JP2022074203A - Opening adjustment valve of compressor - Google Patents

Abstract

To provide an opening adjustment valve in which stable movement of a valve element is secured and which therefore enables suppression of the propagation of pressure pulsation, at a low flow rate operation of a compressor.SOLUTION: An opening adjustment valve 30 provided in a suction passage reaching a suction chamber from a suction port is constituted of: a cylindrical guide cylinder 31 with open one end portion; a valve element 41 arranged movably in the guide cylinder: a stopper 51 in which a through-hole 52 for flowing a refrigerant is formed at the center thereof, and which is provided at one end portion of the guide cylinder 31, and blocks the through-hole 52 while the valve element 41 abuts on the stopper 51; and a spring 61 energizing the valve element 41 toward the stopper side. A window portion 37 is provided at a sidewall 33 of the guide cylinder 31 and is adjusted in an opening area according to a position of the valve element 41, the upstream side inner edge shape of the window portion 37 includes a linear short side 37a arranged in an orientation orthogonal to a moving direction of the valve element 41, and having a prescribed length, and a sideway side 37b which is spread in a fan shape toward a downstream side than both ends of the short side.SELECTED DRAWING: Figure 2

Description

The present invention relates to an opening adjustment valve having a function of varying the opening of the suction passage from the suction port of the compressor to the suction chamber, and stabilizes the behavior of the valve body particularly at a low flow rate, and the pressure from the suction chamber. The present invention relates to an opening adjustment valve of a compressor capable of reducing pulsation propagation.

In a variable displacement swash plate compressor, in order to reduce the propagation of pressure pulsation to the evaporator due to the vibration of the suction valve, the opening of this passage is set in the suction passage from the suction port of the compressor to the suction chamber. It is known to arrange an opening degree adjusting valve for adjusting. Such an opening adjustment valve incorporates an urging member (spring) that urges the valve body in the closing direction, so that the valve opening is determined when the pressure from the working fluid and the spring force are balanced. It has become.

For example, Patent Document 1 describes a valve housing having a storage space inside and having an inlet that communicates with a suction port and a storage space, and a valve housing having an outlet that communicates between a suction chamber and the storage space, and a storage space. A valve body that is accommodated in the air and moves in the accommodation space based on the pressure difference between the front and rear to adjust the opening of the outlet, and the valve body is urged to reduce the opening of the outlet and close the inlet. A compressor is disclosed in which an opening degree adjusting valve provided with an urging member is provided in a suction passage. The outlet (window portion) formed on the side surface of the valve housing is formed in a rectangular shape.

International release WO2017 / 115715

In this configuration, since the window portion is formed in a rectangular shape, the opening area of the window portion changes linearly with the displacement of the valve body. Therefore, when the valve body is displaced from the state where the window portion is blocked by the valve body and the window portion starts to open, the opening area of the window portion (opening of the opening adjustment valve) suddenly increases, and the upstream side The pressure of the valve suddenly drops to the downstream side, and the pressure difference between the front and rear of the valve body suddenly decreases. Therefore, the valve body moves in the direction of closing the window portion by the urging force of the urging member, and when the window portion is closed, the pressure difference between the front and rear of the valve body becomes large again, and the valve body increases the opening area of the window portion. The valve body is hunted by repeating this operation by making it excessively large (the opening of the opening adjusting valve becomes unstable). Therefore, at a low flow rate, there is a problem that the propagation of pressure pulsation from the suction chamber cannot be sufficiently suppressed.
On the other hand, at the time of high flow rate, the pressure on the upstream side is sufficiently increased, so that the valve body is largely displaced against the urging force of the urging member, and the opening area of the window portion becomes sufficiently large. Therefore, even if the opening area of the window portion changes due to a slight displacement of the valve body, the pressure difference between the front and rear of the valve body does not excessively fluctuate, and the valve body does not cause hunting.

The present invention has been made in view of the above circumstances, and eliminates the inconvenience of propagating pressure pulsation from the suction chamber due to hunting of the valve body at a low flow rate, that is, stability of the valve body even at a low flow rate. The main task is to provide an opening adjustment valve that can secure the movement and suppress the propagation of pressure pulsation.

