Vehicle cooling system structure

Abstract

Provided is a vehicle cooling system structure for an electric vehicle comprising: an internal combustion engine; a drive device including an electric motor as a travel drive source; a battery that is charged with electric power generated by driving the internal combustion engine; a first coolant pipe connected to the drive device; a second coolant pipe connected to the battery; and a radiator that is disposed in the front part of the vehicle to dissipate heat of the coolant flowing through the first coolant pipe and the second coolant pipe. In this vehicle cooling system structure, the internal combustion engine and the drive device are disposed in parallel respectively in one side region and the other side region different from the one side region in the vehicle width direction of the electric vehicle. The second coolant pipe extends from the radiator and is connected to the battery via a drive device outside region in the other side region. In particular, the drive device outside region is a region located outside the drive device in the vehicle width direction and on the side opposite to the internal combustion engine.

Description

Technical Field

[0001] The present invention relates to a vehicle cooling system structure in an electric vehicle including a drive device having an electric motor as a driving power source, a battery, and a cooling system for cooling these components.

Background Art

[0002] JP2021 - 000860A discloses a vehicle cooling system structure of an electric vehicle equipped with a battery under the cabin and electric equipment including a driving motor at the rear axle, and having a cooling system for cooling these components. In this vehicle cooling system structure, a radiator for battery cooling and a radiator for high - voltage electric component cooling are arranged at the front of the vehicle, and the cooling water pipes led from the left and right of these radiators are close to each other in the area under the front hood, and then are connected to the battery and the driving motor via the vicinity of the center of the vehicle.

Summary of the Invention

[0003] Some electric vehicles may adopt a layout in which an internal combustion engine for power generation is mounted in the lower space (engine room) under the front hood. When applying the vehicle cooling system structure of JP2021 - 000860A to such an electric vehicle, the cooling water pipes will be arranged close to the high - temperature internal combustion engine. Therefore, the amount of heat transfer from the internal combustion engine to the cooling water pipes increases. In particular, the cooling water flowing through the cooling water pipes connected to the battery is required to be maintained at a lower temperature compared to the cooling water used for cooling electric equipment (high - voltage electric components) including the driving motor. Therefore, if the amount of heat transfer from the internal combustion engine to the cooling water pipes connected to the battery increases, there is a risk that the desired cooling function cannot be achieved.

[0004] Therefore, an object of the present invention is to provide a vehicle cooling system structure capable of suppressing heat transfer from an internal combustion engine to the cooling water pipes connected to the battery.

[0005] According to one aspect of the present invention, a vehicle cooling system structure for an electric vehicle is provided, comprising an internal combustion engine, a drive unit including an electric motor as a driving source, a battery for charging electricity generated by driving the internal combustion engine, a first refrigerant pipe connected to the drive unit, a second refrigerant pipe connected to the battery, and a radiator located at the front of the vehicle for dissipating heat from the refrigerant flowing through the first and second refrigerant pipes. In this vehicle cooling system structure, the internal combustion engine and the drive unit are arranged in parallel in one side region and the other side region, respectively, which are separated in the vehicle width direction of the electric vehicle. The second refrigerant pipe extends from the radiator through the drive unit outer region in the other side region and is connected to the battery. In particular, the drive unit outer region is the region outside the drive unit in the vehicle width direction and located on the opposite side from the internal combustion engine. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 is a plan view of the main parts of a vehicle cooling system structure according to the first embodiment. [Figure 2] Figure 2 is a side view of the main part of the vehicle cooling system structure according to the first embodiment. [Figure 3] Figure 3 is a block diagram illustrating the configuration of a cooling system installed in an electric vehicle. [Figure 4] Figure 4 shows the structure of a radiator according to the first embodiment. [Figure 5] Figure 5 is a plan view of the main parts of the vehicle cooling system structure according to the second embodiment. [Figure 6] Figure 6 is a side view of the main part of the vehicle cooling system structure according to the second embodiment. [Figure 7] Figure 7 shows the structure of the radiator according to the second embodiment. [Figure 8] Figure 8 is a side view of the main part of the vehicle cooling system structure according to the first modified example. [Figure 9] Figure 9 is a side view of the main part of the vehicle cooling system structure according to the second modified example. [Modes for carrying out the invention]

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0008] [First Embodiment] Figure 1 is a plan view of the main part of the vehicle cooling system structure of the electric vehicle V according to this embodiment. Figure 2 is a side view of the main part of the vehicle cooling system structure. In the figures described below, the front of the electric vehicle V in the longitudinal direction is denoted by the symbol "F r " and the sign "R" r The left side in the vehicle width direction is represented by the symbol "L" and the right side by the symbol "R," and the top side in the vehicle vertical direction is represented by the symbol "U" and the bottom side by the symbol "D." In addition, in Figures 1 and 2, for the sake of simplifying the drawings, only the radiators and refrigerant pipes are shown as elements of the cooling system in the vehicle cooling system structure, and other elements included in each cooling system (pumps, valves, etc.) are omitted.

