JP2003228423A - Capacity control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacity control valve for controlling a control fluid with a suction pressure by the action of the suction pressure, set by a receiving pressure area of an actuating rod and which is low cost and trouble-fee. <P>SOLUTION: A capacity control valve 1 is configured, in a manner such that an effective receiving pressure area Ab of a pressure-sensitive device 22, a seal-receiving pressure area As contacting a valve part face 21A of a valve body 21 and a valve base 6A, and a receiving pressure area Ar2 of the valve body 21 or an actuating rod 23 are having the same or approximately the same area. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a displacement control valve that variably controls the volume or pressure of a working fluid. In particular, the present invention relates to a capacity control valve that controls the capacity of a control chamber of an air machine or the like so that the capacity can be varied by suction pressure.

[0002]

2. Description of the Related Art As a related art relating to the present invention, a displacement control valve for a swash plate type variable displacement compressor belonging to an air machine is conventionally known. As a conventional example of this displacement control valve, there is one shown in FIG.

A pressure sensing element 210 is arranged in a suction chamber 206 provided at the lower end of the capacity control valve 200 shown in FIG. The pressure sensitive element 210 is formed by a resilient bellows having a spring therein and is sucked from the outside by a suction pressure P.
It is configured so that it contracts by s and the upper end is displaced. Further, at the upper end of the pressure sensitive element 210, the intermediate rod 2
07 is movably arranged in a guide hole provided in the housing 220. Further, the valve body 201 connected to the intermediate rod 207 is connected to the valve hole 20 in the upper portion of the housing 220 in the figure.
It is located at 8. By the opening / closing movement of the valve body 201, the valve hole 208 is opened / closed by coming into contact with / separating from the valve seat of the valve hole 208.

The housing 220 has a Ps suction hole,
A Pd discharge hole and a Pc crank chamber inflow hole are formed, and the Pd discharge hole and the valve hole 208 communicate with each other through a connecting path 209. Then, when the valve hole 208 opens and closes,
The fluid flows into the crank chamber (not shown) by communicating with the valve hole 208 and the Pc crank chamber inflow hole. The valve section 201 is opened and closed by changing and setting the set inflow pressure (Ps set value) of the pressure sensing element 210 according to the load generated by the electromagnetic coil device 202 provided at the upper end of the capacity control valve 200 in the figure. Body 20
The amount of discharge pressure Pd introduced into the crank chamber of the variable displacement compressor is controlled according to the opening of 1, and the crank pressure Pc of the crank chamber is adjusted to control the displacement of the variable displacement compressor.

A pressure sensitive element 210 disposed in the suction chamber 206
Is set to a load characteristic that expands and contracts in the working pressure range of the suction pressure Ps in response to the suction pressure Ps. When the electromagnetic coil device 202 is not energized, the valve body 201 is held in the fully opened state by the spring force of the valve opening spring 203. This fully open state is a full unload operation state. When a current is applied to the electromagnetic coil device 202, the plunger 20
An electromagnetic attraction force is generated between the No. 4 and the fixed iron core 205. Until the electromagnetic attraction force that opposes the spring load of the valve opening spring 203 becomes equal to or more than the valve opening spring load, the valve body 201 is kept in the fully opened state and is in the dead zone state.

On the other hand, when the electromagnetic attraction force exceeds the valve opening spring load, the valve body 201 moves in the valve closing direction by the electromagnetic attraction force and enters the Ps control range. In this case, the valve closing force increases as the coil current increases, and the Ps set value decreases. Also, since the diameters of the connected rods are different, when fluid pressure is applied to the pressure receiving area of the rods, the force acting on the operating mechanism of the rod including the valve body is balanced (depending on the ratio of the pressure receiving areas of the rods) to the valve. It greatly affects the opening of the body 201. Further, the crank pressure Pc, which changes variously depending on the operating condition of the compressor, unavoidably becomes a disturbance factor of the suction pressure Ps. For this reason, it is difficult to improve the variable accuracy of the capacity due to the set suction pressure even if accuracy is required in controlling the energization of the electromagnetic coil.

The connecting rod between the pressure-sensitive element 210 and the fixed iron core 205 is the intermediate rod 207 or the valve body rod 20.
1A and the plunger rod 204A are connected to operate. Each of the connected rods affects the valve opening of the valve body 202 when the connecting portion of the rods is worn during operation. Further, since the operating characteristics of the connecting rod between the pressure-sensitive element 210 and the valve body 201 are connected only by the contact of the respective rods, they are adversely affected by the contact such as abrasion.

[0008]

Since the displacement control valve for the variable displacement compressor is configured as described above, it has the following problems. First, in the capacity control valve, the coil current reaches a maximum value at a low Ps set value which is generally used, so that there arises a problem that the coil power consumption increases in an actual use range. Further, when the control current of the electromagnetic attraction force is large, the hysteresis due to the frictional resistance of the sliding portion of the plunger 204, which is generated in the electromagnetic coil portion, becomes large, so that the hysteresis at the set value of the low Ps suction pressure, which is often used, becomes large. Therefore, the control characteristics of the displacement control valve are adversely affected.

The present invention has been made in view of the above-mentioned problems, and the problem to be solved by the present invention is to completely reduce the power consumption in the operation of the valve body and to increase the power consumption. It is to be able to control the accuracy. Furthermore, the balance of the forces acting on the actuation mechanism of the rod including the valve body is selected,
It is to obtain a capacity control valve that can accurately control the capacity or pressure of the control chamber at a set arbitrary suction pressure Pset without being affected by the control pressure. Furthermore, a displacement control valve is used in a variable displacement compressor so that the crank chamber pressure Pc or the control pressure Pd of the crank chamber can be controlled by a set suction pressure Ps without being affected by this pressure. is there.