In order to achieve the above problems, the opening degree adjusting valve of the compressor according to the present invention is provided in the suction passage from the suction port of the compressor to the suction chamber, and the flow rate of the working fluid flowing through the suction passage is increased or decreased. An opening adjustment valve that adjusts the opening of the suction passage.
At least a cylindrical guide tube with one end open toward the suction port side,
A valve body movably arranged in the guide cylinder and
A stopper provided at the one end of the guide cylinder and having a through hole for flowing a refrigerant in the center, and a stopper.
It has an urging member that urges the valve body toward the stopper side, and has.
The side wall of the guide cylinder is provided with a window portion whose opening area is adjusted according to the position of the valve body, and the through hole is closed by the valve body coming into contact with the stopper, and the window portion is closed. The shape of the inner edge on the upstream side of the valve body is a linear short side having a predetermined length extending in a direction orthogonal to the moving direction of the valve body, and diverging toward the downstream side from both ends of the short side. It is characterized by including the sides that spread out in.

Therefore, when the valve body separates from the stopper (opens) at a low flow rate and the tip portion passes the short side of the window portion, an elongated shape is formed between the short side of the window portion and the tip of the valve body. Refrigerant begins to flow through the opening. Further, in the process in which the valve body is further displaced and the tip portion of the valve body moves on the side side, the opening area does not suddenly increase with the movement of the valve body, but gradually increases. Therefore, even when the flow rate is low, the pressure difference between the front and rear of the valve body does not change significantly with respect to the change in the flow rate, so that the movement of the valve body is stable and the opening degree of the opening adjustment valve (opening of the window portion). It becomes easier to maintain a small area). As a result, the pressure pulsation propagating from the suction chamber to the suction port (pressure pulsation transmitted to the suction pipe) can be effectively reduced.
Moreover, when the valve is opened at a low flow rate, the refrigerant flows through an elongated opening having a short side as one side, so that the propagation of pressure pulsation can be further suppressed.

On the other hand, at the time of high flow rate, the valve body is largely displaced against the urging member, and the window portion is greatly opened away from the side side, so that it is almost the same as the conventional rectangular window portion. It is possible to make the opening area the same, and it is possible to reduce the pressure loss in the opening adjustment valve and suppress the deterioration of performance.

In the above configuration, a throttle flow path forming means for forming a throttle flow path leading to the window portion may be provided on the outside of the portion where the stopper of the valve body abuts. ..
In such a configuration, the working fluid is formed by the throttle flow path forming means when the valve body is separated from the stopper even until the valve body is separated from the stopper and the tip of the valve body approaches the window portion. It begins to flow downstream through the throttle flow path. For this reason, the refrigerant does not flow to the downstream side only when the tip of the valve body reaches the window portion, so that the change in the flow rate with respect to the displacement amount of the valve body can be made more gradual, and even at an extremely low flow rate. It is possible to stabilize the movement of the valve body.

Here, the throttle flow path forming means forms a tapered surface on the outside of the contact portion with the stopper of the valve body, and forms this tapered surface so that a part of the tapered surface overlaps with the window portion at the valve closing position of the valve body. It may be configured by.
In such a configuration, since the window portion of the guide cylinder overlaps with the throttle flow path forming means at the valve closed position, the working fluid on the upstream side of the valve body passes through the throttle flow path at the same time as the valve body separates from the stopper. It begins to flow from the window to the downstream side. As a result, this opening adjustment valve can stabilize the movement of the valve body and effectively reduce the pressure pulsation transmitted to the suction pipe at the time of extremely low flow rate before the tip of the valve body reaches the window portion. Will be.

It is desirable that the periphery of the contact end portion with which the valve body of the stopper comes into contact is covered with the side wall of the guide cylinder.
By arranging the side wall of the guide cylinder on the outside (periphery) of the contact end where the valve body of the stopper abuts, the ease of escape of the refrigerant to the downstream side is restricted, and the valve body opens away from the stopper. When the regulating valve is opened, the pressure on the upstream side is suddenly released, and it becomes possible to prevent hunting in which the valve body repeatedly opens and closes.

