WO2017115715A1

WO2017115715A1 - Compressor

Info

Publication number: WO2017115715A1
Application number: PCT/JP2016/088364
Authority: WO
Inventors: 剛古西
Original assignee: 株式会社ヴァレオジャパン
Priority date: 2015-12-28
Filing date: 2016-12-22
Publication date: 2017-07-06
Also published as: EP3415756A4; JP6857946B2; EP3415756B1; JPWO2017115715A1; EP3415756A1

Abstract

[Problem] Provided is a compressor provided with a valve mechanism that increases the speed of startup of the compressor by reducing the pressure differential between a suction intake port and a suction intake chamber when the compressor is shut down, while suppressing the propagation of pressure pulsations when the flow rate is low. [Abstract] A non-return valve forming body 30 is provided with: a valve housing 31 which includes internally a valve body accommodating space 32, and which is provided with an inflow opening 38 communicating with the suction intake port, and an outflow opening 39 communicating with the suction intake chamber; a valve body 41 which is accommodated in the valve body accommodating space 32 and which is capable of causing the state of communication between the inflow opening 38 and the outflow opening 39 to change; and a spring 51 which urges the valve body 41 in a direction in which communication between the inflow opening 38 and the outflow opening 39 is interrupted. The valve housing 31 fits loosely into an annular groove 26 formed in a cylinder head 4, allowing the valve housing 31 to move in an axial direction. In a state in which the valve housing 31 abuts a peripheral edge portion on the suction intake chamber side of the annular groove 26, the valve housing 31 interrupts the flow of working fluid outside the valve housing 31, and in a state in which the valve housing 31 is separated from the peripheral edge portion on the suction intake chamber side of the annular groove 26, the working fluid is allowed to flow outside the valve housing 31.

Description

Compressor

The present invention relates to a compressor having a valve mechanism that varies the opening degree of a suction passage extending from a suction port to a suction chamber, and more particularly, to a compressor that is accelerated.

In the piston type compressor, a stopper having a predetermined depth is formed at a position facing the tip of the suction valve of the cylinder block, and when the refrigerant gas is sucked into the cylinder bore, the tip of the suction valve is the stopper. The suction valve is prevented from causing self-excited vibration.

However, when the amount of gas sucked into the cylinder bore is small, the amount of displacement of the suction valve is so small that the tip of the suction valve does not hit the stopper. For this reason, the suction valve causes self-excited vibration, which causes pressure pulsation in the suction chamber. This pressure pulsation propagates through the suction path of the system and reaches the evaporator, and this evaporator is vibrated to generate abnormal noise. There is a disadvantage of generating.

Therefore, conventionally, in order to reduce the propagation of pressure pulsation to the evaporator, an opening adjustment valve for adjusting the opening of this passage is arranged in the suction passage from the suction port of the compressor to the suction chamber. I have to.

As such an opening adjustment valve, for example, the one disclosed in Patent Document 1 is known. As shown in FIG. 5 (a), a valve body 104 that opens and closes a flow path 103 between the suction port 100 and the suction chamber 101, a recess 105 that slidably accommodates the valve body 104, A spring 106 disposed in the recess 105, a communication passage 107 that allows the recess 105 and the suction chamber 101 to communicate with each other, and a communication hole 108 formed in the valve body 104. A valve seat 109 with which the valve body 104 abuts is formed.

According to such a configuration, the refrigerant gas sucked from the evaporator of the refrigeration circuit is sucked into the suction chamber 101 through the flow path 103 that is a variable path and the

communication paths

108 and 107 that are fixed paths. These passages generate a pressure loss when the refrigerant gas passes, and the difference between the primary side pressure and the secondary side pressure of the valve body 104 caused by this causes the valve body to resist the biasing force of the spring 106. Thus, it acts in the direction of increasing the opening degree of the flow path 103. Therefore, when the flow rate of the refrigerant gas is large, the difference between the primary side pressure and the secondary side pressure of the valve body 104 is large, thereby increasing the opening degree of the flow path 103, and the refrigerant gas passes through a passage having a sufficient area. Through the suction chamber 101. On the other hand, when the flow rate of the refrigerant gas decreases, the difference between the primary side pressure and the secondary side pressure of the valve body 104 decreases, so that the opening degree of the flow path 103 is increased against the biasing force of the spring 106. Accordingly, the force for urging the valve body 104 is weakened, and the opening degree of the flow path 103 is reduced.

