JP2001020857A - Control valve for variable displacement type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the increase of the number of parts and the number of installation processes and besides to prevent complication of passage structure. SOLUTION: A ball valve element 37 is provided to open and close communication passages 32, 34, and 33 to execute intercommunication between the suction port of a compressor and a crank chamber. The ball valve element 37 is energized in an opening direction through the spring force of a compression coil spring 44 and a bellows device 40 is provided to drive the ball valve element 37 in an opening direction resultant from application of the suction pressure of the compressor. The ball valve element 37 and the bellows device 40 are directly interconnected with the ball valve element 37 forming an automatic centripetal ball. A valve housing 31 is joined at its one end with the ball valve element 37 and a discharge pressure introduction hollow pipe body 49 is provided to directly exert the discharge pressure of the compressor in the opening direction of the ball valve element 37. A compression coil spring 50 energizes the ball valve element 37 through the discharge pressure introduction hollow pipe body 49.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control valve for a variable displacement compressor, and more particularly, to a displacement control valve for a swash plate type variable displacement compressor used in a vehicle air conditioner or the like.

[0002]

2. Description of the Related Art As a capacity control valve for a swash plate type variable displacement compressor, Japanese Patent Publication No. 3-53474 and Japanese Utility Model Publication No.
A capacity control valve disclosed in JP-A-17010 and JP-A-8-177735 is conventionally known.

[0003] This displacement control valve basically reduces the displacement in response to a rise in the pressure in the crankcase of a compressor incorporating a swash plate, and increases the displacement in response to a decrease in the pressure in the crankcase. In a variable displacement compressor, a communication path connecting a suction port of the compressor and a crank chamber is provided with an equilibrium relationship between a valve opening force of a pressure responsive device responding to a suction pressure of the compressor and a spring force of a valve closing spring. A control valve that opens and closes with a valve body driven by the compressor and controls a suction pressure of a compressor supplied to a crank chamber, further exerts a discharge pressure of the compressor in a valve opening direction to open and close the valve body. The point is shifted in accordance with the discharge pressure, and the capacity is controlled in accordance with the outside air load (discharge pressure).

[0004]

The above-mentioned conventional capacity control valves all achieve the intended purpose, but the number of parts and the number of assembling steps are increased, and the compressor housing is not provided. In the case of directly incorporating the pressure control valve into the compressor, the passage structure for guiding the suction pressure and the discharge pressure to each part of the displacement control valve becomes complicated, and the degree of freedom of the arrangement position in the compressor housing is limited. Not satisfactory.

As a pressure responsive device, there are a diaphragm device, a bellows device, and the like, and the driving force of these pressure responsive devices needs to act as an axial force on the valve element. Prying occurs, and the smoothness of the opening and closing movement of the valve body is impaired. For this reason, in the conventional capacity control valve, a spring and an automatic centripetal ball must be provided between the valve element and the pressure responsive device, and the number of parts and the number of assembling steps are increased.

The present invention has been made in view of the above problems, and does not require a special automatic centripetal ball or the like, simplifies the structure, and increases the number of parts and the number of assembling steps. To provide a control valve for a variable displacement compressor, which does not have a complicated passage structure as a compressor housing built-in type and has a high degree of freedom in arrangement position in the compressor housing. It is an object.

[0007]

In order to achieve the above object, a control valve for a variable displacement compressor according to the first aspect of the present invention includes a communication passage for communicating a suction port of the compressor with a crank chamber. A valve housing, a ball valve body provided in the valve housing to open and close the communication passage, a spring for urging the ball valve body in a valve closing direction, and the ball as an automatic centripetal ball using the ball valve body. A pressure responsive device that is directly connected to the valve body and is driven by the suction pressure of the compressor to drive the ball valve body in the valve opening direction; slidably fitted to the valve housing; During discharge pressure introduction, which is connected to the ball valve body and has an inlet for the discharge pressure of the compressor at the other end, and causes the discharge pressure of the compressor to act as a force in the valve opening direction on the back surface of the ball valve body through an internal passage. With an empty tube That.