[0010]

The present invention has been made to solve the above-mentioned technical problem, and the technical solution is configured as follows. A displacement control valve of the present invention according to claim 1 controls a valve opening of a valve hole provided in a valve housing and supplies a fluid of a control pressure flowing through the valve hole to a control chamber to control a flow rate in the control chamber or A capacity control valve for controlling pressure, the capacity chamber being provided at one end of the valve housing and communicating with a second communication passage that is capable of communicating with the control chamber, and the capacity chamber communicating with the capacity chamber via a valve hole. And a valve chamber having a valve seat capable of communicating with the first communication passage for the control pressure fluid, a working chamber communicating with the valve chamber and a detection communication passage for the suction pressure fluid, and sliding of the working chamber. An operation rod having a pressure receiving area at which the suction pressure from the detection communication passage acts on the other end, and an operation rod integrally disposed with the operation rod and movably disposed in the valve chamber, and the other end face having A valve body having a valve seat and a valve portion surface that can be opened and closed; A connecting rod that is integral with the valve body and that fits with the valve hole and a clearance passage, and an effective pressure-receiving area that is connected to the connecting rod and that is disposed in the volume chamber and that is sensitive to the working fluid pressure in the volume chamber. A pressure sensitive device for urging the valve body in a direction to close the valve body by the pressure received in the pressure receiving effective area and urging the valve body in a direction to open the valve body by a unique spring force, The effective pressure receiving area of the pressure sensing device, the contact seal area between the valve portion surface of the valve element and the valve seat, and the pressure receiving area of the operating rod are the same or substantially the same area.

In the displacement control valve according to the first aspect of the present invention, the force balance equation acting on the operating mechanism of each pressure receiving area of the fluid including the pressure sensitive device, the valve body and the operating rod is Pc (Ab
-Ar1) -Pc (As-Ar1) + Pd (As-Ar
2) + Ps × Ar2 = Fb−S1. Rewriting this formula, Pc (Ab-As) + Pd (As-Ar2) +
Ps × Ar2 = Fb−S1. However, in this equation, S1 can be set to 0, so that elastic means need not be provided. When the effective pressure receiving area Ab of the pressure sensing device, the seal pressure receiving area As which the valve seat surface 6A contacts and the pressure receiving area Ar2 of the operating rod are configured to be the same or substantially the same pressure receiving area (Ab = As = Ar2), the above formula is Ps × Ar
2 = Fb, the control fluid pressure Pd and the control chamber pressure Pc
Even if acting on each pressure receiving surface through the valve hole, this acting force is canceled and canceled, so that the force acting on the valve body is 0
Becomes In the capacity control valve, the suction pressure Ps acts on the effective pressure receiving area on the back surface of the valve body, and the control pressure Pd is closed when the valve is closed. It is a structure that acts only on the outer peripheral surface that does not operate the body. Therefore, when the valve is closed, the set suction pressure Ps
Is a function of the acting force of the actuating rod and the biasing force Fb of the spring constant of the pressure sensitive device itself. The discharge pressure Pd is related to the valve body only when the valve is opened.

Therefore, the capacity control valve can completely exclude the influence of the control chamber pressure from the factors for determining the valve opening degree with respect to the valve body. In addition, by additionally issuing a command to open the valve by a computer or the like, it becomes possible to accurately perform the valve opening adjustment operation according to the change of the suction pressure Ps. Moreover, it is possible to reduce the hysteresis at the time of the set low suction pressure Ps that is normally used, and prevent the control characteristics of the displacement control valve from being adversely affected. Particularly, when the electromagnetic attraction force is used, this hysteresis increases, but in the capacity control valve of the present invention having no electromagnetic coil portion, the hysteresis is prevented and the control range of the set value by the suction pressure Ps is expanded. It becomes possible to do. Therefore, the displacement control valve can be accurately controlled by the suction pressure Ps.

The capacity control valve of the present invention according to claim 2 is
The displacement control valve controls the displacement in the crank chamber of the variable displacement compressor.

In the control valve of the present invention according to claim 2, as in the above formula, the balance formula of the force acting on the operating mechanism of each pressure receiving area including the valve body of the control valve is Pc (Ab-Ar1).
-Pc (As-Ar1) + Pd (As-Ar2) + Ps
XAr2 = Fb-S1. Rewriting this formula, P
c (Ab-As) + Pd (As-Ar2) + Ps × Ar
2 = Fb-S1. However, in this formula, S1 is 0
Since it also functions as, it is not necessary to provide an elastic means.
Then, the effective pressure receiving area Ab of the pressure sensing device, the seal pressure receiving area Ar2 in contact with the valve seat of the valve portion surface of the valve portion, and the pressure receiving area Ar2 of the working rod or the valve body of the suction pressure Ps are the same or substantially equal. Then, the above formula is Ps × Ar2 =
It becomes Fb. As a result, the discharge pressure (control pressure) Pb and the crank chamber pressure (control chamber pressure) Pc cancel each other out on the pressure receiving surface of the fluid through the valve hole, so that the force acting on the operating mechanism of each pressure receiving area is cancelled. Excluded from the balance.
For this reason, it is possible to obtain a displacement control valve for control that excludes the crank chamber pressure Pc and the discharge pressure Pd. In addition, in the displacement control valve, the discharge pressure Pd is configured to act around the valve body, so that it is possible to perform control that reliably ignores the effect of the discharge pressure Pd when the valve is closed.