As described above, according to the present invention, the inner edge shape on the upstream side of the window portion provided on the side wall of the guide cylinder of the opening degree adjusting valve provided in the suction passage from the suction port of the compressor to the suction chamber is defined. It has a linear short side having a predetermined length extending in a direction orthogonal to the movement direction of the valve body, and a side side extending toward the downstream side from both ends of the short side. Since it is configured, when the valve is opened at a low flow rate, the change in the opening area due to the displacement of the valve body can be gradually increased. Therefore, since the pressure difference between the front and rear of the valve body does not change significantly with respect to the change in the flow rate, it is possible to avoid hunting of the valve body and stabilize the movement of the valve body, and the opening even at a low flow rate. It is possible to maintain the opening degree of the adjusting valve (opening of the window portion) in a small state. Moreover, in the initial stage when the window portion opens, an elongated opening having a short side as one side is formed, so that the pressure pulsation is more difficult to propagate. As a result, it is possible to effectively reduce the pressure pulsation transmitted to the suction pipe at a low flow rate.

In addition, when operating at a high flow rate, the opening adjustment valve on the suction passage is almost fully opened, so it is possible to secure a sufficient opening as in the past, reducing pressure loss and reducing performance. Can be prevented.

FIG. 1 is a side sectional view showing a variable capacity swash plate type compressor which is an example of the compressor according to the present invention. 2A and 2B are views showing an example of an opening degree adjusting valve used in the compressor of FIG. 1, where FIG. 2A is a perspective view showing the appearance thereof, and FIG. 2B is a perspective view showing the internal structure thereof. FIG. 3 is a cross-sectional view showing a mounting state of an opening degree adjusting valve mounted on the suction passage. FIG. 4 is a side view of the opening degree adjusting valve according to the present invention, and is a view of the window portion as viewed from the front. FIG. 5 is a diagram showing a structure in the vicinity where the valve body and the stopper come into contact with each other, and is a diagram for explaining a state in which the valve body starts to separate from the state where the valve body comes into contact with the stopper. FIG. 6 is a characteristic diagram showing a change in the opening degree (opening area of the window portion) of the opening degree adjusting valve with respect to the displacement amount of the valve body of the opening degree adjusting valve according to the present invention, and the broken line is a conventional opening degree adjusting. The characteristics of the valve are shown, and the solid line shows the characteristics of the opening degree adjusting valve according to the present invention. 7A and 7B are views showing a state of an opening degree adjusting valve at a high flow rate when the displacement amount of the valve body becomes large, FIG. 7A is a side view thereof, and FIG. 7B is a side sectional view thereof. FIG. 8 is a diagram showing a state of the opening degree adjusting valve at a low flow rate when the displacement amount of the valve body is small and the tip of the valve body approaches the side surface of the window portion, and FIG. 8A is a side view thereof. (B) is a side sectional view thereof. FIG. 9 is a diagram showing a state of the opening degree adjusting valve at an extremely low flow rate in which the displacement amount of the valve body is further small and the tip of the valve body does not reach the short side of the window portion, and FIG. 9A is a side view thereof. FIG. 3B is a side sectional view thereof. FIG. 10 is a side view showing a modified example of the opening degree adjusting valve according to the present invention, and is a view of the window portion viewed from the front.

Hereinafter, a case where a variable capacity swash plate type compressor is used as the compressor according to the present invention will be described with reference to the attached drawings.

FIG. 1 shows a variable capacitance swash plate compressor 1 (hereinafter referred to as a compressor 1) that forms a part of a refrigeration circuit together with a condenser, an expansion valve, and an evaporator (not shown). The compressor 1 is assembled so as to cover the cylinder block 2, the rear housing 4 attached to 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 above. The front housing 6, the cylinder block 2, the valve plate 3, and the rear housing 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-rear direction are provided on the peripheral edge 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.

The valve plate 3 is formed with a suction hole 17 and a discharge hole 18 corresponding to the respective cylinder bores 12, and the rear housing 4 has a suction chamber 20 for accommodating the working fluid to be supplied to the compression chamber 16. 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 rear housing 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 radially so as to penetrate the annular discharge chamber 21, and the discharge chamber 21 , Communicats with a discharge port (not shown) connected to the high pressure side (condenser inlet side) 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 communicates with the compression chamber 16 via 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 1, an opening degree adjusting valve 30 that changes the opening degree of the suction passage 25 is provided on the downstream side of the suction port 22 of the rear housing, that is, the suction passage 25 leading from the suction port 22 to the suction chamber 20. Is provided.

