Electric vehicles

Abstract

Reduce the number of main components in the temperature control system. [Solution] The electric-powered vehicle is equipped with a temperature control system that adjusts the temperature of the battery and the driver's cab. The temperature control system includes an air conditioning heat exchanger, a battery heat exchanger, an outside air heat exchanger, a temperature sensor for detecting the battery temperature, a switching means for switching between heating and cooling the driver's cab, a control device, and a valve system for switching the direction in which the heat transfer medium flows. Based on the battery temperature and the operation signal from the switching means, the control device selects a first heat exchanger through which the heat transfer medium flowing from the compressor toward the expansion valve passes, and a second heat exchanger through which the heat transfer medium flowing from the expansion valve toward the compressor passes, and controls the valve system so that the heat transfer medium discharged from the compressor is guided to the first heat exchanger and the heat transfer medium discharged from the expansion valve is guided to the second heat exchanger.

Description

Technical Field

[0001] The present invention relates to an electric vehicle.

Background Art

[0002] An electric vehicle equipped with a temperature control system for adjusting the temperature of a driver's cab or a storage battery is known (see Patent Document 1). The temperature control system described in Patent Document 1 includes a refrigerant flow path for battery cooling having a pump, a refrigerant flow path for in-vehicle air conditioning having a compressor, a condenser, and an evaporator, and a heat medium flow path for in-vehicle air conditioning having a pump, an electric heater, and a heater core. In the electric vehicle described in Patent Document 1, a heat exchanger is provided between the refrigerant flow path of the in-vehicle air conditioning cooling system and the refrigerant flow path of the battery cooling system, and the refrigerant for in-vehicle air conditioning is configured to cool the refrigerant for battery cooling through the heat exchanger.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the system of the electric vehicle described in Patent Document 1, a discharge device (pump, compressor) for discharging a heat medium (refrigerant, heat medium) to circulate the heat medium in the flow path is provided in each of the refrigerant flow path for battery cooling, the refrigerant flow path for in-vehicle air conditioning, and the heat medium flow path for in-vehicle air conditioning. Therefore, in the temperature control system described in Patent Document 1, the number of main devices such as discharge devices, heat exchangers, and electric heaters is large, and there is room for improvement in this regard.

[0005] An object of the present invention is to reduce the number of main devices of a temperature control system.

Means for Solving the Problems

[0006] An electric-driven vehicle according to one aspect of the present invention comprises an electric motor for driving wheels, a storage battery for supplying power to the electric motor, and a temperature control system for adjusting the temperature of the storage battery and the driver's cab. The temperature control system comprises a compressor for compressing and discharging a heat transfer medium, an expansion valve for depressurizing and expanding the heat transfer medium, an air conditioning heat exchanger which is a heat exchanger that performs heat exchange between the heat transfer medium and the air in the driver's cab, a battery heat exchanger which is a heat exchanger that performs heat exchange between the heat transfer medium and the storage battery, an outside air heat exchanger which is a heat exchanger that performs heat exchange between the heat transfer medium and the outside air, a temperature sensor for detecting the temperature of the storage battery, a switching means that can switch between heating and cooling the driver's cab, and a control device that controls the temperature of the storage battery and the driver's cab based on the switching state of the switching means. The temperature control system comprises a valve system having a plurality of directional control valves that can switch the direction in which the heat transfer medium pressurized by the compressor flows and the direction in which the heat transfer medium depressurized by the expansion valve flows. The control device, based on the temperature of the storage battery detected by the temperature sensor and the operation signal from the switching means, selects the heat exchanger that allows the heat medium flowing from the compressor toward the expansion valve to pass through from among the air conditioning heat exchanger, the battery heat exchanger, and the outside air heat exchanger as the first heat exchanger, and selects the heat exchanger that allows the heat medium flowing from the expansion valve toward the compressor to pass through from among the air conditioning heat exchanger, the battery heat exchanger, and the outside air heat exchanger as the second heat exchanger, and controls the valve system so that the heat medium discharged from the compressor is guided to the first heat exchanger and the heat medium discharged from the expansion valve is guided to the second heat exchanger. [Effects of the Invention]

[0007] According to the present invention, the number of main components in a temperature control system can be reduced. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a side view of a wheel loader. [Figure 2]Figure 2 shows the electric drive system of a wheel loader. [Figure 3] Figure 3 shows the temperature control system for a wheel loader. [Figure 4] Figure 4 is a flowchart illustrating an example of the processing flow performed by the control device. [Figure 5] Figure 5 illustrates the flow of the heat transfer medium when the first pattern of valve switching control is performed. [Figure 6] Figure 6 illustrates the flow of the heat transfer medium when the second pattern of valve switching control is performed. [Figure 7] Figure 7 illustrates the flow of the heat transfer medium when the third pattern of valve switching control is performed. [Figure 8] Figure 8 illustrates the flow of the heat transfer medium when the fourth pattern of valve switching control is executed. [Figure 9] Figure 9 illustrates the flow of the heat transfer medium when the fifth valve switching control pattern is executed. [Figure 10] Figure 10 illustrates the flow of the heat transfer medium when the sixth valve switching control pattern is executed. [Figure 11] Figure 11 illustrates the flow of the heat transfer medium when the seventh pattern of valve switching control is executed. [Figure 12] Figure 12 shows a modified example of a hydraulic fluid temperature control system for a wheel loader. [Modes for carrying out the invention]

[0009] An electric-driven vehicle according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, an example in which the electric-driven vehicle is a wheel loader will be described.

[0010] Figure 1 is a side view of the wheel loader 10. As shown in Figure 1, the wheel loader (hereinafter also simply referred to as the vehicle) 10 comprises a body 8 and a multi-jointed working device 6 mounted in front of the body 8. The body 8 employs an articulated steering system (body articulation type). The body 8 comprises a front body (front frame) 8A with front wheels 7A (wheels 7) mounted on the left and right sides, a rear body (rear frame) 8B with rear wheels 7B (wheels 7) mounted on the left and right sides, and a center joint 13 connecting the front body 8A and the rear body 8B. Steering cylinders 9 are provided on both the left and right sides of the center joint 13 to connect the front body 8A and the rear body 8B.

[0011] The working device 6 is attached to the front body 8A. The working device 6 comprises an arm cylinder 4, a lift arm (hereinafter simply referred to as "arm") 2 which moves in accordance with the extension and retraction of the arm cylinder 4, a bucket cylinder 5, and a bucket 3 which moves in accordance with the extension and retraction of the bucket cylinder 5. One arm 2 and one arm cylinder 4 are provided on each side of the front body 8A. A Z-link type (bell crank type) link mechanism is used to operate the bucket 3. The bucket cylinder 5 is included in this link mechanism.

[0012] On the rear body 8B, a driver's cab 12 is mounted at the front and a machine room 16 at the rear. Inside the driver's cab 12 are control devices for operating various parts of the wheel loader 10. These control devices include, for example, an arm control device for operating the arm cylinder 4 (arm 2) of the work device 6, a bucket control device for operating the bucket cylinder 5 (bucket 3) of the work device 6, a forward / reverse switching device for switching the forward and reverse movement of the body 8, an accelerator control device for instructing the body 8 to accelerate, a brake control device for instructing the body 8 to decelerate, and a steering control device for instructing the left and right direction of travel of the body 8.

[0013] In the machine room 16, there are stored a storage battery 61, 62 (see Fig. 2), a traveling motor 26 which is an electric motor for driving the wheels 7 of the traveling device 11, a hydraulic pump 153 (see Fig. 2) of the working device 6, a working motor 152 (see Fig. 2) which is an electric motor for driving the hydraulic pump 153, a control valve 154 (see Fig. 2), a temperature control system 120 (see Fig. 2) including an electric compressor (compressor) 125, etc. The storage battery 61 is a high-voltage battery capable of supplying high-voltage power to the traveling motor 26, the working motor 152, and the electric compressor 125. The storage battery 62 is a low-voltage battery capable of supplying low-voltage power to various electric motors and the control device 100 mounted on the vehicle body 8. The storage batteries 61, 62 are constituted by, for example, lithium-ion secondary batteries. The electric motors to which low-voltage power is supplied include, for example, an air-conditioning fan motor 31 for driving a fan 41 for vehicle interior air conditioning, a heat medium cooling fan motor 33 for driving a fan 43 for heat medium cooling, and an oil cooling fan motor 34 for driving a fan 44 for hydraulic oil cooling.

[0014] Fig. 2 is a diagram showing an electric drive system of the wheel loader 10. As shown in Fig. 2, the wheel loader 10 is an electric drive type work vehicle in which the drive unit of the traveling device 11 is electrified. The electric drive system of the wheel loader 10 drives the traveling motor 26 with the power of the storage battery 61 to rotate the wheels 7 of the traveling device 11. Further, the electric drive system of the wheel loader 10 drives the working motor 152 with the power of the storage battery 61 to operate the working device 6.

[0015] The wheel loader 10 includes storage batteries 61, 62, a control device 100 that controls each part of the vehicle, a traveling motor 26 that is rotationally driven by the electric power supplied from the storage battery 61, a traveling inverter (inverter for traveling motor) 27 that controls the traveling motor 26 based on a command input from the control device 100, a traveling device 11 that is driven by the traveling motor 26 to move the vehicle body 8, a working motor 152 that is driven by the electric power supplied from the storage battery 61 to drive the working device 6, a working inverter (inverter for working motor) 151 that controls the working motor 152 based on a command input from the control device 100, a hydraulic pump 153 that is rotationally driven by the working motor 152, a hydraulic actuator (arm cylinder 4, bucket cylinder 5, and steering cylinder 9) 155 that is driven by the hydraulic oil discharged from the hydraulic pump 153, and a control valve 154 that controls the flow of the hydraulic oil supplied from the hydraulic pump 153 to the hydraulic actuator 155. The working device 6 and the traveling device 11 are driven independently of each other.

[0016] The traveling device 11 has four wheels 7 and a power transmission device that transmits the power from the traveling motor 26 to the wheels 7. The power transmission device is configured to include a transmission, an axle, a differential device, a propeller shaft, and the like.

[0017] The hydraulic pump 153 is driven by the working motor 152 to discharge hydraulic oil. The hydraulic pump 153 is a variable displacement type hydraulic pump whose discharge capacity can be changed by controlling the tilt angle of a swash plate or a swash shaft. The discharge capacity of the hydraulic pump 153 is controlled by a regulator (not shown). The hydraulic oil discharged from the hydraulic pump 153 is controlled in terms of flow rate and flow direction by the control valve 154. The control valve 154 is controlled based on the operation direction and operation amount of an arm operation device, a bucket operation device, and a steering operation device. When the control valve 154 is controlled, hydraulic oil is supplied to the hydraulic actuator (hydraulic cylinder) 155 corresponding to the operated operation device, and the hydraulic actuator 155 is driven.