[0009] The vehicle cooling system structure of this embodiment is applied to an electric vehicle V. Here, the electric vehicle V is assumed to be a so-called hybrid vehicle, in particular a series hybrid vehicle in which an electric motor (driving motor) is used as the driving source to drive the vehicle, a generator motor is regenerated by the driving force of an internal combustion engine (engine) for power generation, and the generated power is used to charge a battery 16.

[0010] More specifically, the vehicle cooling system structure according to this embodiment comprises an engine 12 which is an internal combustion engine, an HEV unit 14 which is a drive device including a drive motor, a battery 16 which charges the electricity generated by driving the engine 12, a first refrigerant pipe 18 connected to the HEV unit 14, a second refrigerant pipe 20 connected to the battery 16, and a radiator 22 which is located at the front of the vehicle and dissipates heat from the refrigerant (cooling water) flowing through the first refrigerant pipe 18 and the second refrigerant pipe 20.

[0011] The engine 12 and the HEV unit 14 are housed in a housing (not shown) and integrated as an electric motor unit, which is located in the motor room mr at the front of the electric vehicle V. In the vehicle cooling system structure of this embodiment, a predetermined area on the right side in the vehicle width direction (the area to the right of the center in the vehicle width direction, shown by a dashed line in Figure 1) is defined as one side area RA, and a predetermined area on the left side in the vehicle width direction (the area to the left of the center in the vehicle width direction) is defined as the other side area LA. The electric motor unit is then arranged in the motor room mr such that the engine 12 is located in the one side area RA and the HEV unit 14 is located in the other side area LA. In other words, the engine 12 and the HEV unit 14 are arranged parallel to each other in the vehicle width direction within the motor room mr.

[0012] The HEV unit 14 is configured as a unit that includes a drive motor, a power generation motor, an inverter, and the like.

[0013] The battery 16 is configured as an on-board energy storage device, such as a lithium-ion battery. The battery 16 is located behind the electric motor unit and in the space below the passenger compartment (not shown). The battery 16 is electrically connected to the HEV unit 14 via power supply wiring (not shown).

[0014] The first refrigerant pipe 18 connects the radiator 22 and the HEV unit 14 and functions as a refrigerant supply passage for circulating coolant between them. In other words, the first refrigerant pipe 18 functions as a refrigerant supply passage in the power cooling system C1 that cools the power equipment 50, including the HEV unit 14, which will be described later. On the other hand, the second refrigerant pipe 20 connects the radiator 22 and the battery 16 and functions as a refrigerant supply passage for circulating coolant between them. In other words, the second refrigerant pipe 20 functions as a refrigerant supply passage in the battery cooling system C2 that cools the battery 16, which will be described later.

[0015] In particular, in the vehicle cooling system structure of this embodiment, the second refrigerant pipe 20 extends from the radiator 22 through the HEV outer region SA in the other side region LA and is connected to the battery 16. The HEV outer region SA is the region outside the HEV unit 14 in the vehicle width direction and is located on the opposite side from the engine 12. That is, the second refrigerant pipe 20 is located in the HEV outer region SA within the electric vehicle V, which is in the other side region LA, different from the one side region RA where the heat source engine 12 is located, and is spaced apart from the engine 12 via the HEV unit 14. As a result, the second refrigerant pipe 20 can be sufficiently spaced apart from the engine 12, and heat transfer from the engine 12 to the coolant flowing through the second refrigerant pipe 20 can be suppressed.

[0016] Furthermore, in the vehicle cooling system structure of this embodiment, the first refrigerant pipe 18 extends from the radiator 22 through the other side region LA and connects to the HEV unit 14. That is, the first refrigerant pipe 18 is also positioned within the electric vehicle V at a certain distance from the one side region RA where the engine 12 is located. This makes it possible to suppress heat transfer from the engine 12 to the coolant flowing through the first refrigerant pipe 18.

[0017] The radiator 22 dissipates the heat contained in the coolant in the first refrigerant piping 18 and the second refrigerant piping 20 through heat exchange with the outside air. The radiator 22 is located in a forward position of the electric vehicle V, more specifically, in front of the electric motor unit and behind the front grille 32. In particular, the radiator 22 of this embodiment is composed of a first radiator 22a and a second radiator 22b, which are separate from each other.

