Refrigerant circulation structure

Abstract

To provide a refrigerant distribution structure that allows for space saving. [Solution] The refrigerant flow structure formed in the housing 4 of the vehicle drive unit 1 is such that the housing 4 comprises a housing body 4A, and the housing body 4A has a refrigerant flow path 10 through which refrigerant circulating between it and the air conditioning unit that provides heating and cooling for the vehicle interior flows.

Description

Technical Field

[0001] The present invention relates to a refrigerant flow structure through which a refrigerant flows.

Background Art

[0002] Vehicles are equipped with various devices, and many of these devices generate heat when driven. In order to cool such heat-generating devices, a cooling fluid is used. As a technique related to the cooling of devices using such a cooling fluid, for example, there is one described in Patent Document 1 cited below.

[0003] Patent Document 1 describes a case for a rotating electric machine. This case for a rotating electric machine has a main body formed of an aluminum alloy and a flow path formed between the inner peripheral portion and the outer peripheral portion of the main body. The refrigerant as the above-described cooling fluid flows through this flow path, and is configured to cool the stator of the rotating electric machine and the like.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The case for a rotating electric machine described in Patent Document 1 is provided in a motor room on the front side in the traveling direction of the passenger compartment in a vehicle. Such a motor room may be equipped with an air conditioning unit for adjusting the temperature of the passenger compartment. In this case, refrigerant flow paths through which the refrigerant flows are provided in the case for a rotating electric machine and the air conditioning unit provided in the motor room, respectively. Therefore, for example, a refrigerant module having a refrigerant flow path for the air conditioning unit and members for assembling the refrigerant module to the vehicle are required, and there is room for improvement from the viewpoint of space saving.

[0006] Therefore, a refrigerant distribution structure that can save space is required. [Means for solving the problem]

[0007] The characteristic configuration of the refrigerant flow structure according to the present invention is a refrigerant flow structure formed in the housing of a vehicle drive system, wherein the housing comprises a housing body, and the housing body has a refrigerant flow path through which a refrigerant circulating between it and an air conditioning unit that provides heating and cooling for the vehicle's interior flows.

[0008] With this configuration, the refrigerant flow path for the air conditioning unit can be formed within the housing. Compared to cases where the refrigerant flow path is provided separately from the housing, the refrigerant flow structure can be made smaller, and the proportion of the volume occupied by the refrigerant flow structure in a given space can be reduced. Therefore, the space required for the vehicle drive system can be reduced. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram showing the refrigerant flow structure. [Figure 2] This is an exploded view of the refrigerant distribution structure. [Figure 3] This is a diagram showing the circuit configuration of the air conditioning system. [Figure 4] This is an exploded view of a refrigerant flow structure according to another embodiment. [Modes for carrying out the invention]

[0010] The refrigerant flow structure according to the present invention is configured to save space. The refrigerant flow structure of this embodiment will be described below. However, the refrigerant flow structure is not limited to the following embodiment and can be modified in various ways without departing from the spirit of the invention.

[0011] Figure 1 is a perspective view of a vehicle drive unit 1 to which a refrigerant flow structure is applied. Figure 2 is an exploded view of the vehicle drive unit 1 to which a refrigerant flow structure is applied. Figure 3 shows the circuit configuration of an air conditioning system 5 equipped with an air conditioning unit 6. The vehicle drive unit 1 is mounted on a vehicle, and in Figures 1 and 2, the front side of the vehicle in the direction of travel is indicated by "F" and the rear side of the vehicle in the direction of travel is indicated by "B". Looking at the front side F in the direction of travel, the left side in the vehicle width direction is indicated by "L" and the right side in the vehicle width direction is indicated by "R". Furthermore, the upper side in the vertical direction of the vehicle is indicated by "U" and the lower side in the vertical direction of the vehicle is indicated by "D".