[0018] When the arm operating device is operated, the arm 2 rotates vertically in accordance with the extension and retraction of the arm cylinder 4. When the bucket operating device is operated, the bucket 3 rotates vertically in accordance with the extension and retraction of the bucket cylinder 5. When the steering operating device is operated, the rear body 8B and the front body 8A bend (rotate) around the center joint 13 as the steering cylinder 9 is driven to extend and retract.

[0019] The wheel loader 10 is also equipped with a DC-DC converter that can step down the power of the storage battery (high-voltage battery) 61 and supply it to a low-voltage circuit, as well as a charging device that charges the storage battery 61 via an external power source.

[0020] Figure 3 shows the temperature control system 120 of the wheel loader 10. As shown in Figure 3, the temperature control system 120 uses a single heat transfer medium to adjust the temperature of the operator's cab 12 (the temperature of the air inside the operator's cab 12) and the temperature of the battery 61. The temperature control system 120 includes, as refrigeration cycle equipment, an electric compressor 125 which is a discharge device that compresses and discharges the heat transfer medium, an expansion valve 126 which depressurizes and expands the heat transfer medium, an air conditioning heat exchanger 121 which is a heat exchanger that performs heat exchange between the heat transfer medium and the air inside the operator's cab 12, a battery heat exchanger 122 which is a heat exchanger that performs heat exchange between the heat transfer medium and the battery 61, and an outdoor air heat exchanger (outdoor heat exchanger) 123 which is a heat exchanger that performs heat exchange between the heat transfer medium and the outside air (the air outside the operator's cab 12). The electric compressor 125 has a compressor body and an electric motor that drives the compressor body.

[0021] In the refrigeration cycle of the temperature control system 120, the heat transfer medium is pressurized (contracted) by the electric compressor 125 to generate a high-temperature, high-pressure heat transfer medium. This high-temperature, high-pressure heat transfer medium is supplied to one of the heat exchangers. As the high-temperature, high-pressure heat transfer medium passes through the heat exchanger, it releases heat and is cooled, then guided to the expansion valve 126. The heat transfer medium is depressurized (expanded) by the expansion valve 126 to generate a low-temperature, low-pressure heat transfer medium. This low-temperature, low-pressure heat transfer medium is supplied to one of the heat exchangers. As the low-temperature, low-pressure heat transfer medium passes through the heat exchanger, it absorbs heat and is heated, then returns to the electric compressor 125. The expansion valve 126 is a bidirectional expansion valve capable of depressurizing and expanding the heat transfer medium in both cases: when the heat transfer medium flows from one side to the other, and when the heat transfer medium flows from the other side to the other.

[0022] When a high-temperature, high-pressure heat transfer medium is supplied to the internal flow path of the air conditioning heat exchanger 121, the air sent from the in-vehicle air conditioning fan 41 is heated, and warm air is supplied into the driver's cab 12. When a low-temperature, low-pressure heat transfer medium is supplied to the internal flow path of the air conditioning heat exchanger 121, the air sent from the in-vehicle air conditioning fan 41 is cooled, and cold air is supplied into the driver's cab 12. In other words, the air conditioning heat exchanger 121 is used to regulate the temperature of the driver's cab 12.

[0023] The battery heat exchanger 122 is installed, for example, so as to be in contact with the bottom surface of the containers of the multiple cell batteries that make up the storage battery 61. When a high-temperature, high-pressure heat transfer medium is supplied to the internal flow path of the battery heat exchanger 122, the heat from the heat transfer medium is transferred to the storage battery 61, and the storage battery 61 is heated. When a low-temperature, low-pressure heat transfer medium is supplied to the internal flow path of the battery heat exchanger 122, the heat from the storage battery 61 is absorbed by the heat transfer medium, and the storage battery 61 is cooled. In other words, the battery heat exchanger 122 is used to regulate the temperature of the storage battery 61.

[0024] When a high-temperature, high-pressure heat transfer medium is supplied to the internal flow path of the outside air heat exchanger 123, the heat from the heat transfer medium is discharged to the outside of the vehicle body 8 by air (outside air) supplied by the fan 43 for cooling the heat transfer medium. When a low-temperature, low-pressure heat transfer medium is supplied to the internal flow path of the outside air heat exchanger 123, the heat transfer medium is heated by absorbing the heat from the air supplied by the fan 43 for cooling the heat transfer medium. In other words, the outside air heat exchanger 123 is used to discharge heat from the heat transfer medium or to allow the heat transfer medium to absorb heat.

[0025] The temperature control system 120 includes a valve system 130 having multiple directional control valves that can switch the direction in which the heat transfer medium pressurized by the electric compressor 125 flows and the direction in which the heat transfer medium depressurized by the expansion valve 126 flows. The multiple directional control valves can switch the communication between the electric compressor 125 and each of the air conditioning heat exchanger 121, the battery heat exchanger 122, and the outside air heat exchanger 123. In addition, the multiple directional control valves can switch the communication between the expansion valve 126 and each of the air conditioning heat exchanger 121, the battery heat exchanger 122, and the outside air heat exchanger 123.

[0026] The multiple directional control valves include a first control valve 131 connected to the electric compressor 125, a second control valve 132 connected in series with the first control valve 131, a third control valve 133 provided on one side of the battery heat exchanger 122, a fourth control valve 134 provided on the other side of the battery heat exchanger 122, and a fifth control valve 135 provided between the expansion valve 126 and the outside air heat exchanger 123.

[0027] These five directional control valves are all electromagnetic switching valves whose flow path is switched by controlling the excitation current to the solenoid coil (hereinafter also referred to as the solenoid). When no excitation current is supplied to the solenoid, each directional control valve is switched to its initial position by a spring. When excitation current is supplied to the solenoid, the valve body is switched to a position different from the initial position, against the elastic force of the spring. By switching the valve body, the flow path (the direction of the flow of the heat transfer medium) is switched. Note that supplying excitation current to the solenoid to switch the position of the valve body is also referred to as outputting an ON signal to the solenoid. Conversely, outputting an OFF signal to the solenoid means supplying a standby current to the solenoid. Note that instead of outputting an OFF signal, no current may be supplied to the solenoid at all.

[0028] The air conditioning heat exchanger 121, the battery heat exchanger 122, and the outside air heat exchanger 123 are connected in parallel to the electric compressor 125 and the expansion valve 126, respectively. The first control valve 131 and the second control valve 132 are connected in series to each other between each heat exchanger (121-123) and the electric compressor 125.

[0029] The first control valve 131 is located between the electric compressor 125 and the second control valve 132. In other words, the first control valve 131 is located in the flow path connecting the electric compressor 125 and the second control valve 132. The first control valve 131 is a 4-port, 2-position directional control valve. The first control valve 131 has a discharge port connected to the discharge flow path 173 of the electric compressor 125 and a return port connected to the return flow path (suction flow path) 174 of the electric compressor 125. The first control valve 131 also has two ports connected to the second control valve 132.

[0030] The first control valve 131 has a heating position 131a that can be switched when heating at least one of the operator's cab 12 and the battery 61, and a cooling position 131b that can be switched when cooling at least one of the operator's cab 12 and the battery 61.

[0031] When the first control valve 131 is switched to the heating position 131a, the discharge passage 173 of the electric compressor 125 communicates with the first port (first inlet / outlet port) P1 of the second control valve 132, and the return passage 174 of the electric compressor 125 communicates with the second port (second inlet / outlet port) P2 of the second control valve 132. When the first control valve 131 is switched to the cooling position 131b, the discharge passage 173 of the electric compressor 125 communicates with the second port P2 of the second control valve 132, and the return passage 174 of the electric compressor 125 communicates with the first port P1 of the second control valve 132.

[0032] When the first control valve 131 is switched to the heating position 131a, the heat transfer medium pressurized by the electric compressor 125 is led to at least one of the air conditioning heat exchanger 121 and the battery heat exchanger 122, and the heat transfer medium that has been depressurized by the expansion valve 126 and passed through the outside air heat exchanger 123 is led to the electric compressor 125. When the first control valve 131 is switched to the cooling position 131b, the heat transfer medium pressurized by the electric compressor 125 is led to the outside air heat exchanger 123, and the heat transfer medium that has been depressurized by the expansion valve 126 and passed through at least one of the air conditioning heat exchanger 121 and the battery heat exchanger 122 is led to the electric compressor 125.

[0033] The second control valve 132 is installed between the first control valve 131 and each heat exchanger (121, 122, 123). In other words, the second control valve 132 is installed in the flow path connecting the first control valve 131 and each heat exchanger. The second control valve 132 is a 5-port, 3-position directional control valve. The second control valve 132 has two inlet / outlet ports (first port P1 and second port P2) connected to the discharge flow path 173 or return flow path 174 of the electric compressor 125 via the first control valve 131, and three ports (third port P3, fourth port P4, and fifth port P5) connected to each heat exchanger (121, 122, 123). The third port P3 is connected to the air conditioning heat exchanger 121. For this reason, the third port P3 is also referred to as the air conditioning port. The fourth port P4 is connected to the battery heat exchanger 122 via the third control valve 133. Therefore, the fourth port P4 is also referred to as the battery port. The fifth port P5 is connected to the outside air heat exchanger 123. The fifth port P5 is also connected to the battery heat exchanger 122 via the third control valve 133.

[0034] The second control valve 132 has a first position 132a that connects the first port P1 with the third port P3 and the fourth port P4, and connects the second port P2 with the fifth port P5; a second position 132b that connects the first port P1 with the fourth port P4, and connects the second port P2 with the fifth port P5; and a third position 132c that connects the first port P1 with the third port P3, and connects the second port P2 with the fifth port P5. In other words, the first position 132a is a switching position that connects the third port P3 and the fourth port P4 to the first port P1, the second position 132b is a switching position that connects the fourth port P4 to the first port P1 and blocks the connection between the third port P3 and the first port P1, and the third position 132c is a switching position that blocks the connection between the fourth port P4 and the first port P1 and connects the third port P3 and the first port P1.

[0035] When the first control valve 131 is switched to the heating position 131a and the second control valve 132 is switched to the first position 132a, the discharge passage 173 of the electric compressor 125 communicates with the air conditioning heat exchanger 121 and the battery heat exchanger 122, respectively. When the first control valve 131 is switched to the cooling position 131b and the second control valve 132 is switched to the first position 132a, the return passage 174 of the electric compressor 125 communicates with the air conditioning heat exchanger 121 and the battery heat exchanger 122, respectively.