FIG. 2 shows a configuration example of the opening degree adjusting valve 30. The opening degree adjusting valve 30 includes a guide cylinder 31, a valve body 41 arranged in the guide cylinder 31, a stopper 51 provided at the end of the guide cylinder 31, and a spring 61 as an urging member. Has and is configured.

The guide cylinder 31 is provided with a side wall 33 having a columnar valve body accommodating space 32 inside, and one end directed toward the suction port side is opened, and the other end is closed by a bottom wall 34. It is formed in a tubular shape. A flange-shaped abutting portion 35 projecting outward in the radial direction is formed on the peripheral edge of the open end of the guide cylinder 31 (side wall 33). Further, in the immediate vicinity of the abutting portion 35 of the side wall 33, a plurality (for example, four) slits 36 are formed at equal intervals in the circumferential direction so as to be able to lock the engaging claws 56 of the stopper 51 described later.

A plurality of window portions 37 penetrating the inside and outside of the guide cylinder 31 are formed at equal intervals in the circumferential direction (for example, four at equal intervals in the circumferential direction in the same phase as the slit 36) in the intermediate portion in the axial direction of the side wall 33. ing.
Further, the bottom wall 34 of the guide cylinder 31 is formed with a pressure equalizing port 38 that matches the back of the valve body 41 housed in the valve body accommodating space 32 with the suction chamber pressure.

The stopper 51 has a through hole 52 formed in the center for allowing the refrigerant to flow, and is attached to one end on the upstream side of the guide cylinder 31.
Specifically, the stopper 51 is formed by following the inner frame wall 53 having an outer peripheral surface having a diameter substantially equal to the inner peripheral surface of the guide cylinder 31 (side wall 33) and the guide cylinder 31. A flange portion 54 whose diameter has been expanded so that it can abut on the open end (butting portion 35) in the axial direction, a fitting portion 55 projecting outward from the flange portion 54, and an outer circumference of the inner wall 53. A seat portion 57 having an engaging claw 56 provided on the surface and with which the valve body 41 described later abuts is formed over the entire circumference of the downstream end of the inner wall 53.

The slit 36 is closed from the inside by the inner wall 53 of the stopper 51, and is located on the upstream side of the seat portion 57. Further, the window portion 37 is located on the downstream side of the seat portion 57, and therefore, the periphery of the seat portion 57 is covered by the side wall 33 over the entire circumference.

The fitting portions 55 extend axially from the outer edge of the flange portion 54 and are equidistant in the circumferential direction so as to project diagonally outward in the radial direction from one end (butting portion 35) of the guide cylinder. Multiple (four in this example) are formed, and elastically deformable in the radial direction. Further, the virtual circle connecting the outer edges of the tips of the plurality of fitting portions 55 is formed to be slightly larger than the inner diameter of the suction passage 25.

As shown in FIG. 3, an annular fitting groove 26 is formed on the inner wall of the suction passage 25 near the suction chamber 20, and a guide cylinder 31 is abutted on the downstream side of the fitting groove 26. A step portion 27 is formed in which the portion 35 abuts from the upstream side in the axial direction of the suction passage 25. The axial dimension from the step portion 27 to the upstream end of the fitting groove 26 is formed to be substantially equal to the axial dimension from the downstream end of the abutting portion 35 to the upstream end of the fitting portion 55. Therefore, in the state where the fitting portion 55 is arranged in the fitting groove 26 provided on the inner wall of the suction passage 25, the tip of the fitting portion 55 is locked to the upstream end of the fitting groove 26 and abuts against the fitting portion 55. The portion 35 is in contact with the step portion 27, and the stopper 51 and the guide cylinder 31 are in a state where the movement of the suction passage 25 in the axial direction is restricted.