[0012] As shown in Figures 1 and 2, the refrigerant flow structure is formed in the housing 4 of the vehicle drive unit 1. The vehicle drive unit 1 includes a drive unit 2 that moves the vehicle and a power module 3 that drives the drive unit 2. The vehicle drive unit 1 is housed in a motor room (location of the vehicle drive unit 1) which is separated from the passenger compartment by a partition wall of the dashboard (not shown).

[0013] The drive unit 2 is located at the lower part (downward D in the vertical direction) of the vehicle drive unit 1. The drive unit 2 has a motor 2A and a gear mechanism 2B that output power that allows the vehicle to move. The motor 2A and the gear mechanism 2B are arranged side by side along the vehicle width direction. In this embodiment, the motor 2A is located on the right side R in the vehicle width direction, and the gear mechanism 2B is located on the left side L in the vehicle width direction. The motor 2A is driven by the power module 3. The motor 2A and the gear mechanism 2B are connected via a motor shaft, and the rotation of the motor 2A is input to the gear mechanism 2B via the motor shaft. The gear mechanism 2B reduces the rotation of the motor 2A and outputs it from the gear shaft. The vehicle moves using the output of the motor 2A via the gear mechanism 2B.

[0014] The power module 3 is located at the top (upper vertical U) of the vehicle drive unit 1. Therefore, in this embodiment, the power module 3 is located vertically alongside the vehicle's drive unit 2 (aligned vertically).

[0015] The power module 3 comprises an OBC (On-Board Charger) board 3A, a motor drive board 3B, and a control board 3C that controls the OBC board 3A and the motor drive board 3B. An inverter and a converter are mounted on the OBC board 3A. The inverter is supplied with AC power consisting of AC voltage from the commercial power supply and converts the AC power into DC power including DC voltage. The converter is supplied with the DC power generated by the inverter and boosts the voltage value of the DC voltage that makes up the DC power supplied from the inverter to a DC voltage value necessary for charging the battery mounted on the vehicle. Therefore, the power module 3 is capable of supplying power to the vehicle's battery.

[0016] The motor drive board 3B has a drive inverter mounted on it that controls the drive current that drives the motor 2A. The control board 3C has a control unit mounted on it that controls the inverter and converter. Therefore, the power module 3 is capable of supplying power to the motor 2A. Note that the power module 3 does not necessarily have to include the OBC board 3A or the part of the control board 3C that controls the OBC board 3A (functional unit).

[0017] Housing 4 houses the drive unit 2 and the power module 3. Housing 4 has a first space on the upper vertical side U and a second space partitioned from the first space on the lower vertical side D. As described above, the power module 3 is installed vertically (aligned vertically) along the vertical direction of the vehicle along with the drive unit 2. Therefore, the power module 3 is installed in the first space of housing 4, and the drive unit 2 is installed in the second space of housing 4. The first space and the second space can be partitioned, for example, by a cooling plate having a cooling channel through which coolant flows. By placing the power module 3 on this cooling plate, it is possible to cool the power module 3 by performing heat exchange between the power module 3 and the coolant. Note that housing 4 includes a first housing that houses the power module 3 and a second housing that houses the drive unit 2, and the first housing and the second housing may be installed separately from each other. Furthermore, the portion of the housing 4 that houses the drive unit 2 includes a motor housing portion that houses the motor 2A and a gear housing portion that houses the gear mechanism 2B, and the motor housing portion and the gear housing portion may be provided separately (spaced apart) from each other.

[0018] Figure 3 shows the circuit configuration of the air conditioning system 5. The air conditioning system 5 comprises a refrigerant module 60 and an air conditioning unit 6 mounted on the vehicle. The refrigerant flow structure is configured to allow refrigerant to flow between the air conditioning unit 6 and the system. The refrigerant flows through a refrigerant flow path 10, which is included in the refrigerant module 60. Refrigerants such as hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs) flow through the refrigerant flow path 10. The refrigerant circulates between the air conditioning unit 6, which provides heating and cooling for the vehicle's interior. The air conditioning unit 6 may be provided as an integral part of the vehicle drive system 1 or as a separate unit.