Further, when the flow rate of the refrigerant gas is further reduced, the pressure difference between the suction port 100 and the suction chamber 101 is further reduced and acts on the valve body 104 due to the difference between the primary side pressure and the secondary side pressure of the valve body 104. The force cannot overcome the biasing force of the spring 106. As a result, the valve body 104 is pressed against the valve seat 109 to close the flow path 103 that is a variable passage, and the refrigerant gas introduced from the suction port 100 is communicated with the communication hole formed in the valve body 104 that is a fixed passage. It flows into the suction chamber 101 through 108 and the communication passage 107.

For this reason, when the flow rate is low, the pressure pulsation of the refrigerant gas caused by the self-excited vibration of the intake valve passes through the flow path 103 having a small opening degree, or the communication path 107 and the valve body 104 communicate with each other. As a result, the pressure pulsation caused by the self-excited vibration of the suction valve is prevented from propagating from the suction port 100 to the external cooling circuit, and the vibration noise of the evaporator is reduced. It is like that.

JP 2000-136776 A

As described above, in the above-described opening degree adjusting valve, when the refrigerant flow rate decreases and the difference between the primary side pressure and the secondary side pressure of the opening degree control valve falls below a predetermined value, the flow path that is a variable passage The flow through 103 is blocked, and the refrigerant flows into the suction chamber 101 only through the communication hole 108 and the communication path 107 which are fixed passages. For this reason, as shown in FIG. 5B, the communication area between the suction port and the suction chamber is not adjusted even when the flow rate is reduced and the pressure difference is further reduced, and is always open. The pressure pulsation propagates to the external cooling circuit via the communication hole 108 and the communication path 107, and there remains a disadvantage that causes vibration noise of the evaporator.

In order to eliminate such inconvenience, it is conceivable to arrange a known check valve in the suction passage from the suction port 100 to the suction chamber 101. In such a structure, since there is no fixed passage, the opening of the variable passage is autonomously adjusted according to a slight pressure difference even at a minute flow rate, and the suction port is moved to the suction chamber. It is possible to prevent the pressure pulsation from propagating to the external cooling circuit by sufficiently reducing the communication area.

By the way, when the compressor is stopped when the temperature around the compressor is higher than the temperature around the evaporator, the pressure in the suction chamber 101 (secondary pressure) becomes the pressure in the suction port 100 (primary pressure). May be raised. However, when the compressor in which the check valve is arranged in the above-described suction passage is placed in such a temperature condition, release of pressure from the suction chamber 101 to the suction port 100 is blocked by the check valve, and the suction chamber 101 The pressure is kept higher than the suction port 100 pressure. For this reason, when starting the compressor again from this stopped state, the check valve does not open until the pressure in the suction chamber 101 drops and falls below the pressure on the suction port side, and refrigerant gas suction is blocked. As a result, the start-up of the compressor is delayed.

The present invention has been made in view of such circumstances, and balances the difference between the pressure of the suction port and the pressure of the suction chamber when the compressor is stopped while suppressing the propagation of pressure pulsation at a low flow rate. The main problem is to provide a compressor capable of improving the startability of the compressor.

In order to achieve the above object, a compressor according to the present invention is used in a refrigeration circuit comprising at least a condenser, an expander, an evaporator, and a compressor, and a suction port connected to the low pressure side of the refrigeration circuit; A suction chamber that accommodates the working fluid introduced from the suction port; a compression mechanism that compresses the working fluid sucked from the suction chamber; and a suction passage that connects the suction port and the suction chamber; A check valve assembly that allows only a flow of working fluid from the suction port toward the suction chamber is disposed on the suction passage, and the suction port is only used when the pressure of the suction chamber is higher than the pressure of the suction port. The pressure balancing means for allowing the discharge of the working fluid from the chamber to the suction port is formed outside the internal passage of the check valve assembly.

