Circuit structure of circulating water

Abstract

To improve efficiency of water injection and allow a cooling water circuit to be relieved, in a circuit structure for circulation water.SOLUTION: A circuit structure for circulation water comprises: a cooling water circuit that cools a specified component; a heater circuit in which a heater is arranged; a four-way valve that switches between a state in which the cooling water circuit and the heater circuit are directly connected and a state in which the cooling water circuit and the heater circuit are separated; and a reserve tank that has an air reservoir part and is arranged in the cooling water circuit or the heater circuit. The cooling water circuit and the heater circuit are connected to each other via the reserve tank and a pressure relief path. The pressure relief path is connected to the air reservoir part of the reserve tank.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to a circuit structure of circulating water.

Background Art

[0002] Conventionally, a circuit structure of circulating water mounted on an electric vehicle such as a BEV (Battery Electric Vehicle) usually includes a heater circuit that heats and circulates water by a heater for heating inside the vehicle, a cooling water circuit for cooling a battery or the like of the vehicle, a four-way valve that connects the heater circuit and the cooling water circuit and disconnects the heater circuit and the cooling water circuit, and a reserve tank. When the vehicle environment is at a low temperature, such a circuit structure of circulating water switches to a state in which the heater circuit and the cooling water circuit are directly connected by a four-way valve for battery warming. In an HEV (Hybrid Electric Vehicle), for example, water is heated by an engine and circulated inside the vehicle. Also, in a BEV, there is a type that cools a battery or the like of the vehicle with a refrigerant instead of water flowing through a circuit. For example, in the invention of the temperature adjustment system disclosed in Patent Document 1, an independent cooling path can be switched between an independent state and a communicating state by a four-way valve. Also, for example, in the inventions disclosed in Patent Document 2 or Patent Document 3, the flow of water in the circuit is controlled by a three-way valve, and an independent cooling path is communicated through a reserve tank.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] When filling water into the circuit structure, water is put in from the water injection port on the upper side of the reserve tank. Therefore, the port on the outlet side of the reserve tank where water first enters the circuit structure is set at the lower part of the reserve tank, and water enters in the flowing direction of the running water. The water flowing in the circuit structure returns to the port on the inlet side set at the upper part of the reserve tank together with the air in the circuit structure. Therefore, when filling water, no water enters the port on the inlet side, and air is removed from the circuit structure by the water returning to the port on the inlet side. However, in order to ensure water injection performance, the inlet side of water must be set at the upper part of the reserve tank, and the outlet side where water first enters must be set at the lower part of the reserve tank, which results in mounting constraints.

[0005] Also, when the heater circuit and the cooling water circuit are separated, for example, the pressure in the cooling water circuit where no reserve tank is arranged increases, which affects, for example, the internal pressure strength of the battery and becomes a cause of failure. In addition, equipment other than the battery also needs to be maintained within the allowable internal pressure, and the increase in pressure also causes water leakage in the hoses used in the circuit. Therefore, in the circuit structure of the circulating water mounted on an electric vehicle or the like, there is a problem of improving the efficiency of water injection and enabling absorption of the increase and decrease in pressure within the circuit.

Means for Solving the Problems

[0006] The circuit structure of the circulating water of the present embodiment for solving the above problems includes a cooling water circuit for cooling a predetermined component, a heater circuit in which a heating heater is arranged, a four-way valve for switching between a state where the cooling water circuit and the heater circuit are directly connected and a state where the cooling water circuit and the heater circuit are separated, and a reserve tank having an air accumulation part and arranged in the cooling water circuit or the heater circuit. The cooling water circuit and the heater circuit communicate with each other via a pressure relief path and the reserve tank, and the pressure relief path is connected to the air accumulation part of the reserve tank.

Effects of the Invention

[0007] According to the circuit structure of the circulating water in this embodiment, during water injection, air can be appropriately discharged from the cooling water circuit and the heater circuit to the reserve tank through the pressure relief path, improving the water injection efficiency. Further, in a state where the heater circuit and the cooling water circuit are separated, the generated pressure increase and decrease can be absorbed by the reserve tank through the pressure relief path.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0009] Hereinafter, with reference to the accompanying drawings, an embodiment of the circuit structure 1 of the circulating water in this embodiment will be described. The circuit structure 1 of the circulating water in the embodiment is mounted on an electric vehicle 9 such as a BEV, for example. The circuit structure 1 of the circulating water includes, for example, a cooling water circuit 3 and a heater circuit 4. The cooling water circuit 3 is also referred to as a battery circuit.

