refrigerant in the second heat exchanger 5, and the refrigerant compressed in the compressor 9 into a high-temperature, high-pressure gas heats the air in the condenser 7, thereby heating the vehicle interior. This makes it possible to recover the waste heat of the brake oil via the second heat exchanger 5 and increase the thermal energy of the refrigerant. Note that the fourth switching valve 14 may connect the flow path 24 and the flow path 23, and the coolant may flow to the battery 2. By flowing the coolant to the battery 2, the temperature of the battery 2 can be kept constant.

[0032] In addition, the third switching valve 13 and the fifth switching valve 15 are configured to change the opening degree so as to simultaneously realize the battery warm-up mode and the heating mode. Therefore, when the brake oil is at or above a predetermined temperature, the waste heat of the brake oil can be used to both warm up the battery 2 and heat the vehicle interior.

[0033] When the temperature of the battery 2 is equal to or higher than a predetermined temperature (e.g., 15°C), the vehicle is braked by regenerative braking. At this time, if the temperature of the brake oil is equal to or lower than a predetermined temperature (e.g., 40°C), the first switching valve 11 is switched to connect the flow path 25 and the flow path 20, so that no coolant flows into the braking mechanism 3. In this case, the waste heat of the motor 1 is used to warm up the battery 2 or heat the passenger compartment.

[0034] Next, the cooling structure of the brake oil in the braking mechanism 3 will be described with reference to Fig. 4. Fig. 4 is a schematic diagram of the oil tank 60 and the flow path 26. The oil tank 60 is a container having a substantially rectangular parallelepiped shape, contains brake oil therein, and communicates with the brake pads 61 via the oil flow path 62. The oil flow path 62 extends from the center of the lower surface of the oil tank 60 toward the brake pads 61. When the braking mechanism 3 applies brakes to the vehicle, the brake oil flows between the oil tank 60 and the brake pads 61 via the oil flow path 62.

[0035] The pipes constituting the flow path 26 are arranged on the lower surface of the oil tank 60, and have a cooling section 26A that contacts the lower surface of the oil tank 60. The cooling section 26A is arranged to surround a part of the oil flow path 62, and is expanded from the pipes constituting the flow path 26 so as to have approximately the same area as the lower surface of the oil tank 60. In addition, the connection part with the cooling section 26A on the upstream side of the flow path 26 is provided higher in the direction of gravity than the connection part with the cooling section 26A on the downstream side of the flow path 26. As a result, the cooling liquid flows through the flow path 26 in the direction of gravity, so no pressure loss occurs. In addition, since the flow path 26 has the cooling section 26A, the contact area between the oil tank 60 and the flow path 26 is increased, so that the cooling liquid flowing through the flow path 26 can efficiently cool the brake oil in the oil tank 60.

[0036] Second Embodiment Next, a warm-up system A according to a second embodiment will be described with reference to Fig. 5. Fig. 5 shows a circuit configuration diagram of the warm-up system A according to the second embodiment. As shown in Fig. 5, the warm-up system A includes a refrigerant flow path C1 capable of circulating a cooling fluid between the battery 2 and the braking mechanism 3 through which brake oil flows.

[0037] The refrigerant flow path C1 circulates the refrigerant through the braking mechanism 3, the accumulator 10, the compressor 9, the condenser 7 (cabin condenser), and the air-cooled condenser 40. The refrigerant flow path C1 has a refrigerant path 50, which is connected to a refrigerant path 51 via a seventh switching valve 47, and the refrigerant path 51 is connected to the refrigerant path 50 via an eighth switching valve 48. The accumulator 10 and the compressor 9 are arranged in this order in the refrigerant path 50. The condenser 7, the third expansion valve 43, the air-cooled condenser 40, and the valve 42 are arranged in this order in the refrigerant path 51. Therefore, when the seventh switching valve 47 connects the refrigerant path 50 and the refrigerant path 51, and the eighth switching valve 48 connects the refrigerant path 51 and the refrigerant path 50, the refrigerant circulates through the refrigerant path C1 in the order of the refrigerant path 50, the accumulator 10, the compressor 9, the refrigerant path 51, the condenser 7, the third expansion valve 43, the air-cooled condenser 40, and the refrigerant path 51. Hereinafter, the upstream side and downstream side of the refrigerant flow direction in the refrigerant path C1 will also be simply referred to as the upstream side and the downstream side.

