JP6857946B2 - Compressor - Google Patents

Description

The present invention relates to a compressor provided with a valve mechanism for varying the opening degree of a suction passage from a suction port to a suction chamber, and more particularly to a compressor having an accelerated startability.

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 the tip of the suction valve is this stopper when the refrigerant gas is sucked into the cylinder bore. The suction valve is prevented from causing self-excited vibration by coming into contact with the engine.

However, when the amount of gas sucked into the cylinder bore is small, the tip of the suction valve does not hit the stopper because the displacement amount of the suction valve is small. As a result, the suction valve causes self-excited vibration, which causes pressure pulsation in the suction chamber, which propagates through the suction path of the system and reaches the evaporator, causing the evaporator to vibrate and make noise. There is an inconvenience to generate.

Therefore, conventionally, in order to reduce the propagation of pressure pulsation to the evaporator, an opening adjustment valve for adjusting the opening degree 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 degree adjusting valve, for example, the one shown in Patent Document 1 is known. As shown in FIG. 5A, this includes a valve body 104 that opens and closes a flow path 103 between the suction port 100 and the suction chamber 101, and a recess 105 that slidably accommodates the valve body 104. A spring 106 arranged in the recess 105, a communication passage 107 for communicating the recess 105 and the suction chamber 101, and a communication hole 108 formed in the valve body 104 are provided at the downstream end of the suction port 100. The 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 refrigerating circuit is sucked into the suction chamber 101 through the flow path 103 which is a variable passage and the communication passages 108 and 107 which are fixed passages. These passages generate a pressure loss when the refrigerant gas passes through, 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 urging force of the spring 106. Therefore, 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, which increases the opening degree of the flow path 103, and the refrigerant gas has a sufficient area of the passage. It is guided to the suction chamber 101 via. 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 becomes small, so that the opening degree of the flow path 103 is increased against the urging force of the spring 106. 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 becomes smaller, the pressure difference between the suction port 100 and the suction chamber 101 becomes smaller, and the difference between the primary side pressure and the secondary side pressure of the valve body 104 acts on the valve body 104. The force cannot overcome the urging 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 which is a variable passage, and the refrigerant gas introduced from the suction port 100 is a communication hole formed in the valve body 104 which is a fixed passage. It flows into the suction chamber 101 through 108 and the communication passage 107.

Therefore, when the flow rate is low, the pressure pulsation of the refrigerant gas caused by the self-excited vibration of the suction valve passes through the flow path 103 having a small opening degree, or the communication passage 107 and the valve body 104 communicate with each other. It is dampened as it passes through the hole 108, and as a result, pressure pulsation due to the self-excited vibration of the suction valve is prevented from propagating from the suction port 100 to the external cooling circuit, reducing the vibration noise of the evaporator. It has become like.

Japanese Unexamined Patent Publication No. 2000-136776

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

In order to eliminate such inconvenience, it is conceivable to arrange a well-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 degree of the variable passage is autonomously adjusted according to a slight pressure difference generated even at a minute flow rate, and the suction port is transferred to the suction chamber. It is possible to sufficiently reduce the communication area of the pressure pulsation to prevent the pressure pulsation from propagating to the external cooling circuit.

By the way, when the compressor is stopped under the condition that 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 of the suction port 100 (primary pressure). May be higher than. However, when the compressor having the check valve arranged in the suction passage described above is placed under such a temperature condition, the 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 pressure of the suction port 100. Therefore, when the compressor is to be started again from this stopped state, the check valve does not open until the pressure in the suction chamber 101 drops below the pressure on the suction port side, and the suction of the refrigerant gas is blocked. There is an inconvenience that the start-up of the compressor is delayed.

The present invention has been made in view of the above 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, and is a compressor. The main issue is to provide a compressor that can improve the startability of the.

In order to achieve the above problems, the compressor according to the present invention is used in a refrigeration circuit including at least a condenser, an expander, an evaporator, and a compressor, and has a suction port connected to the low pressure side of the refrigeration circuit. A suction chamber for accommodating the working fluid introduced from the suction port, a compression mechanism for compressing the working fluid sucked from the suction chamber, and a suction passage connecting the suction port and the suction chamber are provided. 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 the suction is performed only when the pressure in the suction chamber is higher than the pressure in the suction port. It is characterized in that a 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 to the suction chamber is placed on the suction passage, and suction is performed from the suction chamber only when the pressure in the suction chamber is higher than the pressure in the suction port. A pressure balancing means that allows the discharge of the working fluid to the port is formed outside the internal passage of the check valve assembly so that the working fluid can be sucked into the suction chamber through the inside of the check valve assembly when the compressor is operating. 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. This avoids the inconvenience that the pressure in the suction chamber is maintained at a high pressure and the start-up of the compressor is delayed even if the compressor is stopped under conditions such as the temperature around the compressor being higher than the temperature around the evaporator. Can be done.