According to a second aspect of the present invention, the discharge pressure introducing hollow tube is slidably fitted in a fitting hole formed in the valve housing.
The outer diameter dimension is equal to the effective diameter of the pressure receiving surface that exerts the discharge pressure of the compressor on the ball valve element.

According to a third aspect of the present invention, in the control valve for a variable displacement compressor, the discharge pressure introducing hollow tube is slidably fitted on an outer peripheral portion of a guide cylinder fixed to the valve housing. Is what it is.

According to a fourth aspect of the present invention, in the control valve for a variable displacement compressor, the valve urging means for urging the ball valve in the valve opening direction via the discharge pressure introducing hollow tube is further provided. It is provided.

According to the control valve for a variable displacement compressor according to the first aspect of the present invention, the discharge pressure of the compressor directly acts on the ball valve body by the discharge pressure introducing hollow tube, and the compression is correlated with the system load characteristic. A high pressure influence characteristic (discharge pressure influence characteristic) corresponding to the machine discharge pressure is set. Further, the ball valve element is an automatic centripetal ball, and the ball valve element is directly connected to the pressure responsive device, so that a special automatic centripetal ball or the like is not required.

According to the control valve for a variable displacement compressor according to the second aspect of the present invention, the discharge pressure introducing hollow pipe slidably fitted in the fitting hole is provided on the end face on the discharge pressure introducing port side. The discharge pressure of the compressor also acts, but since the outer diameter of the discharge pressure introducing hollow tube is equal to the effective diameter of the pressure receiving surface of the ball valve,
The discharge pressure of the compressor acting on the end face on the discharge pressure inlet side of the discharge pressure introducing hollow tube is canceled.

According to the control valve for a variable displacement compressor according to the third aspect of the present invention, the discharge pressure of the discharge pressure introducing hollow tube does not act on the end face of the discharge pressure introducing hollow tube. It is not necessary to match the effective diameter and the outer diameter of the horn.

According to the control valve for a variable displacement type compressor according to the fourth aspect of the present invention, the ball valve is moved in the valve opening direction via the discharge pressure introducing hollow tube by the urging force of the valve urging means. As a result, the vibration resistance of the ball valve body and the pressure responsive device is improved.

[0015]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

(Embodiment 1) FIG. 1 shows a variable displacement compressor incorporating a control valve according to the present invention, and FIG. 2 shows a first embodiment of the capacity control valve according to the present invention.

As shown in FIG. 1, a swash plate type variable displacement compressor 1 communicates with a crank chamber 3 defined by a compressor housing 2 and a crank chamber 3 at one stroke end. And a plurality of cylinder chambers 4. A piston 5 is fitted into each of the cylinder chambers 4 so as to be slidable in the axial direction, and one end of a piston rod 6 is connected to the side of the crank chamber 3 of each piston 5.

The compressor housing 2 rotatably supports a drive shaft 7. The drive shaft 7 is drivingly connected to an engine (not shown) by a drive belt (not shown) stretched over a pulley 8. Is driven to rotate.

The drive shaft 7 is connected to a wobble plate (swash plate) 9 in the crank chamber 3 by a known connecting mechanism (not shown) in a torque transmitting relationship so that the mounting angle can be changed.
A piston rod 6 is engaged with a plate surface of the wobble plate 9 on the cylinder chamber 4 side so as to transmit an axial force.

When the wobble plate 9 is rotated by the drive shaft 7 in an inclined state, the piston 5 of each cylinder chamber 4 reciprocates with a stroke corresponding to the inclination angle of the wobble plate 9, and the inclination angle is determined by the crank angle. The pressure is automatically adjusted in accordance with the pressure difference between the chamber pressure Pc and the suction pressure (compressor suction pressure) Ps of each cylinder chamber 4.

In this case, the compressor 1 has a crank chamber pressure P
c, the inclination angle of the wobble plate 9 is reduced and the stroke of the piston 5 is reduced to reduce the displacement, and the wobble plate 9 is reduced in response to the decrease in the crank chamber pressure Pc.
As the stroke of the piston 5 increases and the stroke of the piston 5 increases, the displacement increases, and the crank chamber pressure Pc becomes substantially equal to the suction pressure Ps, whereby the engine enters a full load operation state.

