JP2007032511A - Pressure reducing device for fluid machine, and fluid machine and refrigerating circuit using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure reducing device for a fluid machine for preventing the occurrence of clogging while sufficiently maintaining a pressure difference between chambers by connecting two chambers different in pressure to each other with a sufficient flow path cross section, and to provide the fluid machine and a refrigerating circuit using the same. <P>SOLUTION: The pressure reducing device for a compressor comprises a communication passage 130 for connecting a crank chamber 20 to a discharge chamber 70, and a pressure reducing unit 132 provided in the communication passage 130 for partitioning the communication passage 130 into a high pressure region 130a on the side of the discharge chamber 70 and a low pressure region 130b on the side of the crank chamber. The pressure reducing unit 132 includes a permeating member 136 for making lubricating oil in the high pressure region 130a permeate toward the low pressure region 130b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a decompression device for a fluid machine, a fluid machine using the decompression device, and a refrigeration circuit.

  For example, in a variable displacement swash plate compressor as a fluid machine applied to a refrigeration circuit of an automotive air conditioning system, a piston that receives power supply from a drive shaft via a swash plate and a shoe reciprocates in a cylinder bore. Accordingly, a series of processes including a suction process of refrigerant as a working fluid from the suction chamber into the cylinder bore, a compression process of the sucked working fluid, and a discharge process of the compressed working fluid from the cylinder bore to the discharge chamber are executed.

  The aforementioned swash plate can tilt with respect to the drive shaft, and the stroke length of the piston is increased or decreased by the pressure difference between the crank chamber and the suction chamber, thereby increasing or decreasing the capacity of the compressor. As such a compressor, the variable displacement swash plate compressor described in FIG. 1 of Patent Document 1 includes a pressure reducing device that reduces the pressure in the discharge chamber and then transmits it to the crank chamber in order to control the stroke length. I have.

  More specifically, the decompression device has a communication passage that communicates between the discharge chamber and the crank chamber, and a part of this communication passage is constituted by a through-passage of a cylinder block. An orifice filter is disposed in the through passage, and the working fluid in the discharge chamber flows out toward the crank chamber through the orifice tube of the orifice filter. At this time, since the working fluid discharged into the discharge chamber contains lubricating oil as refrigeration oil, the lubricating oil stored in the discharge chamber flows out together with the working fluid toward the crank chamber through the orifice tube, It is used for lubrication of the sliding part between the shoe and the bearing of the drive shaft.

Further, in this compressor, the crank chamber and the suction chamber can communicate with each other via a capacity control valve disposed in the center of the cylinder block. The capacity control valve is connected between the crank chamber and the suction chamber. It opens and closes autonomously based on the pressure difference.
Therefore, in this compressor, although the pressure in the discharge chamber is always transmitted to the crank chamber through the pressure reducing device, if the crank chamber and the suction chamber communicate with each other by the opening operation of the capacity control valve, the pressure in the crank chamber is sucked. Escape to the chamber and the pressure difference between the crank chamber and the suction chamber is reduced, thereby increasing the stroke length, ie the compressor capacity. On the other hand, when the displacement between the crank chamber and the suction chamber is interrupted by the closing operation of the capacity control valve, the pressure in the crank chamber rises and the pressure difference between the crank chamber and the suction chamber increases, and thus the compressor Capacity decreases.

When the above-described compressor compresses the HFC-based R134a refrigerant, the pressure in the discharge chamber rises to nearly 3 MPa when the compressor is activated. In the orifice filter that transmits the pressure in the discharge chamber to the crank chamber, the inner diameter of the orifice tube is about 0.3 mm.
JP 2003-49768 (paragraph number 0009, FIG. 1 etc.)

In recent years, in consideration of the global environment, development of a refrigeration circuit using a refrigerant having a low global warming potential has been promoted. An example of this type of refrigerant is natural CO ₂ (carbonic acid) gas. When CO ₂ gas is used as the refrigerant, the refrigerant pressure in the discharge chamber of the compressor of Patent Document 1 reaches about 15 MPa. In this case, in order to control the capacity of the compressor, the inner diameter of the orifice tube is reduced or the length thereof is extended, and the pressure difference between the discharge chamber and the crank chamber is in the range of about 3 MPa to 11 MPa. Must be kept in.

However, it is difficult to process the orifice tube with a smaller hole diameter, and even if the inner diameter is reduced, the cross-sectional area of the flow path is reduced, and the orifice tube is easily clogged. Further, when the length of the orifice tube is extended, there is a problem that it becomes difficult to accommodate the orifice tube in the through hole of the cylinder block. Due to the presence of such a problem, when CO ₂ gas is compressed by the compressor of Patent Document 1, a sufficient pressure difference between the discharge chamber and the crank chamber cannot be secured, and capacity control is difficult.

And, in a fluid machine such as a compressor, not only between the discharge chamber and the crank chamber, a pressure reducing device with a simple configuration capable of connecting two chambers (regions) while maintaining a large pressure difference sufficiently. Is needed.
The present invention has been made on the basis of the above-mentioned circumstances, and its object is to connect two chambers having different pressures with a sufficient flow path cross-sectional area with a simple configuration, thereby causing clogging. It is another object of the present invention to provide a decompression device for a fluid machine that can prevent the above-described problems and maintain a sufficient pressure difference between the chambers, a fluid machine using the decompression device, and a refrigeration circuit.

  In order to achieve the above object, according to the present invention, in a fluid machine including a low pressure chamber and a high pressure chamber that is higher in pressure than the low pressure chamber, the communication path connecting the low pressure chamber and the high pressure chamber is provided. And a decompression unit that is provided in the communication passage and divides the communication passage into a low-pressure region on the low-pressure chamber side and a high-pressure region on the high-pressure chamber side, and the decompression unit contains the fluid in the high-pressure region. There is provided a pressure reducing device for a fluid machine characterized by including a permeable member that allows permeation toward a low-pressure region (Claim 1).

As a preferred aspect, the permeable member includes a resin that allows the fluid to pass therethrough (Claim 2).
As a preferred aspect, the transmission member has a cylindrical shape having an open end and a closed end, and the decompression unit includes a gap between the outer peripheral surface of the transmission member and the inner peripheral surface of the communication path. It further includes an annular seal member that seals at a position spaced apart from the closed end when viewed in the axial direction.

As a preferred aspect, the decompression unit is provided in at least one of a region of the outer peripheral surface of the transmission member closer to the closing end than the seal member and a region of the inner peripheral surface of the communication path surrounding the region, It further includes a recess that forms a flow path for the fluid around the permeable member.
As a preferred aspect, a plurality of grooves are formed as the recesses in the region of the outer peripheral surface of the transmission member.

  According to the present invention, the decompression device for a fluid machine according to any one of claims 1 to 5, the discharge chamber for receiving working fluid discharged from a cylinder bore as the high-pressure chamber, and the low-pressure chamber And a crank chamber that includes a swash plate that is attached to the drive shaft so as to be tiltable and reciprocates the piston in the cylinder bore as the drive shaft rotates. Claim 6).