The capacity control valve of the present invention according to claim 3 is
The control fluid pressure from the first communication passage acts on the outer peripheral surface of the valve body.

In the displacement control valve of the present invention according to claim 3,
Since the control pressure Pd from the first communication passage acts on the outer peripheral surface of the valve element, the valve element may be operated or fluctuated to cause a malfunction even if the control pressure is high. Absent. In particular, if this displacement control valve is used in a variable displacement compressor or the like, the suction pressure Ps causes the discharge pressure P to change.
It is possible to control the pressure or capacity in the crank chamber as set without being affected by d or the crank chamber pressure Pc.

The capacity control valve of the present invention according to claim 4 is
The operating rod, the valve element, and the connecting rod are integrally formed, and one end of the connecting rod can be integrally connected to the pressure sensing device.

In the displacement control valve of the present invention according to claim 4, the entire pressure-sensitive rod is formed into one rod.
Since it is not necessary to connect many rods individually by integrally providing a connecting rod, a valve body, and an operating rod on the rod of the book, the connected end faces are worn and the operation and performance of the capacity control valve deteriorate. Can be effectively prevented.

Further, since one rod may be machined into a pressure-sensitive rod having each function, the centering of the machine tool is improved and the machining accuracy can be improved. Further, since the through hole of the single first valve housing is integrally machined, the pressure sensitive rod to be joined to this through hole is
If the book is used, the assembling becomes easy and the manufacturing cost can be reduced. The pressure-sensitive device and the pressure-sensitive rod can be assembled easily because the pressure-sensitive rod may be joined to the hole of the flange portion of the pressure-sensitive device by fitting or screwing. Therefore, the volume control valve can be easily manufactured to enable mass production, and the cost can be reduced.

The capacity control valve of the present invention according to claim 5 is
A seal portion having a small friction coefficient is provided between the sliding surface of the working chamber and the fitting surface of the working rod.

In the displacement control valve of the present invention according to claim 5, the entire surface on which the pressure sensitive rod slides on the valve housing is only the sliding surface between the operating rod and the operating chamber. Moreover, this sliding surface is an outer diameter surface in which the actuating rod and the valve body have the same diameter. Therefore, if the sliding surfaces are supported by the seal portion having a small friction coefficient, the sliding resistance is minimized, and the responsiveness of the valve body can be improved.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a capacity control valve of a preferred embodiment according to the present invention will be described in detail with reference to the drawings. still,
Each drawing described below is not a conceptual drawing for patent but a design drawing with accurate dimensions.

FIG. 1 is a sectional view of a displacement control valve according to the present invention. In FIG. 1, reference numeral 1 is a displacement control valve. The capacity control valve 1 is provided with a valve housing 2 forming an outer shape. The valve housing 2 includes a first valve housing 2 having a through hole provided therein with a function.
A and a second valve housing 2B that is integrally fitted to one end of the first valve housing 2. The valve housing 2 is made of metal such as iron, aluminum, stainless steel, or synthetic resin material.

The partition adjusting portion 3 is coupled to one end of the through hole, and the second valve housing 2 that seals the other end of the through hole is fitted to the first valve housing 2A. The second valve housing 2B includes a pressure sensitive rod 20.
It is separated from the first valve housing 2A for assembling, and may not have the shape shown in FIG. For example, if the working chamber 7 is sealed with a blind plug, the entire capacity control valve 1 can be made smaller. Further, in this miniaturization, since the valve body and the operating rod can have the same diameter (Ar2), the entire pressure-sensitive rod 20 can be simply configured. And
This results in further miniaturization of the valve housing 2.
Further, the partition adjusting unit 3 is hermetically fitted and fixed to the volume chamber 4 of the first valve housing 2A, but it may be screwed into the hermetically sealed seal so that the partition adjusting unit 3 can be axially moved and adjusted in accordance with the spring constant.

The partition of the through-hole penetrating the first valve housing 2A in the axial direction is formed in the volume chamber 4 on one end side. Further, a valve hole 5 having a diameter smaller than that of the capacity chamber 4 is connected to the through hole so as to communicate with the capacity chamber 4. Further, a valve chamber 6 having a larger diameter than the valve hole 5 communicating with the valve hole 5 is provided in the section of the through hole. Further, a working chamber 7 that communicates with the valve chamber 6 is continuously provided in the section of the through hole. And the valve hole 5 of the valve chamber 6
A valve seat 6A is formed on the side.

A first communication passage 8 is formed in the valve chamber 6 of the valve housing 2. The first communication passage 8 is communicable with an external control fluid, for example, a fluid having a control pressure Pd in the variable displacement compressor. Further, the working chamber 7 of the valve housing 2 is formed with a detection communication passage 10 for introducing a fluid having an external suction pressure Ps. One end side of the working chamber 7 is formed to have a slightly larger diameter surface than the valve chamber 6, and the suction pressure Ps can act on the pressure receiving area of the working rod 23 within the large diameter surface. Further, the valve chamber 6 side of the large diameter surface is formed on a sliding surface 7A so as to seal and slide with the operating rod 23. A seal portion (not shown) can be provided on the sliding surface 7A. The seal portion is made of a material having a low friction coefficient. For example, the seal portion may be a seal film having a fluororesin film adhered to the sliding surface 7A, or a rubber or fluororesin O having a low friction coefficient.
There is a ring. Since the valve element 21 and the operating rod 23 can be configured to have the same cross-sectional area of Ar2 and the same outer diameter, the outer peripheral surface of the valve element 21 or the operating rod 23 is sealed by only an O-ring such as fluororesin. It is possible to support the pressure-sensitive rod 20 movably and improve the response of the entire pressure-sensitive rod 20.