Therefore, a check valve assembly that allows only the flow of working fluid from the suction port toward the suction chamber is arranged on the suction passage, and suction is performed from the suction chamber only when the pressure of the suction chamber is higher than the pressure of the suction port. Since pressure balancing means allowing discharge of the working fluid to the port is formed outside the internal passage of the check valve assembly, the working fluid is sucked into the suction chamber through the check valve assembly during operation of the compressor. When the compressor is stopped, the working fluid can be discharged from the suction chamber to the suction port via the outside of the check valve assembly to balance the pressure. As a result, even if the compressor stops when the temperature around the compressor is higher than the temperature around the evaporator, etc., the inconvenience that the pressure in the suction chamber is maintained at a high pressure and the start-up of the compressor is delayed is avoided. Can do.

The check valve assembly includes a storage space inside, an inflow port that connects the suction port and the storage space, and an outflow port that connects the suction chamber and the storage space. A valve housing, a valve body that is housed in the housing space and moves in the housing space based on a pressure difference between the front and the rear, and adjusts the opening degree of the outlet, and the valve body is made smaller in opening degree of the outlet. And an urging member that urges the inflow port in a closing direction.

Such a check valve assembly is simple in structure, and the opening degree of the outlet is autonomously adjusted according to the flow rate of the working fluid flowing inside, so that it operates at a sufficient opening degree at a high flow rate. The fluid can be flowed, and at the low flow rate at which pulsation is likely to occur, the opening degree of the outlet can be narrowed to suppress the propagation of pulsation to the evaporator. In addition, even when the flow rate is very small, the outlet can be narrowed to a sufficiently small opening by the balance between the pressure difference generated slightly and the force of the biasing member.

Preferably, the valve housing of the check valve assembly has a fitting portion that loosely fits in a holding portion formed in the suction passage so as to allow movement in the axial direction. The flow of the working fluid on the outside of the valve housing is interrupted when it contacts the edge of the holding part on the suction chamber side, and the valve is connected when the fitting part is separated from the edge of the holding part on the suction chamber side. The working fluid may be allowed to flow outside the housing.

In a compressor equipped with such a check valve assembly, when the compressor stops and the suction chamber pressure inside the compressor becomes higher than the suction port pressure, the valve body of the check valve assembly is In addition to the biasing force of the biasing member, the suction chamber pressure moves so as to block the communication state between the inlet and the outlet. However, the valve housing also moves away from the edge of the holding portion on the suction chamber side due to the suction chamber pressure and moves to the suction port side, so that the flow of working fluid is allowed outside the valve housing, and the pressure from the suction chamber to the suction port is increased. It is possible to escape. For this reason, it is possible to achieve a balance between the pressures of the suction chamber and the suction port with a simple structure.

The valve housing having the above-described function includes a radially expanding fitting portion loosely fitted in an annular groove formed in the inner peripheral wall of the suction passage, and the annular groove on the suction chamber side. A seat surface on which the fitting portion is seated may be formed, and a communication portion may be provided in the fitting portion to communicate the outside and the inside.
Here, the communication part may be a hole formed in the fitting part, or a slit or the like formed on the outer peripheral surface of the fitting part.

As described above, according to the present invention, the check valve assembly that allows only the flow of the working fluid from the suction port toward the suction chamber is disposed on the suction passage connecting the suction port and the suction chamber. The pressure balancing means that allows the discharge of the working fluid from the suction chamber to the suction port only when the pressure in the suction chamber is higher than the pressure in the suction port is formed outside the internal passage of the check valve assembly, so that the low flow rate The generation of abnormal noise can be avoided by suppressing the propagation of the low-pressure pulsation generated at the time to the external cooling circuit, and even when the pressure of the suction chamber becomes higher than the pressure of the suction port when the compressor is stopped, Since the pressure in the suction chamber can be released to the suction port through the outside of the internal passage of the check valve assembly, there is no inconvenience that the pressure in the suction chamber is kept high when the compressor is stopped. Early opening It is possible to improve the resistance.