[0010] The cooling water circuit 3 is a circulation path connected by a cooling pipe 36. For example, an electric water pump 30 (hereinafter referred to as the pump 30), a water temperature sensor 31 for measuring the temperature of the water flowing through the cooling water circuit 3, a battery 32, an electronic unit 33, a chiller 35, and a four-way valve 34 are arranged in the above order. In this embodiment, the predetermined component cooled by the cooling water circuit 3 is the battery 32, but the predetermined component is not limited to the battery 32. Also, the configuration arranged in the cooling water circuit 3 is not limited to the above configurations.

[0011] The battery 32 is composed of a battery pack and other electronic devices, etc. The electronic unit 33 is a unit that integrates a current sensor for detecting the charge and discharge current of the battery 32, as well as functions of charging, power conversion, and power distribution. The pump 30 is arranged in the cooling pipe 36 between the four-way valve 34 and the battery 32. The pump 30 is a drive source that circulates the cooling water so as to supply the cooling water cooled by the chiller 35 to the battery 32.

[0012] The four-way valve 34 is arranged in the cooling pipe 36 between the chiller 35 and the pump 30. The four-way valve 34 includes, for example, a disk valve 345 in a casing 340. The disk valve 345 is rotatable within the casing 340 by a pulse motor or the like. The rotation angle of the disk valve 345 from the origin position can be recognized by the number of drive pulses supplied to the pulse motor. First ports 341, second ports 342, third ports 343, and fourth ports 344 are formed in the casing 340 of the four-way valve 34, and the first ports 341 and the second ports 342 communicate with the cooling pipe 36 respectively. Also, the third ports 343 and the fourth ports 344 communicate with the heater pipes 48 of the heater circuit 4 respectively.

[0013] In the state shown in FIG. 1, the four-way valve 34 connects the first port 341 and the second port 342, and connects the third port 343 and the fourth port 344 by means of a disk valve 345 shown horizontally (hereinafter referred to as the disk valve 345 in the disconnect mode), thereby disconnecting the cooling water circuit 3 and the heater circuit 4. That is, the four-way valve 34 makes the cooling water circuit 3 and the heater circuit 4 independent of each other by means of the disk valve 345 in the disconnect mode. When the disk valve 345 of the four-way valve 34 rotates from the horizontally shown state to the vertically shown state in FIG. 2, the first port 341 and the third port 343 communicate with each other, and the second port 342 and the fourth port 344 communicate with each other, so that the cooling water circuit 3 and the heater circuit 4 are directly connected. The disk valve 345 shown vertically in FIG. 2 is hereinafter referred to as the disk valve 345 in the direct connection mode.

[0014] The heater circuit 4 is a circulation path connected by a heater pipe 48. For example, an electric water pump 40 (hereinafter referred to as the pump 40), a water-cooled condenser 41 that functions as a radiator, a heating heater 42 (hereinafter referred to as the heater 42) that heats water in a high-voltage manner, a water temperature sensor 43, a heater core 44 that is a heat exchanger that heats air with heated water for vehicle interior heating, a water temperature sensor 45, a four-way valve 34, and a reserve tank 46 are arranged in the above order. Note that the configuration arranged in the heater circuit 4 is not limited to the above configurations.

[0015] The pump 40 is provided in the heater pipe 48 between the reserve tank 46 and the water-cooled condenser 41, and is a drive source that circulates the heated water so as to supply the water heated by the heater 42 to the heater core 44. The water-cooled condenser 41 operates when the temperature of the water flowing through the heater circuit 4 needs to be lowered. The water temperature sensors 43 and 45 arranged before and after the heater core 44 measure the temperature of the water supplied to the heater core 44 or the temperature of the water that has passed through the heater core 44.