Further, the control pressure Pd flowing into the volume chamber 4
The second communication passage 9 is formed to allow the fluid of FIG. The first communication passage 8, the second communication passage 9, and the detection communication passage 10 pass through the peripheral surface of the valve housing 2 in two equal distributions or four equal distributions. On the contrary, if necessary, the second
It is also possible to introduce the control fluid from the communication passage 9 into the first communication passage 8. The technology to change the location of this passage is the pressure sensitive device 2.
2 effective pressure receiving area Ab and the valve body 21 seal pressure receiving area A
Since s and the pressure receiving area Ar2 on the back surface of the valve body 21 or the back surface of the operating rod 23 are configured to be substantially the same, the effective pressure receiving area Ab of this pressure sensing device 22 and the seal pressure receiving area As of the valve body 21 are Control pressure Pd acting and control chamber pressure Pc
This is because they can be canceled out by canceling. Moreover, even if the arrangement of the passages is changed in this way, various similar effects as the present invention can be obtained. For this reason, when there is a problem in the installation location of the air machine such as the variable displacement compressor, there is an advantage that it can be installed without problems. Furthermore, the outer peripheral surface of the valve housing 2 is formed in four steps, and mounting grooves 40 for O-rings are provided at three locations on the outer peripheral surface of the four cross sections. Then, in each mounting groove 40, an O-ring 4 that seals between the valve housing 2 and the mounting hole of the casing shown by a virtual line for fitting the valve housing 2
1 is attached

A pressure sensitive device 22 is provided in the volume chamber 4. In this pressure-sensitive device 22, one end of a metal bellows 22A is hermetically coupled to the partition adjusting unit 3 and the other end is hermetically coupled to a flange 22B. This bellows 2
2A is made of phosphor bronze or the like, and its spring constant is designed to have a predetermined value. When the spring constant of the bellows 22A is weak, a coil spring (not shown) may be internally provided to bias the spring constant of the bellows 22A. The pressure sensing device 22 is designed to expand and contract within the volume chamber 4 in accordance with the correlation between the inherent spring constant of the pressure sensing device 22 and the control pressure Pd or the control chamber pressure Pc. Vacuum or air is contained in the internal space of the pressure sensitive device 22. The control pressure Pd or the control chamber pressure Pc acts on the effective pressure receiving area Ab of the bellows 22A to cause the pressure sensing device 22 to contract.

As shown in FIG. 2, the male screw portion of the connecting rod 20B at one end of the pressure-sensitive rod 20 is screwed and coupled to the female screw portion of the flange portion 22B. This connecting rod 20
An O-ring is interposed at the joint between B and the flange 22B to seal the joint. The cross-sectional area of the connecting rod 20B provided on the pressure sensitive rod 20 is the pressure receiving area Ar1. The outer diameter of the connecting rod 20B is formed to be smaller than the diameter of the valve hole 5, and is formed in the clearance passage so that the fluid can pass between the valve hole 5 and the connecting rod 20B.

As shown in FIG. 1 or 3, the pressure sensitive rod 2
A valve body 21 continuous with the connecting rod 20B is formed at a part of 0. The valve body 21 is provided with a valve portion surface 21A that is joined to the valve seat 6A. The close contact surface between the valve seat 6A and the valve portion surface 21A may be a flat surface joint, but as shown in FIG. 3, a part of the valve seat 6A may be formed into a tapered surface, or the entire surface of the valve seat 6A may be formed into a tapered surface. Then, it is recognized that the sealing ability is good when the valve is closed. The seal pressure receiving area As to which the valve portion surface 21A is joined is the effective pressure receiving area A of the pressure sensing device 22.
It has the same or substantially the same area as b. or,
The pressure receiving area of the valve body 21 or the operating rod 23 is formed to be Ar2. The outer diameter of the valve body 21 is substantially the same as the inner diameter of the valve chamber 6 and is slidably fitted therein. The outer diameter of the working rod 23 in the boundary region of the same diameter between the valve body 21 and the working rod 23 is fitted to the sliding surface 7A of the valve chamber 6 or the working chamber 7 so that the fluid of the suction pressure Ps does not leak. In the fitted state, the sealing effect is exhibited without providing a seal portion such as an O-ring between the fitted portions. The connecting portion between the valve chamber 6 and the first communication passage 8 is formed in an annular groove having a diameter larger than that of the valve chamber 6, and the discharge pressure Pd
Is configured to easily flow in. And the operating rod 2
3 or the pressure receiving area Ar2 of the valve body 21, the seal pressure receiving area As of the valve portion surface 21A, and the effective pressure receiving area Ab of the pressure sensing device 22 are the same or substantially the same area.

The pressure-sensitive rod 20 is formed with an actuating rod 23 at the end opposite to the pressure-sensitive device 22. Working rod 23
The outer diameter of is substantially the same as the outer diameter of the valve body 21. The other end side of the sliding surface 7A of the working chamber 7 is formed to have a slightly larger diameter surface than the outer shape of the working rod 23, and the fluid of the suction pressure Ps from the detection communication passage 10 easily flows into this large diameter surface. It is configured.

Spring means 24 is provided on the back surface of the operating rod 23. The spring means 24 is seated on the second valve housing 2 </ b> B so that the actuating rod 23 is attached to the pressure sensing device 22.
Is pressed in the direction of. This spring means 24 is designed corresponding to the spring constant of the pressure sensitive device 22. The spring constant of the spring means 24 is designed to be smaller than the spring constant of the pressure sensitive device 22.