The valve body 41 is accommodated in the valve body accommodating space 32 of the guide cylinder 31 so as to be movable in the axial direction. It is composed of a hollow cylindrical piston formed from an extended peripheral wall 43 and whose base end side is open. The outer diameter of the valve body 41 is formed to be substantially equal to the inner diameter of the guide cylinder 31 (valve body accommodating space 32), and the outer peripheral surface of the peripheral wall 43 has a predetermined clearance with respect to the inner peripheral surface of the guide cylinder 31 (side wall 33). It is designed to be rubbed through. The axial length of the valve body 41 is not particularly limited, but the valve body is in a state where the top wall portion 42 of the valve body 41 is in contact with the stopper 51 (the tip of the inner window wall 53). The peripheral wall 43 of 41 is set to a length such that the window portion 37 formed on the side wall 33 of the guide cylinder 31 is closed.

The spring 61 is housed inside the valve body 41 so as to urge the valve body 41 toward the stopper 51. In this example, the spring 61 is impacted with a predetermined setting force between the inner surface of the top wall portion 42 of the valve body 41 and the peripheral edge of the pressure equalizing port 38 of the bottom wall 34 of the guide cylinder 31.

In such a configuration, the side wall 33 of the guide cylinder 31 is formed with a window portion 37 having a shape as shown in FIG. The shape of the inner edge of the window portion 37 on the upstream side is from a linear short side 37a having a predetermined length extending in a direction orthogonal to the moving direction of the valve body 41 and both ends of the short side 37a. It has a side side 37b that spreads toward the downstream side, and this side side 37b extends in the moving direction of the valve body 41 (extended substantially parallel to the moving direction of the valve body 41). It is designed to shift to the edge 37c. Therefore, the circumferential width of the window portion 37 is the length of the short side 37a at the upstream end, gradually widens toward the downstream side, and then becomes constant at the circumferential width defined by both side edges 37c. ..

Further, as shown in FIG. 5, a tapered surface 41a is formed on the outside (periphery) of the contact portion of the valve body 41 with the stopper 51 (seat portion 57). The tapered surface 41a is formed so that a part thereof overlaps with the window portion 37 at the valve closing position of the valve body 41. Therefore, between the valve body 41 and the guide cylinder 31, even when the valve is closed, the outside (periphery) of the contact portion of the valve body 41 with the stopper 51 and the window portion 37 are communicated with each other, and the tapered surface 41a and the guide are communicated with each other. A throttle flow path 39 narrowed down by the side wall 33 of the cylinder 31 is formed.
Therefore, the throttle flow path 39 is in the most throttled state in the valve closed state, and when the valve body 41 is displaced, the passage cross section gradually increases and the throttle flow state is gradually loosened.

With the above configuration, assuming that the displacement amount of the valve body 41 is zero when the valve body 41 is in contact with the seat portion 57 of the stopper 51, the opening degree adjusting valve is increased as the displacement amount of the valve body 41 increases. The opening degree of is shown by the solid line in FIG. That is, until the valve body 41 is separated from the seat portion 57 of the stopper 51 and the tip of the valve body 41 reaches the short side 37a of the window portion 37, it is formed between the valve body 41 and the side wall 33 by the tapered surface 41a of the valve body 41. Due to the throttle flow path 39, the opening degree of the opening degree adjusting valve 30 gradually increases as the displacement amount increases. After that, when the tip of the valve body 41 approaches the short side 37a of the window portion 37 (displacement amount α), thereafter, as the displacement amount of the valve body increases, an elongated trapezoidal shape having the short side 37a as one side. The opening (an elongated opening extending in a direction orthogonal to the moving direction of the valve body 41) gradually increases. Therefore, the increase ratio of the opening degree of the opening degree adjusting valve 30 gradually increases even after the displacement amount α, but increases along a downwardly convex non-linear curve. After that, when the valve body 41 deviates from the side side 47b (displacement amount β), after that, the opening degree of the opening degree adjusting valve 30 increases according to the width defined by both side edges 47c of the window portion 37, and the conventional rectangle It will increase with the same inclination as the opening adjustment valve having a window portion of the shape.