[0036] When the first control valve 131 is switched to the heating position 131a and the second control valve 132 is switched to the second position 132b, the communication between the discharge passage 173 of the electric compressor 125 and the air conditioning heat exchanger 121 is interrupted, and the discharge passage 173 of the electric compressor 125 is connected to the battery heat exchanger 122. When the first control valve 131 is switched to the cooling position 131b and the second control valve 132 is switched to the second position 132b, the communication between the return passage 174 of the electric compressor 125 and the air conditioning heat exchanger 121 is interrupted, and the return passage 174 of the electric compressor 125 is connected to the battery heat exchanger 122.

[0037] When the first control valve 131 is switched to the heating position 131a and the second control valve 132 is switched to the third position 132c, the discharge passage 173 of the electric compressor 125 communicates with the air conditioning heat exchanger 121, and the communication between the discharge passage 173 of the electric compressor 125 and the battery heat exchanger 122 is blocked. When the first control valve 131 is switched to the cooling position 131b and the second control valve 132 is switched to the third position 132c, the return passage 174 of the electric compressor 125 communicates with the air conditioning heat exchanger 121, and the communication between the return passage 174 of the electric compressor 125 and the battery heat exchanger 122 is blocked.

[0038] Thus, the second control valve 132 is connected to the air conditioning heat exchanger 121, the battery heat exchanger 122, and the outside air heat exchanger 123, respectively, and is also connected to the discharge passage 173 and the return passage 174 of the electric compressor 125 via the first control valve 131.

[0039] The third control valve 133 is located between the second control valve 132 and the battery heat exchanger 122. In other words, the third control valve 133 is located in the flow path connecting the second control valve 132 and the battery heat exchanger 122. The third control valve 133 is a first three-port, two-position directional control valve. The third control valve 133 has a first battery connection port Pb1 connected to the fourth port (battery port) P4 of the second control valve 132, a second battery connection port Pb2 connected to the battery heat exchanger 122, and a return connection port Pb3 connected to the return flow path 174 of the electric compressor 125 when the first control valve 131 is switched to the heating position 131a.

[0040] The third control valve 133 has a first position 133a that connects the first battery connection port Pb1 and the second battery connection port Pb2 and blocks communication between the return connection port Pb3 and the second battery connection port Pb2, and a second position 133b that blocks communication between the first battery connection port Pb1 and the second battery connection port Pb2 and connects the return connection port Pb3 and the second battery connection port Pb2.

[0041] When the third control valve 133 is switched to the first position 133a, the fourth port P4 of the second control valve 132 is connected to the battery heat exchanger 122, and the connection between the fifth port P5 of the second control valve 132 and the battery heat exchanger 122 is blocked. When the third control valve 133 is switched to the second position 133b, the connection between the fourth port P4 of the second control valve 132 and the battery heat exchanger 122 is blocked, and the fifth port P5 of the second control valve 132 is connected to the battery heat exchanger 122.

[0042] The fourth control valve 134 is located between the battery heat exchanger 122 and the expansion valve 126. In other words, the fourth control valve 134 is located in the flow path connecting the battery heat exchanger 122 and the expansion valve 126. The fourth control valve 134 is a two-port, two-position directional control valve. The fourth control valve 134 has a port connected to the flow path 171 and a port connected to the merging / dividing flow path 172. The flow path 171 has a flow path connected to the battery heat exchanger 122 and the fourth control valve 134, and a flow path that branches off from this flow path and connects to the fifth control valve 135. The merging / dividing flow path 172 has a flow path connected to the fourth control valve 134 and the expansion valve 126, and a flow path that branches off from this flow path and connects to the air conditioning heat exchanger 121.

[0043] The fourth control valve 134 has a communication position 134a that connects the flow path 171 and the combined flow path 172, and a shut-off position 134b that shuts off the communication between the flow path 171 and the combined flow path 172. When the fourth control valve 134 is switched to the communication position 134a, the battery heat exchanger 122 and the expansion valve 126 are in communication via the fourth control valve 134. When the fourth control valve 134 is switched to the shut-off position 134b, the communication between the battery heat exchanger 122 and the expansion valve 126 via the fourth control valve 134 is shut off.

[0044] The fifth control valve 135 is located between the expansion valve 126 and the outside air heat exchanger 123. In other words, the fifth control valve 135 is located in the flow path connecting the expansion valve 126 and the outside air heat exchanger 123. The fifth control valve 135 is a second three-port, two-position directional control valve. The fifth control valve 135 has a battery cooling port Pc1 connected to a flow path 171 connecting the battery heat exchanger 122 and the fourth control valve 134, a heat transfer medium cooling port Pc2 connected to the outside air heat exchanger 123, and a low-temperature heat transfer medium inlet port Pc3 connected to the expansion valve 126.

[0045] The fifth control valve 135 has a first position 135a that connects the low-temperature heat transfer medium inlet port Pc3 to the heat transfer medium cooling port Pc2 and blocks communication between the low-temperature heat transfer medium inlet port Pc3 and the battery cooling port Pc1, and a second position 135b that blocks communication between the low-temperature heat transfer medium inlet port Pc3 and the heat transfer medium cooling port Pc2 and connects the low-temperature heat transfer medium inlet port Pc3 and the battery cooling port Pc1. When the fifth control valve 135 is switched to the first position 135a, the outside air heat exchanger 123 and the expansion valve 126 are connected, and communication between the battery heat exchanger 122 and the expansion valve 126 is blocked. When the fifth control valve 135 is switched to the second position 135b, communication between the outside air heat exchanger 123 and the expansion valve 126 is blocked, and communication between the battery heat exchanger 122 and the expansion valve 126 is connected.

[0046] The temperature control system 120 includes a temperature sensor 111 that detects the temperature of the battery 61 (for example, the surface temperature of the battery container) and outputs a detection signal to the control device 100 according to the detected temperature; an operation panel 110 which is a switching means that enables switching between heating and cooling of the operator's cab 12; and a control device 100 which controls the directional control valves (131-135), electric compressor 125, and fans 41, 43, and 44 of the valve system 130 based on the temperature of the battery 61 detected by the temperature sensor 111 and the operation signal from the operation panel 110.

[0047] The control panel 110 has a heating / cooling switch, which is a switching device that can be switched between a heating / cooling ON position, an OFF position, and a heating / cooling ON position. When the heating / cooling switch is switched to the heating / cooling ON position, the control panel 110 outputs a heating / cooling ON signal as an operation signal to the control device 100. When the heating / cooling switch is switched to the heating / cooling ON position, the control panel 110 outputs a heating / cooling OFF signal (also simply referred to as an OFF signal) from the control panel 110 to the control device 100. Depending on the operating position (switching state) of the heating / cooling switch, the control panel 110 selectively outputs either a heating / cooling ON signal, a heating ON signal, or an OFF signal. In other words, the control panel 110 outputs an operation signal (a signal indicating the heating / cooling switching state) to the control device 100 according to the operator's operation. The control device 100 controls the temperature of the battery 61 and the operator's cab 12 based on the heating / cooling switching state of the control panel 110 and the temperature of the battery 61.

[0048] The temperature control system 120 according to this embodiment is a heat transfer medium circulation circuit capable of heating or cooling either the battery 61 or the driver's cab 12 individually or both simultaneously. Furthermore, the temperature control system 120 is configured to heat the driver's cab 12 and cool the battery 61. However, the temperature control system 120 is configured in a way that makes it impossible to heat the battery 61 and cool the driver's cab 12. This is because, in the operation of the wheel loader 10, a situation where it is necessary to heat the battery 61 and cool the driver's cab 12 is not anticipated.

[0049] The control device 100 consists of a computer equipped with a processing unit (processor) 101 such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), and DSP (Digital Signal Processor), non-volatile memory 102 such as ROM (Read Only Memory), flash memory, and hard disk drive, volatile memory 103 known as RAM (Random Access Memory), an input interface 104, an output interface 105, and other peripheral circuits. The control device 100 may consist of one computer or multiple computers.

[0050] The non-volatile memory 102 stores a program capable of performing various calculations, and data such as thresholds used in these calculations (for example, temperature thresholds T0 to T2, which will be described later). In other words, the non-volatile memory 102 is a storage device (storage medium) from which the program realizing the functions of this embodiment can be read. The processing unit 101 is an arithmetic unit that loads the program stored in the non-volatile memory 102 into the volatile memory 103 and executes calculation processing. The processing unit 101 performs predetermined calculation processing on signals received from the input interface 104 and the memory (non-volatile memory 102 and volatile memory 103) according to the program.

[0051] The input interface 104 converts operation signals input from the operating device (e.g., accelerator operating device) and the air conditioning control panel 110, as well as sensor signals input from the temperature sensor 111, into data that can be processed by the processing unit 101.

[0052] The output interface 105 generates an output signal according to the calculation result in the processing unit 101 and outputs that signal to the controlled equipment. Examples of controlled equipment include the directional control valves (131-135) of the valve system 130, the travel inverter 27, the work inverter 151, the electric motors (31, 33, 34) that drive the fans (41, 43, 44), the electric compressor 125, the solenoid valve (not shown) that controls the control valve 154, and the pump controller (not shown) that controls the capacity of the hydraulic pump 153.

[0053] Referring to Figures 4 to 11, the control details of the valve system 130 and the electric compressor 125 executed by the control device 100 will be described. Figure 4 is a flowchart showing an example of the processing flow executed by the control device 100. The processing shown in the flowchart of Figure 4 is started when the start switch of the wheel loader 10 is turned on (so-called key on) and is executed repeatedly at a predetermined control cycle. In this embodiment, the control details of fans 41 and 43 are omitted. Furthermore, the rotational speed of the electric compressor 125 during operation is assumed to be controlled to a constant speed.

[0054] The control device 100 controls multiple directional control valves (131-135) to circulate the heat transfer medium in multiple patterns. These patterns include patterns 1 through 7. Based on the temperature Tb of the battery 61 detected by the temperature sensor 111 and the operation signal from the control panel 110, the control device 100 selects one of the multiple patterns and controls the valve system 130 to circulate the heat transfer medium in the selected pattern. In other words, the control device 100 controls the switching position of the multiple directional control valves (131-135) by one of the seven valve switching control patterns. Figures 5 through 11 illustrate the flow of the heat transfer medium when valve switching control patterns 1 through 7 are performed. In the figures, thick solid arrows indicate the flow of high-temperature, high-pressure heat transfer medium compressed by the electric compressor 125, and thick dashed arrows indicate the flow of low-temperature, low-pressure heat transfer medium reduced in pressure and expanded by the expansion valve 126.