[0016] Figure 2 is an explanatory diagram specifically showing the height difference within the electric vehicle 9 of each of the above-described components constituting the heater circuit 4 of the circulating water circuit structure 1 and each of the above-described components constituting the cooling water circuit 3. In this specification, for convenience, the Z-axis direction including the +Z direction and the -Z direction shown in Figure 2 is defined as the height direction of the electric vehicle 9, the +Z direction is approximately the upward direction of the electric vehicle 9, and it is assumed that the height increases as it goes in the +Z direction. Also, the -Z direction is approximately the downward direction of the electric vehicle 9, and it is assumed that the height decreases as it goes in the -Z direction. The cooling water circuit 3 is disposed at a relatively lower position within the electric vehicle 9 than the heater circuit 4.

[0017] As shown in Figure 2, the reserve tank 46 disposed in the heater circuit 4 is, for example, disposed on the uppermost side within the electric vehicle 9 among the heater circuit 4 and the cooling water circuit 3. That is, the reserve tank 46 is disposed at a relatively high position within the heater circuit 4, above the water-cooled capacitor 41, the heater core 44, and the heater 42, as well as the chiller 35 and the electronic unit 33 of the cooling water circuit 3, within the electric vehicle 9.

[0018] The reserve tank 46 is, for example, a sealed reserve tank. The reserve tank 46 is, for example, composed of a hard resin material or the like, and includes a water inlet 461, a water outlet 462 for allowing water to flow out from the inside of the tank 460 to the heater pipe 48, and a water injection port 463 used when injecting water from outside the circuit structure 1 into the inside of the tank 460 and equipped with a pressure cap or the like. Note that, as shown in Figure 2, when injecting water into the circulating water circuit structure 1, the water inlet 461 allows the injected water to flow out into the heater circuit 4.

[0019] In the present embodiment, for example, the water inlet 461 and the water outlet 462 are formed at the bottom 464 of the reserve tank 46. The water inlet 461 communicates with the third port 343 of the four-way valve 34 via the heater pipe 48. Also, the water outlet 462 communicates with the pump 40 via the heater pipe 48. Further, the water injection port 463 is formed, for example, at the top wall 466 which is the uppermost part of the reserve tank 46.

[0020] The reserve tank 46 is set with a maximum allowable water level 467. The space above the maximum allowable water level 467 inside the tank 460 serves as an air reservoir 468 for releasing the increased pressure of the heater circuit 4 and the cooling water circuit 3. For example, when the heater circuit 4 and the cooling water circuit 3 are independent, the increased pressure in the cooling water circuit 3 can be released to the air reservoir 468 through the pressure relief path 50. The maximum allowable water level 467 is determined by, for example, a mark (not shown) indicating the maximum allowable water level 467 preset on the side wall 465 of the reserve tank 46. Note that the maximum allowable water level 467 is not limited to the form determined by a mark (not shown) preset on the side wall 465, and may be determined by the internal volume of the reserve tank 46 or the like. The water inlet 461 and the water outlet 462 are not limited to the configuration formed at the bottom 464, and may be formed, for example, at a position on the side wall 465 of the reserve tank 46 that is at least lower than the maximum allowable water level 467.

[0021] The cooling water circuit 3 and the heater circuit 4 communicate with each other via the pressure relief path 50 shown in FIG. 2 and the reserve tank 46. One end 501 of the pressure relief path 50 is connected to the air reservoir 468 of the reserve tank 46. The pressure relief path 50 is composed of a metal pipe or a rubber hose, and one end 501 of the pressure relief path 50 is at a higher position in the height direction of the electric vehicle 9 than the other end 502 of the pressure relief path 50. The pressure relief path 50 also functions as an air bleeding path for the air existing in the circuit structure 1 during water injection.

[0022] For example, a connection port 469 is formed at a position on the side wall 465 of the reserve tank 46 that is higher than the maximum allowable water level 467. One end 501 of the pressure relief path 50 communicates with the air reservoir 468 through the connection port 469.

[0023] The other end 502 of the pressure relief path 50 is connected to a higher position in the height direction of the electric vehicle 9 where air (in the cooling water circuit 3) can easily escape during water injection in the cooling water circuit 3. Specifically, as shown in FIG. 2, the heater circuit 4 is located relatively higher in the height direction inside the electric vehicle 9 than the cooling water circuit 3, and the chiller 35 of the cooling water circuit 3 is located higher in the height direction inside the electric vehicle 9, similar to the water-cooled condenser 41 and the heater core 44 of the heater circuit 4. The cooling pipe 36 connecting the chiller 35 and the first port 341 of the four-way valve 34 includes, for example, a high-position pipe 361 arranged at a high position inside the electric vehicle 9, and a low-position pipe 362 connected to the high-position pipe 361 and extending downward to a low position in the height direction and connected to the four-way valve 34. The other end 502 of the pressure relief path 50 is connected to the high-position pipe 361.