As a preferred aspect, the communication path has an inlet end opened at the bottom of the discharge chamber, and the fluid machine connects the discharge chamber and the crank chamber, and is located above the inlet end. A pressure transmission channel having an open end opened to the discharge chamber and an electromagnetic valve capable of opening and closing the pressure transmission channel are further provided.
Furthermore, according to the present invention, the pressure reducing device for a fluid machine according to any one of claims 1 to 5 and an oil for storing lubricating oil separated from a working fluid discharged from a scroll unit as the high pressure chamber. A fluid machine is provided that includes a chamber and a drive chamber that houses a swiveling unit for swiveling the movable scroll of the scroll unit as the low-pressure chamber.

The pressure in the low pressure chamber may exceed 3 MPa when the fluid machine is in operation (Claim 9).
Furthermore, according to the present invention, a circulation passage through which a refrigerant of CO ₂ circulates, and the refrigerant suction, compression, and discharge steps are executed by being inserted in the circulation passage. A refrigeration circuit comprising the fluid machine according to claim 10 is provided (claim 10).

  The decompression device for a fluid machine according to the first aspect of the present invention includes a permeable member that does not allow fluid to pass through like an orifice tube but allows fluid to permeate. The permeation amount of the fluid in the permeation member is regulated depending on the permeation coefficient (permeability) of the fluid possessed by the permeation member itself, even if the flow path cross-sectional area in the permeation member is sufficiently secured. For this reason, according to the decompression device of the fluid machine, the low pressure chamber and the high pressure chamber are connected with a sufficient pressure difference without clogging.

  In the case of the decompression device according to the second aspect, the fluid permeates the permeable member through the gap between the polymers constituting the resin. The resin is easy to mold, and the transmission member is easier to manufacture than the orifice tube. As a result, the productivity of this decompression device is high and its manufacturing cost is suppressed. In addition, since the resin is lighter than the metal, the pressure reducing device and thus the fluid machine can be reduced in weight.

In the decompression device according to the third aspect, since the fluid permeates not only the closed end of the permeable member but also the region of the permeable member closer to the closed end than the seal member in the radial direction, a larger flow path cross-sectional area is secured. .
In the case of the decompression device according to claim 4, even if the inner diameter of the communication path is small, the flow path is formed around the transmission member by providing the recess, so that the flow path around the transmission member is formed through this flow path. Fluid supply and discharge proceeds smoothly. For this reason, in this decompression device, the fluid smoothly permeates through the permeable member in the radial direction, thereby ensuring a sufficient flow path cross-sectional area.

In the decompression device according to the fifth aspect, since the concave portion is formed in the transmission member, it is easy to form the concave portion.
A fluid machine according to a sixth aspect of the present invention is a variable displacement swash plate compressor, and the stroke length of the piston is increased or decreased based on the pressure difference between the crank chamber and the suction chamber, thereby increasing or decreasing the capacity. In the case of this fluid machine, the pressure in the discharge chamber is sufficiently reduced and transmitted to the crank chamber without clogging the transmission member of the pressure reducing device, so that the capacity control is stably performed.

  Further, the amount of permeation through the permeable member depends on the pressure difference between the high pressure region and the low pressure region, and the fluid permeation amount increases as the pressure difference increases. Therefore, when the pressure in the discharge chamber of this fluid machine is likely to rise abnormally, the amount of fluid permeated increases and the pressure in the discharge chamber decreases, and the pressure in the crank chamber increases and the capacity is reduced. The For this reason, an abnormal pressure increase is prevented in this fluid machine.

Further, the fluid permeation coefficient of the permeation member has temperature dependence, and the permeation amount of the fluid increases as the temperature rises. Therefore, when the fluid machine is about to be overheated, the amount of fluid permeation increases and the crank chamber pressure rises, thereby reducing the capacity. For this reason, overheating is prevented in this fluid machine.
In the fluid machine according to claim 7, since the lubricating oil accumulated at the bottom of the discharge chamber always flows into the inlet end of the communication path while the fluid machine is operating, the transmission member of the decompression device transmits the lubricating oil exclusively. On the other hand, the working fluid in the discharge chamber passes through the pressure transmission flow path and flows into the crank chamber when the electromagnetic valve is opened. In this way, by supplying lubricating oil and working fluid to the crank chamber through separate paths, the pressure transmission from the discharge chamber to the crank chamber is based on the difference in pressure transmission speed in these paths. The working fluid flowing through the transmission channel is exclusively responsible. Although the pressure transmission passage is opened and closed by the electromagnetic valve, since the lubricating oil hardly flows through the pressure transmission passage, the working fluid is supplied to the crank chamber almost simultaneously with the opening of the electromagnetic valve. Therefore, in this fluid machine, the pressure of the discharge chamber is transmitted to the crank chamber at a high speed, and as a result, the response and accuracy of the capacity control are improved.

The fluid machine of the present invention according to claim 8 is a scroll compressor, and the lubricating oil in the oil chamber is used for lubrication of the swivel unit in the drive chamber. In the case of this fluid machine, a sufficient amount of lubricating oil is stably permeated without clogging the permeation member of the decompression device during operation, so that the lubrication state is kept good.
In the fluid machine according to claim 9, unlike the orifice tube through which the fluid passes, the permeable member transmits the fluid. Therefore, even if the pressure in the low pressure chamber exceeds 3 MPa and the pressure in the high pressure chamber is higher than the pressure in the low pressure chamber. The pressure in the high pressure chamber is sufficiently reduced before being transmitted to the low pressure chamber.

The refrigeration circuit of the present invention according to claim 10 is environmentally friendly because it uses a CO ₂ refrigerant with a low global warming potential. On the other hand, since the fluid machine of the refrigeration circuit includes a permeable member that allows fluid to pass therethrough, the pressure in the high-pressure chamber is sufficient even if the pressure in the high-pressure chamber is higher than that in the case of compressing the conventional HFC refrigerant. And then transmitted to the low pressure chamber.

FIG. 1 shows a schematic configuration of a refrigeration circuit according to an embodiment applied to an automotive air conditioning system. The refrigeration circuit includes, for example, a circulation flow path 2 that circulates a CO ₂ refrigerant (hereinafter simply referred to as a refrigerant) that is a natural refrigerant. In the circulation flow path 2, a compressor 4, a gas cooler 6, an expander 8, and an evaporator 10, which are fluid machines, are sequentially inserted in the refrigerant flow direction.
The compressor 4 is a variable displacement swash plate type and includes a cylinder block 12. A cylindrical casing 14 is integrally connected to an outer peripheral edge of one end surface of the cylinder block 12. The opening end of the casing 14 is airtightly attached by a bottom cover 18 using fastening bolts 16, and a crank chamber 20 is defined between the cylinder block 12 and the bottom cover 18.