[0018] The first radiator 22a mainly dissipates heat to the cooling water flowing through the first refrigerant pipe 18 (i.e., the cooling water of the high-voltage cooling system C1). More specifically, the first radiator 22a has an inlet for allowing the cooling water from the first refrigerant pipe 18 to flow in (hereinafter referred to as the "first cooling water inlet 24") and an outlet for allowing the cooling water to flow out to the first refrigerant pipe 18 (hereinafter referred to as the "first cooling water outlet 26"). In particular, the first radiator 22a of the present embodiment is constituted by a U-flow radiator in which both the first cooling water inlet 24 and the first cooling water outlet 26 are arranged in the other-side region LA.

[0019] The second radiator 22b mainly dissipates heat to the cooling water flowing through the second refrigerant pipe 20 (i.e., the cooling water of the battery cooling system C2). More specifically, the second radiator 22b has an inlet for allowing the cooling water from the first refrigerant pipe 18 to flow in (hereinafter referred to as the "second cooling water inlet 28") and an outlet for allowing the cooling water to flow out to the first refrigerant pipe 18 (hereinafter referred to as the "second cooling water outlet 30"). In particular, in the second radiator 22b of the present embodiment, the second cooling water inlet 28 is arranged in the other-side region LA, and the second cooling water outlet 30 is arranged in the one-side region RA.

[0020] Details of the structure of the radiator 22 will be described later.

[0021] Also, in the vehicle cooling system structure of the present embodiment, the second radiator 22b is arranged below the first radiator 22a. And according to the mutual positional relationship between the first radiator 22a and the second radiator 22b, the second refrigerant pipe 20 is arranged below the first refrigerant pipe 18 in the vehicle vertical direction. Thereby, the second radiator 22b (especially, the entire region in the vertical direction of the second radiator 22b) is arranged to face the front grill 32 formed in the front bumper of the electric vehicle V in the vehicle front-rear direction. That is, since the second radiator 22b is positioned facing the front grill 32 for introducing outside air, the heat dissipation effect of the cooling water by the second radiator 22b can be enhanced more.

[0022] Next, the cooling system S including the first refrigerant pipe 18 and the second refrigerant pipe 20. c The configuration will be explained.

[0023] Figure 3 shows the cooling system S installed on the electric vehicle V. c This is a block diagram illustrating the cooling system S. c It is mainly composed of a high-voltage cooling system C1 and a battery cooling system C2.

[0024] The high-power cooling system C1 is configured such that a first radiator 22a, high-power equipment 50, an intercooler 52, a tank 54, a first pump 55, and a first three-way valve 56 are arranged in a first refrigerant pipe 18, which is a refrigerant passage.

[0025] The high-voltage equipment 50 includes, in addition to the HEV unit 14, a reduction gear (gearbox) interposed between the travel motor and the drive shaft, a charger for charging the battery 16 from an external power source, a power converter (such as a DC / DC converter) for adjusting the voltage between the battery 16 and various auxiliary equipment, and a junction box for collecting and housing the various high-voltage wiring.

[0026] The intercooler 52 is positioned between the supercharger (not shown) and the engine 12. The intercooler 52 performs heat exchange (cooling) between the intake air taken in by the supercharger and the coolant of the electric cooling system C1. The tank 54 stores the coolant that circulates in the electric cooling system C1. The first pump 55 pressurizes the coolant and circulates it within the electric cooling system C1.

[0027] Furthermore, the first refrigerant piping 18 in this embodiment has a branch pipe 18a located between the first pump 55 and the first radiator 22a. The inflow of cooling water into this branch pipe 18a is regulated by the opening of the first three-way valve 56. In particular, the first three-way valve 56 is operated by a control device (not shown) to normally shut off the inflow of cooling water into the first refrigerant piping 18. On the other hand, if there is a possibility of refrigerant freezing, the first three-way valve 56 is operated to allow cooling water to flow from the first radiator 22a to the first refrigerant piping 18 (reducing or stopping the inflow of cooling water to the high-voltage equipment 50).

[0028] Furthermore, it is preferable that the elements of the high-power cooling system C1, namely the intercooler 52, tank 54, first pump 55, and first three-way valve 56, are all located in the other side region LA to reduce heat transfer from the engine 12 to these elements.

[0029] On the other hand, the battery cooling system C2 is configured such that a second radiator 22b, a battery 16, a heater 62, a second pump 64, a chiller 66, and a second three-way valve 67 are arranged in a second refrigerant pipe 20, which is a refrigerant passage.

[0030] The heater 62 heats the cooling water in the second refrigerant piping 20. In particular, the output of the heater 62 is controlled by a control device (not shown). For example, when the temperature of the battery 16 falls below the lower limit of the operating temperature, the heater 62 is activated by the control device to heat the cooling water. The second pump 64 pumps the cooling water and circulates it within the battery cooling system C2.