[0024] In the present embodiment, for example, the pipe diameter of the pressure relief path 50 is formed smaller than the pipe diameter of the cooling pipe 36 of the cooling water circuit 3 and the pipe diameter of the heater pipe 48 of the heater circuit 4.

[0025] As shown in FIG. 1, in addition to the circuit structure 1 of the circulating water, the electric vehicle 9 includes, for example, an inverter cooling circuit 2 and a heat pump system 7. The inverter cooling circuit 2 arranged, for example, more externally of the electric vehicle 9 than the cooling water circuit 3, the heater circuit 4, and the heat pump system 7 is a circulation path connected by a pipe 25. The inverter cooling circuit 2 is provided with a radiator 20 that dissipates the heat of the water flowing through the inverter cooling circuit 2 through heat exchange with the outside air, and a reserve tank 21 connected to the radiator 20. The inverter cooling circuit 2 is also provided with, for example, a pump 22, an inverter 24 through which the cooling water is sent when the pump 22 rotates, and a water temperature sensor 23 that measures the temperature of the water flowing through the inverter cooling circuit 2. The inverter 24 converts, for example, direct current into alternating current for a traveling motor (not shown) and supplies it to the traveling motor.

[0026] For example, a heat pump system 7 for a car air conditioner is a circulation path connected by a pipe 70. The heat pump system 7 includes an air-cooled condenser 71 that exchanges heat between the atmosphere and the refrigerant, an electric compressor 72 that is a driving source for compressing and circulating the refrigerant flowing in the heat pump system 7, an evaporator 73, an accumulator (pressure tank) 74, a chiller 75, a water-cooled condenser 76, an electric expansion valve 772 disposed at various locations of the pipe 70, and a solenoid valve 773.

[0027] For example, in a conventional circulating water circuit structure, there is a type in which one reserve tank is provided for each of the heater circuit and the cooling water circuit. In the circulating water circuit structure having two of these reserve tanks, in a state where the heater circuit and the cooling water circuit are separated, pressure can be relieved by each reserve tank for each circuit. However, since two reserve tanks are required, the cost increases. Also, when filling water into the empty circuit structure, in order to ensure water injection performance, the mounting restrictions on the inlets and outlets in each reserve tank are severe. Further, since there are two reserve tanks, it is difficult to perform liquid level management of the maximum allowable water level in each reserve tank.

[0028] For example, in a conventional circulating water circuit structure, there is a type that connects the heater circuit and the cooling water circuit with a three-way valve. In this case, regardless of the opening and closing of the three-way valve, the heater circuit and the cooling water circuit are connected in one direction, and even if only one reserve tank is provided in the heater circuit, pressure can be relieved between the heater circuit and the cooling water circuit with only this one reserve tank. However, the cost of piping such as 3WAY joints and water hoses increases. Also, when filling water into the empty circuit structure, in order to ensure water injection performance, the mounting restrictions on the inlets and outlets in each reserve tank are severe. Furthermore, there is no escape path for the air present in the circuit during water filling, the number of water filling times increases, and the water filling time becomes longer.

[0029] For example, in a conventional circulating water circuit structure, there is a type that connects a heater circuit and a cooling water circuit with a four-way valve and directly connects the heater pipe of the heater circuit and the cooling water pipe of the cooling water circuit with a pressure relief path. In this case, regardless of the opening and closing of the four-way valve, the heater circuit and the cooling water circuit are connected in one direction. Even if only one reserve tank is provided in the heater circuit, only this one reserve tank can relieve the pressure between the heater circuit and the cooling water circuit. However, when filling water into an empty circuit structure, in order to ensure water injection performance, the mounting restrictions on the inlet and outlet of the reserve tank are severe. Furthermore, since water injection is performed in one direction in the circuit during water injection, it takes a long time for water injection.

