Mounting structure for accumulator

Abstract

To provide a mounting structure for an accumulator capable of preventing unintended movement of the accumulator.SOLUTION: A mounting structure for an accumulator 30 includes an accumulator 30 incorporated in an in-vehicle air conditioner 10 and configured to separate a refrigerant mainly containing CO2 into a gaseous refrigerant and a liquid refrigerant, and two or more brackets that mount the accumulator 30 to a fixing member 100. The two or more brackets include annular brackets 44U, 44L that surround the accumulator 30 in a circumferential direction, and an axial bracket 60. At least part of the shaft-side bracket is stacked on and coupled to an axial end face of the accumulator 30.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This specification discloses a mounting structure for an accumulator provided in an on-vehicle air conditioning system. [Background technology]

[0002] Generally, air conditioners transfer heat by compressing, expanding, evaporating, and condensing a refrigerant during the process of circulating the refrigerant, thereby generating conditioned air. Such air conditioners often have an accumulator that separates the refrigerant into gas and liquid phases.

[0003] Patent Document 1 discloses a refrigeration and air conditioning system having an accumulator. In Patent Document 1, a refrigerant and PAG oil are stored in the accumulator. In Patent Document 1, a heating device is further provided in the accumulator to prevent the densities of the refrigerant and PAG oil from reversing as the temperature drops. This configuration allows the refrigerant to be properly separated into gas and liquid.

[0004] Incidentally, conventionally, fluorine-based refrigerants have been widely used as refrigerants for air conditioning. However, in recent years, in consideration of the burden on the environment, it has been proposed to use CO2 refrigerants, which are primarily composed of carbon dioxide (hereinafter referred to as "CO2"), instead of fluorine-based refrigerants. CO2 refrigerants have a significantly lower global warming potential than fluorine-based refrigerants. Patent Document 1 uses this CO2 refrigerant. However, CO2 refrigerants need to be pressurized to a higher pressure than fluorine-based refrigerants. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-121926 Summary of the Invention [Problem to be solved by the invention]

[0006] Consider a case where an air conditioning system using such a CO2 refrigerant is installed in a vehicle. In this case, there is a risk of the air conditioning system being subjected to a strong impact due to a vehicle collision or other event. If the CO2 refrigerant piping connected to the accumulator is damaged in this situation, high-pressure CO2 refrigerant will spray out from the accumulator. The pressure of this refrigerant spray could cause the accumulator to move forcefully.

[0007] To prevent such unintended movement of the accumulator, the mounting structure of the accumulator needs to be thoroughly considered. However, in the prior art such as Patent Document 1, the mounting structure of the accumulator has not been sufficiently considered.

[0008] Therefore, this specification discloses an accumulator mounting structure that can prevent unintended movement of the accumulator. [Means for solving the problem]

[0009] The mounting structure for an accumulator disclosed in this specification comprises an accumulator that is incorporated into an on-vehicle air conditioning system and separates a refrigerant whose main component is CO2 into gas and liquid, and two or more brackets that mount the accumulator to a fixing member, wherein the two or more brackets include an annular bracket that circumferentially surrounds the accumulator, and an axial bracket that is at least partially overlapped and joined to the axial end face of the accumulator.

[0010] In this case, two of the annular brackets may be provided spaced apart in the axial direction of the accumulator.

[0011] Furthermore, one end of the shaft-side bracket may be coupled to an axial end surface of the accumulator, and the other end of the shaft-side bracket may be connected to the annular bracket and integrated therewith.

[0012] Another accumulator mounting structure includes an accumulator that is incorporated into an on-vehicle air conditioning system and separates a refrigerant whose main component is CO2 into gas and liquid, and one or more brackets that mount the accumulator to a fixing member, wherein the one or more brackets hold the accumulator so as to restrict movement of the accumulator due to gas injection that occurs when the accumulator or a refrigerant pipe near the accumulator is damaged.

[0013] In this case, the one or more brackets may have a surface facing the accumulator in the direction of the gas injection. [Effects of the Invention]

[0014] The accumulator mounting structure disclosed in this specification allows the bracket to withstand the gas injection pressure that occurs when the accumulator or the refrigerant pipe near the accumulator is damaged, thereby effectively preventing unintended movement of the accumulator. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing the configuration of an air conditioner having an accumulator. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] The mounting structure of the accumulator 30 will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of an air conditioner 10 having an accumulator 30. The air conditioner 10 is mounted on a vehicle to adjust the temperature in the passenger compartment. The type of vehicle on which the air conditioner 10 is mounted is not particularly limited. Therefore, the vehicle may be an engine vehicle powered by an engine, or an electric vehicle powered by a motor. The vehicle may also be a hybrid electric vehicle equipped with both an engine and a motor, a fuel cell vehicle equipped with a fuel cell, or a battery electric vehicle that runs on electricity stored in a battery.