FIG. 1 is a side cross-sectional view of a piston type compressor that is an example of a compressor according to the present invention, with a part cut away. 2A and 2B are views showing a check valve assembly, in which FIG. 2A is a sectional view thereof, FIG. 2B is a plan view thereof, and FIG. 2C is a side view thereof. 3A and 3B are cross-sectional views showing the check valve assembly, in which FIG. 3A shows a state at a high flow rate, FIG. 3B shows a state at a low flow rate, and FIG. 3C shows the pressure in the suction chamber. Is a diagram showing a state in which is higher than the pressure of the suction port. FIG. 4 is a characteristic diagram showing changes in the opening (passage area) of the suction passage from the suction port to the suction chamber when the check valve assembly of the present invention is used. FIG. 5A is a cross-sectional view showing a conventional opening control valve, and FIG. 5B shows the opening of the suction passage from the suction port to the suction chamber when the conventional opening control valve is used. It is a characteristic line figure showing change of (passage area).

Hereinafter, the case where a piston type compressor is used as the compressor according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a piston type compressor 1 that forms a part of a refrigeration circuit together with a condenser, an expansion valve, and an evaporator (not shown). The piston type compressor 1 is assembled so as to cover a cylinder block 2, a cylinder head 4 assembled on the rear side of the cylinder block 2 via a valve plate 3, and a front side of the cylinder block 2. A front housing 6 defining a crank chamber 5 on the front side of the block 2 is provided. The front housing 6, the cylinder block 2, the valve plate 3, and the cylinder head 4 are fastened in the axial direction by fastening bolts (not shown) to constitute a compressor housing 7.

The drive shaft 8 disposed in the crank chamber 5 is rotatably held by the front housing 6 and the cylinder block 2 via a bearing 9 (only the cylinder block side is shown). And is connected to a travel engine (not shown) via a belt and a pulley, and the power of the travel engine is transmitted to rotate.

The cylinder block 2 is formed with a support hole 11 in which the bearing 9 is accommodated, and a plurality of cylinder bores 12 arranged at equal intervals on a circumference around the support hole 11. 12, a single-head piston 13 is inserted so as to be reciprocally slidable.

In the crank chamber 5, a swash plate 14 that rotates in synchronization with the rotation of the drive shaft 8 is provided on the drive shaft, and a peripheral portion of the swash plate 14 is provided with a pair of shoes 15 provided at the front and rear. The engaging portion 13a of the single-head piston 13 is moored.

Accordingly, when the drive shaft 8 is rotated, the swash plate 14 is rotated accordingly, and the rotational motion of the swash plate 14 is converted into the reciprocating linear motion of the single-headed piston 13 via the shoe 15, and the single-headed piston in the cylinder bore 12. The volume of the compression chamber 16 formed between 13 and the valve plate 3 is changed.

The valve plate 3 is formed with suction holes 17 and discharge holes 18 corresponding to the respective cylinder bores 12, and the cylinder head 4 has a suction chamber 20 that contains working fluid supplied to the compression chamber 16, and A discharge chamber 21 for accommodating the working fluid discharged from the compression chamber 16 is provided. In this example, the suction chamber 20 is formed in the center portion of the cylinder head 4, and the discharge chamber 21 is formed in an annular shape around the suction chamber 20.

The suction chamber 20 communicates with the low pressure side (the outlet side of the evaporator) of the external refrigerant circuit via a suction port 22 extending in the radial direction so as to penetrate the annular discharge chamber 21. The discharge port (not shown) connected to the high-pressure side of the external refrigerant circuit (the inlet side of the condenser) communicates. The suction chamber 20 can communicate with the compression chamber 16 via the suction hole 17 opened and closed by the suction valve 23, and the discharge chamber 21 is communicated via the discharge hole 18 opened and closed by the discharge valve 24. Thus, communication with the compression chamber 16 is possible.

Accordingly, during the suction stroke, the refrigerant is sucked into the compression chamber 16 from the suction chamber 20 through the suction hole 17 opened and closed by the suction valve 23, and the discharge hole 18 opened and closed by the discharge valve 24 during the compression stroke. The refrigerant compressed via the compressor is discharged from the compression chamber 16 to the discharge chamber 21.

In such a compressor, a check valve assembly 30 that varies the opening degree of the suction passage 25 is provided on the downstream side of the suction port 22, that is, in the suction passage 25 that leads from the suction port 22 to the suction chamber 20. ing.