  A drive shaft 22 is disposed in the crank chamber 20, and the drive shaft 22 is rotatably supported by the cylinder block 12 and the bottom cover 18 via bearings 24 and 26. One end of the drive shaft 22 protrudes to the outside through a cylindrical portion provided in the center of the bottom cover 18 and is connected to a driven unit of the electromagnetic clutch 28. A rotor 30 which is a drive side unit of the electromagnetic clutch 28 is rotatably supported by a cylindrical portion of the bottom cover 18 via a ball bearing 32 and transmits a power from the engine 36 to a pulley 34 formed on the outer periphery thereof. 37 is routed.

In addition, an annular swash plate 38 that is penetrated by the drive shaft 22 is accommodated in the crank chamber 20, and the swash plate 38 can be rotated together with the drive shaft 22 via the tilting unit, and the drive shaft. 22 can be tilted.
More specifically, the swash plate 38 is fitted to a cylindrical tilt rotor 39. The tilt rotor 39 is connected to a sleeve 40 disposed on the inner side thereof by using a pin 42 so as to be tiltable. The sleeve 40 is fitted to the drive shaft 22 so as to be reciprocally movable from the outside. A base rotor 46 is provided between the sleeve 40 and the bottom cover 18 with an urging spring 44 interposed therebetween. The base rotor 46 is fixed to the drive shaft 22 so as not to tilt.

  Both the tilt and base rotors 39 and 46 are integrally provided with arm portions 48 and 50 projecting toward the other rotor 46 and 39 at circumferential positions orthogonal to the axial direction of the pin 42, respectively. The rotors 39 and 46 are connected to each other via an engagement hole 52 and an engagement pin 54 formed at the tips of 48 and 50. Here, in order to allow the tilt rotor 39 to tilt and reciprocate with respect to the drive shaft 22, the engagement pin 54 extends in parallel with the pin 42, and the engagement hole 52 has an oval shape.

  A plurality of cylinder bores 56 are formed in the cylinder block 12 adjacent to the crank chamber 20, and the cylinder bores 56 penetrate the cylinder block 12 in the axial direction and are arranged at equal intervals in the circumferential direction. Pistons 58 are slidably fitted in the respective cylinder bores 56, and one ends of these pistons 58 project into the crank chamber 20 from the cylinder bores 56. A U-shaped tail portion 60 is formed at the protruding end of the piston 58, and the tail portion 60 sandwiches the outer peripheral edge of the swash plate 38 via a pair of shoes 62.

  A cylinder head 66 is airtightly fixed to the other end surface of the cylinder block 12 with a fastening bolt 16 via a valve plate 64. The cylinder head 66 has a cup shape opened toward the valve plate 64, and a discharge port connected to the forward path of the circulation flow path 2 and the circulation flow path 2 are not shown on the peripheral wall of the cylinder head 66. And a suction port connected to the return path.

An annular suction chamber 68 is defined in the cylinder head 66, and the suction chamber 68 is connected to the return path of the circulation flow path 2 through the aforementioned suction port. On the other hand, the suction chamber 68 communicates with each cylinder bore 56 via a plurality of suction holes 76 formed in the valve plate 64, and each suction hole 76 is opened and closed by a suction reed valve (not shown) from the cylinder bore 56 side. The
A discharge chamber 70 is defined in the cylinder head 66, and the discharge chamber 70 is surrounded by a suction chamber 68. The discharge chamber 70 is connected to the forward path of the circulation flow path 2 through the above-described discharge port, and communicates with each cylinder bore 56 through a plurality of discharge holes 80 formed in the valve plate 64. Is opened and closed from the discharge chamber 70 side by a discharge reed valve comprising a reed valve body (not shown) and a valve presser 82.

Further, a control valve chamber 86 is defined in the cylinder head 66 between the end wall of the cylinder head 66 and the discharge chamber and the suction chamber, and an electromagnetic valve 88 is disposed in the control valve chamber 86.
Here, FIG. 2 shows a schematic configuration of a pressure adjusting mechanism that controls the pressure of the crank chamber 20 together with the enlarged electromagnetic valve 88.
The electromagnetic valve 88 has an input port 90a, an output port 90b, and a pressure-sensitive port 90c, and regions of the control valve chamber 86 where the ports 90a, b, c are opened are airtightly separated from each other. The electromagnetic valve 88 includes a valve unit that can be intermittently connected between the input port 90a and the output port 90b, and an electromagnetic drive unit and a pressure drive unit that drive the valve unit in cooperation with each other.

More specifically, the input and output ports 90a and 90b are provided in the sleeve 92, and an input chamber and an output chamber in which the input and output ports 90a and 90b are opened are defined in the sleeve 92. The input chamber and the output chamber communicate with each other through a valve hole 94, the periphery of the opening of the valve hole 94 opened to the input chamber is formed as a valve seat, and a ball valve body 96 sits on the valve seat.
The tip of the connecting rod 98 abuts on the ball valve body 96 from the side opposite to the valve hole 94, and the base of the connecting rod 98 is connected to the front surface of the mover 100. The mover 100 is disposed at the center of the solenoid 104 in the solenoid housing 102, and a compression coil spring 106 is disposed between the back surface of the mover 100 and the end wall of the solenoid housing 102.

  When energized, the solenoid 104 generates an electromagnetic force that urges the mover 100 toward the valve hole 94, and power is supplied to the solenoid 104 from a drive circuit 108 provided outside the compressor 4. . The drive circuit 108 performs power supply by a control signal from an ECU (electronic control unit) 110 that performs overall control of the automotive air conditioning system, and various sensors 112 are electrically connected to the ECU 110. ECU 110 performs calculations based on various information obtained via sensor 112 and data stored in the memory, and causes drive circuit 108 to perform power supply based on the calculation results.

  On the other hand, the tip of the pressure-sensitive rod 114 is in contact with the ball valve body 96 through the valve hole 94. The pressure sensing rod 114 extends beyond the output chamber to the pressure sensing chamber 116 defined at the tip of the sleeve 92, and the base of the pressure sensing rod 114 is connected to a pressure sensor 118 disposed in the pressure sensing chamber 116. . The pressure sensing chamber 116 and the output chamber are hermetically separated, and a pressure sensing port 90 c is opened in the pressure sensing chamber 116.

  The pressure sensor 118 has a bellows, and both ends of the bellows are airtightly closed by caps that sandwich the compression coil spring 120 therebetween. The base of the pressure-sensitive rod 114 is connected to the outside of one cap, and the other cap is fixed to the end wall of the sleeve 92. Accordingly, although the pressure sensor 118 urges the ball valve body 96 in the valve opening direction via the pressure sensing rod 114, the magnitude of the urging force is determined by the urging force of the compression coil spring 120. The value is obtained by subtracting the pressure difference between inside and outside.