[0055] As shown in Figure 4, in step S110, the control device 100 determines whether the temperature Tb of the storage battery 61 detected by the temperature sensor 111 is less than the battery priority temperature threshold T0. If it is determined that the temperature Tb of the storage battery 61 is less than the battery priority temperature threshold T0, the process proceeds to step S116. If it is determined that the temperature Tb of the storage battery 61 is equal to or greater than the battery priority temperature threshold T0, the process proceeds to step S120.

[0056] In step S116, the control device 100 outputs an ON signal to the electric compressor 125, starting the electric compressor 125. If the electric compressor 125 is already running, its operating state is maintained.

[0057] In the next step S118, the control device 100 controls the valve system 130 so that the heat transfer medium circulates in the first pattern. As shown in Figure 5, in the first pattern of valve switching control (S118), the control device 100 outputs an off signal to the solenoid S1 of the first control valve 131, an on signal to the first solenoid S21 of the second control valve 132, an off signal to the second solenoid S22 of the second control valve 132, an off signal to the solenoid S3 of the third control valve 133, an off signal to the solenoid S4 of the fourth control valve 134, and an off signal to the solenoid S5 of the fifth control valve 135. As a result, the first control valve 131 is switched to the heated position 131a, the second control valve 132 is switched to the second position 132b, the third control valve 133 is switched to the first position 133a, the fourth control valve 134 is switched to the communication position 134a, and the fifth control valve 135 is switched to the first position 135a. In other words, the first, third to fifth control valves 131, 133 to 135 maintain their initial positions, and only the valve body of the second control valve 132 is switched from its initial position.

[0058] As a result of the valve control in the first pattern, the heat transfer medium pressurized by the electric compressor 125 is supplied to the battery heat exchanger 122 through the first control valve 131 and the second control valve 132. The heat transfer medium releases heat in the battery heat exchanger 122, warming the storage battery 61. The heat transfer medium that has passed through the battery heat exchanger 122 is supplied to the expansion valve 126 through the fourth control valve 134. The heat transfer medium, depressurized by the expansion valve 126, is supplied to the outside air heat exchanger 123 through the fifth control valve 135. The heat transfer medium absorbs heat in the outside air heat exchanger 123. The heat transfer medium that has passed through the outside air heat exchanger 123 returns to the electric compressor 125 through the second control valve 132 and the first control valve 131.

[0059] As shown in Figure 4, in step S120, the control device 100 determines whether the temperature Tb of the storage battery 61 detected by the temperature sensor 111 is less than the first temperature threshold T1. If it is determined that the temperature Tb of the storage battery 61 is less than the first temperature threshold T1, the process proceeds to step S123. If it is determined that the temperature Tb of the storage battery 61 is equal to or greater than the first temperature threshold T1, the process proceeds to step S130. The first temperature threshold T1 is a value higher than the battery priority temperature threshold T0.

[0060] In step S123, the control device 100 determines whether or not a heating ON signal has been input from the control panel 110. If it is determined that a heating ON signal has been input from the control panel 110, the process proceeds to step S126. If it is determined that no heating ON signal has been input from the control panel 110, the process proceeds to step S116.

[0061] In step S126, the control device 100 outputs an ON signal to the electric compressor 125, similar to step S116, and starts the electric compressor 125.

[0062] In the next step S128, the control device 100 controls the valve system 130 so that the heat transfer medium circulates in the second pattern. As shown in Figure 6, in the second pattern valve switching control (S128), the control device 100 outputs an off signal to the solenoid S1 of the first control valve 131, to the first solenoid S21 and the second solenoid S22 of the second control valve 132, to the solenoid S3 of the third control valve 133, to the solenoid S4 of the fourth control valve 134, and to the solenoid S5 of the fifth control valve 135. As a result, the first control valve 131 is switched to the heated position 131a, the second control valve 132 is switched to the first position 132a, the third control valve 133 is switched to the first position 133a, the fourth control valve 134 is switched to the communication position 134a, and the fifth control valve 135 is switched to the first position 135a. In other words, the first to fifth control valves 131 to 135 maintain their initial positions.

[0063] As a result of the second valve control pattern, the heat transfer medium pressurized by the electric compressor 125 is supplied to both the battery heat exchanger 122 and the air conditioning heat exchanger 121 through the first control valve 131 and the second control valve 132. The heat transfer medium releases heat in the battery heat exchanger 122 and the air conditioning heat exchanger 121, warming the storage battery 61 and the operator's cab 12. The heat transfer medium that has passed through the battery heat exchanger 122 is supplied to the expansion valve 126 through the fourth control valve 134. The heat transfer medium that has passed through the air conditioning heat exchanger 121 merges with the heat transfer medium that has passed through the battery heat exchanger 122 and is supplied to the expansion valve 126. The heat transfer medium, depressurized by the expansion valve 126, is supplied to the outside air heat exchanger 123 through the fifth control valve 135. The heat transfer medium absorbs heat in the outside air heat exchanger 123. The heat transfer medium that has passed through the outside air heat exchanger 123 returns to the electric compressor 125 through the second control valve 132 and the first control valve 131.

[0064] As shown in Figure 4, in step S130, the control device 100 determines whether the temperature Tb of the storage battery 61 detected by the temperature sensor 111 is less than the second temperature threshold T2. If it is determined that the temperature Tb of the storage battery 61 is less than the second temperature threshold T2, the process proceeds to step S133. If it is determined that the temperature Tb of the storage battery 61 is greater than or equal to the second temperature threshold T2, the process proceeds to step S163. The second temperature threshold T2 is a higher value than the first temperature threshold T1.

[0065] In step S133, the control device 100 determines whether or not a heating ON signal has been input from the control panel 110. If it is determined that a heating ON signal has been input from the control panel 110, the process proceeds to step S136. If it is determined that no heating ON signal has been input from the control panel 110, the process proceeds to step S143.

[0066] In step S136, the control device 100 outputs an ON signal to the electric compressor 125, similar to step S116, and starts the electric compressor 125.

[0067] In the next step S138, the control device 100 controls the valve system 130 so that the heat transfer medium circulates in the third pattern. As shown in Figure 7, in the third pattern valve switching control (S138), the control device 100 outputs an off signal to the solenoid S1 of the first control valve 131, an off signal to the first solenoid S21 of the second control valve 132, an on signal to the second solenoid S22 of the second control valve 132, an off signal to the solenoid S3 of the third control valve 133, an off signal to the solenoid S4 of the fourth control valve 134, and an off signal to the solenoid S5 of the fifth control valve 135. As a result, the first control valve 131 is switched to the heated position 131a, the second control valve 132 is switched to the third position 132c, the third control valve 133 is switched to the first position 133a, the fourth control valve 134 is switched to the communication position 134a, and the fifth control valve 135 is switched to the first position 135a. In other words, the first, third to fifth control valves 131, 133 to 135 maintain their initial positions, and only the valve body of the second control valve 132 is switched from its initial position.

[0068] As a result of the third valve control pattern, the heat transfer medium pressurized by the electric compressor 125 is supplied to the air conditioning heat exchanger 121 through the first control valve 131 and the second control valve 132. The heat transfer medium releases heat in the air conditioning heat exchanger 121, warming the operator's room 12. The heat transfer medium that has passed through the air conditioning heat exchanger 121 is supplied to the expansion valve 126. The heat transfer medium, depressurized by the expansion valve 126, is supplied to the outside air heat exchanger 123 through the fifth control valve 135. The heat transfer medium absorbs heat in the outside air heat exchanger 123. The heat transfer medium that has passed through the outside air heat exchanger 123 returns to the electric compressor 125 through the second control valve 132 and the first control valve 131.

[0069] As shown in Figure 4, in step S143, the control device 100 determines whether or not an air conditioning ON signal has been input from the control panel 110. If it is determined that an air conditioning ON signal has been input from the control panel 110, the process proceeds to step S146. If it is determined that no air conditioning ON signal has been input from the control panel 110, the process proceeds to step S156.

[0070] In step S146, the control device 100 outputs an ON signal to the electric compressor 125, similar to step S116, and starts the electric compressor 125.

[0071] In the next step, S148, the control device 100 controls the valve system 130 so that the heat transfer medium circulates in the sixth pattern. As shown in Figure 10, in the sixth pattern valve switching control (S148), the control device 100 outputs an ON signal to the solenoid S1 of the first control valve 131, an OFF signal to the first solenoid S21 of the second control valve 132, an ON signal to the second solenoid S22 of the second control valve 132, an OFF signal to the solenoid S3 of the third control valve 133, an OFF signal to the solenoid S4 of the fourth control valve 134, and an OFF signal to the solenoid S5 of the fifth control valve 135. As a result, the first control valve 131 is switched to the cooling position 131b, the second control valve 132 is switched to the third position 132c, the third control valve 133 is switched to the first position 133a, the fourth control valve 134 is switched to the communication position 134a, and the fifth control valve 135 is switched to the first position 135a. In other words, the third to fifth control valves 133 to 135 maintain their initial positions, while the valve bodies of the first control valve 131 and the second control valve 132 are switched from their initial positions.

[0072] As a result of the sixth valve control pattern, the heat transfer medium pressurized by the electric compressor 125 is supplied to the outside air heat exchanger 123 through the first control valve 131 and the second control valve 132. The heat transfer medium releases heat in the outside air heat exchanger 123. The heat transfer medium that has passed through the outside air heat exchanger 123 is supplied to the expansion valve 126 through the fifth control valve 135. The heat transfer medium, depressurized by the expansion valve 126, is supplied to the air conditioning heat exchanger 121. The heat transfer medium absorbs heat in the air conditioning heat exchanger 121 and cools the operator's room 12. The heat transfer medium that has passed through the air conditioning heat exchanger 121 returns to the electric compressor 125 through the second control valve 132 and the first control valve 131.

[0073] As shown in Figure 4, in step S156, the control device 100 outputs an off signal to the electric compressor 125, causing the electric compressor 125 to stop.

[0074] In the next step S158, the control device 100 does not perform control of the valve system 130 and terminates the process shown in the flowchart of Figure 4.

[0075] In step S163, the control device 100 determines whether or not a heating ON signal has been input from the control panel 110. If it is determined that a heating ON signal has been input from the control panel 110, the process proceeds to step S166. If it is determined that no heating ON signal has been input from the control panel 110, the process proceeds to step S173.

[0076] In step S166, the control device 100 outputs an ON signal to the electric compressor 125, similar to step S116, and starts the electric compressor 125.