[0031] The chiller 66 is a device that performs heat exchange between the liquid refrigerant supplied to the air conditioner heat exchange circuit (including the air conditioning condenser, etc.), which is not shown, and the cooling water of the battery cooling system C2. In particular, the chiller 66 is located in the branch piping 20a that bypasses the battery 16 via the second three-way valve 67 to the second radiator 22b.

[0032] Furthermore, the amount of cooling water flowing into this branch pipe 20a (the amount of cooling water supplied to the chiller 66) is adjusted by operating the opening degree of the second three-way valve 67. In particular, the second three-way valve 67 is operated by a control device (not shown) to an opening degree corresponding to the respective cooling requirements of the battery 16 and the air conditioner heat exchange circuit.

[0033] Furthermore, it is preferable that the heater 62, second pump 64, chiller 66, and second three-way valve 67, which are elements of the battery cooling system C2, are all located in the other side region LA (particularly the HEV outer region SA) to reduce heat transfer from the engine 12 to these elements.

[0034] Furthermore, the cooling system S of this embodiment c The system includes bypass pipes 70 and 71 connecting the first refrigerant pipe 18 and the second refrigerant pipe 20, and third three-way valves 72 and valves 73 respectively located in each bypass pipe 70 and 71. The bypass pipes 70 and 71 function as refrigerant passages that allow cooling water to flow from the first refrigerant pipe 18 to the second refrigerant pipe 20 or from the second refrigerant pipe 20 to the first refrigerant pipe 18. The third three-way valves 72 and valves 73 function as bypass on / off valves that switch between allowing and blocking the inflow of cooling water into the bypass pipes 70 and 71.

[0035] In particular, one end of the bypass pipe 70 is connected to the second refrigerant pipe 20 via a third three-way valve 72. The third three-way valve 72 is located, for example, downstream of the branch pipe 20a in the second refrigerant pipe 20 and upstream of the second radiator 22b. The other end of the bypass pipe 70 is connected to the first refrigerant pipe 18 downstream of the first pump 55 and upstream of the first radiator 22a.

[0036] Furthermore, one end of the bypass pipe 71 is connected to the second refrigerant pipe 20 downstream of the second radiator 22b and upstream of the second three-way valve 67. The other end of the bypass pipe 71 is connected to the first refrigerant pipe 18 downstream of the first radiator 22a and upstream of the high-voltage equipment 50. The bypass pipe 71 is also provided with a valve 73 that switches between the flow and shutoff of cooling water in the bypass pipe 71.

[0037] With the above configuration, a control device (not shown) can switch between a state in which the flow of cooling water between the first refrigerant pipe 18 and the second refrigerant pipe 20 is permitted and a state in which it is blocked by operating the third three-way valve 72 and / or valve 73 in response to the respective cooling requirements of the high-voltage cooling system C1 and the battery cooling system C2.

[0038] For example, in situations where the cooling requirement for the high-voltage equipment 50 is high, such as during rapid acceleration of the electric vehicle V (when the drive motor is under high load), by appropriately operating the third three-way valve 72 and valve 73 to circulate cooling water from the second refrigerant pipe 20 to the first refrigerant pipe 18, a single cooling system (a cooling system that combines the heat dissipation functions of the first radiator 22a and the second radiator 22b) is formed by integrating the battery cooling system C2 with the high-voltage cooling system C1, and the high-voltage equipment 50 can be cooled by this integrated cooling system. In other words, in situations where the cooling requirement for the high-voltage equipment 50 is high, a higher cooling function for the high-voltage equipment 50 can be ensured by using the high-voltage cooling system C1 and the battery cooling system C2 in combination.

[0039] Furthermore, it is preferable that the bypass pipes 70, 71, the third three-way valve 72, and the valve 73 described above are all located in the other side region LA (particularly the HEV outer region SA) to reduce heat transfer from the engine 12 to these elements.

[0040] Next, the structure of the radiator 22 in this embodiment will be described.

[0041] Figure 4 shows the structure of the radiator 22 (first radiator 22a and second radiator 22b). The first radiator 22a and the second radiator 22b have similar structures, although their areas (especially the size of the heat exchange region) differ from each other.

[0042] As already described, the first radiator 22a is composed of a U-flow radiator in which the first coolant inlet 24 and the first coolant outlet 26 are concentrated in the other side region LA. That is, the first coolant inlet 24, the first coolant introduction tank 80, the first coolant discharge tank 81, and the first coolant outlet 26 can be concentrated on one side (edge) of the first radiator 22a.