According to the electromagnetic valve 88 described above, when the force in the valve closing direction consisting of the electromagnetic force acting on the mover 100 and the biasing force of the compression coil spring 106 overcomes the force in the valve opening direction consisting of the biasing force of the pressure sensor 118. The ball valve body 96 is positioned at the valve closing position. On the other hand, when the force in the valve opening direction overcomes the force in the valve closing direction, the ball valve body 96 is positioned at the valve opening position.
Therefore, in this electromagnetic valve 88, when the pressure in the pressure sensing chamber 116 is equal to or lower than a predetermined pressure, even if the solenoid 104 is energized, the urging force of the pressure sensor 118 overcomes the force in the valve closing direction, and the ball valve body 96 Remains in the open position. Further, when the pressure in the pressure sensing chamber 118 is equal to or higher than a predetermined pressure, the force in the valve closing direction overcomes the urging force of the pressure sensor 118 without energizing the solenoid 104, and the ball valve body 96 is positioned at the closed position. It is done.

That is, the pressure sensor 118 constitutes a pressure drive unit, and the solenoid 104 and the mover 100 constitute an electromagnetic drive unit.
The region of the control valve chamber 86 where the input port 90a of the electromagnetic valve 88 is opened and the discharge chamber 70 communicate with each other via the input hole 122 formed in the cylinder head 66, while the output port 90b is opened. The region of the control valve chamber 86 and the crank chamber 20 are connected by an output path 124. In other words, the electromagnetic valve 88 is inserted into a flow path (pressure transmission flow path) connecting the crank chamber 70 and the discharge chamber 20, and the pressure transmission flow path includes the input hole 122 and the output path 124. The output path 124 includes a series of through holes formed in the cylinder block 12, the valve plate 64, and the cylinder head 66, respectively.

  The area of the control valve chamber 86 where the pressure sensing port 90c of the electromagnetic valve 88 is opened communicates with the suction chamber 68 via a pressure sensing hole 126 formed in the cylinder head 66, while The crank chamber 20 communicates with the crank chamber 20 via a decompression flow path 128. The decompression flow path 128 is composed of a series of through holes formed in the valve plate 64 and the cylinder head 66, respectively, and functions as a throttle because the flow path cross-sectional area is small.

Further, the compressor 4 includes a pressure reducing device for supplying the lubricating oil accumulated in the discharge chamber 70 to the crank chamber 20 as shown together with the pressure adjusting mechanism in FIG.
More specifically, the decompression device has a communication passage 130 that connects the discharge chamber 70 and the crank chamber 20, and the communication passage 130 is also configured by a series of through holes formed in the valve plate 64 and the cylinder head 66, respectively. Has been.

A decompression unit 132 is disposed in the communication path 130, and the decompression unit 132 divides the communication path 130 into a high pressure region 130 a on the discharge chamber 70 side and a low pressure region 130 b on the crank chamber 20 side, and fluid in the high pressure region 130 a. Can be supplied to the low-pressure zone 130b.
The compressor 4 is installed in the engine room of the vehicle so that the vertical direction of FIG. 1 substantially matches the vertical direction. For this reason, the open end (inlet end) of the communication passage 130 on the discharge chamber 70 side opens at the bottom of the discharge chamber 70 and is positioned below the open end of the input hole 122 that also opens into the discharge chamber 70. (See FIG. 1).

  FIG. 3 is an enlarged view of the decompression unit 132 and a part of the periphery thereof. The decompression unit 132 is disposed in the through hole 134 of the cylinder block 12 that constitutes the communication path 130. More specifically, the through hole 134 extends in parallel with the cylinder bore 56, and the decompression unit 132 is provided in the vicinity of the end of the cylindrical transmission member 136 fitted in the through hole 134 and the transmission member 136 on the discharge chamber 70 side. The O-ring 138 is disposed.

The transmitting member 136 is made of a glass fiber reinforced nylon resin, and the content of the nylon resin in the transmitting member 136 is 50% by mass or more. The transmission member 136 has a cylindrical peripheral wall 140, and the peripheral wall 140 has an open end on the discharge chamber 70 side, and has a closed end closed by an end wall 142 on the crank chamber 20 side.
As shown in FIG. 4, a circumferential groove 144 is formed on the outer peripheral surface of the peripheral wall 140 in the vicinity of the opening end. The aforementioned O-ring 138 is fitted in the circumferential groove 144 and seals between the outer peripheral surface of the transmissive member 136 and the inner peripheral surface of the through hole 134.

A plurality of grooves 146 are formed on the outer peripheral surface of the peripheral wall 140, and each groove 146 extends along the axial direction of the peripheral wall 140 from the front side of the peripheral groove 144 to the outer surface of the end wall 142. Between the grooves 146, lands 148 that also extend in the axial direction are formed, and each land 148 is in contact with the inner peripheral surface of the through hole 134.
Each groove 146 has an opening end opened at the outer surface of the end wall 142, and the depth of each groove 146 is deep with a step near the opening end. However, the hollow portion 140a surrounded by the peripheral wall 140 does not reach this step.

As shown in an enlarged view in FIG. 5, a reduced diameter portion 150 is formed in the inner peripheral surface of the through hole 134 in the vicinity of the opening on the crank chamber 20 side. Protruding. The reduced diameter portion 150 has an annular tapered surface 150a inward as viewed in the axial direction of the through-hole 134, and the corner portion 148a of the land 148 formed in an R shape contacts the tapered surface 150a.
The inner diameter of the tapered surface 150 a is gradually reduced from the end wall 142 toward the crank chamber 20, but the innermost peripheral portion of the open end of each groove 148 is tapered in the radial direction of the through hole 134. It is located inside the surface 150 a, that is, the reduced diameter portion 150, and faces the crank chamber 20 through the reduced diameter portion 150 in the axial direction of the through hole 134.

Hereinafter, the operation of the above-described refrigeration circuit will be described.
In this refrigeration circuit, when the compressor 4 is operated by receiving power supply from the engine 36, the compressor 4 sucks and compresses low-temperature and low-pressure gas refrigerant (CO ₂ refrigerant) from the return path of the circulation flow path 2 to increase the temperature. A high-pressure supercritical refrigerant is discharged to the forward path of the circulation channel 2. The discharged supercritical refrigerant is cooled when passing through the gas cooler 6 and its temperature is lowered. The refrigerant whose temperature has been reduced expands when passing through the expander 8, and its temperature and pressure are reduced to enter a gas-liquid mixed state. When the refrigerant in the gas-liquid mixed state flows into the evaporator 10, the liquid refrigerant in the gas-liquid mixed state vaporizes in the evaporator 10, and the gas refrigerant flows out of the evaporator 10. The gas refrigerant flowing out of the evaporator 10 is sucked into the compressor 4 through the return path of the circulation flow path 2.

  In addition, in the vicinity of each of the gas cooler 6 and the evaporator 10, a heat dissipating fan and a cooling fan (not shown) that form air passing outside the gas cooler 6 and the evaporator 10 are arranged, respectively, and the gas cooler 6 blows air. By receiving, the refrigerant | coolant which passes the gas cooler 6 is cooled. Further, the air passing through the evaporator 10 is deprived of vaporization heat by the liquid refrigerant in the evaporator 10 and becomes cold air, and the cold air is blown out to the vehicle interior, thereby cooling the vehicle interior.