Each cylinder chamber 4 has a suction port 14 and a discharge port 15 each having a one-way valve having a suction valve 12 and a discharge valve 13. The suction port 14 of each cylinder chamber 4 is formed by a suction passage 16. The suction port 17 communicates with the suction port 17, and the discharge port 15 communicates with the discharge connection port 19 through the discharge passage 18. The evaporator 20, the expansion valve 21, the condenser 22, and the like are connected to the suction connection port 17 and the discharge connection port 19. Is connected.

A control valve receiving hole 23 having a bottomed hole is formed in the compressor housing 2.
The control valve 30 according to the present invention is inserted and fixed therein.

The control valve 30 has a cylindrical valve housing 31 inserted into the control valve receiving hole 23.

As shown in FIG. 2, the valve housing 31 includes a crank chamber-side passage 32 and a suction port-side passage 33 extending radially across an intermediate portion of the valve housing 31; A valve chamber 34 is formed inside 31 and between the crank chamber side passage 32 and the suction port side passage 33. Also, the valve housing 3
On the outer peripheral portion of the cylinder 1, an annular peripheral groove 35 for the crank chamber side passage 32 and an annular peripheral groove 36 for the suction port side passage 33 are formed.

A ball valve body 37 is disposed in the valve chamber 34. The ball valve body 37 is selectively seated on a valve seat 38 so that the crank chamber-side passage 32 and the suction port-side passage 3 are disposed.
3. Communication with 3 is cut off.

A bellows housing case 39 is caulked to one end (lower end) of the valve housing 31.

A bellows device 40 having a closed structure, which is a pressure responsive device, is disposed in the bellows housing case 39. The bellows device 40 includes a bellows-shaped bellows body 41 having an end plate 43 integrally at one end, and a bellows body 41.
Is closed by an end plate 42, and the inside is at a vacuum pressure. End plate 42 and end plate 4 in bellows body 41
3 between the bellows device 40 in the extension direction (valve closing direction)
, A compression coil spring 44 (corresponding to a spring in the claims) is provided. An abutment member 45 is provided on the end plate 43 side in the bellows main body 41, and a stopper surface portion 45a of the abutment member 45 and a stopper surface portion 4 of the end plate 42 are provided.
The maximum contraction amount of the bellows device 40 is defined by the contact with the bellows 2a.

An adjusting screw member 46 is screw-engaged with the bellows accommodating case 39. The adjusting screw member 46 is formed of a ball 47 disposed at the axis of the adjusting screw member 46 and a stopper surface 42a of the end plate 42. One end of the bellows device 40 is held by a spherical joint structure formed by a spherical recess 42b formed at the axial center portion (bellows center) of the bellows. That is, the bellows device 40 and the bellows housing case 39 are spherically connected by the spherical joint structure via the adjusting screw member 46.

The bellows device 40 is directly connected to the ball valve body 37 in a spherical joint manner at a spherical recess 43a formed at the axial center portion (bellows center) of the end plate 43. The axial force is transmitted to the valve body 37.

The bellows storage case 39 communicates with the suction port side passage 33, and the bellows device 40 expands and contracts in accordance with the differential pressure between the suction pressure introduced into the bellows storage case 39 from the suction port side passage 33 and the bellows internal pressure. .

A fitting hole 48 is formed at the other end (upper end) of the valve housing 31 so as to pass through the center of the valve housing 31 in the axial direction. A discharge pressure introducing hollow tube 49 is fitted in the fitting hole 48 so as to be slidable in the axial direction. One end (lower end) of the discharge pressure introducing hollow tube 49 is connected to the ball valve 37.
And welded together. The other end side (upper end side) of the discharge pressure introducing hollow tube 49 is in the fitting hole 48 and forms an inlet 49c for the discharge pressure Pd of the compressor 1. The diameter of the discharge pressure introducing hollow tube 49 is increased at a joint (lower end) with the ball valve body 37, and the outer diameter dimension Da of the discharge pressure introducing hollow tube 49 and the discharge pressure introducing hollow tube 49. The effective diameter Db of the pressure receiving surface portion 37a of the pressure exerted on the ball valve body 37 is equal to each other.