In this displacement control valve 1, the relational expression between the respective spring constants for generating the pressing force and the balance force generated by the inflowing working fluid pressure is considered based on the configuration shown in FIG. , Pc (Ab-Ar1) -Pc (As-
Ar1) + Pd (As-Ar2) + Ps * Ar2 = Fb
-S1. When this relational expression is arranged, Pc (Ab-
As) + Pd (As-Ar2) + Ps * Ar2 = Fb-
It becomes S1. However, in this formula, since the function is possible even if S1 is set to 0, the elastic means 24 may not be provided. When the relation between the pressure-sensitive device 22 and each pressure-receiving area of the pressure-sensitive rod 20 is Ab = As = Ar, the above equation is Ps × Ar2 =
It becomes Fb. That is, the effective pressure receiving area Ab of the pressure sensing device 22.
When the seal pressure receiving area As of the valve portion surface 21A and the pressure receiving area Ar2 of the valve body 21 or the operating rod 23 are made the same,
The displacement control valve 1 can control the operation only by the suction pressure Ps flowing from the detection communication passage 10. still,
The symbols in the above equation are as follows. Ab ... Effective pressure receiving area of the pressure sensing device As ... Seal pressure receiving area of the valve body Ar1 ... Pressure receiving area (cross-sectional area) of the connecting rod 20B Ar2 ... Pressure of the valve body 21 or the operating rod 23 Area Fb ... Unique spring constant S1 of pressure-sensitive device ... Spring constant Ps of spring means 24 ... Suction pressure Pd ... Discharge pressure (control pressure) Ps ... Crank chamber pressure (control chamber pressure)

FIG. 4 shows an open state in which the valve body 21 is fully opened when the suction pressure Ps does not act on the displacement control valve 1 from the detection communication passage 10. In this case, the control pressure Pd passes from the first communication hole 8 through the valve hole 5 into the capacity chamber 4, and acts on the effective pressure receiving area Ab of the pressure sensing device 22 while the second communication passage 9 is being operated.
To a control chamber (not shown) to control the control chamber pressure Pc in the control chamber by the control pressure Pd. The action of the capacity control valve 1 at this time is canceled by canceling the force due to the fluid pressure acting on the effective pressure receiving area Ab of the pressure sensing device 22 and the force due to the fluid pressure acting on the seal pressure receiving area As of the valve portion surface 21A. It Then, the set suction pressure Ps of the working chamber 7
As a result, the control flow rate flowing through the valve hole 5 is accurately controlled. That is, the capacity control valve 1 is controlled by the suction pressure Ps, and the force acting on the pressure sensing device 22 and the force acting on the valve body 21 are canceled out.
Is pressed to control the degree of valve opening / closing between the valve portion surface 21A of the valve body 21 and the valve seat 6A. Since the volume of the control pressure Pd fluid of the volume control valve 1 is controlled by the suction pressure Ps, a minute flow rate control of the control chamber from a high pressure to a constant pressure can be performed by this controlled control fluid.

FIG. 5 shows a position in which the suction pressure Ps acts on the operating rod 23 of the displacement control valve 1 to bring the opening degree of the valve body 21 to the intermediate state. Even in this state, as in the fully opened state described above, the effective pressure receiving area Ab of the pressure sensitive device 22 and the valve portion surface 21.
Since the forces acting on the seal pressure receiving area As of A are the same, they cancel each other out and the valve opening degree of the valve body 21 can be minutely controlled by the suction pressure Ps.

FIG. 6 shows a position where the suction rod Ps of the displacement control valve 1 is acted on by the suction pressure Ps at its maximum and the opening degree of the valve body 21 is closed. In this case, suction pressure P
Force acting on s (Ps × Ar2) and force S of the spring means 24
1 is greater than the opposing force Fb of the pressure-sensitive device 22, and the total force acts on the actuating rod 23 to join the valve body 21 to the valve seat 6A and close the valve. In this state, the valve body 21 is tightly joined to the valve seat 6A, and the fluid of the control pressure Pd introduced from the first communication passage 8 does not flow into the valve body 2
Since it acts on the outer peripheral surface of No. 1, the valve body 21 does not fluctuate even if the fluid having the control pressure Pd is at high pressure. As a result, the fluid having the control pressure Pd can be surely closed.

The main structure of this displacement control valve 1 is composed of a valve housing 2, a pressure sensitive rod 20, and a pressure sensitive device 22. The valve housing 2 can be joined by simply fitting the second valve housing 2B to one end of the first valve housing 2A as shown in FIG. In addition to this, this connection can be achieved by a method of stopping it from the outer circumference of the second valve housing 2 via a set screw or by screwing together the screw portions. If the fitting surfaces to be joined are joined via an O-ring (not shown), the joining surfaces between them can be reliably sealed. Therefore, the assembly of the valve housing 2 can be integrated very easily.

Further, the pressure-sensitive rod 20 including the connecting rod 20B, the valve body 21 and the operating rod 23 is connected to the pressure-sensitive device 22 as shown in FIG.
As shown in FIG.
A groove is provided on the other end of the pressure sensitive rod, and a snap ring (not shown) is fitted into the groove to couple the flange portion B so as not to separate from the pressure sensitive rod 20, or further, press the pressure sensitive rod 20 into the flange portion 22B. The pressure-sensitive rod 20 and the pressure-sensitive device 22 can be easily coupled by fitting. Therefore, the pressure-sensitive rod 20 can be easily integrated.