[0030] Regarding the circulating water circuit structure 1 of the present embodiment that can solve the problems existing in the conventional circulating water circuit structure as described above, the case of performing water injection to enable the use of the circuit structure 1 will be described. When performing water injection, as shown in FIG. 2, the heater circuit 4 and the cooling water circuit 3 are set in a state of being directly connected by a four-way valve 34. Then, the pressure cap of the water injection port 463 of the reserve tank 46 is removed, and an operator pours water into the reserve tank 46 from the water injection port 463.

[0031] In parallel with the water being injected into the reserve tank 46, water flows from the water outlet 462 formed at the bottom 464 of the reserve tank 46 in the order of the pump 40, water-cooled condenser 41, heater 42, heater core 44, fourth port 344 of the four-way valve 34, second port 342, cooling pipe 36 of the cooling water circuit 3, pump 30, battery 32, electronic unit 33, and chiller 35 of the heater circuit 4. Also, together with the water flowing in this way, the air in the heater circuit 4 and the cooling water circuit 3 existing in the above flow path also flows to the chiller 35. Furthermore, since air moves from the water and air flowing into the high-position pipe 361 from the chiller 35 to the air accumulation part 468 of the reserve tank 46 through the pressure relief path 50 connected to the high-position pipe 361, air is vented.

[0032] During water injection, water also flows from the water inlet 461 formed at the bottom 464 of the reserve tank 46 in the order of the third port 343 of the four-way valve 34, the first port 341, and the low-position pipe 362 of the cooling water circuit 3. Along with the water flowing in this way, the air in the heater circuit 4 and the cooling water circuit 3 existing in the above flow path also flows to the low-position pipe 362. Furthermore, the water in the low-position pipe 362 merges with the water flowing from the water outlet 462 side in the high-position pipe 361. Also, since air moves from the water and air flowing from the low-position pipe 362 to the high-position pipe 361 to the air accumulation part 468 of the reserve tank 46 through the pressure relief path 50 connected to the high-position pipe 361, air is vented. Therefore, during water injection, the air existing in the heater circuit 4 and the air existing in the cooling water circuit 3 are appropriately vented.

[0033] In this way, during water injection, air can be appropriately vented from the cooling water circuit 3 and the heater circuit 4 through the pressure relief path 50 in the reserve tank 46, so the number of water injection times and the water injection time can be reduced and the efficiency of water injection can be improved. In addition, by forming the water inlet 461 and the water outlet 462 at the bottom 464 of the reserve tank 46 as in this embodiment, the water injection rate into the circuit structure 1 in one water injection can be increased. As a result, different from the conventional circulating water circuit structure, the circulating water circuit structure 1 of this embodiment can complete the water injection and air venting operations before water injection completion with fewer times, and the water injection time can be shortened.

[0034] In addition, in the conventional circulating water circuit structure, when the inlet position is too high, the water flowing back through the circuit structure drops to the liquid level in the reserve tank, entraining air into the water in the reserve tank. When air mixes into the circuit structure, since the specific heat of water is different from that of air, the cooling performance and temperature control performance deteriorate. On the other hand, when the inlet position of the reserve tank is too low, water flows backward from the reserve tank inlet during water injection, and water also enters the circuit structure in the direction opposite to the flowing water direction, blocking the air vent path and preventing air from escaping from anywhere in the circuit structure. Therefore, it is necessary to repeatedly perform the air vent operation by turning on the pump after water injection, increasing the number of times of water injection and air vent operations. Thus, the conventional circulating water circuit structure had mounting constraints. However, as in this embodiment, for example, since both the water inlet 461 and the water outlet 462 are formed at the bottom 464 of the tank interior 460, the mounting constraints of the water inlet and outlet can be relaxed compared to the conventional circulating water circuit structure.

[0035] Next, the water flow in the heater circuit 4 and the cooling water circuit 3 when water injection is completed will be described. As shown in FIG. 3, during normal operation, the four-way valve 34 sets the disk valve 345 to the cut-off mode and sets the state of separating the heater circuit 4 and the cooling water circuit 3.

[0036] When the pump 40 of the heater circuit 4 operates, water flows in the order of the water-cooled condenser 41, the heater 42, the heater core 44, the fourth port 344 of the four-way valve 34, the third port 343 of the four-way valve 34, and the reserve tank 46, and the water heated by the heater circuit 4 circulates. Then, the heater core 44 functions to heat the interior of the electric vehicle 9.