In FIG. 2, a schematic configuration diagram of the check valve assembly 30 is shown. The check valve assembly 30 includes a valve housing 31, a valve body 41 accommodated in the valve housing 31, and a spring 51 as an urging member.

The valve housing 31 has a cylindrical shape in which a cylindrical valve body accommodating space 32 is formed, and allows axial movement with respect to the inner wall of the suction passage 25 extending from the suction port 22 to the suction chamber 20. Are loosely fitted.
Specifically, the valve housing 31 includes a cylindrical peripheral wall 33, a valve seat portion 34 provided at the upstream end of the peripheral wall 33, a bottom wall 35 provided at the downstream end of the peripheral wall 33, and a valve seat portion. 34 and an annular fitting portion 36 protruding radially outward from the peripheral edge of the valve housing 31 (periphery of the upstream end in the axial direction of the valve housing 31), and the compressor housing 7 (cylinder block 2). An annular groove (holding portion) 26 is formed in the inner wall of the suction passage 25 extending from the suction port 22 to the suction chamber 20, and the axial dimension of the annular groove 26 is set larger than the axial dimension of the fitting portion 36. A fitting portion 36 is fitted into the annular groove 26 so as to allow movement in the axial direction.

The fitting portion 36 extends radially outward from the outer periphery of the valve body (in this example, the peripheral edge of the upstream valve seat portion), and extends toward the upstream side following the shoulder portion 36a. The locking wall 36b is formed, and the locking wall 36b is made elastically deformable by gradually increasing its diameter toward the upstream side.

The diameter R1 upstream of the annular groove 26 of the suction passage 25 is substantially equal to or larger than the diameter R2 of the shoulder 36a and smaller than the tip diameter R3 of the locking wall 36b. The downstream diameter R4 of the annular groove 26 is smaller than the diameter R2 of the shoulder 36a. Therefore, an annular seat surface 26a on which the shoulder portion 36a of the fitting portion 36 can be seated is formed on the suction chamber side of the annular groove 26, and the fitting portion 36 is provided on the suction port side of the annular groove 26. A stopper surface 26b that can lock the tip of the locking wall is formed.

In this example, the fitting portion 36 is illustrated as an integral member together with the valve seat portion 34, the peripheral wall 33, and the bottom wall 35, but the fitting portion 36 and the peripheral wall 33 are formed integrally. The body valve seat portion 34 may be attached, or the fitting portion 36 and the valve seat portion 34 may be integrally formed and attached to a separate peripheral wall 33.
The fitting portion 36 may be formed of an elastic material such as rubber or may be formed of a synthetic resin.

In the locking wall 36b of the fitting portion 36, a plurality of communication holes (communication portions) 37 for communicating the outside and the inside are formed at equal intervals in the circumferential direction (for example, every 90 degrees).

In the valve housing 31, the valve seat portion 34 is formed with an inlet 38 for communicating the suction port 22 and the valve body accommodation space 32, and the suction chamber 20 and the valve body accommodation space 32 are formed on the peripheral wall 33. A plurality of outflow ports 39 communicating with each other are formed at regular intervals in the circumferential direction (for example, every 90 degrees). Furthermore, a pressure equalizing port 40 is formed in the bottom wall 35 of the valve housing 31 so that the back of a later-described valve body 41 housed in the valve body housing space 32 matches the suction chamber pressure.

The valve body 41 is housed in the valve body housing space 32 of the valve housing 31 so as to be movable in the axial direction, and includes a top wall portion 42 and a peripheral wall portion 43 formed continuously from the periphery of the top wall portion 42. Is formed of a hollow cylindrical piston that is integrally formed and whose bottom is released. The outer diameter of the valve body 41 is formed substantially equal to the inner diameter of the valve body housing space 32, and the outer peripheral surface of the peripheral wall 43 is slidably contacted with the inner peripheral surface of the valve body housing space 32 through a predetermined clearance. It is like that. The length of the valve body 41 in the axial direction is not particularly limited, but the top wall portion 42 of the valve body 41 comes into contact with the peripheral edge of the inlet 38 of the valve seat portion 34 of the valve casing 31 from the inside. In such a state, the length is set such that the outlet 39 is closed by the peripheral wall 43 of the valve body 41.