Hereinafter, the operation of the compressor 4 will be described in detail.
When the engine 36 is operated, power from the engine 36 is transmitted to the pulley 34 of the compressor 4 via the belt 37. When the electromagnetic clutch 28 is turned on at this time, the pulley 34 is driven integrally. The shaft 22 is rotationally driven. Along with the rotation of the drive shaft 22, the swash plate 38 is also rotationally driven through the base rotor 46 and the tilt rotor 39, and the rotational motion of the swash plate 38 is converted into the reciprocating motion of the piston 58 through the shoe 62. . By the reciprocating motion of each piston 58, the suction process in which the refrigerant in the suction chamber 68 is sucked into the cylinder bore 56 through the suction valve, the compression process in which the refrigerant is compressed in the cylinder bore 56, and the compressed refrigerant is discharged into the discharge lead. A discharge step of discharging into the discharge chamber 70 through the valve is performed.

While the compressor 4 is performing the above-described suction, compression, and discharge steps, the ECU 110 opens and closes the electromagnetic valve 88 via the drive circuit 108 based on information from the sensor 112, thereby circulating from the compressor 4. The amount of compressed refrigerant discharged in the forward path of the flow path 2 is adjusted.
More specifically, when reducing the discharge amount of the refrigerant, the solenoid valve 88 is opened, and one of the compressed refrigerant in the discharge chamber 70 is directed from the discharge chamber 70 to the crank chamber 20 through the input hole 122 and the output path 124. Supply part. As a result, when the pressure (back pressure) in the crank chamber 20 becomes larger than the pressure in the suction chamber 68, that is, the pressure in the cylinder bore 56 performing the suction process, the front (valve plate) 64 side) is applied. For this reason, the stroke length of the piston 58 is reduced, and the amount of compressed refrigerant discharged from each cylinder bore 56 into the discharge chamber 70 is reduced.

Since the forward biasing force applied to the piston 58 is also transmitted to the swash plate 38 via the tail portion 60, the swash plate 38 is parallel to a virtual plane orthogonal to the drive shaft 22 by this biasing force. Tilt to approach
On the other hand, when the discharge amount of the refrigerant is increased, the solenoid valve 88 is closed and the supply of the compressed refrigerant from the discharge chamber 70 to the crank chamber 20 is shut off. Here, since the crank chamber 20 is always in communication with the suction chamber 68 via the decompression flow path 128 having a function as a throttle, the pressure in the crank chamber 20 gradually decreases to the pressure of the suction chamber 68. Therefore, since the forward biasing force applied to the piston 58 is reduced, the stroke length of the piston 58 is increased, and the discharge amount of the compressed refrigerant from each cylinder bore 56 into the discharge chamber 70 is increased.

As the forward biasing force applied to the piston 58 decreases, the swash plate 38 tilts with respect to a virtual plane orthogonal to the drive shaft 22.
The solenoid valve 88 autonomously opens and closes separately from the control by the ECU 110.
For example, when the refrigerant discharge amount becomes excessive, the refrigerant pressure after being vaporized in the evaporator 10 is reduced, and the pressure in the suction chamber 68 is extremely reduced, the electromagnetic valve 88 is connected to the pressure through the pressure sensing hole 126. It senses the drop and opens automatically. That is, the pressure sensor 118 extends due to the pressure drop in the pressure sensing chamber 116, and the ball valve body 96 is biased in the valve opening direction via the pressure sensing rod 114. Thereby, a part of the compressed refrigerant is supplied from the discharge chamber 70 into the crank chamber 20 through the input hole 122 and the output path 124, and the discharge amount is reduced.

  In addition, when the heat load on the evaporator 10 increases, the refrigerant pressure evaporated in the evaporator 10 increases, and the pressure in the suction chamber 68 rises extremely, the electromagnetic valve 88 passes through this pressure-sensitive hole 126 to this pressure. Senses ascent and closes autonomously. That is, the pressure sensor 118 is shortened by the pressure increase in the pressure sensing chamber 116 and is urged in the valve closing direction by the compression coil spring 106. Thereby, supply of the compressed refrigerant from the discharge chamber 70 to the crank chamber 20 through the input hole 122 and the output path 124 is shut off, and the discharge amount increases.

On the other hand, while the compressor 4 performs the above-described suction, compression, and discharge processes, the lubricating oil accumulated at the bottom of the discharge chamber 70 is removed from the crank chamber 20 via the pressure reducing unit 132 disposed in the communication path 130. And is used for lubricating the drive shaft 22, piston 58, swash plate 38, tilting unit and the like in the crank chamber 20.
In the decompression unit 132, since the space between the outer peripheral surface of the cylindrical transmission member 136 and the inner peripheral surface of the through hole 134 is sealed by the O-ring 138, the lubricating oil that has flowed out of the discharge chamber 70 is retained in the transmission member 136. It flows into the hollow part 140a surrounded by the peripheral wall 140. Based on the pressure difference between the discharge chamber 70 and the crank chamber 20, the lubricating oil that has flowed into the hollow portion 140 a permeates the end wall 142 in the axial direction and permeates the peripheral wall 140 in the radial direction.

  The lubricating oil that has passed through the end wall 142 oozes out from the outer surface of the end wall 142 and the stepped surface of the groove 146, while the lubricating oil that has passed through the peripheral wall 140 a in the radial direction oozes out from the bottom surface of the groove 146 and oozes out the lubricating oil. The oil flows in the groove 146 toward the end wall 142 side. Then, the lubricating oil that has flowed through the groove 146 merges with the lubricating oil that has oozed out of the step surface, and further merges with the lubricating oil that has oozed out from the outer surface of the end wall 142. It flows into the crank chamber 20 through the reduced diameter portion 150 of the through hole 134.

Here, when the permeation amount of the lubricating oil in the permeation member 136 is Q, the permeation amount Q can be estimated based on the following equation (1).
Q = S × (1 / E) × κ × ΔP × τ (1)
In the equation, S is a transmission area, E is a transmission thickness, κ is a transmission coefficient, ΔP is a pressure difference, τ is a transmission time, and the pressure difference ΔP is the pressure P _{high in the} discharge chamber 70, that is, the high pressure region 130a. And the pressure P _low of the suction chamber 20, that is, the low pressure region 130 b (ΔP = P _high −P _low ).

Further, the transmission coefficient κ depends on the material of the transmission member 136 and also on the temperature T as shown in the following equation (2).
logκ = A + B / T (2)
However, A represents a positive constant (A> 0), and B represents a negative constant (B <0).
The refrigeration circuit described above is environmentally friendly because it uses a CO ₂ refrigerant with a low global warming potential.

  On the other hand, in the compressor 4 applied to the refrigeration circuit, the lubricating oil accumulated at the bottom of the discharge chamber 70 always flows into the inlet end of the communication passage 130 while the compressor 4 is operating. The decompression unit 132 allows only the lubricating oil to pass therethrough, while the refrigerant in the discharge chamber 70 passes through the pressure transmission channel, that is, the input hole 122 and the output channel 124 when the electromagnetic valve 88 of the pressure adjusting mechanism is opened. It flows into the crank chamber 20.