[0037] Also, when the pump 30 of the cooling water circuit 3 operates, water flows in the order of the battery 32, the electronic unit 33, the chiller 35, the first port 341 of the four-way valve 34, and the second port 342 of the four-way valve 34, and the cooled water that circulates through the cooling water circuit 3 cools the battery 32. Here, in the present embodiment, the pipe diameter of the pressure relief path 50 is formed to be smaller than the pipe diameter of the cooling pipe 36 of the cooling water circuit 3. Further, the pressure relief path 50 is a single path. Therefore, when the pressure in the cooling water circuit 3 is within an acceptable range, it is possible to suppress the cooled water circulating through the cooling water circuit 3 from flowing into the heater circuit 4 through the pressure relief path 50. That is, since the pressure relief path 50 is pre-filled with water, the water in the pressure relief path 50 serves as a wall that blocks heat exchange between the heater circuit 4 and the cooling water circuit 3 where the internal pressure is within an acceptable range. Therefore, it is possible to keep the operating efficiency of the heater circuit 4 and the cooling water circuit 3 high.

[0038] For example, when the state where the cooling water circuit 3 in which water circulates and the heater circuit 4 in which water circulates are separated continues for a predetermined time, the pressure in the cooling water circuit 3 where the reserve tank 46 is not provided increases. When the pressure in the cooling water circuit 3 rises to a state where it is about to exceed the allowable range, the water circulating in the cooling water circuit 3 also flows into the pressure relief path 50 and enters the reserve tank 46 of the heater circuit 4. Therefore, the increase in the pressure of the cooling water circuit 3 is absorbed by the reserve tank 46. That is, pressure relief is performed so that the pressure in the cooling water circuit 3 remains within the allowable range. Therefore, an increase in the internal pressure of the electronic device of the battery 32 disposed in the cooling water circuit 3 can be alleviated, and the reliability of the battery 32 can be improved. In addition, since the internal pressure fluctuations between the heater circuit 4 and the cooling water circuit 3 are reduced, the 4-way valve 34 can ensure the sealing performance even if the spring pressing the seal reduces the seal tightening force, and the operating efficiency of the heater circuit 4 and the cooling water circuit 3 in an independent state can be kept high. That is, it is possible to prevent a situation where the 4-way valve 34 cannot be sealed due to internal pressure fluctuations and water with a temperature difference between the heater circuit 4 and the cooling water circuit 3 is mixed when it is not desired to mix them. In addition, since it is not necessary to increase the power for switching the disk valve 345 of the 4-way valve 34, the electricity cost is improved. Thus, different from the conventional circulating water circuit structure, the circulating water circuit structure 1 of the present embodiment can release the pressure in the cooling water circuit 3 even if there is only one reserve tank 46.

[0039] Next, when the vehicle environment is at a low temperature or the like, the 4-way valve 34 sets the disk valve 345 to the direct connection mode in order to warm the battery 32 of the cooling water circuit 3. As a result, as shown in FIG. 4, the cooling water circuit 3 and the heater circuit 4 are directly connected.

[0040] Water circulates in the order of the pump 40, water-cooled condenser 41, heater 42, heater core 44, fourth port 344 of the four-way valve 34, second port 342 of the four-way valve 34, cooling pipe 36 of the cooling water circuit 3, pump 30, battery 32, electronic unit 33, chiller 35, first port 341 of the four-way valve 34, third port 343 of the four-way valve 34, and reserve tank 46 of the heater circuit 4. Therefore, the battery 32 is warmed by the water heated in the heater circuit 4. Note that the chiller 35 is not operating in the state shown in FIG. 4 to warm the battery 32.