The check valve assembly has an internal accommodation space, and includes an inlet that communicates the suction port and the accommodation space, and an outlet that communicates the suction chamber and the accommodation space. A valve housing, a valve body that is housed in the accommodation space and moves in the accommodation space based on a pressure difference between the front and rear to adjust the opening degree of the outlet, and a valve body that reduces the opening degree of the outlet. At the same time, it is preferable to provide an urging member that urges the inflow port in a direction of closing the inflow port.

Such a check valve assembly has a simple structure, and the opening of the outlet is autonomously adjusted according to the flow rate of the working fluid flowing inside, so that the check valve assembly operates with a sufficient opening at the time of high flow rate. When the flow rate is low, where fluid can flow and pulsation is likely to occur, the opening of the outlet can be narrowed to suppress the propagation of pulsation to the evaporator. Further, the outlet can be narrowed down to a sufficiently small opening degree by balancing the pressure difference generated slightly and the force with the urging member even at a minute flow rate.

The valve housing of the check valve assembly, have a fitting portion which loosely fitted so as to permit axial movement of the holding portion formed in the suction passage, to the fitting portion, its outer A communication portion for communicating with the inside is provided, and the pressure balancing means blocks the flow of the working fluid on the outside of the valve housing when the fitting portion abuts on the edge of the holding portion on the suction chamber side. and, may fitting portion is formed by allowing via the communication unit a flow of the working fluid at the outside of the valve housing when away from the edge of the suction chamber side of the holding portion.

In a compressor equipped with such a check valve assembly, when the compressor is stopped and the suction chamber pressure inside the compressor becomes higher than the pressure of the suction port, the valve body of the check valve assembly is changed. , In addition to the urging force of the urging member, the suction chamber pressure moves so as to block the communication state between the inflow port and the outflow port. However, since the valve housing also moves away from the suction chamber side edge of the holding portion to the suction port side due to the suction chamber pressure, the flow of the working fluid is allowed outside the valve housing, and the pressure from the suction chamber to the suction port is allowed. Can be escaped. Therefore, it is possible to balance the pressures of the suction chamber and the suction port with a simple structure.

As for the configuration of the valve housing having the above-mentioned function, the holding portion of the valve housing is configured by an annular groove formed on the inner peripheral wall of the suction passage, and the fitting portion is loosely fitted in the annular groove. As described above, the valve housing may be formed by expanding in the radial direction so as to form a seat surface on which the fitting portion is seated on the suction chamber side of the annular groove.
Further, the communication portion may be a hole formed in the fitting portion, a slit formed on the outer peripheral surface of the fitting portion, or the like.

As described above, according to the present invention, 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 connecting the suction port and the suction chamber. A pressure balancing means is formed outside the internal passage of the check valve assembly to allow 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, so that the flow rate is low. It is possible to suppress the propagation of low-pressure pulsation that occurs at times to the external cooling circuit to avoid the generation of abnormal noise, and even if the pressure in the suction chamber becomes higher than the pressure in the suction port when the compressor is stopped. Since the pressure in the suction chamber can be released to the suction port via 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, and the valve body It is possible to accelerate the valve opening and improve the startability.

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

Hereinafter, a 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.

In FIG. 1, a piston type compressor 1 which forms a part of a refrigerating circuit together with a condenser, an expansion valve, and an evaporator (not shown) is shown. The piston type compressor 1 is assembled so as to cover the cylinder block 2, the cylinder head 4 assembled on the rear side of the cylinder block 2 via the valve plate 3, and the front side of the cylinder block 2. It is configured to have a front housing 6 that defines a crank chamber 5 on the front side of the block 2. The front housing 6, the cylinder block 2, the valve plate 3, and the cylinder head 4 are axially fastened by fastening bolts (not shown) to form the compressor housing 7.

The drive shaft 8 arranged 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 the drive shaft 8 is rotatably held by the front housing 6. It protrudes from the engine and is connected to a traveling engine (not shown) via a belt and a pulley so that the power of the traveling engine is transmitted to rotate the engine.

The cylinder block 2 is formed with a support hole 11 in which the bearing 9 is housed and a plurality of cylinder bores 12 arranged at equal intervals on the circumference centered on the support hole 11, and each cylinder bore is formed. A single-headed piston 13 is inserted into the 12 so as to be slidable back and forth.

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 pair of shoes 15 provided in the front and rear are provided on the peripheral portion of the swash plate 14. The engaging portion 13a of the single-headed piston 13 is moored.