[0077] In the next step, S168, the control device 100 controls the valve system 130 so that the heat transfer medium circulates in the fourth pattern. As shown in Figure 8, in the fourth pattern valve switching control (S168), the control device 100 outputs an off signal to the solenoid S1 of the first control valve 131, an off signal to the first solenoid S21 of the second control valve 132, an on signal to the second solenoid S22 of the second control valve 132, an on signal to the solenoid S3 of the third control valve 133, an on signal to the solenoid S4 of the fourth control valve 134, and an on signal to the solenoid S5 of the fifth control valve 135. As a result, the first control valve 131 is switched to the heating position 131a, the second control valve 132 is switched to the third position 132c, the third control valve 133 is switched to the second position 133b, the fourth control valve 134 is switched to the shut-off position 134b, and the fifth control valve 135 is switched to the second position 135b. In other words, only the first control valve 131 maintains its initial position, while the valve bodies of the second to fifth control valves 132 to 135 are switched from their initial positions.

[0078] As a result of the fourth valve control pattern, the heat transfer medium pressurized by the electric compressor 125 is supplied to the air conditioning heat exchanger 121 through the first control valve 131 and the second control valve 132. The heat transfer medium releases heat in the air conditioning heat exchanger 121, warming the operator's cab 12. The heat transfer medium that has passed through the air conditioning heat exchanger 121 is supplied to the expansion valve 126. The heat transfer medium, depressurized by the expansion valve 126, is supplied to the battery heat exchanger 122 through the fifth control valve 135. The heat transfer medium absorbs heat in the battery heat exchanger 122, cooling the storage battery 61. The heat transfer medium that has passed through the battery heat exchanger 122 returns to the electric compressor 125 through the second control valve 132 and the first control valve 131.

[0079] In the fourth pattern, the third to fifth control valves 133 to 135 are switched compared to the valve arrangement in the third pattern, which only heats the driver's cab 12. In the fourth pattern, the driver's cab 12 can be heated while the battery 61 is cooled.

[0080] As shown in Figure 4, in step S173, the control device 100 determines whether or not an air conditioning ON signal has been input from the control panel 110. If it is determined that an air conditioning ON signal has been input from the control panel 110, the process proceeds to step S176. If it is determined that no air conditioning ON signal has been input from the control panel 110, the process proceeds to step S186.

[0081] In step S176, the control device 100 outputs an ON signal to the electric compressor 125, similar to step S116, and starts the electric compressor 125.

[0082] In the next step, S178, the control device 100 controls the valve system 130 so that the heat transfer medium circulates in the seventh pattern. As shown in Figure 11, in the seventh pattern valve switching control (S178), the control device 100 outputs an ON signal to the solenoid S1 of the first control valve 131, an OFF signal to the first solenoid S21 and the second solenoid S22 of the second control valve 132, an OFF signal to the solenoid S3 of the third control valve 133, an OFF signal to the solenoid S4 of the fourth control valve 134, and an OFF signal to the solenoid S5 of the fifth control valve 135. As a result, the first control valve 131 is switched to the cooling position 131b, the second control valve 132 is switched to the first position 132a, the third control valve 133 is switched to the first position 133a, the fourth control valve 134 is switched to the communication position 134a, and the fifth control valve 135 is switched to the first position 135a. In other words, the second to fifth control valves 132 to 135 maintain their initial positions, while only the valve body of the first control valve 131 is switched from its initial position.

[0083] As a result of the seventh valve control pattern, the heat transfer medium pressurized by the electric compressor 125 is supplied to the outside air heat exchanger 123 through the first control valve 131 and the second control valve 132. The heat transfer medium releases heat in the outside air heat exchanger 123. The heat transfer medium that has passed through the outside air heat exchanger 123 is supplied to the expansion valve 126 through the fifth control valve 135. The heat transfer medium, depressurized by the expansion valve 126, is supplied to the air conditioning heat exchanger 121. The heat transfer medium, depressurized by the expansion valve 126, is also supplied to the battery heat exchanger 122 through the fourth control valve 134. The heat transfer medium absorbs heat in the battery heat exchanger 122 and the air conditioning heat exchanger 121, cooling the storage battery 61 and the operator's cab 12. The heat transfer medium that has passed through the battery heat exchanger 122 and the third control valve 133 merges with the heat transfer medium that has passed through the air conditioning heat exchanger 121 and returns to the electric compressor 125 through the second control valve 132 and the first control valve 131.

[0084] As shown in Figure 4, in step S186, the control device 100 outputs an ON signal to the electric compressor 125, similar to step S116, and starts the electric compressor 125.

[0085] In the next step, S188, the control device 100 controls the valve system 130 so that the heat transfer medium circulates in the fifth pattern. As shown in Figure 9, in the fifth pattern valve switching control (S188), the control device 100 outputs an ON signal to the solenoid S1 of the first control valve 131, an ON signal to the first solenoid S21 of the second control valve 132, an OFF signal to the second solenoid S22 of the second control valve 132, an OFF signal to the solenoid S3 of the third control valve 133, an OFF signal to the solenoid S4 of the fourth control valve 134, and an OFF signal to the solenoid S5 of the fifth control valve 135. As a result, the first control valve 131 is switched to the cooling position 131b, the second control valve 132 is switched to the second position 132b, the third control valve 133 is switched to the first position 133a, the fourth control valve 134 is switched to the communication position 134a, and the fifth control valve 135 is switched to the first position 135a. In other words, the third to fifth control valves 133 to 135 maintain their initial positions, while the valve bodies of the first control valve 131 and the second control valve 132 are switched from their initial positions.

[0086] As a result of the fifth valve control pattern, the heat transfer medium pressurized by the electric compressor 125 is supplied to the outside air heat exchanger 123 through the first control valve 131 and the second control valve 132. The heat transfer medium releases heat in the outside air heat exchanger 123. The heat transfer medium that has passed through the outside air heat exchanger 123 is supplied to the expansion valve 126 through the fifth control valve 135. The heat transfer medium that has been depressurized by the expansion valve 126 is supplied to the battery heat exchanger 122 through the fourth control valve 134. The heat transfer medium absorbs heat in the battery heat exchanger 122, cooling the storage battery 61. The heat transfer medium that has passed through the battery heat exchanger 122 returns to the electric compressor 125 through the third control valve 133, the second control valve 132, and the first control valve 131.

[0087] Furthermore, once the processes shown in steps S118, S128, S138, S148, S158, S168, S178, and S188 in Figure 4 are completed, the processes shown in the flowchart of Figure 4 for this control cycle are finished, and in the next control cycle, the processes from step S110 onwards will start again.

[0088] In this embodiment, the control device 100 prioritizes temperature adjustment of the storage battery 61. First, it determines whether temperature adjustment of the storage battery 61 is necessary (steps S110, S120, S130), then it determines whether temperature adjustment of the operator's cab 12 is necessary (steps S123, S133, S143, S163, S173), and then it controls the on / off of the electric compressor 125 and the directional control valves (131-135) of the valve system 130.

[0089] If the temperature Tb of the battery 61 is less than the first temperature threshold T1, the control device 100 controls the electric compressor 125 and the directional control valves (131-135) of the valve system 130 to heat the battery 61. If the temperature Tb of the battery 61 is less than the battery priority temperature threshold T0, the control device 100 operates the electric compressor 125 and energizes the first solenoid S21 of the second control valve 132 to heat only the battery 61 with the highest priority (first pattern). If the temperature Tb of the battery 61 is greater than or equal to the battery priority temperature threshold T0 and less than the first temperature threshold T1, the control device 100 operates the electric compressor 125 to heat the battery 61. If the heating / cooling switch is operated to the off position, the control device 100 energizes the first solenoid S21 of the second control valve 132 to heat only the battery 61 (first pattern). When the heating / cooling switch is operated to the heating ON position, the control device 100 does not energize the solenoids of the directional control valves (131-135). As a result, both the battery 61 and the driver's cab 12 are heated (Pattern 2).

[0090] If the temperature Tb of the storage battery 61 is between the first temperature threshold T1 and the second temperature threshold T2, the control device 100 determines that temperature adjustment of the storage battery 61 is unnecessary. If the heating / cooling switch is operated to the heating ON position, the control device 100 operates the electric compressor 125 and energizes the second solenoid S22 of the second control valve 132 to heat the operator's cab 12 (third pattern). If the heating / cooling switch is operated to the cooling ON position, the control device 100 operates the electric compressor 125 and energizes the solenoid S1 of the first control valve 131 and the second solenoid S22 of the second control valve 132 to cool the operator's cab 12 (sixth pattern). If the heating / cooling switch is operated to the OFF position, the control device 100 stops the electric compressor 125. Also, the control device 100 does not energize the solenoids of the directional control valves (131 to 135). In other words, the driver's cab 12 will not be heated or cooled.

[0091] If the temperature Tb of the battery 61 is equal to or greater than the second temperature threshold T2, the control device 100 operates the electric compressor 125 and controls the directional control valves (131-135) to cool the battery 61. If the heating / cooling switch is operated to the heating ON position, the control device 100 energizes the second solenoid S22 of the second control valve 132, the solenoid S3 of the third control valve 133, the solenoid S3 of the fourth control valve 134, and the solenoid S5 of the fifth control valve 135. As a result, the battery 61 is cooled and the cab 12 is heated (Pattern 4). If the heating / cooling switch is operated to the cooling ON position, the control device 100 energizes the solenoid S1 of the first control valve 131. As a result, both the battery 61 and the cab 12 are cooled (Pattern 7). When the heating / cooling switch is operated to the off position, the control device 100 energizes the solenoid S1 of the first control valve 131 and the first solenoid S21 of the second control valve 132. This cools the storage battery 61 (Pattern 5).

[0092] According to the above-described embodiment, the following effects are achieved.

[0093] (1) Based on the temperature Tb of the storage battery 61 detected by the temperature sensor 111 and the operation signals from the control panel (switching means) 110 (heating on signal, cooling on signal, and off signal indicating the switching status of heating and cooling), the control device 100 selects the heat exchanger that allows the heat transfer medium flowing from the electric compressor (compressor) 125 toward the expansion valve 126 to pass through from among the air conditioning heat exchanger 121, the battery heat exchanger 122, and the outside air heat exchanger 123 to pass through to the electric compressor 125 as the first heat exchanger, and selects the heat exchanger that allows the heat transfer medium flowing from the expansion valve 126 toward the electric compressor 125 to pass through from among the air conditioning heat exchanger 121, the battery heat exchanger 122, and the outside air heat exchanger 123 as the second heat exchanger. The control device 100 controls the valve system 130 so that the heat transfer medium discharged from the electric compressor 125 is guided to the first heat exchanger, and the heat transfer medium discharged from the expansion valve 126 is guided to the second heat exchanger.