In the above configuration, in order to attach the opening degree adjusting valve 30 to the compressor 1, the suction passage is provided with the bottom wall 34 of the guide cylinder 31 as the insertion end with the stopper 51 attached to the guide cylinder 31 accommodating the valve body 41. Insert it into 25 from the suction port 22 and push it in. As a result, the fitting portion 55 of the stopper 51 moves in the suction passage 25 while elastically deforming so as to shrink inward. Then, when the opening degree adjusting valve 30 is pushed in until the abutting portion 35 of the guide cylinder 31 comes into contact with the step portion 27, the upstream end of the fitting portion 55 reaches the fitting groove 26, and the fitting portion 55 restores itself. It is restored by force and expands in the fitting groove 26, and the fitting portion 55 is fitted into the fitting groove 26 so as to restrict axial movement.

Next, the operation when the above-mentioned compressor 1 having the opening degree adjusting valve 30 attached to the suction passage 25 is used for the air conditioner will be described.

Immediately after the compressor 1 is operated by the command of the air conditioning control device, it is operated at a high refrigerant flow rate in order to secure the cooling power of the air conditioning device. Therefore, in the opening adjustment valve 30 on the suction passage 25, as shown in FIG. 7, the valve body 41 housed in the guide cylinder 31 resists the urging force of the spring 61 by the fluid flowing from the suction port 22. The valve is opened by a large displacement, and the window portion 37 is in a substantially fully opened state. Therefore, the flow rate of the refrigerant can be increased as compared with the state in which the opening degree of the valve body is small.

After that, when sufficient cooling power is secured, the air conditioning control device controls the operation of the compressor 1 to reduce the flow rate of the refrigerant. In particular, in the variable capacity swash plate type compressor, the piston stroke is reduced in order to reduce the refrigerant flow rate, the refrigerant flow rate is reduced, and the compressor is operated in a low flow rate state. When the flow rate of the refrigerant becomes low, as shown in FIG. 8, the opening of the window 37 of the valve body 41 of the opening adjustment valve 30 becomes smaller due to the balance between the spring force and the flow rate of the refrigerant, and the suction passage 25 is narrowed. Acts on. Therefore, since the suction passage 25 is throttled by the opening degree adjusting valve 30, it is possible to prevent the pulsation generated by the suction valve 23 from propagating to the suction pipe.

However, in the conventional opening adjustment valve having a rectangular window portion, when the opening of the valve becomes smaller as the flow rate of the refrigerant decreases, the relative change in the opening area is large with respect to the minute movement of the valve body. .. Therefore, in this conventional opening adjustment valve, when the movement of the valve body becomes slightly large due to vibration or the like, the opening area becomes excessively large, and the pressure on the upstream side of the opening adjustment valve is suddenly released as the valve opens. When the valve moves in the direction of closing and the pressure on the upstream side of the opening adjustment valve increases again, hunting occurs in which the movement is repeated in the direction of increasing the opening, and the movement of the valve body 41 becomes difficult to stabilize. As a result, in the conventional opening adjustment valve, the throttle of the suction passage 25 by the opening adjustment valve becomes unstable during operation at a low flow rate, so that the pressure pulsation generated from the suction valve 23 passes through the opening adjustment valve. Therefore, the inconvenience of propagating to the suction pipe cannot be avoided.

On the other hand, in the opening degree adjusting valve 30 according to the present invention, the inner edge shape on the upstream side of the window portion 37 has a predetermined length extending in a direction orthogonal to the moving direction of the valve body 41. It is configured to have a linear short side 37a and a side side 37b that spreads toward the downstream side from both ends of the short side 37a. In the opening adjustment valve 30 having this configuration, when the tip of the valve body 41 passes the short side 37a of the window portion 37 and the window portion starts to open at a low flow rate, the opening area due to the movement of the valve body 41 gradually increases. Will increase to. Therefore, since the pressure difference between the front and rear of the valve body does not change significantly, the opening of the opening opening adjusting valve 30 is stable and small without causing hunting in which the valve body 41 repeatedly increases or decreases the opening area. The opening area can be maintained. Moreover, at the initial stage of opening of the window portion 37, the opening degree adjusting valve 30 is via an elongated trapezoidal opening having a short side as one side (an elongated opening extending in a direction orthogonal to the moving direction of the valve body 41). The refrigerant will flow.