[0019] As shown in FIG. 3, the refrigerant module 60 includes a compressor 71, a condenser 72, an expansion valve 73, and an evaporator 74, and the refrigerant flow path 10 is configured to allow the refrigerant to flow through the compressor 71, the condenser 72, the expansion valve 73, and the evaporator 74. An accumulator 81 and a switching valve 82 are further provided in the refrigerant flow path 10 of the present embodiment.

[0020] According to the air conditioning unit 6, as described above, it is possible to perform air conditioning in the passenger compartment. First, the case of performing cooling in the passenger compartment by the air conditioning unit 6 will be described. The accumulator 81 stores the liquid refrigerant and separates the gas and liquid of the stored refrigerant. The gaseous refrigerant separated by the accumulator 81 flows through the first refrigerant path 91 and is sent to the compressor 71.

[0021] The compressor 71 compresses the refrigerant from the accumulator 81. As a result, the refrigerant becomes a high-temperature compressed gas. The compressor 71 sends the refrigerant that has become the high-temperature compressed gas to the condenser 72 via the second refrigerant path 92. Therefore, the compressor 71 pressure-feeds the refrigerant from the accumulator 81 to the condenser 72.

[0022] The condenser 72 condenses the refrigerant compressed by the compressor 71. The condenser 72 is configured such that a coolant that exchanges heat with the refrigerant flows through it. The condenser 72 is configured such that the flow path through which the refrigerant flows and the flow path through which the coolant flows are separate from each other. The refrigerant is condensed and liquefied by being deprived of heat by the coolant. The liquefied refrigerant is sent to the third refrigerant path 93. The condenser 72 may be an air-cooled condenser provided near the radiator.

[0023] The refrigerant sent from the condenser 72 to the third refrigerant path 93 is sent to the cooling expansion valve 73A that constitutes the expansion valve 73. In the cooling expansion valve 73A, the refrigerant (liquefied refrigerant) flowing through the third refrigerant path 93 during cooling of the passenger compartment is expanded into a low-temperature and low-pressure mist. The mist-like refrigerant is sent to the fourth refrigerant path 94.

[0024] The evaporator 74 evaporates the refrigerant expanded in the cooling expansion valve 73A and sends it to the fifth refrigerant passage 95. As described above, the refrigerant expanded in the cooling expansion valve 73A and atomized into low temperature, low pressure refrigerant flows through the evaporator 74, and this refrigerant is sent to the evaporator 74. In the evaporator 74, the atomized refrigerant evaporates, for example, by absorbing heat from the outside air. The evaporated and vaporized refrigerant flows through the fifth refrigerant passage 95 to the accumulator 81.

[0025] The air conditioning unit 6 consists of an evaporator 74 and a blower 85. The blower 85 draws in outside air and sends the drawn-in outside air to the evaporator 74.

[0026] In the evaporator 74, heat exchange takes place between the outside air supplied from the blower 85 and the refrigerant supplied via the fourth refrigerant passage 94, and the air after heat exchange is introduced into the passenger compartment. Specifically, the outside air is cooled in the evaporator 74, and cool air is introduced into the passenger compartment. This makes it possible to cool the passenger compartment.

[0027] Furthermore, when the passenger compartment is being cooled, the switching valve 82 sets the refrigerant flow state in the refrigerant flow path 10 to the first state in which the refrigerant flows during cooling. In this embodiment, the switching valve 82 is in the closed state, and the refrigerant sent from the condenser 72 is configured to flow to the cooling expansion valve 73A. In addition, the heating expansion valve 73B, which constitutes the expansion valve 73, is set to have its valve bore diameter at its maximum, and is configured so that the refrigerant does not expand in the heating expansion valve 73B. Moreover, the cabin condenser 86 of the air conditioning unit 6 is configured so that the airflow is blocked and no heat exchange occurs.