The enlarged diameter portion 49a of the discharge pressure introducing hollow tube 49
A compression coil spring 50 (corresponding to a valve element urging means in the claims) for urging the ball valve element 37 in the valve opening direction is provided between the valve housing 31 and the valve housing 31.

When the ball valve body 37 is opened, the spring load of the compression coil spring 50 is increased.
The bellows device 40 is set to such a value that the bellows device 40 does not rattle due to vibration during operation of the compressor 1.

As shown in FIG. 1, the control valve 30 having the above-described configuration is inserted and fixed in the control valve receiving hole 23 of the compressor housing 2, and the crank chamber side passage 32 and the annular peripheral groove 35 are connected to the crank chamber. The pressure passage 24 communicates with the crank chamber 3, the suction port side passage 33 and the annular circumferential groove 36 communicate with the suction port 14 via the suction pressure passage 25, and the fitting hole 4.
Numeral 8 communicates with the discharge port 15 through a discharge pressure passage 26.

The crank chamber pressure passage 24, the suction pressure passage 25, and the discharge pressure passage 26 are pressure passages formed inside the compressor housing 2.

Next, the operation of the control valve 30 having the above configuration will be described.

When the suction pressure Ps of the compressor 1 is
4 through the suction pressure passage 25 to reach the annular peripheral groove 36 and the suction port side passage 33, and further enters the bellows storage case 39 to act on the bellows device 40. Thus, the bellows device 40 expands and contracts in accordance with the pressure difference between the suction pressure Ps of the compressor 1 and the bellows internal pressure, and contracts against the spring force of the compression coil spring 44 as the suction pressure Ps increases. The discharge pressure Pd of the compressor, which is introduced by the discharge pressure introduction hollow pipe 49, is applied to the ball valve body 37 by the pressure receiving surface portion 37a.
, And is urged in the valve opening direction by the spring force of the compression coil spring 50, so that the valve is opened by contraction of the bellows device 40 due to an increase in the suction pressure Ps.

Assuming that the discharge pressure Pd acting as a correction pressure on the pressure receiving surface 37a is constant, the ball valve body 37 closes the valve due to the suction pressure Ps acting on the bellows device 40 and the valve closing force due to the spring force of the compression coil spring 44. It is driven to open and close by the balance relationship with the force.

Therefore, the suction pressure Ps is reduced by the compression coil spring 4
When the pressure is equal to or lower than the control valve set pressure (reference set pressure Pss) determined by the set load of No. 4, the ball valve element 37 moves to close by the spring force of the compression coil spring 44 and sits on the valve seat 38 to close the valve. . Thus, the supply of the suction pressure Ps to the crank chamber 3 is stopped, the crank chamber pressure Pc increases, and the compressor 1 enters the unload operation state.

On the other hand, when the suction pressure Ps becomes equal to or higher than the control valve set pressure (reference set pressure Pss), the ball valve body 37 opens and moves against the spring force of the compression coil spring 44, and the valve seat 38. Open the valve further apart. As a result, the suction pressure Ps is supplied to the crank chamber 3, the crank chamber pressure Pc becomes equal to the suction pressure Ps, and the compressor 1 enters a full load operation state.

As described above, when the discharge pressure Pd acting as the correction pressure on the pressure receiving surface portion 37a is fixed, that is, when the high pressure correction is not performed, the compressor 1 is indicated by a broken line in FIG. As shown, the capacity control operation is performed in which the suction pressure Ps is constant at the reference set pressure Pss.

Assuming that the effective area of the pressure receiving surface 37a is Ah, the discharge pressure Pd of the compressor 1 introduced into the discharge pressure introducing hollow tube 49 acts directly on the pressure receiving surface 37a of the ball valve body 37 as a correction pressure. , Ah · Pd is applied to the ball valve body 37.