  As described above, the lubricating oil and the refrigerant are supplied to the crank chamber 20 through different paths, so that the pressure transmission from the discharge chamber 70 to the crank chamber 20 is caused by the difference in the pressure transmission speed in these paths. Based on this, the refrigerant flowing through the pressure transmission channel is exclusively responsible. Although the pressure transmission flow path is opened and closed by the electromagnetic valve 88, the lubricating oil hardly flows through the pressure transmission flow path, so that the refrigerant is supplied to the crank chamber 20 almost simultaneously with the opening of the electromagnetic valve 88. Therefore, in this compressor 4, the pressure of the discharge chamber 70 is transmitted to the crank chamber 20 at a high speed, and as a result, the capacity control response is high.

  Further, it is assumed that the fluid discharged from the cylinder bore 56 to the discharge chamber 70 is a mixture of supercritical refrigerant and lubricating oil having different densities, and this mixture is supplied to the crank chamber 20 through the electromagnetic valve 88. In this case, even if the opening degree of the electromagnetic valve 88 is constant, the flow rate of the mixture passing through the electromagnetic valve 88 changes due to the variation in the mixing ratio between the refrigerant and the lubricating oil in the mixture, and the accuracy of capacity control is low. Become. On the other hand, in this compressor 4, since the refrigerant passes exclusively through the electromagnetic valve 88, the flow rate of the refrigerant passing through the electromagnetic valve 88 can be accurately adjusted by controlling the opening degree of the electromagnetic valve 88. As a result, the accuracy of capacity control is high.

  Further, the decompression unit 132 of the decompression device includes a transmission member 136 that allows the lubricating oil to pass therethrough, instead of an orifice tube that allows the lubricating oil to pass therethrough. The permeation amount Q of the lubricating oil in the transmissive member 136 is such that the transmittance κ of the transmissive member 136 itself and the thickness of the peripheral wall 140 and the end wall 142 are sufficient even if the cross-sectional area of the hollow portion 140a in the transmissive member 136 is sufficiently secured. Regulated depending on E.

  Therefore, according to the decompression unit 132, even if the pressure in the crank chamber 20 exceeds 3 MPa and the pressure in the discharge chamber 70 is higher than the pressure in the crank chamber 20, the gap between the discharge chamber 70 and the crank chamber 20 is clogged. Without being connected, with a pressure difference in the range of approximately 3 MPa to 11 MPa. For this reason, in the case of the compressor 4, the capacity control by the pressure adjusting mechanism is stably performed, and at the same time, the lubrication state is kept good.

  According to the decompression unit 132 of this decompression device, the lubricating oil penetrates not only the end wall 142 of the transmission member 136 but also the region of the peripheral wall 140 closer to the end wall 142 than the O-ring 138 in the radial direction. Lubricating oil permeates almost the entire inner peripheral surface of the peripheral wall 140, and a permeation area (channel cross-sectional area) is sufficiently secured. For this reason, a sufficient amount of lubricating oil is supplied to the crank chamber 20 through the decompression unit 132.

  And according to the decompression unit 132 of this decompression device, since the glass fiber reinforced resin is easy to mold, the production of the transmissive member 136 is easier than the production of the metal orifice tube. As a result, the productivity of the transmitting member 136 is high, and the manufacturing cost is suppressed. In addition, since the glass fiber reinforced resin is lighter than metal, the pressure adjustment mechanism, and thus the compressor 4 can be reduced in weight.

  Further, in this decompression device, although the through hole 134 has a small inner diameter, the groove 146 is provided on the outer peripheral surface of the peripheral wall 140 of the transmission member 136, thereby forming a lubricating oil flow path around the transmission member 136. ing. Therefore, the lubricating oil that has permeated in the radial direction through the transmission member 136 flows smoothly toward the crank chamber 20 through the groove 146. As a result, in this permeable member 136, the permeation of the lubricating oil in the radial direction also proceeds smoothly, thereby ensuring a sufficient flow path cross-sectional area.

Further, in this decompression device, the groove 146 is integrally formed on the outer peripheral surface of the peripheral wall 140 of the transmission member 136, and a lubricating oil flow path is easily formed around the transmission member 136.
On the other hand, the permeation amount Q of the lubricating oil through the permeation member 136 depends on the pressure difference ΔP between the high pressure region 130a and the low pressure region 130b, and the permeation amount Q of the lubricating oil increases as the pressure difference ΔP increases. Increase. Therefore, when the pressure in the discharge chamber 70 is likely to rise abnormally, the permeation amount Q of the lubricating oil is increased to suppress the pressure increase in the discharge chamber, and the pressure in the crank chamber 20 is increased to increase the capacity. Reduced. For this reason, this compressor 4 prevents an abnormal pressure increase.

And the permeation coefficient κ of the lubricating oil in the permeable member 136 has temperature dependence, and as the temperature T increases, the permeation amount Q of the lubricating oil increases. Therefore, when the compressor 4 is about to be overheated, the permeation amount Q of the lubricating oil is increased and the pressure in the crank chamber 20 is increased, thereby reducing the capacity. For this reason, this compressor 4 prevents overheating.
The present invention is not limited to the above-described embodiment, and various modifications can be made.

For example, in the refrigeration circuit of the above-described embodiment, the CO ₂ refrigerant circulates as the refrigerant. However, the type of the refrigerant is not particularly limited, and an HFC refrigerant or the like may be used as the refrigerant.
In the compressor 4 according to the above-described embodiment, the crank chamber 20 and the suction chamber 68 are always in communication with each other through the decompression flow path 128 having a function as a throttle. However, as shown in FIG. Are connected by a decompression channel 160 having a larger cross-sectional area than the decompression channel 128, and a low-pressure side electromagnetic valve 162 for opening and closing the decompression channel 160 is inserted in the decompression channel 160. Good. In this case, the opening / closing operation of the low-pressure side electromagnetic valve 162 is also controlled by the ECU 110 via the drive circuit 108, and the opening degree of the decompression flow path 160 is adjusted by the ECU 110. For this reason, even if the pressure of the crank chamber 20 exceeds 3 MPa, the inner diameter of the decompression flow path 160 may be large, and the formation of the decompression flow path 160 is easier than the formation of the decompression flow path 128. .

  In the compressor 4 according to the embodiment described above, the space between the discharge chamber 70 and the crank chamber 20 includes the input hole 122 and the output path 124, the pressure transmission flow path through which the refrigerant exclusively flows, and the continuous flow through which the lubricating oil flows exclusively. Although connected with the passage 130, the input hole 122, the output passage 124, and the electromagnetic valve 88 are omitted as shown in FIG. 7, and the pressure in the crank chamber 20 is adjusted by opening and closing the low-pressure side electromagnetic valve 162. It may be.