Therefore, when the drive shaft 8 rotates, the swash plate 14 rotates accordingly, and the rotational motion of the swash plate 14 is converted into a 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 the 13 and the valve plate 3 is changed.

A suction hole 17 and a discharge hole 18 are formed in the valve plate 3 corresponding to each cylinder bore 12, and a suction chamber 20 for accommodating a working fluid to be supplied to the compression chamber 16 is formed in the cylinder head 4. A discharge chamber 21 for accommodating the working fluid discharged from the compression chamber 16 is defined. In this example, the suction chamber 20 is formed in the central 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 (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, and the discharge chamber 21 , It communicates with a discharge port (not shown) connected to the high pressure side (inlet side of the condenser) of the external refrigerant circuit. Further, the suction chamber 20 can communicate with the compression chamber 16 through the suction hole 17 opened and closed by the suction valve 23, and the discharge chamber 21 passes through the discharge hole 18 opened and closed by the discharge valve 24. It is possible to communicate with the compression chamber 16.

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

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

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

The valve housing 31 has a tubular shape having a columnar valve body accommodating space 32 formed therein, and allows axial movement with respect to the inner wall of the suction passage 25 from the suction port 22 to the suction chamber 20. It is loosely fitted in.
Specifically, the valve housing 31 is provided with 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. It is formed by having an annular fitting portion 36 projecting radially outward from the peripheral edge of 34 (the peripheral edge of the axially upstream end of the valve housing 31), and also of the compressor housing 7 (cylinder block 2). An annular groove (holding portion) 26 is formed on the inner wall of the suction passage 25 from the suction port 22 to the suction chamber 20, and the axial dimension of the annular groove 26 is set to be larger than the axial dimension of the fitting portion 36. The fitting portion 36 is fitted into the annular groove 26 so as to allow axial movement.

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. It is composed of the locking wall 36b, and the locking wall 36b is elastically deformable by gradually forming a larger diameter toward the upstream side.

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

In this example, the fitting portion 36 is shown 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 integrally formed and separated. The valve seat portion 34 of the body may be attached, or the fitting portion 36 and the valve seat portion 34 may be integrally formed and attached to the peripheral wall 33 of a separate body.
Further, the fitting portion 36 may be formed of an elastic material such as rubber or a synthetic resin.

The locking wall 36b of the fitting portion 36 is formed with a plurality of communication holes (communication portions) 37 for communicating the outside and the inside 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 inflow port 38 that communicates the suction port 22 and the valve body accommodating space 32, and the peripheral wall 33 is provided with the suction chamber 20 and the valve body accommodating space 32. A plurality of communicating outlets 39 are formed at equal intervals in the circumferential direction (for example, every 90 degrees). Further, the bottom wall 35 of the valve housing 31 is formed with a pressure equalizing port 40 that matches the back of the valve body 41, which will be described later, accommodated in the valve body accommodating space 32 with the suction chamber pressure.

The valve body 41 is accommodated in the valve body accommodating 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 peripheral edge of the top wall portion 42. Is integrally formed and is composed of a hollow cylindrical piston with an open bottom. The outer diameter of the valve body 41 is formed to be substantially equal to the inner diameter of the valve body accommodating space 32, and the outer peripheral surface of the peripheral wall portion 43 is slidably contacted with the inner peripheral surface of the valve body accommodating space 32 via a predetermined clearance. It has become like. The axial length of the valve body 41 is not particularly limited, but the top wall portion 42 of the valve body 41 contacts the peripheral edge of the inflow port 38 of the valve seat portion 34 of the valve casing 31 from the inside. In this state, the length is set so that the outlet 39 is blocked by the peripheral wall portion 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 abut on the valve seat portion 34 of the valve housing 31. When the outflow port 39 is closed, the communication state between the inflow port 38 and the outflow port 39 is cut off. Therefore, the lift section from the state where the valve body 41 is in contact with the upstream end wall of the valve housing 31 until the state where the outflow port 39 is closed on the outer peripheral surface of the valve body 41 is released is the inflow port 38. It is a closed section in which the interruption of the communication state between the 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 portion 34 of the valve housing 31, and in this example, the top wall portion 42 of the valve body 41. It is mounted with a predetermined setting force between the inner surface and the peripheral edge of the pressure equalizing port 40 of the bottom wall 35 of the valve housing 31.

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 into the suction passage 25 from the suction port 22 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 36a comes into contact with the seat surface 26a and the fitting portion 36 due to its own restoring force. It is restored and expanded into the annular groove 26, and the fitting portion 36 is loosely fitted into the annular groove 26 so as to allow axial movement.