The end face 4 of the discharge pressure introducing hollow tube 49 which is slidably fitted in the fitting hole 48 on the side of the introduction port 49c.
Although the discharge pressure Pd of the compressor 1 also acts on 9b, since the outer diameter dimension Da of the discharge pressure introducing hollow tube 49 is equal to the effective diameter Db of the pressure receiving surface portion 37a of the ball valve body 37, the discharge pressure is being introduced. The discharge pressure Pd of the compressor 1 acting on the end face 49b of the hollow pipe 49 is canceled.

Since the valve opening force of Ah · Pd which is correlated with the discharge pressure Pd acts on the ball valve body 37, the reference set pressure Pss in the balance state at the reference discharge pressure Pds.
Is set, the discharge pressure Pd decreases (the discharge pressure Pd
<Reference discharge pressure Pds) and required suction pressure P to open the valve
s increases, and the suction pressure Ps required for opening the valve decreases due to an increase in the discharge pressure Pd (discharge pressure Pd> reference discharge pressure Pds).

That is, when the discharge pressure Pd decreases to Pd ', the valve opening force decreases by Ah (Pd-Pd'),
From the ratio between the valve opening force and the effective pressure receiving area Ad of the bellows device 40, a pressure characteristic in which the valve opening pressure increases according to Ah (Pd-Pd ') / Ad is obtained.

This is shown by the following equation.
Discharge pressure introducing hollow tube 4 for determining the effective area Ah of 7a
By selecting an effective diameter of 9, the intended high pressure influence characteristics can be obtained. Ps = Pss-Ah (Pd-Pds) / Ad

As a result, as shown by the solid line in FIG. 3, the suction pressure Ps increases in proportion to the increase in the discharge pressure Pd.
Is obtained, and the control characteristics of the displacement control compressor can be matched by the discharge pressure Pd correlated with the system load characteristics.

This means that in the refrigerant circuit system, the evaporation load and the condensation load are in a proportional relationship, the evaporation load is proportional to the refrigerant circulation amount, and the pressure loss in the evaporator is proportional to the refrigerant circulation amount. As a result, the capacity of the compressor can be controlled effectively as an efficient energy saving system.

Further, the ball valve element 37 is connected to the bellows device 40.
And the ball valve element 37 acts as an automatic centripetal ball of the spherical joint between the valve element and the pressure responsive device, so that the driving force of the bellows device 40 is reduced without requiring a special automatic centripetal ball or the like. It acts well on the valve body 37 as an axial force.

(Embodiment 2) FIG. 4 shows Embodiment 2 of a control valve for a variable displacement compressor according to the present invention.
In FIG. 3, the portions corresponding to those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2, and the description thereof will be omitted.

In this embodiment, a guide cylinder 52 is inserted and fixed in a hole 51 corresponding to the fitting hole (48) of the first embodiment. The tube 49 is slidably fitted.

Also in this embodiment, the discharge pressure introducing hollow tube 4 is provided as a correction pressure on the pressure receiving surface portion 37a of the ball valve body 37.
9, the discharge pressure Pd of the compressor 1 introduced directly acts,
The same operation and effect as those of the first embodiment can be obtained, and the control valve characteristics at the time of actual operation can be made characteristics correlated with the discharge pressure Pd.

In this embodiment, since the discharge pressure Pd of the compressor 1 does not act on the end face 49a of the discharge pressure introducing hollow tube 49, the effective diameter of the discharge pressure introducing hollow tube 49 is reduced. There is no need to match the outer diameter.

It should be noted that also in this embodiment, the ball valve 3
7 is directly connected to the bellows device 40 and the ball valve 37
Acts as an automatic centripetal ball of a spherical joint between the valve element and the pressure responsive device, so that the driving force of the bellows device 40 is reduced without requiring a special automatic centripetal ball or the like.
7 works well as axial force.

In each of the above embodiments, the pressure responsive device is the bellows device 40 having a closed structure. However, the pressure responsive device is not limited to the bellows device 40.
A third embodiment in which a control valve for a variable displacement compressor in which a pressure responsive device is constituted by a diaphragm device, which may be a diaphragm device or the like, is described below as a third embodiment.