The outlet 39 is formed at a position away from the valve seat portion 34, and therefore the outer peripheral surface of the valve body 41 even if the top wall portion 42 of the valve body 41 does not contact the valve seat portion 34 of the valve housing 31. Thus, when the outlet 39 is closed, the communication state between the inlet 38 and the outlet 39 is cut off. Therefore, the lift section from the state in which the valve body 41 is lifted from the state in which the valve body 41 is in contact with the upstream end wall of the valve housing 31 to the state where the outlet 39 is closed on the outer peripheral surface of the valve body 41 is the inlet section 38. And a closed section in which the communication state between the outlet 39 and the outlet 39 is maintained.

The spring 51 is housed inside the valve body 41 so as to urge the valve body 41 toward the valve seat 34 of the valve housing 31. In this example, the spring 51 of the top wall 42 of the valve body 41 is accommodated. Between the inner surface and the peripheral edge of the pressure equalizing port 40 of the bottom wall 35 of the valve housing 31, it is elastically mounted with a predetermined set force.

In the above configuration, in order to attach the check valve assembly 30 to the compressor 1, the valve housing 31 containing the valve body 41 is inserted from the suction port 22 into the suction passage 25 with the opposite side of the fitting portion 36 as the insertion end. And push it in. As a result, the fitting portion 36 is elastically deformed so as to shrink inward, and when the fitting portion 36 reaches the annular groove 26, the shoulder portion 36 a comes into contact with the seat surface 26 a and the fitting portion 36 is caused by its own restoring force. It is restored and spreads in the annular groove 26, and the fitting portion 36 is loosely fitted in the annular groove 26 so as to allow movement in the axial direction.

According to the compressor 1 to which such a check valve assembly 30 is attached, when there is a large amount of working fluid flowing into the suction chamber 20 from the suction port 22 (flowing through the suction passage 25), FIG. As shown in a), the check valve assembly 30 is biased to the downstream side by the fluid pressure of the working fluid, and the shoulder portion 36a of the valve housing 31 is the peripheral edge of the annular groove 26 (holding portion) on the suction chamber side. The working fluid flowing outside the valve housing 31 is shut off by abutting against the seat surface 26a formed in the section. Further, the valve body 41 accommodated in the valve housing 31 moves in a direction to increase the communication state between the inlet port 38 and the outlet port 39 against the urging force of the spring 51 by the fluid flowing in from the suction port 22, The working fluid flowing in from the suction port 22 is sucked into the suction chamber 20 through the valve housing 31.

Further, even when the amount of working fluid flowing from the suction port 22 into the suction chamber 20 is small, the check valve assembly 30 is moved downstream by the fluid pressure of the working fluid, as shown in FIG. The shoulder portion 36a of the valve housing 31 abuts against the seat surface 26a to block the working fluid flowing outside the valve housing 31. However, since the valve body 41 accommodated in the valve housing 31 has a small flow rate of the working fluid, the valve body 41 moves in a direction to narrow the communication state between the inflow port 38 and the outflow port 39 by the urging force of the spring 51. Therefore, the working fluid flowing in from the suction port 22 is sucked into the suction chamber 20 through the valve housing 31, but the opening of the suction passage 25 is narrowed, so that the low-pressure pulsation generated at the low flow rate Propagation from the chamber 20 to the suction port 22 becomes difficult, and propagation to the external cooling circuit is suppressed, so that generation of abnormal noise can be avoided.

In particular, even when the flow rate is extremely low (when there is almost no difference between the primary side pressure and the secondary side pressure), the top wall portion 42 of the valve body 41 is not provided with a communication hole. The inflowing working fluid is sucked into the suction chamber 20 only through the outlet 39 that is throttled in accordance with the balance between the slightly generated pressure difference and the urging force of the spring 51, so that low-pressure pulsation propagates to the external refrigerant circuit. Therefore, it is possible to reliably prevent the occurrence of abnormal noise.