[0017] The air conditioner 10 has a refrigerant circuit 12. The refrigerant circuit 12 is a circuit that generates heat and latent heat by compressing, expanding, condensing, and evaporating the refrigerant in the process of circulating the refrigerant. The heat generated in the refrigerant circuit 12 is used for heating, and the latent heat is used for cooling. Note that the circuit shown in FIG. 1 is used exclusively for cooling, and heat generated by another heat source (for example, an engine or an electric heater) is used for heating.

[0018] Conventionally, fluorine-based refrigerants have been widely used as refrigerants. However, fluorine-based refrigerants have the problem of placing a heavy burden on the environment. Therefore, in this example, a CO2 refrigerant, which is primarily composed of CO2, is used. CO2 refrigerants have a lower global warming potential and less burden on the environment than fluorine-based refrigerants. On the other hand, CO2 refrigerants must be used under higher pressures than fluorine-based refrigerants. For example, fluorine-based refrigerants are used in a pressure range of 0.02 MPaG to 2 MPaG, while CO2 refrigerants are used in a pressure range of 0.8 MPaG to 10 MPaG. Therefore, equipment that handles CO2 refrigerants is required to have high pressure resistance.

[0019] The refrigerant circuit 12 has a refrigerant pipe 14 through which a CO2 refrigerant flows. Along the route of this refrigerant pipe 14, a compressor 16, a gas cooler 18, an accumulator 30, a cooling expansion valve 26, and an evaporator 27 are provided. The compressor 16 compresses the gaseous CO2 refrigerant. As mentioned above, CO2 refrigerant needs to be pressurized to a higher pressure than fluorinated refrigerants. To meet this pressure requirement, a large, high-output compressor 16 is selected.

[0020] The gas cooler 18 is a heat exchanger that exchanges heat between the CO2 refrigerant and outside air. During cooling operation, the gas cooler 18 functions as a condenser that condenses the gaseous CO2 refrigerant. A fan 19 is located behind the gas cooler 18 to efficiently draw in outside air.

[0021] The accumulator 30 separates the CO2 refrigerant into gas and liquid, and sends only the gaseous CO2 refrigerant to the compressor 16.

[0022] 1, the accumulator 30 has a main body 32 that separates the CO2 refrigerant into gas and liquid, and a heat exchanger 34 arranged around the main body 32. The CO2 refrigerant after heat dissipation output from the gas cooler 18 passes through the heat exchanger 34 and heads toward the air conditioning expansion valve 26. While flowing through the heat exchanger 34, the CO2 refrigerant after heat dissipation exchanges heat with the gas-liquid mixed CO2 refrigerant stored in the main body 32. Heat dissipation from the CO2 refrigerant in the heat exchanger 34 to the CO2 refrigerant in the main body 32 promotes evaporation of the CO2 refrigerant in the main body 32.

[0023] In the following, of the multiple pipes connected to the accumulator 30, the pipe connecting the accumulator 30 and the compressor 16 will be referred to as the "first pipe P1," and the pipe connecting the gas cooler 18 and the accumulator 30 will be referred to as the "second pipe P2." Furthermore, the pipe connecting the accumulator 30 and the cooling expansion valve 26 will be referred to as the "third pipe P3," and the pipe connecting the evaporator 27 and the accumulator 30 will be referred to as the "fourth pipe P4." As shown in FIG. 2, which will be described later, the first pipe P1 and the second pipe P2 are connected to a lower part of the accumulator 30, and the third pipe P3 and the fourth pipe P4 are connected to an upper part of the accumulator 30.

[0024] The cooling expansion valve 26 is a solenoid valve that is throttled during cooling operation and completely closed during heating operation. When the cooling expansion valve 26 is throttled, the CO2 refrigerant is rapidly depressurized as it passes through the cooling expansion valve 26. The evaporator 27 evaporates the liquid CO2 refrigerant and is disposed in the air conditioning airflow path provided in the unit case 70. The air around the evaporator 27 is cooled by the latent heat generated during this evaporation.