  In this case, the position of the opening end of the communication passage 130 in the discharge chamber 70 is appropriately selected so that the refrigerant and the lubricating oil in the discharge chamber 70 are supplied to the crank chamber 20 through the communication passage 130, and the vertical direction in FIG. It is not necessary to install the compressor 4 in the engine room so as to match the above. Since the refrigerant is allowed to permeate, the material of the permeable member 136 and the shape such as the thickness E of the peripheral wall 140 and the end wall 142 are appropriately selected in order to optimize the permeability coefficient κ.

That is, the permeation member 136 of the decompression unit 132 not only allows the lubricant (liquid) to permeate, but also allows a mixture of the refrigerant (fluid) and the lubricant in a supercritical state or a gas state to permeate. Can pass through the refrigerant exclusively.
However, when the permeable member 136 transmits only the lubricating oil, the lubricating oil may contain a small amount of refrigerant. When the transmitting member 136 transmits only the refrigerant, the refrigerant may include a small amount of refrigerant. Of course there is.

Furthermore, although the variable capacity swash plate compressor 4 is applied to the refrigeration circuit of the above-described embodiment, the scroll compressor 170 illustrated in FIG. 8 may be applied.
The scroll compressor 170 includes a housing 172, and the housing 172 includes a drive casing 174 and a compression casing 176. The drive and compression casings 174 and 176 are connected to each other by a plurality of connection bolts 178. The compressor 170 is also installed in the engine room of the vehicle so that the vertical direction in FIG. 1 substantially coincides with the vertical direction because the lubricating oil is stored in the bottom of the compression casing 176 as will be described later. The

  A drive shaft 180 is disposed in the drive casing 174, and the drive shaft 180 has a large diameter end portion 182 on the compression casing 176 side, and a small diameter shaft portion 184 extends from the large diameter end portion 182. A needle bearing 186 and a ball bearing 188 are interposed between the drive casing 174 and the large-diameter end portion 182 and the small-diameter shaft portion 184, and the drive shaft 180 is rotatable to the drive casing 174 via these bearings 186 and 188. It is supported.

Further, a lip seal 190 is attached to the small-diameter shaft portion 184 between the ball bearing 188 and the large-diameter end portion 182. The lip seal 190 is slidably contacted with the small-diameter shaft portion 184 so that the inside of the drive casing 174 is airtight. It is divided into.
A small diameter shaft portion 184 of the drive shaft 180 protrudes from the drive casing 174, and a driven unit of the electromagnetic clutch 192 is attached to the protruding end. Here, although the type of the electromagnetic clutch 192 is different from the type of the electromagnetic clutch 28, the configuration thereof is substantially the same, so members having the same function are denoted by the same reference numerals and description thereof is omitted. .

On the other hand, although not shown, the compression casing 176 is formed with a suction port and a discharge port on its peripheral wall, and the suction port and the discharge port are connected to the evaporator 10 or the gas cooler 6 of the refrigeration circuit via the circulation flow path 2. Is done.
A scroll unit 194 is accommodated in the compression casing 176, and a drive chamber 196 is formed between the scroll unit 194 and the inner end wall of the drive casing 174, and the scroll unit 194 and the outer peripheral wall of the compression casing 176 are formed. A suction chamber 198 communicating with the suction port of the compression casing 176 is formed therebetween.

The scroll unit 194 includes a movable scroll 200 and a fixed scroll 202, and each of the movable and fixed scrolls 200 and 202 includes a substrate 204 and a spiral wall 206 formed integrally with the substrate 204, respectively.
The movable and fixed scrolls 200 and 202 are arranged so that the spiral walls 206 are engaged with each other, and a compression chamber 208 is formed between them via a tip seal provided at the tip of the spiral wall 206. The movable scroll 200 can be swiveled with respect to the fixed scroll 202, and the compression chamber 208 is moved along the spiral wall 206 from the radially outer side of the substrate 204 toward the center portion along with the swirl movement. During this movement, the volume of the compression chamber 208 gradually decreases and becomes minimum at the center of the substrate 204.

  In order to impart a turning motion to the movable scroll 200 described above, a turning unit is disposed in the drive chamber 196. More specifically, the movable scroll 200 and the large-diameter end 182 of the drive shaft 180 are connected to each other via a needle bearing 210, an eccentric bush 212, and a crank pin 214, and between the movable scroll 200 and the drive casing 174. A ball-type orbiting thrust bearing 216 that prevents the movable scroll 200 from rotating is disposed. Reference numeral 218 in FIG. 1 indicates a counterweight, and this counterweight 218 is attached to the eccentric bush 212.

On the other hand, the fixed scroll 202 is fixed in the compression casing 176 via a plurality of fixing bolts (not shown). Between the fixed scroll 202 and the end wall 176a of the compression casing 176, the discharge chamber 220 and the oil chamber 222 are provided. Are partitioned vertically via a partition wall 224.
In addition, an oil separation chamber 226 is defined in the discharge chamber 220. More specifically, a cylindrical partition wall 228 extends vertically from the partition wall 224 to the outer peripheral wall of the compression casing 176 along the end wall 176a, and the oil separation pipe 230 is concentrically within the partition wall 228. It is fixed. The oil separation chamber 226 is formed by a region of the partition wall 228 below the large diameter end 231 of the oil separation pipe 230. Although the upper end of the partition wall 228 is closed by the seal bolt 232, a horizontal hole 234 connected to the discharge port is opened on the inner peripheral surface of the partition wall 228 between the seal bolt 232 and the oil separation pipe 230. is doing.

  The discharge chamber 220 communicates with the upstream compression chamber 208 via a discharge valve 236, and communicates with the downstream oil separation chamber 226 via two introduction holes 238 formed in the partition wall 228. That is, the compression chamber 208 is connected to the discharge port via the discharge chamber 220 and the oil separation chamber 226. The discharge valve 236 includes a discharge hole 240 serving as a valve hole provided through the central portion of the substrate 204 of the fixed scroll 202, a reed valve body 242 for opening and closing the discharge hole 240, and an opening of the reed valve body 242. And a stopper plate 244 for regulating the degree.

On the other hand, the oil separation chamber 226 communicates with the oil chamber 222 through a bottom hole 245 formed in the partition wall 224, and a communication path provided in the fixed scroll 202 between the oil chamber 222 and the drive chamber 196. 246 to communicate with each other.
More specifically, the portion of the spiral wall 206 of the fixed scroll 202 located near the bottom of the compression casing 176 is formed as a thick wall portion 206a, and the communication path 246 has the thick wall portion 206a parallel to the drive shaft 180. It is constituted by a through hole 248 penetrating in the direction. In addition, the above-described decompression unit 132 is disposed in the communication path 246.

According to the scroll compressor 170 described above, the movable scroll 200 orbits through the crankpin 214 and the eccentric bush 212 as the drive shaft 180 rotates. Along with this turning motion, the compression chamber 208 performs the following process.
The compression chamber 208 moves toward the central portion in the radial direction after sucking the refrigerant through the suction port and the suction chamber 198 at the outer peripheral portion of the scroll unit 194. During this movement, the sucked refrigerant is compressed due to the volume reduction of the compression chamber 208, and the compressed refrigerant is discharged to the discharge chamber 220 through the discharge valve 236.