For operation at more compressors running when the compressor 1 is stopped, the pressure P ₂ of the compressor inside the suction chamber 20 becomes higher than the pressure P ₁ of the low-pressure pipe side of the compressor outside, FIG. as shown in 3 (c), the valve element 41 is seated on the valve seat 34 moves toward the upstream side by the pressure P ₂ in the suction chamber 20 in addition to the biasing force of the spring 51, flow the inlet 38 The communication state with the outlet 39 is shut off. That is, the passage inside the check valve assembly 30 is closed. However, if the pressure P ₂ such suction chamber 20 is higher than the pressure P ₁ of the low-pressure pipe side of the compressor exterior, even the whole check valve assembly 30 moves to the upstream side by the pressure in the suction chamber 20, Since the fitting portion 36 is separated from the seat surface 26a (the peripheral portion on the suction chamber side of the annular groove 26) and abuts on the peripheral portion (stopper surface 26b) on the suction port side of the annular groove 26, the working fluid in the suction chamber 20 Is opened to the suction port 22 between the shoulder portion 36a of the valve housing 31 and the seat surface 26a, outside the fitting portion 36, and through the communication hole 37 (on the outside of the internal passage of the check valve assembly 30). The flow of the working fluid is allowed), and the pressure in the suction chamber 10 and the suction port 22 can be balanced. Therefore, the change of the opening degree (opening area) of the suction passage 25 provided with the check valve assembly 30 of the present invention has a characteristic as shown in FIG.
For this reason, there is no inconvenience that the pressure in the suction chamber 20 is kept high when the compressor 1 is stopped, and it is possible to avoid the inconvenience that the opening of the valve body 41 is delayed and the startability is impaired.

In the above-described configuration, the communication portion provided in the fitting portion 36 is configured by the communication hole 37, but may be configured by forming a slit on the outer peripheral surface of the fitting portion 36.

In the above configuration, the piston type compressor is taken as an example, but the present invention can be applied to other types of compressors as long as the compressor generates suction pulsation.

DESCRIPTION OF SYMBOLS 1 Piston type compressor 2 Cylinder block 3 Valve plate 4 Cylinder head 12 Cylinder bore 13 Piston 16 Compression chamber 17 Suction hole 20 Suction chamber 22 Suction port 23 Suction valve 26 Annular groove 26a Seat surface 30 Check valve assembly 31 Valve housing 32 Valve Body accommodating space 36 Fitting portion 37 Communication hole 38 Inlet 39 Outlet 41 Valve body 51 Spring

Claims

A suction port that is used in a refrigeration circuit including at least a condenser, an expander, an evaporator, and a compressor, and is connected to a low-pressure side of the refrigeration circuit; and a suction chamber that accommodates a working fluid introduced from the suction port; In a compressor comprising a compression mechanism that compresses the working fluid sucked from the suction chamber, and a suction passage that connects the suction port and the suction chamber.
A check valve assembly that allows only a flow of working fluid from the suction port toward the suction chamber is disposed on the suction passage.
Pressure balancing means that allows the discharge of working fluid from the suction chamber to the suction port only when the pressure in the suction chamber is higher than the pressure in the suction port is formed outside the internal passage of the check valve assembly. A compressor characterized by that.
The check valve assembly has a housing space therein, and includes an inlet that communicates the suction port and the housing space, and an outlet that communicates the suction chamber and the housing space. And a valve body that is housed in the housing space and moves within the housing space based on a pressure difference between the front and rear to adjust the opening degree of the outlet, and the valve body is made to reduce the opening degree of the outlet. The compressor according to claim 1, further comprising: an urging member that urges the inflow port in a closing direction.
The valve housing of the check valve assembly has a fitting portion that is loosely fitted to a holding portion formed in the suction passage so as to allow axial movement.
When the fitting portion comes into contact with the edge portion of the holding portion on the suction chamber side, the flow of the working fluid outside the valve housing is blocked, and the fitting portion is on the suction chamber side of the holding portion. 3. The compressor according to claim 2, wherein the pressure balance means is formed by allowing the flow of the working fluid outside the valve housing when separated from the edge of the valve housing.
The valve housing includes a radially enlarged fitting portion that is loosely fitted in an annular groove formed in an inner peripheral wall of the suction passage.
A seat surface on which the fitting portion is seated is formed on the suction chamber side of the annular groove,
The compressor according to claim 2 or 3, wherein the fitting portion is provided with a communication portion that allows communication between the outside and the inside.