[0025] 1, the refrigerant circuit 12 is provided with several solenoid valves for switching the flow direction of the air-conditioning refrigerant. Furthermore, the refrigerant circuit 12 is provided with multiple PT sensors 28 for detecting the pressure and temperature of the CO2 refrigerant flowing through the refrigerant pipe 14.

[0026] A blower mechanism 72 is disposed within the vehicle cabin. The blower mechanism 72 cools or heats air taken in from outside or inside the vehicle and blows the air into the vehicle interior. The blower mechanism 72 has a unit case 70, a blower fan 20, and a heater core 22. An air outlet (not shown) is formed at the downstream end of the unit case 70 for directing conditioned air into the vehicle interior. The evaporator 27 and the heater core 22 are also disposed within the unit case 70. During cooling operation, the evaporator 27 cools the air sent from the blower fan 20 by using the latent heat generated when the air-conditioning refrigerant evaporates. The cooled conditioned air is output into the vehicle interior to cool the vehicle interior.

[0027] During heating operation, the heater core 22 is heated by another heat source. The other heat source may be, for example, an engine or an electric heater. The heater core 22 is heated directly by the other heat source or indirectly via a refrigerant such as water. A mode switching door 24 is disposed upstream of the heater core 22. The mode switching door 24 adjusts the amount of air passing through the heater core 22. During heating operation, the mode switching door 24 moves to a position (the position indicated by the dashed line in FIG. 1) that does not block the air flow toward the heater core 22. This allows the air sent from the blower fan 20 to pass through the heater core 22 and be heated. The heated air-conditioned air is output into the vehicle interior, heating the vehicle cabin.

[0028] Such operation of the air conditioner 10 has been known for some time, and therefore a detailed description thereof will be omitted here. The configuration of the air conditioner 10 shown in FIG. 1 is one example and may be modified as appropriate. Next, the mounting structure of the accumulator 30 will be described with reference to FIGS. 2 to 4. FIG. 2 is a perspective view of the accumulator 30 and its surroundings. FIG. 3 is a side view of the accumulator 30 and its surroundings, and FIG. 4 is an enlarged view of a main portion of the lower bracket 42. In FIGS. 2 to 4, Fr, Up, and Rh mean the front, upper, and right side of the vehicle, respectively.

[0029] As mentioned above, CO2 refrigerant has a higher pressure than fluorine-based refrigerants. If the accumulator 30 or the surrounding refrigerant pipe 14 is damaged due to a vehicle collision or other reasons, this high-pressure CO2 refrigerant will be ejected. The thrust generated by this ejection could cause the accumulator 30 to "launch" with great force, like a rocket. In this example, to prevent the accumulator 30 from "launching," the movement of the accumulator 30 is restrained by brackets 40, 42. This will be described in detail below.

[0030] The accumulator 30 is disposed, for example, in a power unit compartment at the front of the vehicle. The power unit compartment is a space in which the vehicle's power source (for example, an engine or a motor, or both) is disposed. In addition to the power source, this power unit compartment usually also contains part of the air conditioning device 10 (for example, the gas cooler 18 and the compressor 16). The accumulator 30 is disposed in this power unit compartment and attached to a fixed member 100 such as the vehicle body via brackets 40 and 42, which will be described later.

[0031] As shown in Figures 2 and 3, the accumulator 30 has a generally cylindrical shape that is elongated in the vertical direction. A main body 32 and a heat exchanger 34 are housed inside this cylindrical housing. Two connectors 36 are provided on the top surface of the accumulator 30. A third pipe P3 and a fourth pipe P4 are connected to the two connectors 36, respectively. The third pipe P3 and the fourth pipe P4 extend horizontally from the connectors 36 and then bend in the vertical direction.

[0032] Two connectors 36 are also provided on the bottom surface of the accumulator 30. A first pipe P1 and a second pipe P2 are connected to the two connectors 36, respectively. The first pipe P1 extends horizontally and then bends upward. The second pipe P2 extends horizontally from the connector 36 while bending several times, and is connected to the lower part of the gas cooler 18.