[0094] In this embodiment, which is presented as an example, if the heat exchanger 122 for the battery is selected as the first heat exchanger and the heat exchanger 123 for the outside air is selected as the second heat exchanger, the heat transfer medium circulates in the first pattern shown in Figure 5. If the heat exchanger 121 for the air conditioning and the heat exchanger 122 for the battery are each selected as the first heat exchanger and the heat exchanger 123 for the outside air is selected as the second heat exchanger, the heat transfer medium circulates in the second pattern shown in Figure 6. If the heat exchanger 121 for the air conditioning is selected as the first heat exchanger and the heat exchanger 123 for the outside air is selected as the second heat exchanger, the heat transfer medium circulates in the third pattern shown in Figure 7. If the heat exchanger 121 for the air conditioning is selected as the first heat exchanger and the heat exchanger 122 for the battery is selected as the second heat exchanger, the heat transfer medium circulates in the fourth pattern shown in Figure 8. When the outdoor air heat exchanger 123 is selected as the first heat exchanger and the battery heat exchanger 122 is selected as the second heat exchanger, the heat transfer medium circulates in the fifth pattern shown in Figure 9. When the outdoor air heat exchanger 123 is selected as the first heat exchanger and the air conditioning heat exchanger 121 is selected as the second heat exchanger, the heat transfer medium circulates in the sixth pattern shown in Figure 10. When the outdoor air heat exchanger 123 is selected as the first heat exchanger and the air conditioning heat exchanger 121 and the battery heat exchanger 122 are selected as the second heat exchangers, the heat transfer medium circulates in the seventh pattern shown in Figure 11.

[0095] In this configuration, the temperature of the driver's cab 12 and the battery 61 can be controlled using a single heat transfer medium, simplifying the temperature control circuit system. For example, the electric heater in the heating circuit used in the conventional technology is no longer required. In the conventional technology, each of the heating circuit, cooling circuit, and battery cooling circuit was provided with a discharge device to discharge the heat transfer medium. In contrast, in this embodiment, a single electric compressor 125 is provided as the discharge device. In other words, in this embodiment, the number of discharge devices installed is reduced compared to the conventional technology. Since the discharge devices are driven by power supplied from the battery, the reduction in the number of discharge devices installed contributes to improving the energy efficiency of the system. In other words, in this embodiment, the energy efficiency of the temperature control system 120 is improved compared to the conventional technology. Furthermore, since heating does not use an electric heater and uses the heat generated by the refrigeration cycle, the COP (Coefficient of Performance) is increased, and the power consumption of the battery 61 can be effectively suppressed. As a result, the time until the battery 61 needs to be charged using an external power source, i.e., the working time of the wheel loader 10, can be extended, thereby improving work efficiency.

[0096] (2) When the temperature Tb of the storage battery 61 detected by the temperature sensor 111 is less than the first temperature threshold T1, the control device 100 controls the first control valve 131 and the second control valve 132 so that the heat transfer medium pressurized by the electric compressor 125 is supplied to the battery heat exchanger 122 and the heat transfer medium depressurized by the expansion valve 126 is supplied to the outside air heat exchanger 123 (Yes in S120, S118 (first pattern), S128 (second pattern) in Figure 4). The control device 100 controls the first control valve 131 and the second control valve 132 so that if the temperature Tb of the storage battery 61 detected by the temperature sensor 111 is higher than or equal to the second temperature threshold T2, which is higher than the first temperature threshold T1, the heat transfer medium pressurized by the electric compressor 125 is supplied to the outside air heat exchanger 123, and the heat transfer medium depressurized by the expansion valve 126 is supplied to the battery heat exchanger 122 (No. S168 (fourth pattern), S178 (seventh pattern), S188 (fifth pattern) in S130 of Figure 4). When the control device 100 receives an operation signal to turn on the heating from the control panel 110, it controls the first control valve 131 and the second control valve 132 so that the heat transfer medium pressurized by the electric compressor 125 is supplied to the air conditioning heat exchanger 121, and the heat transfer medium depressurized by the expansion valve 126 is supplied to the outside air heat exchanger 123 (Yes at S123, S128 (second pattern), Yes at S133, S138 (third pattern) in Figure 4). When the control device 100 receives an operation signal to turn on the air conditioning from the control panel 110, it controls the first control valve 131 and the second control valve 132 so that the heat transfer medium pressurized by the electric compressor 125 is supplied to the outside air heat exchanger 123, and the heat transfer medium depressurized by the expansion valve 126 is supplied to the air conditioning heat exchanger 121 (Yes at S143, S148 (6th pattern), and S173, S178 (7th pattern) in Figure 4).If the temperature Tb of the storage battery 61 detected by the temperature sensor 111 is less than the battery priority temperature threshold T0, which is lower than the first temperature threshold T1, the control device 100 controls the first control valve 131 and the second control valve 132 so that, regardless of the operation signal from the control panel 110, the heat transfer medium pressurized by the electric compressor 125 is supplied to the battery heat exchanger 122 without being supplied to the air conditioning heat exchanger 121, and the heat transfer medium depressurized by the expansion valve 126 is supplied to the outside air heat exchanger 123 (Yes in S110, S118 (first pattern) in Figure 4).

[0097] In this configuration, when the temperature Tb of the battery 61 is below the first temperature threshold T1, the battery 61 is heated, and when the temperature Tb of the battery 61 is above the second temperature threshold T2, the battery 61 is cooled. Therefore, a decrease in the output of the battery 61 caused by a decrease in the temperature of the battery 61 can be suppressed. In addition, degradation of the battery 61 caused by a rise in the temperature of the battery 61 can be suppressed.

[0098] In this configuration, when the temperature Tb of the battery 61 is equal to or greater than the battery priority temperature threshold T0, heating and cooling are controlled according to the operator's operation on the control panel 110. However, if the temperature Tb of the battery 61 is less than the battery priority temperature threshold T0, the operation of the wheel loader 10 will be hindered due to insufficient output from the battery 61. As a result, work cannot be started with the wheel loader 10. For work vehicles (work machines) such as the wheel loader 10, there is a demand to prioritize improved work efficiency over the comfort of the driver's cab 12. Therefore, in this embodiment, when the temperature Tb of the battery 61 is less than the battery priority temperature threshold T0, only the battery 61 is heated regardless of the operator's operation. This makes it possible to efficiently raise the temperature of the battery 61. As a result, the start of work with the wheel loader 10 can be accelerated.

[0099] (3) The first control valve 131 is provided between the electric compressor 125 and the second control valve 132. The first control valve 131 is a two-position directional control valve (4-port two-position solenoid switching valve) that can be switched to either the heating position 131a or the cooling position 131b. The second control valve 132 is a three-position directional control valve (5-port three-position solenoid switching valve) that can be switched to either the first position 132a, the second position 132b, or the third position 132c. Here, for example, the second control valve 132 can be made to have the same function by using multiple two-position directional control valves. In this embodiment, by using a three-position directional control valve for the second control valve 132, the number of valves, fittings, and piping can be reduced and the system configuration can be simplified. Simplifying the system configuration leads to space saving for the temperature control system 120.

[0100] (5) The control device 100 controls multiple directional control valves (131-135) to circulate the heat transfer medium in multiple patterns. The multiple patterns include a fourth pattern (see Figure 8). In the fourth pattern, the heat transfer medium pressurized by the electric compressor 125 is supplied to the air conditioning heat exchanger 121, and the heat transfer medium that has passed through the air conditioning heat exchanger 121 is supplied to the expansion valve 126. In the fourth pattern, the heat transfer medium that has been depressurized by the expansion valve 126 is supplied to the battery heat exchanger 122, and the heat transfer medium that has passed through the battery heat exchanger 122 is returned to the electric compressor 125. With this configuration, when the temperature Tb of the storage battery 61 rises due to continuous high-load work during winter (or cold regions), the operator's cab 12 can be warmed while the storage battery 61 is cooled. This ensures comfort in the operator's cab 12 while suppressing deterioration of the storage battery 61.

[0101] (6) The valve system 130 includes a third control valve 133 provided between the second control valve 132 and the battery heat exchanger 122, a fourth control valve 134 provided between the battery heat exchanger 122 and the expansion valve 126, and a fifth control valve 135 provided between the expansion valve 126 and the outside air heat exchanger 123. In this embodiment, the heat transfer medium can be circulated in the fourth pattern (see Figure 8) by controlling the third to fifth control valves 133 to 135. Here, for example, the same function can be achieved by providing four or more poppet valves instead of the third to fifth control valves 133 to 135. In this embodiment, by using the third to fifth control valves 133 to 135, the number of valves, fittings, and piping can be reduced and the system configuration can be simplified. Simplifying the system configuration leads to space saving for the temperature control system 120.

[0102] The following modifications are also within the scope of the present invention, and it is possible to combine the configurations shown in the modifications with the configurations described in the embodiments described above, or to combine the configurations described in the following different modifications.

[0103] <Example 1> Referring to Figure 12, a wheel loader 10 according to Modification 1 of this embodiment will be described. Figure 12 is a diagram showing the hydraulic oil temperature control system 150 of the wheel loader 10 according to Modification 1. The same reference numerals are used for components that are the same as or equivalent to those described in the above embodiment, and the differences will be mainly explained. As shown in Figure 12, the wheel loader 10 according to Modification 1 further includes a hydraulic oil heat exchanger 124, which is a heat exchanger that performs heat exchange between hydraulic oil and a heat transfer medium. The hydraulic oil heat exchanger 124 has an internal oil passage through which hydraulic oil flows and an internal flow path through which the heat transfer medium flows. For example, a tube-type heat exchanger or a plate-type heat exchanger can be used for the hydraulic oil heat exchanger 124.

[0104] The hydraulic oil heat exchanger 124 is connected in series with the battery heat exchanger 122 so that the low-temperature, low-pressure heat transfer medium, which has been depressurized by the expansion valve 126, flows through the battery heat exchanger 122 and then the hydraulic oil heat exchanger 124. In other words, the hydraulic oil heat exchanger 124 is connected in series with the battery heat exchanger 122 so that the high-temperature, high-pressure heat transfer medium, which has been pressurized by the electric compressor 125, flows through the hydraulic oil heat exchanger 124 and then the battery heat exchanger 122. In this modified example 1, the hydraulic oil heat exchanger 124 is located in the flow path connecting the third control valve 133 and the battery heat exchanger 122.

[0105] In work machines such as the wheel loader 10, when high-load work is performed continuously, the temperature of the battery 61 rises, as does the temperature of the hydraulic fluid. Therefore, in work machines, the timing for cooling the battery 61 and the timing for cooling the hydraulic fluid are roughly the same. Also, in winter (or in cold regions), when work machines such as the wheel loader 10 are parked, the temperature of the battery 61 and the hydraulic fluid will be low, so warming up before starting work is necessary. Therefore, in work machines, the timing for warming the battery 61 and the timing for warming the hydraulic fluid are roughly the same.