Then, the compressed refrigerant flows from the discharge chamber 220 into the oil separation chamber 226 through the introduction hole 238 and flows downward so as to turn in the annular space in the oil separation chamber 226. At this time, the mist-like lubricating oil contained in the refrigerant is centrifuged and adheres to the inner peripheral surface of the partition wall 228, and the separated lubricating oil descends due to its own weight and flows into the oil chamber 222 through the bottom hole 245. To do.
The compressed refrigerant from which the lubricating oil is thus separated flows into the oil separation pipe 230 from the lower end of the oil separation pipe 230 and rises, and is supplied to the gas cooler 6 of the refrigeration circuit through the discharge port.

On the other hand, the lubricating oil stored in the oil chamber 222 utilizes the pressure difference between the drive chamber 196 and the oil chamber 222, permeates the permeation member of the decompression unit and is circulated into the drive chamber 196, and the swivel unit is It supplies to each sliding part, such as the needle bearing 210 which comprises. That is, the lubricating oil filtered by passing through the transmission member is supplied to the drive chamber 196.
When the scroll compressor 170 is in operation, the transmission member 136 of the decompression unit 132 maintains a pressure difference between the oil chamber 222 and the drive chamber 196 and supplies a sufficient amount of lubricating oil without clogging. In order to make it permeate | transmit stably, a lubricating state is kept favorable.

That is, the decompression unit 132 can be applied to various fluid machines, and is not limited to the connection between the discharge chamber 70 and the crank chamber 20, but connects two chambers having different pressures while maintaining a pressure difference. Can be applied to.
In any of the above-described embodiments, the transmitting member 136 is cylindrical. However, the transmitting member may be a rectangular tube, and the lubricating oil is transmitted through the peripheral wall 140 toward the radially inner side. In addition, the transmission member 136 may be disposed in the through hole 134 in the reverse direction. If there is an installation space, the transmission member may be a flat plate shape, and the seal member of the decompression unit 132 is not limited to the O-ring 138.

In any of the above-described embodiments, a groove as a recess that forms a flow path around the transmission member 136 may be formed on the inner peripheral surface of the through holes 134 and 248. If the diameter is sufficiently larger than the outer diameter of the transmission member 136, the recesses need not be provided on both sides.
In any of the above-described embodiments, the transmitting member 136 is made of glass fiber reinforced nylon resin. However, the material of the transmitting member 136 is the pressure difference between the two chambers to be connected while maintaining the pressure difference. For example, a transmissive member made of a sintered metal or ceramics may be used. In the case of the transmissive member 136, the content ratio of the nylon resin in the glass fiber reinforced nylon resin is preferably 50% by mass or more in order to provide an appropriately large transmittance κ.

It is the figure which showed schematic structure of the refrigerating circuit of one Example of this invention with the longitudinal cross-section of the compressor. It is the figure which showed schematic structure of the pressure adjustment mechanism and pressure reduction apparatus in the compressor of FIG. 1 with the longitudinal cross-section of the solenoid valve of a pressure adjustment mechanism. It is the figure which expanded and showed the vicinity of the pressure reduction unit in the compressor of FIG. 3 shows a transmission member applied to the decompression unit of FIG. 3, (a) is a perspective view, (b) is a front view, and (c) is a cross-sectional view. FIG. 4 is an enlarged view of the vicinity of the opening end of the through hole on the crank chamber side in FIG. 3. It is the figure which showed schematic structure of the pressure adjustment mechanism and pressure reduction apparatus of the modification applied to the compressor of FIG. 1 with the longitudinal cross-section of the solenoid valve of a pressure adjustment mechanism. It is the figure which showed schematic structure of the pressure adjustment mechanism which concerns on the other modification applied to the compressor of FIG. It is the figure which showed the longitudinal cross-section of the compressor of the modification applied to the refrigeration circuit of FIG.

Explanation of symbols

4 Compressor 20 Crank chamber 70 Discharge chamber 88 Solenoid valve 130 Communication path 132 Pressure reducing unit 134 Through hole 136 Transmission member 138 O-ring (seal member)
140 peripheral wall 142 end wall 146 groove (recess)
148 rand

Claims (10)

In a fluid machine having a low-pressure chamber and a high-pressure chamber that becomes higher pressure during operation than the low-pressure chamber,
A communication path connecting the low pressure chamber and the high pressure chamber;
A pressure reducing unit that is provided in the communication path and divides the communication path into a low pressure region on the low pressure chamber side and a high pressure region on the high pressure chamber side;
The decompression unit is
A pressure reducing device for a fluid machine, comprising: a transmission member that allows the fluid in the high-pressure region to permeate toward the low-pressure region.   The pressure reducing device for a fluid machine according to claim 1, wherein the transmission member includes a resin that allows the fluid to pass therethrough. The transmission member has a cylindrical shape having an open end and a closed end,
The decompression unit is
It further includes an annular seal member that seals between the outer peripheral surface of the transmission member and the inner peripheral surface of the communication path at a position spaced from the closed end when viewed in the axial direction of the transmission member. The decompression device for a fluid machine according to claim 1 or 2. The decompression unit is
Provided in at least one of a region of the outer peripheral surface of the transmission member closer to the closed end than the seal member and a region of the inner peripheral surface of the communication path surrounding the region, and the flow of the fluid around the transmission member The pressure reducing device for a fluid machine according to claim 3, further comprising a recess that forms a path.   The pressure reducing device for a fluid machine according to claim 4, wherein a plurality of grooves are formed as the recesses in the region of the outer peripheral surface of the transmission member. A decompression device for a fluid machine according to any one of claims 1 to 5,
A discharge chamber for receiving the working fluid discharged from the cylinder bore as the high-pressure chamber;
A fluid machine comprising: a crank chamber containing a swash plate for reciprocating a piston in the cylinder bore as the low-pressure chamber. The communication path has an inlet end opened at the bottom of the discharge chamber;
The fluid machine is:
A pressure transmission flow path having an open end connected to the discharge chamber and the crank chamber, the upper end being open to the discharge chamber above the inlet end;
The fluid machine according to claim 6, further comprising an electromagnetic valve capable of opening and closing the pressure transmission flow path. A decompression device for a fluid machine according to any one of claims 1 to 5,
As the high-pressure chamber, an oil chamber for storing lubricating oil separated from the working fluid discharged from the scroll unit;
A fluid machine comprising: a drive chamber containing a swiveling unit for swiveling the movable scroll of the scroll unit as the low pressure chamber.   The fluid machine according to any one of claims 6 to 8, wherein the pressure of the low-pressure chamber exceeds 3 MPa when the fluid machine is operated. A circulation passage through which the CO ₂ refrigerant circulates;
A refrigeration circuit comprising the fluid machine according to any one of claims 6 to 9, wherein the fluid machine is interposed in the circulation flow path and executes the suction, compression, and discharge steps of the refrigerant.

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