When the pressure-sensitive rod 20 thus formed is assembled in the valve housing 2, the capacity control valve 1 can be easily assembled.
Is assembled. As a result, it is possible to reduce the assembly cost and provide the capacity control valve 1 at low cost.

Since the pressure-sensitive rod 20 is wholly integrated, the centering of the whole is easy even by machining, and the precision of the fitting surfaces of the valve body 21, the operating rod 23, etc. can be improved. Therefore, it becomes possible to reduce the sliding resistance when the pressure-sensitive rod 20 slides and improve the responsiveness during operation.
Further, as described above, since the respective functional portions of the through hole of the valve housing 2 can be machined at the same time, the machining accuracy can be improved and the sliding resistance with the pressure sensitive rod 20 can be reduced. It becomes possible to do.

Next, the capacity control valve 1 of the present invention can be used in an air machine such as an air pump or a compressor.
Hereinafter, a case where the compressor is used in a variable displacement compressor will be described as an embodiment.

FIG. 7 is a sectional view showing the relationship between the variable displacement compressor 50 and the displacement control valve 1. Of these, the displacement control valve 1 has the same configuration as that of FIG. 1, and therefore the configuration of the displacement control valve 1 has been described above.

In FIG. 7, the variable capacity compressor 50 is
Cylinder block 5 provided with a plurality of cylinder bores 51A
1, a front housing 52 provided at one end of the cylinder block 51, and a rear housing 53 connected to the cylinder block 51 via a valve plate device 54 form a casing having an outer shape. The casing includes a cylinder block 51 and a front housing 52.
A crank chamber 55 partitioned by and is provided, and a shaft 56 traversing the crank chamber 55.
Is provided. A disk-shaped swash plate 57 is arranged around the center of the shaft 56. This swash plate 57
Is a rotor 58 fixed to the shaft 56 and a connecting portion 59.
It is configured so that the tilted angle can be changed.

One end of the shaft 56 extends through the inside of the boss portion 52A projecting to the outside of the front housing 52 to the outside. An electromagnetic clutch 70 is provided around the boss portion 52A via a bearing 76. The electromagnetic clutch 70 is provided around the boss 52A via a bearing 76.

A seal portion 75 is arranged between the shaft 56 and the boss portion 52A, and the inside and the outside are blocked by the seal portion 75. Further, the other end of the shaft 56 exists inside the cylinder block 51, and the other end is supported by the support portion. The thrust bearings 77A and 77B that rotatably support the shaft 56 are
6 are provided at both ends of the shaft 6, and rotatably support the shaft 56.

A piston 62 is provided in the cylinder bore 51A.
Is provided. The piston 62 and the swash plate 57 are connected by a connecting rod having balls 63 at both ends. The swash plate 57 and the connecting portion 59 are rotatably connected to each other via a thrust bearing. The piston 62 and the swash plate 57 are configured to interlock with each other.

The rear housing 53 is formed by dividing a suction chamber 65 and a discharge chamber 64. The suction chamber 65 and the cylinder bore 51A communicate with each other through a suction valve provided in the valve plate device 54. The discharge chamber 64 has the cylinder bore 5
1A and the valve plate device 54 are in communication with each other via a discharge valve. The suction chamber 65 communicates with the crank chamber 55 via a passage having an orifice.

An empty chamber (not shown) is provided in the convex portion on the right side of the rear housing 53, and the capacity control valve 1 is arranged in this empty chamber. In FIG. 1, this capacity control valve 1
Is drawn out to the outside for easy understanding.

In the configuration of the displacement control valve 1 and the variable displacement compressor 50, since the swash plate 57 rotates together with the rotation of the rotor 58, the piston 63 reciprocates as the inclination angle of the swash plate 57 changes. . The refrigerant discharged from the discharge chamber 64 according to the reciprocating motion of the piston 63 is supplied from the condensation chamber P to the evaporation chamber G via the expansion valve, and returns to the suction chamber 65 while performing the cooling as set. ing.

An example of the operation of the capacity control valve 1 will be described below. Now, when the discharge pressure (control pressure) Pd is constant and the suction pressure Ps falls below the control point (set suction pressure Ps1), the effective pressure receiving area Ab of the pressure sensing device 22 and the seal pressure receiving area As of the valve portion surface 21A are Pressure receiving area Ar2 of the operating rod 23
Are configured in the same manner, the valve body 21 is opened from the valve seat 6A in accordance with the self-spring constant of the bellows 22A or the like provided in the pressure sensing device 22 which is set to the largest value. The open state of the capacity control valve 1 becomes the state shown in FIG.
Then, when the valve body 21 opens, the capacity chamber 4 and the valve chamber 6 communicate with each other through the valve hole 5. Due to this valve opening operation, the discharge chamber 6
The fluid having the discharge pressure Pd of 4 flows into the first communication passage 8. The fluid having the discharge pressure Pd flowing from the first communication passage 8 into the valve chamber 6 flows into the capacity chamber 4 from the valve hole 5, flows into the second communication passage 9, and flows into the crank chamber 55, which is a control chamber.

Discharge pressure Pd flowing into the crank chamber 55
Increases the pressure in the crank chamber 55, the suction chamber 6
5 suction pressure Ps and crank chamber 55 crank chamber pressure P
The differential pressure with respect to c becomes large, and the inclination angle of the swash plate 57 of the variable displacement compressor 50 is reduced. For this reason, the volume of fluid in the piston chamber is reduced, so that the suction pressure Ps is controlled to approach the set control point.