[0043] Furthermore, the heat exchange region of the first radiator 22a is divided into a first heat exchange region 82 that communicates with the first coolant inlet 24 and a second heat exchange region 83 that communicates with the first coolant outlet 26, and the first heat exchange region 82 and the second heat exchange region 83 are connected to each other by a first coolant communication tank 84.

[0044] Furthermore, a first coolant introduction tank 80 is positioned between the first coolant inlet 24 and the first heat exchange region 82. The first coolant introduction tank 80 temporarily stores the coolant introduced from the first coolant inlet 24 and supplies it to the first heat exchange region 82 so that the coolant is distributed throughout the entire region.

[0045] The first cooling water communication tank 84 supplies cooling water supplied from the first heat exchange region 82 to the second heat exchange region 83 so that the cooling water is distributed throughout the entire second heat exchange region 83.

[0046] Furthermore, a first cooling water discharge tank 81 is positioned between the first cooling water outlet 26 and the second heat exchange region 83. The first cooling water discharge tank 81 temporarily stores the cooling water supplied from the second heat exchange region 83 and discharges it to the first cooling water outlet 26.

[0047] On the other hand, as already described, the second radiator 22b has a second coolant inlet 28 located in the other side region LA and a second coolant outlet 30 located in the one side region RA.

[0048] Furthermore, the second radiator 22b has a heat exchange region 85 that communicates with the second coolant inlet 28 and the second coolant outlet 30. In addition, a second coolant introduction tank 86 is positioned between the second coolant inlet 28 and the heat exchange region 85. The second coolant introduction tank 86 temporarily stores the coolant introduced from the second coolant inlet 28 and supplies it to the heat exchange region 85 so that the coolant can circulate throughout the entire region.

[0049] Furthermore, a second refrigerant discharge tank 87 is positioned between the second cooling water outlet 30 and the heat exchange region 85. The second refrigerant discharge tank 87 temporarily stores the cooling water supplied from the heat exchange region 85 and discharges it to the second cooling water outlet 30.

[0050] Furthermore, the second radiator 22b is set to have a smaller heat exchange area compared to the first radiator 22a. The reason for this is as follows: First, the amount of heat removed by the battery 16 is set lower than the amount of heat removed by the high-power equipment 50 and the intercooler 52. For this reason, the high-power equipment 50 requires a higher cooling function than the battery 16. Therefore, by making the heat exchange area of ​​the second radiator 22b smaller than that of the first radiator 22b, it is possible to achieve a heat dissipation function for individual coolants that is adjusted to an appropriate balance according to the respective cooling requirements of the high-power equipment 50 and the battery 16. In particular, by adjusting the ratio of the sizes of the heat exchange areas of the first radiator 22a and the second radiator 22b without changing the overall size or structure of the radiator 22, it is possible to set a desired balance for the heat dissipation function obtained for the respective coolants of the high-power equipment 50 and the battery 16.

[0051] Furthermore, it is preferable to set the flow resistance of the coolant in the first radiator 22a to be approximately the same as the flow resistance of the coolant in the first refrigerant piping 18. This reduces the overall refrigerant flow resistance of the power cooling system C1, thereby reducing the power consumption of the first pump 55 and allowing the first pump 55 to be made smaller. Similarly, it is preferable to set the flow resistance of the coolant in the second radiator 22b to be approximately the same as the flow resistance of the coolant in the first refrigerant piping 18. This reduces the overall coolant flow resistance of the battery cooling system C2, thereby reducing the power consumption of the second pump 64 and allowing the second pump 64 to be made smaller.

[0052] The configuration of the vehicle cooling system structure of this embodiment and its effects will be described below.

[0053] According to this embodiment, a vehicle cooling system structure for an electric vehicle V is provided, comprising an internal combustion engine (engine 12), a drive unit (HEV unit 14) including an electric motor (driving motor) as a driving source, a battery 16 for charging electricity generated by driving the engine 12, a first refrigerant pipe 18 connected to the HEV unit 14, a second refrigerant pipe 20 connected to the battery 16, and a radiator 22 positioned at the front of the vehicle for dissipating heat from the refrigerant (cooling water) flowing through the first refrigerant pipe 18 and the second refrigerant pipe 20.

[0054] In particular, in this vehicle cooling system structure, the engine 12 and the HEV unit 14 are arranged in parallel in one side region RA and the other side region LA, respectively, which are separated in the vehicle width direction (LR direction) of the electric vehicle V. Furthermore, the second refrigerant pipe 20 extends from the radiator 22 through the drive unit outer region (HEV outer region SA) in the other side region LA and connects to the battery 16. Specifically, the HEV outer region SA is the region located outside the HEV unit 14 in the vehicle width direction and on the opposite side from the engine 12.