[0028] Furthermore, in this embodiment, the battery is configured to be cooled by a battery cooler 87. When the battery is cooled by the battery cooler 87, refrigerant from the condenser 72 flows to the battery expansion valve 73C, and the refrigerant, which has been cooled by passing through the battery expansion valve 73C, is supplied to the battery cooler 87. This makes it possible to cool the battery. The refrigerant used to cool the battery in the battery cooler 87 is sent to the accumulator 81.

[0029] Next, we will explain the case where the vehicle interior is heated by the air conditioning unit 6. The accumulator 81 stores liquid refrigerant and performs gas-liquid separation of the stored refrigerant. The gaseous refrigerant separated by the accumulator 81 flows through the first refrigerant passage 91 and is sent to the compressor 71.

[0030] The compressor 71 compresses the refrigerant from the accumulator 81. This causes the refrigerant to become a high-temperature compressed gas. The compressor 71 then sends this high-temperature compressed gas to the cabin condenser 86 via the second refrigerant passage 92.

[0031] The cabin condenser 86 is a heat source during heating and releases the heat of condensation generated by the compressor 71 into the passenger compartment. The cabin condenser 86 then sends the refrigerant, from which the heat of condensation has been released, to the second refrigerant passage 92.

[0032] The refrigerant discharged from the cabin condenser 86 is sent to the heating expansion valve 73B. When the cabin is heated, the valve diameter of the heating expansion valve 73B is narrowed. As a result, the refrigerant expands in the heating expansion valve 73B. The condenser 72 evaporates the refrigerant that has expanded in the heating expansion valve 73B and sends it to the third refrigerant passage 93 via the second refrigerant passage 92.

[0033] When the passenger compartment is being heated, the switching valve 82 sets the refrigerant flow state in the refrigerant passage 10 to a second state in which refrigerant flows during heating. In this embodiment, the switching valve 82 is set to the open state, and the refrigerant sent from the condenser 72 is configured to flow to the accumulator 81. In this case, the cooling expansion valve 73A and the battery expansion valve 73C are configured so that refrigerant does not flow through them. That is, the valve bore diameters of the cooling expansion valve 73A and the battery expansion valve 73C are restricted.

[0034] The refrigerant flow structure of this embodiment is realized by forming a part of such an air conditioning system 5 in the housing 4. As shown in Figures 1 and 2, the housing 4 comprises a housing body 4A and a lid 4B. As described above, the housing 4 forms a first space and a second space inside which the travel drive unit 2 and the power module 3 are housed. These first and second spaces are formed in the housing body 4A.

[0035] A groove 4D is formed on the outer surface 4C of the housing body 4A. The outer surface 4C of the housing 4 corresponds to the outer wall on the opposite side of the inner wall, not the inner wall that forms the first and second spaces that house the travel drive unit 2 and the power module 3 inside the housing 4.

[0036] In this embodiment, the groove 4D is formed on the outer surface 4C that is closer to the power module 3 than to the drive unit 2. Specifically, it is formed on the left side L in the vehicle width direction of the upper vertical U portion of the housing body 4A. Therefore, the groove 4D is formed on the first housing that houses the power module 3, and not on the second housing that houses the drive unit 2. By forming the groove 4D on the outer surface 4C that is closer to the power module 3, the refrigerant can be circulated to the side closer to the power module 3. Therefore, it becomes possible to cool the power module 3 with a refrigerant that is at a relatively lower temperature.

[0037] The cover 4B is fixed to the outer surface 4C of the housing body 4A. In this embodiment, the cover 4B is fastened and fixed with bolts 50 with a metal plate 20, which functions as a gasket, interposed between the outer surface 4C where the groove 4D is formed. The metal plate 20 can be made of, for example, copper or aluminum. The groove 4D is covered by the cover 4B, forming the refrigerant flow path 10. The refrigerant flow path 10 includes a flow path through which the refrigerant circulates between the air conditioning unit 6 and the refrigerant flow path, as described above.