Contrary to the above, when the suction pressure Ps becomes equal to or higher than the control point, the effective pressure receiving area Ab of the pressure sensing device 22 and the seal pressure receiving area As of the valve face 21A are configured to be the same. , The forces acting on the pressure receiving areas Ab and As are canceled and canceled, and the suction pressure Ps is reduced to the operating rod 2.
(3) The valve body 21 is moved to the valve seat 6A by acting on the pressure receiving area Ar2 to reduce the flow rate of the valve hole 5, and finally the valve is closed. When the valve body 21 is closed, the fluid having the discharge pressure Pd acts only on the outer peripheral surface of the valve body 21,
There is no acting force that moves the valve body 21 in the valve opening direction.

For this reason, the differential pressure between the crank chamber pressure Pc of the crank chamber 55 and the suction pressure Ps becomes small, and conversely to the above, the inclination angle of the swash plate 57 of the variable displacement compressor 50 becomes large, The flow rate of the fluid having the discharge pressure Pd of the variable displacement compressor 50 is controlled to increase.

Thus, the variable capacity compressor 50 of the present invention
According to this, the effective pressure receiving area Ab of the pressure sensitive device 22 and the valve portion surface 2
Since the seal pressure receiving area As of 1A and the pressure receiving area Ar2 of the operating rod 23 are configured to be the same, the displacement control valve 1 can be operated only by the suction pressure Ps, and the solenoid portion that operates the displacement control valve 1 can be operated. do not need. For this reason, since it is not necessary to attach components such as a solenoid portion, the cost of the capacity control valve 1 can be greatly reduced. Further, the operation of the capacity control valve 1 by the solenoid portion sometimes causes malfunction, but since the capacity control valve 1 of the present invention can be operated by the suction pressure Ps acting only on the pressure receiving area Ar2 of the operation rod 23, There are few malfunctions, and furthermore, if the control point of the suction pressure Ps is arbitrarily set, the refrigerant of the variable displacement compressor 50 can be accurately controlled.

Further, the capacity control valve 1 has few parts as a whole,
Furthermore, since the structure is simple, it is possible to reduce failures. Further, the valve housing 2 and the pressure sensitive rod 2
The structure of No. 0 is simple and easy to assemble, and machining is easy, and high precision can be easily obtained. Therefore, it can be expected to provide the volume control valve 1 that can be mass-produced and is low in cost.

[0056]

The capacity control valve according to the present invention has the following effects. According to the capacity control valve of the present invention according to claim 1, since the effective pressure receiving area of the pressure sensing device and the seal pressure receiving area of the valve body are configured to be the same or substantially the same, the control fluid pressure and the control chamber pressure are Even if the control fluid acts on each pressure receiving surface through the valve hole, this acting force cancels out. Therefore, it is possible to eliminate the acting force that adversely affects the valve element. Moreover, since the pressure receiving area of the suction pressure acting on the actuating rod is the same as the seal pressure receiving area, it is possible to improve the operation response accuracy with respect to the control pressure of the valve body and to simplify the structure of the valve body. Due to the balance of the forces acting on the operating mechanism of each pressure receiving surface including the valve body, the suction pressure acts on the pressure receiving area of the back surface of the valve body (the back surface of the operating rod) in the capacity control valve, and controls when the valve is closed. The fluid of pressure acts only on the outer peripheral surface that does not operate the valve element, and an effect that enables control without malfunction is achieved.

Further, when the valve is closed, the acting force of the actuating rod due to the suction pressure, the biasing force of the spring constant of the pressure sensing device itself, and the elastic means for closing the valve body are a function of the opening. Only when the valve is opened, the control pressure exerts an excellent effect of controlling the valve body by relating it. Further, it becomes possible to reduce the hysteresis in the operation at the set low suction pressure which is usually used frequently, and prevent the control characteristics of the displacement control valve from being adversely affected. In particular,
When using the electromagnetic attraction force, this hysteresis increases. However, in the capacity control valve of the present invention having no electromagnetic coil portion, the hysteresis can be prevented and the control range of the set value by the suction pressure can be expanded. It will be possible. Then, the displacement control valve can be accurately controlled by the suction pressure.

According to the displacement control valve of the present invention according to claim 2, in the variable displacement compressor, the discharge pressure and the crank chamber pressure are canceled by both pressure receiving surfaces which receive the discharge pressure through the valve hole. Since it is canceled, it is excluded from the balance of the forces acting on the operating mechanism of each pressure receiving surface. Therefore, it is possible to obtain a displacement control valve that enables highly accurate control by the suction pressure excluding the crank chamber pressure and the discharge pressure. Moreover, in the displacement control valve, the discharge pressure is configured to act around the valve body,
When the valve is closed, it is possible to perform control to cancel the action of the discharge pressure on the valve body. Moreover, since the displacement control valve can configure the pressure-sensitive rod in a small size, the displacement control valve can be attached to an optimum location of the displacement control type compressor, and the displacement control type compressor can be downsized.

According to the capacity control valve of the third aspect of the present invention, the control fluid pressure from the first communication passage acts on the outer peripheral surface of the valve body. Even if the value is high, the valve element is not activated or fluctuated to cause a malfunction. In particular, if this capacity control valve is adopted in a variable capacity compressor, etc., the effect of controlling the pressure or capacity in the control chamber as set without being affected by not only the discharge pressure but also the control chamber pressure by the suction pressure Play.