[0033] An upper bracket 40 and a lower bracket 42 are also attached to the accumulator 30. Both the upper bracket 40 and the lower bracket 42 are metal fittings for connecting the accumulator 30 to a fixing member 100 (see FIG. 3). The upper bracket 40 is configured by combining an annular bracket 44U that surrounds the outer periphery of the accumulator 30 with a mounting portion 62U. The annular bracket 44U sandwiches the body of the accumulator 30 between two semi-annular bodies 46. Each semi-annular body 46 has a flat plate portion 47 that protrudes radially outward from its circumferential end. The flat plate portions 47 of the two semi-annular bodies 46 are overlapped in the thickness direction and fastened together with bolts 50a. Note that although FIGS. 2 and 3 are simplified, the semi-annular bodies 46 actually have flanges 54 that protrude radially outward at their upper and lower ends, similar to the lower annular bracket 44L shown in FIG. 4. By providing the flanges 54 in this manner, the section modulus of the half-ring 46 is improved, and the rigidity of the half-ring 46 is improved.

[0034] 2 and 3, a portion of the flat plate portion 47 is further extended to form a mounting portion 62U that is directly or indirectly attached to a fixed member 100. In the example of FIGS. 2 and 3, the mounting portion 62U is generally L-shaped, extending upward from the flat plate portion 47 and then bending horizontally. The end of the mounting portion 62U is fastened to an intermediate bracket 76U by a bolt 50b. A rubber mount 52 is disposed between the mounting portion 62U and the intermediate bracket 76U, and the rubber mount 52 absorbs vibrations generated by the accumulator 30 and the vehicle. The intermediate bracket 76 is fastened to a fixed member 100 such as a vehicle body. The mounting portion 62U may be fastened directly to the fixed member 100 without using the intermediate bracket 76.

[0035] A lower bracket 42 is attached to the bottom of the accumulator 30. The lower bracket 42 is broadly divided into an annular bracket 44L, a shaft-side bracket 60, and a mounting portion 62L. Note that in Figure 2, the shaft-side bracket 60 and the mounting portion 62L are hidden by the accumulator 30 and cannot be seen.

[0036] The annular bracket 44L has substantially the same configuration as the annular bracket 44U of the upper bracket 40. That is, it has two half-annular bodies 46 that sandwich the accumulator 30, and these two half-annular bodies 46 are fastened together with bolts 50c. As shown in FIG. 4, each half-annular body 46 has flanges 54 that protrude radially outward from its upper and lower ends.

[0037] An attachment portion 62L is connected to the flange 54 extending from the upper end of the half-annular body 46, and an axle-side bracket 60 is connected to the flange 54 extending from the lower end. As shown in Figure 3, the attachment portion 62L extends from the annular bracket 44L and is connected to a fixed member 100 directly or indirectly via an intermediate bracket 76L. Although not visible in Figure 3, a rubber mount is provided at a fastening portion 104 between the intermediate bracket 76L and the fixed member 100, and vibrations are absorbed by this rubber mount.

[0038] 3 and 4, the shaft-side bracket 60 extends radially outward from the half-annular body 46, then continues downward, makes a U-turn, and extends radially inward. Therefore, the shaft-side bracket 60 has an overall angular U-shape. An end of the shaft-side bracket 60 is placed on the axial end face of the accumulator 30 and is connected to the accumulator 30 by bolts 50d.

[0039] As is clear from the above description, in this example, the annular brackets 44U, 44L and the shaft-side bracket 60 are attached to the accumulator 30. This more reliably prevents unintended movement of the accumulator 30. That is, as described above, if the accumulator 30 or the refrigerant pipes 14 around it are damaged due to a vehicle collision or the like, a strong gas injection pressure acts on the accumulator 30. There is a risk that this gas injection pressure could cause the accumulator 30 to be unintentionally "launched" with force like a rocket.

[0040] For example, consider a case where the fourth pipe P4 falls off the connector 36 at position B1 in FIG. 2. In this case, high-pressure CO2 refrigerant will spray out radially from the damaged area, potentially causing the accumulator 30 to be forcefully "launched" in the radial direction (i.e., the direction of arrow A1 in FIG. 2). However, in this example, annular brackets 44U and 44L are attached to the accumulator 30. The annular brackets 44U and 44L have surfaces that face the accumulator 30 in the radial direction (i.e., the launch direction). Therefore, even if the accumulator 30 attempts to move radially, the movement is restricted by the annular brackets 44U and 44L. As a result, the accumulator 30 is prevented from being "launched" in the radial direction.