Then, according to the compressor 1 to which the 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 urged 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 that comes into contact with the seat surface 26a formed in the portion and flows outside the valve housing 31 is blocked. Further, the valve body 41 housed in the valve housing 31 moves in a direction of increasing the communication state between the inflow port 38 and the outflow 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 passes through the valve housing 31 and is sucked into the suction chamber 20.

Further, even when the working fluid flowing from the suction port 22 into the suction chamber 20 is small, the check valve assembly 30 is moved to the downstream side due to the fluid pressure of the working fluid as shown in FIG. 3 (b). The shoulder portion 36a of the valve housing 31 abuts on the seat surface 26a to block the working fluid flowing outside the valve housing 31. However, since the valve body 41 housed in the valve housing 31 has a small flow rate of the working fluid, it moves in a direction of narrowing 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 degree of the suction passage 25 is narrowed, so that the low pressure pulsation generated at a low flow rate is sucked. It becomes difficult to propagate from the chamber 20 to the suction port 22, and the propagation to the external cooling circuit is suppressed, so that the generation of abnormal noise can be avoided.

In particular, even at an extremely low flow rate (when there is almost no difference between the primary side pressure and the secondary side pressure), since the top wall portion 42 of the valve body 41 is not provided with a communication hole, the suction port 22 can be used. Since the inflowing working fluid is sucked into the suction chamber 20 only through the outflow port 39 narrowed according to the balance between the slightly generated pressure difference and the urging force of the spring 51, the low pressure pulsation propagates to the external refrigerant circuit. Can be reliably prevented, and the generation of abnormal noise can be reliably suppressed.

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 exit 39 is cut off. That is, the passage inside the check valve assembly 30 is closed. However, when the pressure P _{2 of the suction chamber 20 is higher than the pressure P 1} on the low pressure piping side outside the compressor, the entire check valve assembly 30 also moves upstream due to the pressure of the suction chamber 20. Since the fitting portion 36 separates from the seat surface 26a (the peripheral edge portion of the annular groove 26 on the suction chamber side) and comes into contact with the peripheral edge portion (stopper surface 26b) of the annular groove 26 on the suction port side, the working fluid of the suction chamber 20 Is open 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 working fluid is allowed), allowing the pressures of the suction chamber 10 and the suction port 22 to be balanced. Therefore, the change in the opening degree (opening area) of the suction passage 25 provided with the check valve assembly 30 of the present invention has the characteristics shown in FIG.
Therefore, there is no inconvenience that the pressure in the suction chamber 20 is maintained in a high state when the compressor 1 is stopped, and it is possible to avoid the inconvenience that the valve opening of the valve body 41 is delayed and the startability is impaired.

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

Further, in the above configuration, the piston type compressor is taken as an example, but it can be applied to other types of compressors as long as it is a compressor that generates suction pulsation.

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 Ring groove 26a Seat surface 30 Check valve assembly 31 Valve housing 32 valve Body accommodation space 36 Fitting part 37 Communication hole 38 Inlet 39 Outlet 41 Valve body 51 Spring

Claims (2)

A suction port used in a refrigeration circuit consisting of at least a condenser, an expander, an evaporator, and a compressor and connected to the low pressure side of the refrigeration circuit, and a suction chamber for accommodating the working fluid introduced from the suction port. In a compressor provided with a compression mechanism for compressing the working fluid sucked from the suction chamber and a suction passage connecting the suction port and the suction chamber.
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.
The check valve assembly has an internal accommodation space, and is a valve housing provided with an inflow port communicating the suction port and the accommodation space and an outflow port communicating the suction chamber and the accommodation space. A valve body that is accommodated in the accommodation space and moves in the accommodation space based on the pressure difference between the front and rear to adjust the opening degree of the outlet, and the valve body that reduces the opening degree of the outlet. An urging member that urges the inflow port in a closing direction is provided.
The valve housing of the check valve assembly has a fitting portion that is loosely fitted into a holding portion formed in the suction passage so as to allow axial movement.
The fitting portion is provided with a communication portion for communicating the outside and the inside thereof.
The check valve assembly is provided with a 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.
The pressure balancing means blocks the flow of the working fluid outside the valve housing when the fitting portion abuts on the edge of the holding portion on the suction chamber side, and the fitting portion holds the holding portion. The compression is formed by allowing the flow of the working fluid on the outside of the valve housing through the communication portion when the portion is separated from the edge portion on the suction chamber side. Machine. The holding portion of the valve housing is an annular groove formed in the inner peripheral wall of the suction passage .
The fitting portion is formed by expanding the valve housing in the radial direction so as to be loosely fitted in the annular groove.
The compressor according to claim 1, wherein a seat surface on which the fitting portion is seated is formed on the suction chamber side of the annular groove.

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