[0038] The refrigerant passage 50 is connected to the refrigerant passage 52 via the seventh switching valve 47. The check valve 41 and the battery 2 are arranged in this order in the refrigerant passage 52, and the refrigerant passage 52 is connected to the refrigerant passage 51 downstream of the condenser 7 and upstream of the third expansion valve 43. A refrigerant passage 53 branches off from the refrigerant passage 52 upstream of the battery 2 and downstream of the check valve 41. A fourth expansion valve 44 is arranged in the middle of the refrigerant passage 53, and the refrigerant passage 53 is connected to the refrigerant passage 51 downstream of the air-cooled condenser 40 and upstream of the valve 42. The fourth expansion valve 44 is opened only when the battery 2 is cooled, and the refrigerant condensed in the air-cooled condenser 40 flows through the refrigerant passage 53 and flows into the fourth expansion valve 44, becoming a low-temperature, low-pressure mist, and then flows through the battery 2 to cool the battery 2. Except when the battery 2 is being cooled, the fourth expansion valve 44 is closed, so that the refrigerant does not flow through the refrigerant passage 53.

[0039] A refrigerant path 54 branches off from the refrigerant path 51 downstream of the connection point with the refrigerant path 53 and upstream of the valve 42. A fifth expansion valve 45 and an evaporator 8 are disposed in this order in the middle of the refrigerant path 54, and the refrigerant path 54 connects to the refrigerant path 51 downstream of the valve 42. The fifth expansion valve 45 is opened only when the evaporator 8 is in use (when cooling is used), and therefore the refrigerant does not flow through the refrigerant path 54 when cooling is not used.

[0040] Further, the refrigerant path 51 is connected to the refrigerant path 55 via the eighth switching valve 48. The braking mechanism 3 is disposed midway through the refrigerant path 55, and the refrigerant path 55 is connected to the refrigerant path 50 upstream of the accumulator 10. That is, the eighth switching valve 48 switches between a state in which the refrigerant flows through the braking mechanism 3 and a state in which the refrigerant does not flow through the braking mechanism 3. The other configurations are similar to those of the first embodiment, and therefore will not be described.

[0041] Next, a case where the warm-up system A is in the battery warm-up mode will be described with reference to FIG. 6. When the temperature of the battery 2 is equal to or lower than a predetermined temperature (for example, 15°C) and the temperature of the brake oil is equal to or higher than a predetermined temperature (for example, 40°C), the braking control unit switches the vehicle braking from regenerative braking to braking by the braking mechanism 3, and the control unit sets the warm-up system A to the battery warm-up mode. In the battery warm-up mode, the braking mechanism 3 and the battery 2 communicate with each other. That is, the seventh switching valve 47 connects the refrigerant path 50 to the refrigerant path 52, and the eighth switching valve 48 connects the refrigerant path 51 to the refrigerant path 55. At this time, the fourth expansion valve 44 is in a closed state, and when cooling is not used, the fifth expansion valve 45 is also in a closed state. Therefore, the refrigerant circulates through the refrigerant paths 55, 50, 52, and 51. In the battery warm-up mode shown in FIG. 6, the refrigerant flows through the flow path indicated by the thick dashed line.

[0042] In the battery warm-up mode, the refrigerant absorbs waste heat from the brake oil in the braking mechanism 3, and after the liquid refrigerant is separated in the accumulator 10, it is pressurized in the compressor 9 to become a high-temperature, high-pressure gas. The high-temperature, high-pressure gas refrigerant flows into the refrigerant passage 52 via the seventh switching valve 47 and provides heat to the battery 2 to warm up the battery 2. After warming up the battery 2, the refrigerant becomes a low-temperature, low-pressure mist in the third expansion valve 43, cools the air in the air-cooled condenser 40, is condensed, and then flows back into the braking mechanism 3.

[0043] Next, a case where the warm-up system A is in the heating mode will be described with reference to FIG. 7. When the temperature of the brake oil is equal to or higher than a predetermined temperature during heating, the control unit sets the warm-up system A to the heating mode. In the heating mode, the brake mechanism 3 and the condenser 7 communicate with each other. That is, the seventh switching valve 47 connects the refrigerant path 50 to the refrigerant path 51, and the eighth switching valve 48 connects the refrigerant path 51 to the refrigerant path 55. In addition, the fifth expansion valve 45 is in a closed state. Therefore, the refrigerant circulates through the refrigerant paths 55, 50, and 51. In the heating mode shown in FIG. 7, the refrigerant flows through the flow paths indicated by the thick dashed lines.

[0044] In the heating mode, the refrigerant absorbs waste heat from the brake oil in the braking mechanism 3, and after the liquid refrigerant is separated in the accumulator 10, it is pressurized in the compressor 9 to become a high-temperature, high-pressure gas. The high-temperature, high-pressure gas refrigerant flows into the refrigerant passage 51 via the seventh switching valve 47 and heats the air in the condenser 7. The refrigerant flowing out of the condenser 7 becomes a low-temperature, low-pressure mist in the third expansion valve 43, cools the air in the air-cooled condenser 40, is condensed, and then flows back into the braking mechanism 3. The opening of the third expansion valve 43 is controlled according to the target temperature.