[0106] In this modified configuration, the hydraulic fluid heat exchanger 124 and the battery heat exchanger 122 are connected in series with each other. This allows the storage battery 61 and the hydraulic fluid to be cooled or heated at the same time. According to this modified configuration, the temperature of the hydraulic fluid can be controlled more efficiently.

[0107] The control device 100 controls the work inverter 151, which drives the hydraulic pump 153 via the work motor (electric motor) 152 to pump hydraulic fluid from the hydraulic fluid tank 156 to the control valve 154. The control device 100 controls the control valve 154, which operates the hydraulic actuator 155. The return hydraulic fluid from the control valve 154 is supplied to the internal oil passages of the hydraulic fluid heat exchanger 124 through the oil cooler 157. Heat exchange takes place between the heat transfer medium and the hydraulic fluid as the heat transfer medium flows through the internal oil passages of the hydraulic fluid heat exchanger 124 and the hydraulic fluid flows through the internal oil passages of the hydraulic fluid heat exchanger 124. As a result, the hydraulic fluid returns to the hydraulic fluid tank 156 with its temperature adjusted.

[0108] When heating the hydraulic fluid, the control device 100 stops the oil cooling fan motor 34. Since the fan 44 stops rotating, it prevents the hydraulic fluid from being cooled by the oil cooler 157. On the other hand, when cooling the hydraulic fluid, the control device 100 rotates the oil cooling fan motor 34. Since the fan 44 rotates, the hydraulic fluid is cooled by the oil cooler 157.

[0109] The control of the valve system 130 is the same as in the embodiment described above. Therefore, a detailed explanation of the control of the valve system 130 is omitted. Alternatively, the temperature of the hydraulic fluid may be detected by an oil temperature sensor, and the valve system 130 may be controlled based on the detected hydraulic fluid temperature.

[0110] In this modified example, when cooling the battery 61 and the hydraulic oil, the heat transfer medium flows in the order of the battery heat exchanger 122 and then the hydraulic oil heat exchanger 124 (patterns 4, 5, and 7). This allows the battery 61 to be cooled preferentially. On the other hand, during the warm-up operation when starting the vehicle, the coolant flows in the order of the hydraulic oil heat exchanger 124 and then the battery heat exchanger 122. Here, the control device 100 prohibits the operation of the work device 6 and the running device 11, or limits their output, until the warm-up operation is complete. The completion of the warm-up operation is determined, for example, by whether the temperature of the battery 61 has risen to a predetermined value. For this reason, the hydraulic oil is not circulating during the warm-up operation. Therefore, according to the configuration of this modified example, the battery 61 can be heated preferentially.

[0111] <Modification 2> In the above embodiment, an example in which the expansion valve 126 is a bidirectional expansion valve was described, but the present invention is not limited thereto. A bidirectional expansion valve device having the same function as a bidirectional expansion valve may be configured with two unidirectional expansion valves and a plurality of valves.

[0112] <Variation 3> In the above embodiment, an example was described in which the rotational speed of the electric compressor 125 is controlled at a constant speed. However, the control device 100 may change the rotational speed of the electric compressor 125 when it is turned on. Regarding the heating and cooling of the storage battery 61 and the operator's cab 12, if it is desired to strengthen the temperature control, the rotational speed of the electric compressor 125 should be increased from the current set speed. Conversely, if it is desired to weaken the temperature control, the rotational speed of the electric compressor 125 should be decreased from the current set speed.

[0113] For example, the temperature control system 120 may further include an indoor temperature sensor that detects the temperature inside the operator's cab 12 and an outdoor temperature sensor that detects the temperature outside the operator's cab 12, and the control device 100 may control the rotational speed of the electric compressor 125 taking into account the detection results of the indoor temperature sensor and the outdoor temperature sensor.

[0114] <Modification 4> In the above embodiment, an example was described in which the second control valve 132 is an electromagnetic switching valve. However, the second control valve 132 may also be configured as an electromagnetic proportional valve whose opening area is adjusted according to the magnitude of the excitation current to the solenoids S21 and S22. In this configuration, when it is desired to prioritize heating either the storage battery 61 or the operator's cab 12, the excitation current to the second control valve 132 can be controlled to increase the flow rate of the heat transfer medium to the heat exchanger with higher priority.

[0115] <Modification 5> In the above embodiment, an example was described in which the fourth control valve 134 is an electromagnetic switching valve. However, the fourth control valve 134 may also be configured as an electromagnetic proportional valve whose opening area is adjusted according to the magnitude of the excitation current to the solenoid S4. In this configuration, when cooling the storage battery 61 and the operator's cab 12, if it is desired to reduce the cooling of the storage battery 61, the excitation current to the fourth control valve 134 can be controlled to reduce the flow rate of the heat transfer medium flowing to the battery heat exchanger 122.

[0116] <Variation 6> In the above embodiment, an example was described in which the fifth control valve 135 is an electromagnetic switching valve. However, the fifth control valve 135 may also be configured as an electromagnetic proportional valve whose opening area is adjusted according to the magnitude of the excitation current to the solenoid S5. In this configuration, when cooling the storage battery 61 and heating the operator's cab 12, if it is desired to reduce the cooling of the storage battery 61, the excitation current to the fifth control valve 135 can be controlled to reduce the flow rate of the heat transfer medium flowing to the battery heat exchanger 122.

[0117] <Example 7> The control device 100 may also perform rotational speed control of the fan 41 that blows air from the air conditioning heat exchanger 121 into the operator's room 12, and flow path switching control to switch the duct flow path within the air conditioning unit (not shown). This allows for temperature adjustment of the heating and cooling of the operator's room 12.

[0118] <Differentiation Example 8> In the above embodiment, an example was described in which the second control valve 132 is a 5-port 3-position directional control valve. However, the second control valve 132 may also be configured as a 3-port 3-position directional control valve. In this case, the second port P2 and the fifth port P5 described above are omitted.

[0119] <Modification 9> The fourth valve control pattern may be omitted. In this case, the third to fifth control valves 133 to 135 and the flow path connecting the fifth control valve 135 to the battery heat exchanger 122 can be omitted, making the system configuration simpler.

[0120] <Variation 10> In the above embodiment, an example was described in which the electric drive vehicle equipped with the temperature control system 120 is a wheel loader 10, but the present invention is not limited thereto. The temperature control system 120 can be installed in various electric drive vehicles powered by the battery 61, such as work machinery like hydraulic excavators, dump trucks and road machinery, as well as ordinary automobiles.

[0121] <Variation 11> In the above embodiment, an example was described in which the air conditioning heat exchanger 121 and the battery heat exchanger 122 are connected in parallel in the flow path between the electric compressor 125 and the expansion valve 126. However, the air conditioning heat exchanger 121 and the battery heat exchanger 122 may be connected in series. However, in this case, for example, if the air conditioning / heating switch on the control panel 110 is operated to the air conditioning ON position, the storage battery 61 will be cooled regardless of the temperature of the storage battery 61, and if the temperature of the storage battery 61 becomes too high, the operator's room 12 will be cooled regardless of the operation of the control panel 110. For this reason, as in the above embodiment, it is preferable that the air conditioning heat exchanger 121 and the battery heat exchanger 122 are connected in parallel in the flow path between the electric compressor 125 and the expansion valve 126.

[0122] The air conditioning heat exchanger 121 and the battery heat exchanger 122 are connected in parallel, allowing for individual temperature control of the operator's cab 12 and the battery 61. Furthermore, control can be performed to heat only the battery 61, regardless of the operation of the control panel 110 (Pattern 1 in Figure 5). Additionally, control can be performed to heat the operator's cab 12 and cool the battery 61 (Pattern 4 in Figure 8).

[0123] <Variation 12> The third control valve 133 described in the above embodiment can be replaced with multiple poppet valves. Similarly, the fifth control valve 135 can be replaced with multiple poppet valves. As in the above embodiment, by configuring the third control valve 133 and the fifth control valve 135 as 3-port 2-position directional control valves, the number of valves, fittings, and piping can be reduced, contributing to space saving of the temperature control system 120.

[0124] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. [Explanation of Symbols]

[0125] 2...Arm, 3...Bucket, 4...Arm cylinder (hydraulic actuator, hydraulic cylinder), 5...Bucket cylinder (hydraulic actuator, hydraulic cylinder), 6...Working device, 7...Wheel, 8...Vehicle body, 9...Steering cylinder (hydraulic actuator, hydraulic cylinder), 10...Wheel loader (electric drive vehicle), 11...Running gear, 12...Driver's cab, 16...Machine room, 26...Running motor (electric motor), 27...Running inverter, 31...Air conditioning fan motor (electric motor), 33...Heat transfer medium cooling fan motor (electric motor), 34...Oil cooling fan motor (electric motor), 41,43,44...Fan, 61...Storage battery (high voltage battery), 62...Storage battery (low voltage battery), 100...Control device, 101...Processing device (processor), 102...Non-volatile memory (storage device, memory), 103...Volatile memory (storage device, memory), 104...Input interface, 105...Output interface, 110...Operation panel (switching means), 111...Temperature sensor, 120...Temperature control system, 121...Heat exchanger for air conditioning (heat exchanger), 122...Heat exchanger for batteries (heat exchanger) Container), 123... Heat exchanger for outside air (heat exchanger), 124... Heat exchanger for hydraulic oil (heat exchanger), 125... Electric compressor (compressor), 126... Expansion valve, 130... Valve system, 131... First control valve (directional control valve), 131a... Heating position, 131b... Cooling position, 132... Second control valve (directional control valve), 132a... First position, 132b... Second position, 132c... Third position, 133... Third control valve (directional control valve), 133a... First position, 133b... Second position, 134 ...Fourth control valve (directional control valve), 134a...Communication position, 134b...Shut-off position, 135...Fifth control valve (directional control valve), 135a...First position, 135b...Second position, 151...Work inverter, 152...Work motor (electric motor), 153...Hydraulic pump, 154...Control valve, 155...Hydraulic actuator (hydraulic cylinder), 156...Hydraulic oil tank, 157...Oil cooler, 171...Flow path, 172...Flow diverting / combining flow path, 173...Discharge flow path, 174...Return flow path (suction) (Flow path), P1...1st port (1st inlet / outlet port), P2...2nd port (2nd inlet / outlet port), P3...3rd port (air conditioning port), P4...4th port (battery port), P5...5th port, Pb1...1st battery connection port, Pb2...2nd battery connection port, Pb3...return connection port, Pc1...battery cooling port, Pc2...heat transfer medium cooling port, Pc3...low temperature heat transfer medium inlet port, T0...battery priority temperature threshold, T1...1st temperature threshold, T2...2nd temperature threshold, Tb...battery temperature,