[0038] The housing 4 is provided with a hole 40 that communicates with the refrigerant flow path 10 and to which a heat exchanger that exchanges heat with the refrigerant is connected. The heat exchanger that exchanges heat with the refrigerant is, for example, a condenser 72. The hole 40 is provided across the housing body 4A and the lid 4B. In this embodiment, a metal plate 20 is provided between the housing body 4A and the lid 4B, and a hole 21 is formed in this metal plate 20 at a position corresponding to the hole 40.

[0039] Furthermore, the housing 4 is provided not only with a hole 40 to which the heat exchanger is connected, but also with holes 41 to which the expansion valve 73 and the switching valve 82 are connected. Of course, the metal plate 20 also has holes 22 formed at positions corresponding to these holes 41.

[0040] In this embodiment, the housing 4 integrates the condenser 72, expansion valve 73, and switching valve 82. Therefore, the refrigerant module 60 can be integrated with the vehicle drive unit 1, and the refrigerant flow structure can be miniaturized.

[0041] [Other Embodiments] Next, other embodiments of the refrigerant flow structure will be described.

[0042] In the above embodiment, the vehicle drive unit 1 and the air conditioning system 5 have been described, but these are illustrative examples and it is possible to have configurations different from those of the above embodiment.

[0043] In the above embodiment, it was explained that the housing 4 is provided with a hole 40 to which the heat exchanger is connected. However, instead of connecting the heat exchanger to the housing 4, a flow path for introducing and exiting the refrigerant directly into the heat exchanger may be provided, and the heat exchanger may be connected to these flow paths.

[0044] In the above embodiment, the heat exchanger was described as being integrated into the housing 4. However, the heat exchanger may be provided fixed to a bracket different from the housing 4, for example.

[0045] In the above embodiment, the vehicle drive system 1 was described as having a drive unit 2 and a power module 3 housed in a housing 4, but the housing 4 may contain only one of the drive unit 2 and the power module 3.

[0046] In the above embodiment, the groove 4D was described as being formed on the outer surface 4C closer to the power module 3 than the drive unit 2. However, the groove 4D may be formed on the outer surface 4C located midway between the drive unit 2 and the power module 3, or it may be formed on the outer surface 4C closer to the drive unit 2 than the power module 3. Also, although the groove 4D was described as being formed on the left side L in the vehicle width direction, the groove 4D may be formed on the right side R in the vehicle width direction, on the front side F in the direction of travel, or on the rear side B in the direction of travel. Of course, the groove 4D may also be formed on the upper vertical side U of the housing body 4A.

[0047] In the above embodiment, the housing body 4A and the lid 4B are constructed as separate parts, and the lid 4B is fixed to the outer surface 4C of the housing body 4A, and the refrigerant flow path 10 is formed by the groove 4D being covered by the lid 4B. However, the refrigerant flow path 10 can also be formed by opening at the outer surface 4C of the housing body 4A and by providing a hole 31 in the wall 30 of the housing body 4A. In this case, as shown in Figure 4, it is preferable to drill the hole 31 from the side of the wall 30 of the housing body 4A using a drill or the like. That is, the hole 31 is provided in the wall 30 as a horizontal or vertical hole. When providing a hole 31 in the wall 30 of the housing body 4A, from the viewpoint of accuracy of the hole 31, it is desirable to first form a pilot hole using a mold (not shown) and then form the hole 31 along this pilot hole using a drill or the like. Furthermore, the open end 32 of the hole 31 that opens in the outer surface portion 4C of the housing body 4A is preferably blocked by connecting an expansion valve 73 (cooling expansion valve 73A, heating expansion valve 73B, battery expansion valve 73C), piping (not shown) connected to the condenser 72, evaporator 74, etc., or a plug 33. Note that in Figure 4, only a portion of the refrigerant flow path 10 is shown. In addition, the hole portion 40 to which the condenser 72 described in the above embodiment is connected, and the hole portion 41 to which the expansion valve 73 and switching valve 82 are connected may utilize the open end 32 of the hole 31.