[0045] In this case, the fourth expansion valve 44 may be in an open state to cool the battery 2. When the fourth expansion valve 44 is in an open state, the refrigerant flowing out from the air-cooled condenser 40 flows into the refrigerant passage 53 and is converted into a low-temperature, low-pressure mist by the fourth expansion valve 44, and then flows into the battery 2 to cool the battery 2.

[0046] If the temperature of the brake oil is equal to or lower than a predetermined temperature, the eighth switching valve 48 is switched to connect the refrigerant path 51 with the refrigerant path 50, so that no refrigerant flows into the braking mechanism 3.

[0047] Next, the brake oil cooling structure of the brake mechanism 3 in the second embodiment will be described with reference to FIG. 8. FIG. 8 is a schematic diagram of the oil flow path 62 and the coolant path 55. The oil tank 60 is connected to the brake pad 61 via the oil flow path 62. Here, the pipe connecting the oil tank 60 and the brake pad 61 has a double pipe structure, and the inner pipe of the double pipe constitutes the oil flow path 62. The outer pipe of the double pipe constitutes the coolant path 55. Therefore, the coolant that has flowed through the coolant path 55 via the eighth switching valve 48 flows through the outer pipe of the oil flow path 62 in the brake mechanism 3, and removes heat from the brake oil to cool the brake oil. Note that a part of the pipe connecting the oil tank 60 and the brake pad 61 may be a double pipe, and heat exchange may be performed at that part.

[0048] In the above-described embodiment, the following configurations are envisaged. (1) A warm-up system A comprising: a motor 1 which transmits drive torque to the vehicle's running system; a battery 2 which supplies power to the motor 1; a braking mechanism 3 which brakes the vehicle using the hydraulic pressure of brake oil stored in an oil tank 60; and cooling paths (coolant path B, refrigerant path C1) which can circulate a cooling fluid between the battery 2 and the braking mechanism 3, wherein the cooling fluid exchanges heat with the brake oil, and the waste heat of the brake oil is utilized to warm up the battery 2 or to heat the vehicle interior.

[0049] In an automobile equipped with a braking mechanism 3 that brakes the vehicle using hydraulic pressure of brake oil, there is a risk of vapor lock occurring due to boiling of the brake oil. Therefore, according to this configuration, by performing heat exchange between the brake oil and the cooling fluid, it is possible to cool the brake oil and suppress the occurrence of the vapor lock phenomenon. Furthermore, the cooling fluid that has absorbed heat from the brake oil supplies the heat to the battery 2, thereby warming up the battery 2. Furthermore, when it is not necessary to warm up the battery 2, the heat is used to heat the passenger compartment, resulting in a warm-up system that can effectively utilize the waste heat of the brake oil.

[0050] (2) In the warm-up system A of (1), the cooling flow path is a refrigerant flow path C1 that circulates the refrigerant compressed by the compressor 9 as a cooling fluid, and it is preferable that the refrigerant flow path C1 has a switching valve (seventh switching valve 47) that can be switched between a battery warm-up mode in which the battery 2 and the braking mechanism 3 are connected and a heating mode in which the condenser 7 used for heating and the braking mechanism 3 are connected.

[0051] According to this configuration, by switching the refrigerant flow path C1 to a battery warm-up mode in which the battery 2 and the braking mechanism 3 are in communication, the refrigerant exchanges heat with the brake oil, and the waste heat of the brake oil can be used to warm up the battery 2. Also, by switching the refrigerant flow path C1 to a heating mode in which the condenser 7 used for heating is in communication with the braking mechanism 3, the waste heat of the brake oil can be used to heat the vehicle interior. Therefore, compared to the case in which heat is exchanged between the coolant and the brake oil, heat exchange between the coolant and the refrigerant is not required when heating the vehicle interior, and the configuration of the warm-up system A can be simplified.

[0052] (3) In the warm-up system A of (1), the cooling flow path has a coolant flow path B that circulates coolant as a cooling fluid between the battery 2 and the braking mechanism 3, and a refrigerant flow path C that circulates refrigerant compressed by the compressor 9, and further includes a first heat exchanger 6 that transfers heat of the refrigerant circulating through the refrigerant flow path C to the coolant circulating through the coolant flow path B, and a second heat exchanger 5 that transfers heat of the coolant circulating through the coolant flow path B to the refrigerant circulating through the refrigerant flow path C, and it is preferable that the coolant flow path B has switching valves (a third switching valve 13 and a fifth switching valve 15) that can be switched between a battery warm-up mode in which the first heat exchanger 6 and the braking mechanism 3 are connected and a heating mode in which the first heat exchanger 6 and the braking mechanism 3 are not connected.