Claims

1. The electric motor that drives the wheels, A storage battery that supplies power to the aforementioned electric motor, The system includes a temperature control system for adjusting the temperature of the battery and the driver's cab, The aforementioned temperature control system is A compressor that compresses and discharges a heat transfer medium, An expansion valve that depressurizes and expands the heat transfer medium, An air conditioning heat exchanger is a heat exchanger that performs heat exchange between a heat transfer medium and the air inside the driver's cabin, A heat exchanger for batteries, which is a heat exchanger that performs heat exchange between a heat transfer medium and the storage battery, An outside air heat exchanger is a heat exchanger that performs heat exchange between a heat transfer medium and the outside air, A temperature sensor for detecting the temperature of the storage battery, A switching means that allows switching between heating and cooling in the driver's cab, An electric drive vehicle comprising a control device that controls the temperature of the storage battery and the driver's cab based on the switching state of the switching means, The temperature control system includes a valve system having a plurality of directional control valves that can switch the direction in which the heat transfer medium pressurized by the compressor flows and the direction in which the heat transfer medium depressurized by the expansion valve flows. The control device is Based on the temperature of the storage battery detected by the temperature sensor and the operation signal from the switching means, the heat exchanger that passes the heat medium flowing from the compressor toward the expansion valve is selected as the first heat exchanger from among the air conditioning heat exchanger, the battery heat exchanger, and the outside air heat exchanger, and the heat exchanger that passes the heat medium flowing from the expansion valve toward the compressor is selected as the second heat exchanger from among the air conditioning heat exchanger, the battery heat exchanger, and the outside air heat exchanger. The valve system is controlled such that the heat transfer medium discharged from the compressor is guided to the first heat exchanger, and the heat transfer medium discharged from the expansion valve is guided to the second heat exchanger. An electric vehicle characterized by the following features.

2. In the electric drive vehicle according to claim 1, Hydraulic pump and A hydraulic actuator driven by hydraulic fluid discharged from the aforementioned hydraulic pump, A heat exchanger for hydraulic fluid, which is a heat exchanger that performs heat exchange between hydraulic fluid and a heat transfer medium, is further provided. The aforementioned heat exchanger for hydraulic fluid is connected in series with the heat exchanger for battery so that the heat transfer medium, depressurized by the expansion valve, flows through the heat exchanger for battery and then the heat exchanger for hydraulic fluid. An electric vehicle characterized by the following features.

3. In the electric drive vehicle according to claim 1, The air conditioning heat exchanger, the battery heat exchanger, and the outside air heat exchanger are connected in parallel to the compressor. The plurality of directional control valves include the air conditioning heat exchanger, the battery heat exchanger, and a first control valve and a second control valve connected in series between the battery heat exchanger and the compressor. The control device is If the temperature of the storage battery detected by the temperature sensor is below the first temperature threshold, the first control valve and the second control valve are controlled so that the heat transfer medium pressurized by the compressor is supplied to the battery heat exchanger, and the heat transfer medium depressurized by the expansion valve is supplied to the outside air heat exchanger. If the temperature of the storage battery detected by the temperature sensor is higher than or equal to a second temperature threshold, which is higher than the first temperature threshold, the first control valve and the second control valve are controlled so that the heat transfer medium pressurized by the compressor is supplied to the outside air heat exchanger, and the heat transfer medium depressurized by the expansion valve is supplied to the battery heat exchanger. When a heating ON operation signal is input from the switching means, the first control valve and the second control valve are controlled so that the heat transfer medium pressurized by the compressor is supplied to the air conditioning heat exchanger, and the heat transfer medium depressurized by the expansion valve is supplied to the outside air heat exchanger. When an operation signal to turn on the air conditioning is input from the switching means, the first control valve and the second control valve are controlled so that the heat transfer medium pressurized by the compressor is supplied to the outside air heat exchanger, and the heat transfer medium depressurized by the expansion valve is supplied to the air conditioning heat exchanger. If the temperature of the storage battery detected by the temperature sensor is below a battery priority temperature threshold which is lower than the first temperature threshold, the first control valve and the second control valve are controlled so that, regardless of the operation signal from the switching means, the heat transfer medium pressurized by the compressor is supplied to the battery heat exchanger without being supplied to the air conditioning heat exchanger, and the heat transfer medium depressurized by the expansion valve is supplied to the outside air heat exchanger. An electric vehicle characterized by the following features.

4. In the electric drive vehicle described in claim 3, The first control valve is, Provided between the compressor and the second control valve, A heating position is provided where the heat transfer medium pressurized by the compressor is guided to at least one of the air conditioning heat exchanger and the battery heat exchanger, and the heat transfer medium, which has been depressurized by the expansion valve and passed through the outside air heat exchanger, is guided to the compressor; and a cooling position is provided where the heat transfer medium pressurized by the compressor is guided to the outside air heat exchanger, and the heat transfer medium, which has been depressurized by the expansion valve and passed through at least one of the air conditioning heat exchanger and the battery heat exchanger, is guided to the compressor. The second control valve is, When the first control valve is switched to the heating position, it connects the discharge passage of the compressor to the air conditioning heat exchanger and the battery heat exchanger, respectively, and when the first control valve is switched to the cooling position, it connects the return passage of the compressor to the air conditioning heat exchanger and the battery heat exchanger, respectively, and When the first control valve is switched to the heating position, the second position blocks communication between the compressor's discharge passage and the air conditioning heat exchanger, and connects the compressor's discharge passage to the battery heat exchanger; when the first control valve is switched to the cooling position, the second position blocks communication between the compressor's return passage and the air conditioning heat exchanger, and connects the compressor's return passage to the battery heat exchanger; The system has a third position in which, when the first control valve is switched to the heating position, the discharge passage of the compressor is connected to the air conditioning heat exchanger and the communication between the compressor's discharge passage and the battery heat exchanger is blocked, and when the first control valve is switched to the cooling position, the return passage of the compressor is connected to the air conditioning heat exchanger and the communication between the compressor's return passage and the battery heat exchanger is blocked. An electric vehicle characterized by the following features.

5. In the electric drive vehicle according to claim 4, The plurality of directional control valves include a third control valve provided between the second control valve and the heat exchanger for the battery, a fourth control valve provided between the heat exchanger for the battery and the expansion valve, and a fifth control valve provided between the expansion valve and the heat exchanger for outside air. The second control valve has an inlet / outlet port connected to the discharge or return flow path of the compressor via the first control valve, an air conditioning port connected to the air conditioning heat exchanger, and a battery port connected to the battery heat exchanger. The third control valve has a first battery connection port connected to the battery port, a second battery connection port connected to the battery heat exchanger, and a return connection port connected to the return flow path of the compressor when the first control valve is switched to the heating position. The fifth control valve has a battery cooling port connected to a flow path connecting the battery heat exchanger and the fourth control valve, a heat transfer medium cooling port connected to the outside air heat exchanger, and a low-temperature heat transfer medium inlet port connected to the expansion valve. The third control valve has a first position that connects the first battery connection port and the second battery connection port and blocks communication between the return connection port and the second battery connection port, and a second position that blocks communication between the first battery connection port and the second battery connection port and connects the return connection port and the second battery connection port. The fourth control valve has a communication position that connects the heat exchanger for the battery and the expansion valve, and a shut-off position that blocks communication between the heat exchanger for the battery and the expansion valve. The fifth control valve has a first position that connects the low-temperature heat transfer medium inlet port and the heat transfer medium cooling port and blocks communication between the low-temperature heat transfer medium inlet port and the battery cooling port, and a second position that blocks communication between the low-temperature heat transfer medium inlet port and the heat transfer medium cooling port and connects the low-temperature heat transfer medium inlet port and the battery cooling port. An electric vehicle characterized by the following features.

6. In the electric drive vehicle according to claim 1, The control device controls a plurality of directional control valves to circulate the heat transfer medium in a plurality of patterns, Multiple of the aforementioned patterns are, In the first pattern, the heat transfer medium pressurized by the compressor is supplied to the battery heat exchanger, the heat transfer medium that has passed through the battery heat exchanger is supplied to the expansion valve, the heat transfer medium that has been depressurized by the expansion valve is supplied to the outside air heat exchanger, and the heat transfer medium that has passed through the outside air heat exchanger returns to the compressor. In the second pattern, the heat transfer medium pressurized by the compressor is supplied to both the battery heat exchanger and the air conditioning heat exchanger, the heat transfer medium that has passed through the battery heat exchanger and the air conditioning heat exchanger is supplied to the expansion valve, the heat transfer medium that has been depressurized by the expansion valve is supplied to the outside air heat exchanger, and the heat transfer medium that has passed through the outside air heat exchanger returns to the compressor. A third pattern is in which the heat transfer medium pressurized by the compressor is supplied to the air conditioning heat exchanger, the heat transfer medium that has passed through the air conditioning heat exchanger is supplied to the expansion valve, the heat transfer medium that has been depressurized by the expansion valve is supplied to the outside air heat exchanger, and the heat transfer medium that has passed through the outside air heat exchanger returns to the compressor. A fourth pattern is in which the heat transfer medium pressurized by the compressor is supplied to the air conditioning heat exchanger, the heat transfer medium that has passed through the air conditioning heat exchanger is supplied to the expansion valve, the heat transfer medium that has been depressurized by the expansion valve is supplied to the battery heat exchanger, and the heat transfer medium that has passed through the battery heat exchanger returns to the compressor. A fifth pattern is in which the heat transfer medium pressurized by the compressor is supplied to the outside air heat exchanger, the heat transfer medium that has passed through the outside air heat exchanger is supplied to the expansion valve, the heat transfer medium that has been depressurized by the expansion valve is supplied to the battery heat exchanger, and the heat transfer medium that has passed through the battery heat exchanger returns to the compressor, A sixth pattern is in which the heat transfer medium pressurized by the compressor is supplied to the outside air heat exchanger, the heat transfer medium that has passed through the outside air heat exchanger is supplied to the expansion valve, the heat transfer medium that has been depressurized by the expansion valve is supplied to the air conditioning heat exchanger, and the heat transfer medium that has passed through the air conditioning heat exchanger returns to the compressor. A seventh pattern is included in which the heat transfer medium pressurized by the compressor is supplied to the outside air heat exchanger, the heat transfer medium that has passed through the outside air heat exchanger is supplied to the expansion valve, the heat transfer medium that has been depressurized by the expansion valve is supplied to both the battery heat exchanger and the air conditioning heat exchanger, and the heat transfer medium that has passed through the battery heat exchanger and the air conditioning heat exchanger returns to the compressor. An electric vehicle characterized by the following features.

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