[0048] [Summary of the above embodiment] The following is an overview of the refrigerant distribution structure described above.

[0049] (1) The refrigerant flow structure is a refrigerant flow structure formed in the housing 4 of the vehicle drive unit 1, the housing 4 comprises a housing body 4A, and the housing body 4A has a refrigerant flow path 10 through which refrigerant circulating between it and the air conditioning unit 6 that provides heating and cooling for the passenger compartment flows.

[0050] With this configuration, the refrigerant flow path 10 for the air conditioning unit 6 can be formed in the housing 4. Compared to the case where the refrigerant flow path 10 is provided separately from the housing 4, the refrigerant flow structure can be made smaller, and the proportion of the volume occupied by the refrigerant flow structure in a given space (motor room) can be reduced. Therefore, the space required for the vehicle drive unit 1 can be reduced.

[0051] (2) In the refrigerant flow structure described in (1), it is preferable that the housing 4 is provided with a hole 40 to which a heat exchanger (condenser 72) that communicates with the refrigerant flow path 10 and performs heat exchange with the refrigerant is connected.

[0052] With this configuration, the refrigerant can be introduced into the heat exchanger (condenser 72) via the housing 4. Therefore, it becomes possible to easily route the flow path for the refrigerant.

[0053] (3) In the refrigerant flow structure described in (2), it is preferable that a heat exchanger (condenser 72) is integrated into the housing 4.

[0054] With this configuration, since the heat exchanger (condenser 72) is integrated with the housing 4, it can be made smaller compared to the case where the heat exchanger (condenser 72) is not integrated with the housing 4.

[0055] (4) In the refrigerant flow structure described in (1) to (3), the vehicle drive unit 1 preferably has a housing 4 which is provided with a cover 4B fixed to the outer surface 4C of the housing body 4A, the housing body 4A has a groove 4D formed on the outer surface 4C, and the refrigerant flow path 10 is formed such that the groove 4D is covered by the cover 4B.

[0056] With this configuration, the refrigerant flow path 10 can be formed by fixing the lid 4B to the outer surface 4C of the housing body 4A. Therefore, the refrigerant flow path 10 can be easily formed.

[0057] (5) In the refrigerant flow structure described in (1) to (3), it is preferable that the refrigerant flow path 10 is formed by an opening in the outer surface portion 4C of the housing body 4A and by a hole 31 provided in the wall 30 of the housing body 4A.

[0058] According to this configuration, the hole 31 provided in the wall 30 of the housing body 4A is used as the refrigerant flow path 10, and by connecting piping connected to, for example, a heat exchanger (condenser 72) to the opening of the hole 31, the refrigerant circuit can be easily configured. [Industrial applicability]

[0059] The technology disclosed herein can be used in refrigerant distribution structures. [Explanation of Symbols]

[0060] 1: Vehicle drive unit, 4: Housing, 4A: Housing body, 4B: Cover, 4C: Outer surface, 4D: Groove, 6: Air conditioning unit, 10: Refrigerant flow path, 30: Wall, 31: Hole, 40: Hole section, 72: Condenser (heat exchanger)

Claims

1. A refrigerant flow structure formed in the housing of a vehicle drive system, The housing comprises a housing body, The housing body has a refrigerant flow path through which a refrigerant circulates between it and an air conditioning unit that provides heating and cooling for the vehicle interior.

2. The refrigerant flow structure according to claim 1, wherein the housing is provided with a hole through which a heat exchanger that communicates with the refrigerant flow path and performs heat exchange with the refrigerant is connected.

3. The refrigerant flow structure according to claim 2, wherein the heat exchanger is integrated into the housing.

4. The housing comprises a lid fixed to the outer surface of the housing body, The housing body has grooves formed on its outer surface, The refrigerant flow path is formed such that the groove portion is covered by the cover, according to any one of claims 1 to 3.

5. The refrigerant flow path is formed by an opening on the outer surface of the housing body and by a hole provided in the wall of the housing body, according to any one of claims 1 to 3.

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