[0055] As a result, in a cooling system structure having a high-voltage cooling system C1 (first refrigerant piping 18) for cooling the HEV unit 14 and a battery cooling system C2 (second refrigerant piping 20) for cooling the battery 16, the second refrigerant piping 20 of the battery cooling system C2 can be positioned away from the high-temperature engine 12. Therefore, heat transfer from the engine 12 to the coolant of the battery cooling system C2, which should generally be kept at a lower temperature than the coolant of the high-voltage cooling system C1, is suppressed. Consequently, in an electric vehicle V equipped with an engine 12, an HEV unit 14, and a battery 16, the desired cooling function can be more reliably ensured in the battery cooling system C2 for cooling the battery 16.

[0056] Furthermore, in the vehicle cooling system structure of this embodiment, the first refrigerant pipe 18 extends from the radiator 22 through the other side region LA and connects to the HEV unit 14.

[0057] This also suppresses heat transfer from the engine 12 to the coolant of the electric cooling system C1 that cools the HEV unit 14. Furthermore, since the first refrigerant piping 18 and the second refrigerant piping 20 are consolidated and arranged between the radiator 22 and the HEV unit 14 in the other side region LA, the space inside the vehicle can be effectively secured and the layout flexibility of each component can be increased compared to when each refrigerant piping is dispersed between the one side region RA and the other side region LA.

[0058] Furthermore, in this embodiment, the radiator 22 includes a first radiator 22a and a second radiator 22b, which are formed separately from each other. The first radiator 22a is connected to the first refrigerant piping 18, and the second radiator 22b is connected to the second refrigerant piping 20.

[0059] In other words, the radiator 22 is configured as a separate first radiator 22a and second radiator 22b, each prepared individually for the two cooling systems C1 and C2 with different coolant temperatures. This increases the degree of freedom in adjusting the relative positions of each radiator 22a and 22b. For example, it becomes easy to adopt a layout that suppresses heat transfer from the power supply cooling system C1 to the battery cooling system C2, such as separating the elements of the relatively high-temperature power supply cooling system C1 (first refrigerant piping 18, various valves, and the first pump 55, etc.) from the elements of the relatively low-temperature battery cooling system C2 (second refrigerant piping 20, various valves, and the second pump 64, etc.).

[0060] Furthermore, in the vehicle cooling system structure of this embodiment, the second radiator 22b is positioned below the first radiator 22a in the vehicle's vertical direction. In addition, the second refrigerant piping 20 is positioned below the first refrigerant piping 18 in the vehicle's vertical direction (UD direction).

[0061] In the space where the radiator 22 at the front of the vehicle is located (inside the motor room mr), the ambient temperature is lower at the bottom compared to the top. Therefore, by positioning the second radiator 22b below the first radiator 22a and the second refrigerant piping 20 below the first refrigerant piping 18, the balance of heat transfer from the engine 12 to the first refrigerant piping 18 and the second refrigerant piping 20 can be adjusted more appropriately. More specifically, by positioning the first radiator 22a and the first refrigerant piping 18, through which relatively high-temperature coolant flows, at an upper position with a higher ambient temperature, while positioning the second radiator 22b and the second refrigerant piping 20, through which relatively low-temperature coolant flows, at a lower position with a lower ambient temperature, the above balance can be adjusted to reduce the amount of heat transferred from the engine 12 to the second refrigerant piping 20 (increase the amount of heat transferred to the first refrigerant piping 18). In other words, an appropriate arrangement configuration can be achieved according to the difference in the tolerance of heat transfer (heat absorption) from the engine 12 to the first refrigerant piping 18 and the second refrigerant piping 20.

[0062] Furthermore, in the vehicle cooling system structure of this embodiment, the refrigerant inlet (second coolant inlet 28) of the second radiator 22b is located in the other side region LA, and the refrigerant outlet (second coolant outlet 30) is located in the one side region RA. The second refrigerant piping 20 extends from the second coolant outlet 30 to the HEV outer region SA via the region forward of the second radiator 22b.

[0063] As a result, even if the size (thickness) of the second radiator 22b is relatively small, making it impossible to place both the second coolant inlet 28 and the second coolant outlet 30 in the other side region LA, a layout structure that separates the second refrigerant piping 20 from the engine 12 can be realized.

[0064] Furthermore, the vehicle cooling system structure of this embodiment further includes bypass pipes 70 and 71 that connect the first refrigerant pipe 18 and the second refrigerant pipe 20 and allow coolant to flow between the first refrigerant pipe 18 and the second refrigerant pipe 20, and bypass on / off valves (third three-way valve 72 and valve 73) that switch between the flow and shut-off of coolant in the bypass pipes 70 and 71. The bypass pipes 70 and 71, the third three-way valve 72, and the valve 73 are located in the other side region LA.