[0053] According to this configuration, the coolant that has exchanged heat with the brake oil exchanges heat with the refrigerant in the second heat exchanger 5, and the refrigerant to which the heat has been transferred is compressed by the compressor 9 to become a high-temperature compressed fluid. Therefore, in a battery warm-up mode in which the first heat exchanger 6 and the braking mechanism 3 are in communication with each other, the coolant receives heat from the high-temperature compressed refrigerant in the first heat exchanger 6, and the battery 2 can be warmed up by this heat. In a heating mode in which the first heat exchanger 6 and the braking mechanism 3 are not in communication with each other, the heat of the refrigerant that has been compressed to a high temperature by the compressor 9 is used to heat the vehicle interior, making it possible to effectively utilize the waste heat of the brake oil.

[0054] (4) In any one of the warm-up systems A of (1) to (3), it is preferable that the warm-up system A further includes a braking control unit that switches vehicle braking from regenerative braking to braking by the braking mechanism 3 when the battery 2 is at or below a predetermined temperature.

[0055] An electric vehicle equipped with a motor 1 and a battery 2 mainly uses regenerative braking to brake the vehicle, with a braking mechanism 3 that uses hydraulic brake oil pressure to brake the vehicle as an auxiliary. Therefore, according to this configuration, when it is necessary to warm up the battery 2, the braking control unit switches the braking of the vehicle from regenerative braking to braking by the braking mechanism 3, making it possible to effectively utilize the heat generated in the brake oil.

[0056] Other embodiments (1) In the above embodiment, the control unit switches the switching valve to allow cooling fluid to flow through the braking mechanism 3 in accordance with the temperature of the brake oil. However, instead of the temperature of the brake oil, the switching may be performed in accordance with the number of times the driver steps on the brake pedal or the braking time. In this case, it is preferable to have a storage unit that stores the number of times and the time. Also, the switching may be performed in accordance with the amount of increase in the temperature of the brake oil.

[0057] (2) In the above embodiment, the piping connecting the oil tank 60 and the brake pads 61 may have a double piping structure, with the brake oil flowing through the inner piping and the coolant flowing through the outer piping to form the flow path 26. Also, the piping constituting the coolant path 55 may be disposed so as to be in contact with the bottom surface of the oil tank 60.

[0058] (3) In the above embodiment, the piping constituting the flow passage 26 is in contact with the bottom surface of the oil tank 60, but the piping constituting the flow passage 26 may cover the side surface of the oil tank 60. In this case, the piping constituting the flow passage 26 is arranged so as to be wound around the oil tank 60. The piping constituting the flow passage 26 may also be immersed in the oil tank 60. This increases the contact area between the coolant flowing through the flow passage 26 and the oil tank 60, making it possible to cool the brake oil more efficiently. Instead of the flow passage 26, the coolant passage 55 may have a similar configuration. [Industrial Applicability]

[0059] INDUSTRIAL APPLICABILITY The present invention can be used in a warm-up system that utilizes the waste heat of brake oil to warm up a battery or heat a vehicle interior. [Explanation of symbols]

[0060] 1: motor, 2: battery, 3: braking mechanism, 5: second heat exchanger, 6: first heat exchanger, 7: condenser, 13: third switching valve, 15: fifth switching valve, 47: seventh switching valve, B: coolant flow path, C: refrigerant flow path, C1: refrigerant flow path

Claims

1. A motor that transmits drive torque to the vehicle's running system; a battery for supplying power to the motor; a braking mechanism that brakes the vehicle by hydraulic pressure of brake oil stored in an oil tank; a cooling flow path capable of circulating a cooling fluid through the battery and the braking mechanism; A warm-up system in which the cooling fluid exchanges heat with the brake oil, and waste heat of the brake oil is utilized to warm up the battery or to heat the vehicle interior.

2. The cooling flow path is a refrigerant flow path that circulates a refrigerant compressed by a compressor as the cooling fluid, 2. The warm-up system according to claim 1, wherein the refrigerant flow path has a switching valve that can be switched between a battery warm-up mode in which the battery and the braking mechanism are connected to each other and a heating mode in which a condenser used for heating is connected to the braking mechanism.

3. the cooling flow path includes a coolant flow path that circulates a coolant as the cooling fluid through the battery and the braking mechanism, and a refrigerant flow path that circulates a refrigerant compressed by a compressor, a first heat exchanger in which heat of the refrigerant circulating through the refrigerant flow path is transferred to the cooling liquid circulating through the cooling liquid flow path; a second heat exchanger for transferring heat of the cooling liquid circulating through the cooling liquid flow path to the cooling medium circulating through the cooling medium flow path; 2. The warm-up system according to claim 1, wherein the coolant flow path has a switching valve that can be switched between a battery warm-up mode in which the first heat exchanger and the braking mechanism are connected to each other and a heating mode in which the first heat exchanger and the braking mechanism are not connected to each other.

4. 4. The warm-up system according to claim 1, further comprising a braking control unit that switches braking of the vehicle from regenerative braking to braking by the braking mechanism when the battery is at or below a predetermined temperature.

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