Therefore, the opening degree adjusting valve 30 can suppress abrupt movement due to hunting of the valve body 41, can keep the opening of the window portion 37 in a small state at a low flow rate, and is generated from the suction valve 23. It is easy to block the pressure pulsation with a narrowed elongated opening. As a result, the opening degree adjusting valve 30 can effectively reduce the pressure pulsation propagating from the suction chamber 20 to the suction port 22 (pressure pulsation transmitted to the suction pipe).

Further, in the above configuration, the tapered surface 41a is formed on the outside of the contact portion (seat portion 57) of the valve body 41 with the stopper 51. When the valve body 41 is located at the valve closed position, a part of the tapered surface 41a is formed so as to overlap the window portion 37, so that the outside of the contact portion of the valve body 41 with the stopper 51 even when the valve is closed ( A throttle flow path 39 is formed between the perimeter) and the window portion 37. In this configuration, even in a state immediately after the valve body 41 is separated from the stopper 51 and before the tip of the valve body 41 reaches the window portion 37, the refrigerant on the upstream side flows through the window through the throttle flow path 39. A small amount is discharged from the portion 37.

Therefore, as shown in FIG. 9, the refrigerant can flow through the throttle flow path 39 even at an extremely low flow rate such that the tip of the valve body 41 does not reach the window portion 37. Even in such a state, the movement of the valve body 41 can be stabilized, and the pulsation transmitted to the suction pipe can be effectively reduced.
Moreover, since the outside (periphery) of the contact end portion (seat portion 57) with which the valve body 41 of the stopper 51 abuts is covered with the side wall 33 of the guide cylinder 31, it is easy for the refrigerant to escape to the downstream side. Can be more restricted. The opening adjustment valve 30 having this configuration does not have the inconvenience of suddenly releasing the pressure on the upstream side when the valve body 41 separates from the stopper 51, and the valve body 41 repeatedly increases or decreases the opening area. Can be avoided.

The shape of the window portion 37 of the guide cylinder 31 is not limited to the shape shown in FIG. 4 as long as the shape can obtain substantially the same characteristics as the characteristics shown by the solid line in FIG. For example, as shown in FIG. 10, the inner edge shape on the upstream side of the window portion 37 is extended in a direction orthogonal to the moving direction of the valve body 41, and has a longer length than that shown in FIG. It may include a linear short side 37a and a curved side 37b that spreads toward the downstream side from both ends of the short side.

Further, in the above configuration, the variable capacitance swash plate 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 Variable capacity swash plate compressor 20 Suction chamber 22 Suction port 25 Suction passage 30 Opening adjustment valve 31 Guide cylinder 33 Side wall 37 Window 37a Short side 37b Side side 39 Squeezing flow path 41 Valve body 41a Tapered surface 51 Stopper 52 Through hole 61 spring

Claims (4)

An opening adjustment valve provided in the suction passage from the suction port of the compressor to the suction chamber and adjusting the opening of the suction passage according to an increase or decrease in the flow rate of the working fluid flowing through the suction passage.
At least a cylindrical guide tube with one end open toward the suction port side,
A valve body movably arranged in the guide cylinder and
A stopper provided at the one end of the guide cylinder and having a through hole for flowing a refrigerant in the center, and a stopper.
It has an urging member that urges the valve body toward the stopper side, and has.
A window portion whose opening area is adjusted according to the position of the valve body is provided on the side wall of the guide cylinder.
The through hole is closed when the valve body comes into contact with the stopper, and the through hole is closed.
The inner edge shape on the upstream side of the window portion is formed on a linear short side having a predetermined length extending in a direction orthogonal to the moving direction of the valve body and on the downstream side from both ends of the short side. An opening adjustment valve characterized by including a side surface that spreads toward the end. On the outside of the portion of the valve body to which the stopper abuts, a throttle flow path forming means for forming a throttle flow path leading to the window portion before the tip of the valve body reaches the window portion is provided. The opening degree adjusting valve according to claim 1. The throttle flow path forming means has a tapered surface on the outside of the contact portion of the valve body with the stopper so that the tapered surface partially overlaps the window portion at the valve closing position of the valve body. The opening degree adjusting valve according to claim 2, wherein the valve is formed by forming the valve. The opening degree adjusting valve according to claim 1, wherein the periphery of the contact end portion of the stopper with which the valve body abuts is covered with the side wall of the guide cylinder.

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