[0041] Next, consider a case where the connector 36 itself comes off the accumulator 30 at position B2 in Figure 3. In this case, if the shaft-side bracket 60 were not present and only the annular brackets 44U and 44L were present, the accumulator 30 could come off the annular brackets 44U and 44L and be violently "launched" in the axial direction (i.e., the direction of arrow A2 in Figure 3). On the other hand, in this example, the shaft-side bracket 60 is attached to the axial end face of the accumulator 30. The shaft-side bracket 60 has a surface that faces the accumulator 30 in the axial direction (i.e., the launch direction). Therefore, even if the accumulator 30 attempts to move in the axial direction, the movement is restricted by the shaft-side bracket 60. As a result, the accumulator 30 is prevented from being "launched" in the axial direction.

[0042] As described above, in this example, by providing both the annular brackets 44U, 44L and the shaft-side bracket 60, the radial and axial movement of the accumulator 30 is restricted, effectively preventing unintended "firing" of the accumulator 30. Furthermore, the accumulator 30 is typically elongated in the axial direction and has a shape that makes it prone to tipping over. By attaching multiple (two in this example) annular brackets 44U, 44L spaced apart in the axial direction to the accumulator 30, tipping over of the accumulator 30 is effectively prevented. Furthermore, in this example, the shaft-side bracket 60 is integrated with the annular bracket 44L of the lower bracket 42. This eliminates the need for the shaft-side bracket 60 to extend to the fixing member 100, allowing the shaft-side bracket 60 to be made smaller.

[0043] The configuration described above is merely an example, and other configurations may be modified as appropriate as long as the configuration described in claim 1 is included. For example, in the above description, the shaft-side bracket 60 and the lower annular bracket 44L are integrated, but they may also be completely separate components. In this case, the shaft-side bracket 60 may also be provided with an attachment portion that is directly or indirectly connected to the fixing member 100. In the above description, the shaft-side bracket 60 is connected to the bottom surface of the accumulator 30, but it may also be connected to the top surface. In addition, the shape and number of the shaft-side bracket 60 and the annular brackets 44U, 44L may also be modified as appropriate. In addition, although the accumulator 30 in this example has a built-in heat exchanger 34, the attachment structure disclosed in this specification may be applied to an accumulator 30 that does not have a heat exchanger 34. [Explanation of symbols]

[0044] 10 air conditioning unit, 12 refrigerant circuit, 14 refrigerant piping, 16 compressor, 18 gas cooler, 19 fan, 20 blower fan, 22 heater core, 24 mode switching door, 26 cooling expansion valve, 27 evaporator, 28 PT sensor, 30 accumulator, 32 main body, 34 heat exchanger, 36 connector, 40 upper bracket, 42 lower bracket, 44L, 44U annular bracket, 46 half annular body, 47 flat plate portion, 50a, 50b, 50c, 50d bolt, 52 rubber mount, 54 flange, 60 shaft side bracket, 62L, 62U mounting portion, 70 unit case, 72 blowing mechanism, 76L, 76U intermediate bracket, 100 fixing member, 104 fastening portion, P1 first piping, P2 second piping, P3 Third pipe, P4 Fourth pipe.

Claims

1. an accumulator incorporated in an on-vehicle air conditioning system that separates a refrigerant containing CO2 as a main component into gas and liquid; two or more brackets for attaching the accumulator to a fixed member; The two or more brackets are an annular bracket that circumferentially surrounds the accumulator; a shaft-side bracket at least a portion of which is overlapped and coupled to an axial end surface of the accumulator; An accumulator mounting structure comprising:

2. The accumulator mounting structure according to claim 1, The mounting structure for an accumulator, wherein the two annular brackets are provided at an interval in the axial direction of the accumulator.

3. The accumulator mounting structure according to claim 1, one end of the shaft-side bracket is coupled to an axial end surface of the accumulator, and the other end of the shaft-side bracket is connected to the annular bracket and integrated with it; An accumulator mounting structure characterized by the above.

4. an accumulator incorporated in an on-vehicle air conditioning system that separates a refrigerant containing CO2 as a main component into gas and liquid; one or more brackets that attach the accumulator to a stationary member; wherein the one or more brackets hold the accumulator so as to restrict movement of the accumulator due to gas injection that occurs when the accumulator or a refrigerant pipe near the accumulator is damaged. An accumulator mounting structure characterized by the above.

5. The accumulator mounting structure according to claim 4, 10. The mounting structure for an accumulator, wherein the one or more brackets have a surface facing the accumulator in the direction of the gas injection.

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