[0065] This allows for the integration of the high-voltage cooling system C1, which is mainly used to cool the high-voltage equipment 50, and the battery cooling system C2, which is used to cool the battery 16, into a single integrated cooling system, depending on the operating state of the electric vehicle V (for example, the magnitude of the load on the drive motor). This enables the cooling of specific devices to be cooled in either the high-voltage cooling system C1 or the battery cooling system C2. In particular, by operating the third three-way valve 72 and the valve 73 to configure an integrated cooling system that cools the high-voltage equipment 50 (HEV unit 14) while substantially integrating the first radiator 22a and the second radiator 22b into a single radiator 22, the cooling function for the HEV unit 14 can be further enhanced in situations where the cooling requirement increases, such as when the drive motor is under high load. In this embodiment, the bypass pipes 70, 71, the third three-way valve 72, and the valve 73, which are cooling circuit elements for switching between the state in which the high-voltage cooling system C1 and the battery cooling system C2 are used as normal individual cooling systems and the state in which they are used as the integrated cooling system, are also arranged in the other side region LA, similar to the second refrigerant pipe 20. As a result, each refrigerant pipe is concentrated in the other side region LA, and the overall piping length can be made relatively short. Therefore, the effective heat transfer area from the engine 12 to each refrigerant pipe can be reduced, and the amount of heat transferred to each refrigerant pipe can be further reduced.

[0066] [Second Embodiment] The second embodiment will be described below. Elements similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted.

[0067] Figure 5 is a plan view of the main parts of the vehicle cooling system structure according to this embodiment. Figure 6 is a side view of the main parts of the vehicle cooling system structure.

[0068] As shown in the figure, in the vehicle cooling system structure of this embodiment, in addition to the first coolant inlet 24 and first coolant outlet 26 of the first radiator 22a, the second coolant inlet 28 and second coolant outlet 30 of the second radiator 22b are also located in the other side region LA.

[0069] Figure 7 shows the structure of the radiator 22 (first radiator 22a and second radiator 22b) in this embodiment. As shown in the figure, in this embodiment, both the first radiator 22a and the second radiator 22b are composed of U-flow radiators.

[0070] As described above, in the vehicle cooling system structure of this embodiment, the first coolant inlet 24 and the first coolant outlet 26 of the first radiator 22a are both located in the other side region LA, and the second coolant inlet 28 and the second coolant outlet 30 of the second radiator 22b are both located in the other side region LA.

[0071] This allows the first refrigerant pipe 18 and the second refrigerant pipe 20 to be positioned at a distance from the engine 12, thereby suppressing the complexity of the piping layout caused by complex bends in each refrigerant pipe and shortening the total piping length of each refrigerant pipe. Consequently, the effective heat transfer area from the engine 12 to each refrigerant pipe can be reduced, further decreasing the amount of heat transferred to each refrigerant pipe.

[0072] In particular, in this embodiment, the first radiator 22a and the second radiator 22b are each composed of a U-flow radiator in which the coolant inlets 24, 28 and coolant outlets 26, 30 are concentrated on one side (the other side region LA) in the vehicle width direction.

[0073] In this way, by configuring the first radiator 22a and the second radiator 22b using existing U-flow radiators, a structure can be easily realized in which the first refrigerant piping 18 and the second refrigerant piping 20 are separated from the engine 12, which is a heat source.

[0074] [First variation] The first modified example will be described below. Elements identical to those described in the above embodiments will be denoted by the same reference numerals, and their descriptions will be omitted.

[0075] Figure 8 is a side view of the main part of the vehicle cooling system structure according to the first modified example. As shown in the figure, in the vehicle cooling system structure according to this modified example, the configuration of the vehicle cooling system structure described in the first embodiment is used as a basis, but the air conditioning condenser 90 is positioned behind the radiator 22 and in front of the HEV unit 14.

[0076] As already explained, the second refrigerant pipe 20 is constructed to extend from the radiator 22 through the HEV outer region SA in the other side region LA and connect to the battery 16, thereby suppressing heat transfer from the engine 12 to the coolant flowing through the second refrigerant pipe 20 in the battery cooling system C2. As a result, heat transfer from the engine 12 to the air conditioning condenser 90 located behind the second radiator 22b via the battery cooling system C2 is also suppressed. In particular, as already explained, the battery cooling system C2 is equipped with a chiller 66 that performs heat exchange between the liquid refrigerant in the air conditioner heat exchange circuit, including the air conditioning condenser 90, and the coolant in the battery cooling system C2. In contrast, by suppressing heat transfer from the engine 12 to the coolant in the battery cooling system C2, the heat transferred to the liquid refrigerant for air conditioning via heat exchange in the chiller 66 can be reduced, thus reducing the heat load on the air conditioning condenser 90. Therefore, in the air conditioner heat exchange circuit, the power of the air conditioning compressor (not shown) that pressurizes and sends refrigerant to the air conditioning condenser 90 can be reduced, thereby suppressing power consumption (improving the fuel efficiency of the electric vehicle V).