[0041] For example, in the present embodiment, as shown in FIG. 4, when the cooling water circuit 3 and the heater circuit 4 are directly connected by the four-way valve 34 to warm the battery 32, the pressure relief path 50 is arranged to be downstream of a predetermined component, the battery 32, and upstream of the four-way valve 34. The reserve tank 46 is arranged to be downstream of the four-way valve 34, and the heating heater 42 is arranged to be upstream of the battery 32. Therefore, the heated water flowing through the heater circuit 4 flows into the battery 32 before the branch of the pressure relief path 50. Therefore, the promotion of the warming of the battery 32 can be further achieved. Also, in the circulation of the heated water, a part of the water that has passed through the chiller 35 flows from the pressure relief path 50 connected to the high-position pipe 361 to the reserve tank 46 and merges with the water that has passed through the four-way valve 34 in the reserve tank 46. Therefore, the water passing through the four-way valve 34 can be reduced by the amount that the pressure relief path 50 functions as a circulation flow path, and the water flow resistance of the four-way valve 34 can be reduced.

[0042] Furthermore, in the present embodiment, the pressure relief path 50 is not connected to the cooling pipe 36 that connects the battery 32 to the chiller 35, but is connected to the high-position pipe 361 on the downstream side of the chiller 35 and branches off from the high-position pipe 361. Therefore, in a state where the cooling water circuit 3 and the heater circuit 4 are directly connected (the state where the battery 32 is being heated), the chiller 35 is not operating. However, if the pressure relief path 50 branches from the cooling pipe 36 that connects the electronic unit 33 to the chiller 35 toward the reserve tank 46, or if the pressure relief path 50 branches from the cooling pipe 36 that connects the battery 32 to the electronic unit 33 toward the reserve tank 46, more water flows through the chiller 35 and the electronic unit 33 than in other cases. That is, if the pressure relief path 50 branches from the cooling pipe 36 that connects the electronic unit 33 to the chiller 35 toward the reserve tank 46, there is water flowing through the pressure relief path 50, so the water flowing through the electronic unit 33 (the water that has had its heat taken by the battery 32) relatively decreases, and there may be a case where the cooling of the electronic unit 33 that is also operating in the directly connected state cannot be sufficiently exerted. On the other hand, as shown in FIG. 4, since the pressure relief path 50 is connected to the high-position pipe 361 on the downstream side of the chiller 35 and branches off from the high-position pipe 361, the water flowing through the electronic unit 33 does not decrease. Therefore, the cooling of the electronic unit 33 that is also operating in a state where the cooling water circuit 3 and the heater circuit 4 are directly connected is sufficiently ensured.

[0043] As described above, the embodiments of the present invention have been explained. However, the above-described embodiments are presented as examples and are not intended to limit the scope of the present invention. This novel embodiment can be implemented in various other forms. Also, various omissions, replacements, and changes can be made without departing from the gist of the invention. Further, this embodiment is included in the scope and gist of the invention and is included in the invention described in the claims and its equivalent scope.

Description of Reference Numerals

[0044] 1: Circuit structure of circulating water 2: Inverter Cooling Circuit 3: Cooling Water Circuit 30: Water Pump 32: Battery 33: Electronic Unit 34: 4 - Way Valve 35: Chiller 36: Cooling Pipe 361: High - Position Pipe 4: Heater Circuit 40: Water Pump 41: Water - Cooled Condenser 42: Heating Heater 44: Heater Core 46: Reservoir Tank 461: Water Inlet 462: Water Outlet 468: Air Pocket Portion 48: Heater Pipe 50: Pressure Relief Path 7: Heat Pump System 9: Electric Vehicle

Claims

1. A cooling water circuit for cooling a predetermined component, a heater circuit in which a heater is disposed, a four-way valve for switching between a state in which the cooling water circuit and the heater circuit are directly connected and a state in which the cooling water circuit and the heater circuit are disconnected, a reserve tank having an air accumulation portion and disposed in the heater circuit, in the cooling water circuit, the cooling water circulates in the order of the predetermined component, the chiller, and the four-way valve, in the heater circuit, the cooling water circulates in the order of the reserve tank, the heater, and the four-way valve, the cooling water circuit and the heater circuit communicate with each other via a pressure relief path and the reserve tank, the pressure relief path is a circuit structure of circulating water connected to the air accumulation portion of the reserve tank.

2. One end of the pressure relief path is disposed between the chiller and the four-way valve when the cooling water circuit and the heater circuit are directly connected by the four-way valve, when the cooling water circuit and the heater circuit are directly connected by the four-way valve, it is arranged such that the cooling water circulates in the order of the reserve tank, the heater, the four-way valve, the predetermined component, the chiller, and the four-way valve, The circuit structure of circulating water according to Claim 1.

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