According to the capacity control valve of the present invention as defined in claim 4, the entire pressure-sensitive rod is formed into one rod.
Since it is not necessary to connect many rods individually by integrally providing a connecting rod, a valve body, and an operating rod on the rod of the book, the connected end faces are worn and the operation and performance of the capacity control valve deteriorate. Has an effect of effectively preventing.

According to the capacity control valve of the fifth aspect of the present invention, the surface on which the pressure sensitive rod slides on the valve housing is only the sliding surface between the operating rod and the operating chamber. Moreover, since the outer diameter of the valve body and the outer diameter of the operating rod can be made the same, it is possible to seal the sliding surface very easily. For this reason, the frictional resistance between the sliding surfaces can be minimized,
It has the effect of improving the responsiveness in the control of the valve body.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a displacement control valve according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the pressure sensitive device shown in FIG.

3 is an enlarged cross-sectional view of the inside of the valve chamber shown in FIG.

FIG. 4 is a cross-sectional view of an open state of the capacity control valve shown in FIG.

5 is a cross-sectional view of the displacement control valve shown in FIG. 1 in an intermediate valve open state.

FIG. 6 is a cross-sectional view of the displacement control valve shown in FIG. 1 in a closed state.

FIG. 7 is a cross-sectional view of a variable displacement compressor and a displacement control valve according to the present invention.

FIG. 8 is a cross-sectional view of a conventional control valve for a variable displacement compressor.

[Explanation of symbols]

1 Capacity control valve 2 valve housing 2A 1st valve housing 2B 2nd valve housing 3 Partition adjustment section 4 capacity room 5 valve holes 6 valve chambers 6A valve seat 7 working chamber 7A inner diameter surface 8 first passage 9 Second communication passage 10 Detection passage 20 Pressure-sensitive rod 20B connecting rod 21 valve 21A valve face 22 Pressure-sensitive device 22A Bellows 22B Flange part 23 Working rod 24 Spring means Ps suction pressure Pd Discharge pressure (control pressure) PC crank chamber pressure (control chamber pressure) Ab Effective pressure receiving area of pressure sensitive device As Seal area of valve face Ar2 working rod pressure receiving area S1 Spring force Fb Spring force of pressure sensitive device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshiaki Iwa             1-12-15 Shibadaimon, Minato-ku, Tokyo EAG             Within Le Industry Co., Ltd. (72) Inventor Ryosuke             1-12-15 Shibadaimon, Minato-ku, Tokyo EAG             Within Le Industry Co., Ltd. (72) Inventor Yoshihiro Ogawa             1-12-15 Shibadaimon, Minato-ku, Tokyo EAG             Within Le Industry Co., Ltd. (72) Inventor Katsuya Shirai             1-12-15 Shibadaimon, Minato-ku, Tokyo EAG             Within Le Industry Co., Ltd. (72) Inventor Takahiro Maeda             1-12-15 Shibadaimon, Minato-ku, Tokyo EAG             Within Le Industry Co., Ltd. (72) Inventor, Kunsuke Uemura             1-12-15 Shibadaimon, Minato-ku, Tokyo EAG             Within Le Industry Co., Ltd. F term (reference) 3H045 AA04 AA25 BA19 CA02 DA25                       EA13 EA33                 3H056 AA05 BB06 BB22 BB32 CA02                       CB01 CD04 CD06 GG02 GG12                 3H076 AA06 BB32 CC12 CC20 CC84                 5H316 AA11 BB01 DD01 DD03 DD11                       EE02 EE10 EE12 GG01 JJ01                       JJ11 KK01

Claims (6)

[Claims] 1. A capacity control valve for controlling a valve opening of a valve hole provided in a valve housing and introducing a control fluid flowing through the valve hole into a control chamber to control a flow rate or a pressure in the control chamber. A capacity chamber provided at one end of the valve housing and communicating with a second communication passage; and a valve chamber having a valve seat, which communicates with the capacity chamber via a valve hole and is capable of communicating with the first communication passage. An operating chamber that communicates with the valve chamber and also communicates with the detection communication passage; and an operation rod that is movably disposed in the operation chamber and has a pressure-receiving area on the back surface on which suction pressure from the detection communication passage can act. A valve body that is integral with the front surface of the actuating rod and is movably disposed in the valve chamber and has an end face having a valve portion surface that can be opened and closed with the valve seat; and the valve body and the valve hole and the gap passage. Connecting rod to be fitted through the connecting rod, and the connecting rod And having an effective pressure receiving area that is disposed in the volume chamber and is pressure sensitive to the working fluid pressure in the volume chamber, and urges the valve body in the direction to close the valve by the pressure received in the pressure receiving effective area. A pressure sensitive device for urging the valve body in a direction to open the valve body by a unique spring force,
The effective pressure receiving area of the pressure sensing device, the seal pressure receiving area of the valve body surface of the valve body that contacts the valve seat, and the pressure receiving area of the actuating rod or the valve body are the same or substantially equal areas. A capacity control valve characterized in that 2. The displacement control valve according to claim 1, wherein the displacement control valve controls a displacement or pressure in a crank chamber of a variable displacement compressor. 3. The displacement control valve according to claim 1, wherein the control fluid pressure from the first communication passage acts on the outer peripheral surface of the valve body. 4. The operating rod, the valve body, and the connecting rod are integrally formed, and one end of the connecting rod is connectable to a pressure-sensitive device. The capacity control valve according to claim 3. 5. A seal portion having a small friction coefficient for sealing a gap between the sliding surface of the working chamber and the working rod fitted into the sliding face of the working chamber. The capacity control valve described in. 6. The displacement control valve according to claim 1, wherein the valve body has an elastic means for pressing the valve portion surface against the valve seat.