[0077] Furthermore, in the vehicle cooling system structure shown in Figure 8, the first refrigerant piping 18 in the high-voltage cooling system C1 is also located in the other side region LA, so a certain degree of suppression effect is obtained against heat transfer from the engine 12 to the coolant in the high-voltage cooling system C1. As a result, heat transfer from the engine 12 to the air conditioning condenser 90 via the high-voltage cooling system C1 can also be reduced, and the effect of reducing power consumption by reducing the power of the air conditioning compressor can be further enhanced.

[0078] Although this modified example describes the arrangement of the air conditioning condenser 90 based on the vehicle cooling system structure according to the first embodiment, similar effects can be achieved even when the air conditioning condenser 90 is placed in the same position based on the vehicle cooling system structure according to the second embodiment (Figures 5 and 6).

[0079] [Second variation] The following describes a second modified example. Elements identical to those described in the above embodiments are denoted by the same reference numerals, and their descriptions are omitted.

[0080] Figure 9 is a side view of the main part of the vehicle cooling system structure according to the second modified example. As shown in the figure, in the vehicle cooling system structure according to this modified example, the radiator 22 is made up of a U-flow radiator having one coolant inlet 92 and one coolant outlet 94.

[0081] The coolant flowing into and out of the radiator 22 is then branched to the first refrigerant piping 18 (powerful cooling system C1) and the second refrigerant piping 20 (battery cooling system C2) via switching valves 96 and 98. It is preferable that the switching valves 96 and 98 be positioned in the other side region LA in order to suppress the amount of heat transferred from the engine 12. This makes it possible to create a structure that reduces heat transfer from the engine 12 to the coolant flowing through the first refrigerant piping 18 and / or the second refrigerant piping 20, while ensuring the functions of both the battery cooling system C2 and the powerful cooling system C1, even when using a radiator 22 having a single coolant inlet 92 and a single coolant outlet 94.

[0082] Although embodiments of the present invention have been described above, these embodiments represent only 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. Furthermore, the above embodiments can be combined as appropriate.

Claims

1. A vehicle cooling system structure for an electric vehicle comprising: an internal combustion engine; a drive unit including an electric motor as a driving source; a battery for charging electricity generated by driving the internal combustion engine; a first refrigerant pipe connected to the drive unit; a second refrigerant pipe connected to the battery; and a radiator positioned at the front of the vehicle for dissipating heat from the refrigerant flowing through the first and second refrigerant pipes, The internal combustion engine and the drive unit are arranged in parallel in one side region and the other side region, respectively, which are separated in the width direction of the electric vehicle. The second refrigerant piping extends from the radiator through the drive unit outer region in the other side region and is connected to the battery. The outer region of the drive unit is the region located on the outside of the drive unit in the vehicle width direction and on the opposite side from the internal combustion engine. The radiator includes a first radiator and a second radiator, which are formed separately from each other. The first radiator is connected to the first refrigerant piping, The second radiator is connected to the second refrigerant piping, The refrigerant inlet of the second radiator is located in the other side region, and the refrigerant outlet of the second radiator is located in the one side region. The second refrigerant piping extends from the refrigerant outlet of the second radiator through a region forward of the second radiator to the region outside the drive unit. Vehicle cooling system structure.

2. A vehicle cooling system structure according to claim 1, The first refrigerant piping extends from the radiator through the other side region and connects to the drive unit. Vehicle cooling system structure.

3. A vehicle cooling system structure according to claim 1 or 2, The second radiator is positioned below the first radiator in the vehicle's vertical direction. The second refrigerant pipe is positioned below the first refrigerant pipe in the vertical direction of the vehicle. Vehicle cooling system structure.

4. A vehicle cooling system structure according to claim 1 or 2, A bypass pipe connects the first refrigerant pipe and the second refrigerant pipe, and allows the refrigerant to flow between the first refrigerant pipe and the second refrigerant pipe, The system further comprises a bypass on / off valve that switches between the flow and shut-off of the refrigerant in the bypass piping, The bypass piping and the bypass on / off valve are arranged in the other side region. Vehicle cooling system structure.

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