(Embodiment 3) FIG. 5 shows a capacity control valve according to Embodiment 3 of the present invention. In FIG. 5, portions corresponding to those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2, and description thereof will be omitted.

The diaphragm device 60 includes the valve housing 3
1, a dish-shaped upper lid 61 crimped to the lower end portion, a dish-shaped lower lid 63 joined to the upper lid 61 with a diaphragm 62 interposed therebetween, and a cylindrical spring box 6 crimped to the lower lid 63
4 and an adjusting screw 65 screw-engaged with the spring box 64.

The diaphragm 62 defines a diaphragm chamber 66 on the valve housing 31 side and a sealed chamber 67 on the spring box 64 side, and is connected to the holder 68 of the ball valve element 37 on the diaphragm chamber 66 side. I have.

On the side of the closed chamber 67 of the diaphragm 62, there are provided a contact 69, a ball 70, and a spring receiving member 71, and the ball is provided between the spring receiving member 71 and the adjusting screw 65 via the diaphragm 62. A compression coil spring 72 for urging the valve body 37 in the valve closing direction (upward) is provided.

The diaphragm chamber 66 communicates with the valve chamber 34, and receives a suction pressure Ps guided to the valve chamber 34.

Also in this embodiment, since the configuration of the discharge pressure introducing hollow tube 49 and the like are the same as those of the first embodiment, the third embodiment has the same functions and effects as those of the first embodiment. can get.

The ball valve 37 is directly connected to the diaphragm device 60 via the holding member 68. In this case, the ball valve 37 also serves as an automatic centripetal ball of a spherical joint between the valve and the pressure responsive device. As a result, the driving force of the bellows device 40 acts satisfactorily as an axial force on the ball valve element 37 without requiring a special automatic centripetal ball or the like.

In each of the above embodiments, one end (lower end) of the discharge pressure introducing hollow tube 49 is joined to the ball valve body 37 by welding or the like. One end (lower end) of the pressure introducing hollow tube 49
May be pressed against the ball valve body 37.

[0065]

As will be understood from the above description, according to the control valve for a variable displacement compressor according to the first aspect of the present invention, a valve having a communication passage for communicating a suction port of a compressor with a crank chamber. A housing, a ball valve body provided in the valve housing to open and close the communication passage, a spring for urging the ball valve body in a valve closing direction, and the ball valve body as an automatic centripetal ball using the ball valve body. A pressure responsive device that is directly connected to the valve housing and is driven by the suction pressure of the compressor to drive the ball valve body in the valve opening direction; slidably fitted to the valve housing; A discharge pressure introducing hollow tube which has an inlet for the discharge pressure of the compressor at the other end and which acts on the back of the ball valve body as a force in the valve opening direction through an internal passage; It was assumed to have a body.

For this reason, the discharge pressure of the compressor directly acts on the ball valve body by the discharge pressure introducing hollow tube, and the high pressure influence characteristic (discharge pressure influence characteristic) corresponding to the compressor discharge pressure correlated with the system load characteristic. Is set. In this case, an arbitrary high pressure influence characteristic can be obtained by setting the effective diameter of the discharge pressure introducing hollow tube, and the high pressure influence characteristic can be set with a high degree of freedom by selecting the effective diameter of the discharge pressure introducing hollow tube.

Further, since the discharge pressure of the compressor acts directly on the ball valve body by the discharge pressure introducing hollow tube, the number of parts and the number of assembling steps can be reduced as compared with the conventional one, and the compressor can be directly mounted on the compressor housing. In the case of assembling, the passage structure for guiding the suction pressure and the discharge pressure to each part of the displacement control valve is not complicated, and the degree of freedom of the arrangement position in the compressor housing is not limited.

Also, since the ball valve element is directly connected to the pressure response device and the ball valve element acts as an automatic centripetal ball of a spherical joint between the valve element and the pressure response device, a special automatic centripetal ball or the like is required. However, since the driving force of the pressure responsive device works well as the axial force on the ball valve element, the number of parts and the number of assembling steps can be reduced.

According to the control valve for a variable displacement compressor according to the second aspect of the present invention, the discharge pressure introducing hollow tube is slidably fitted into a fitting hole formed in the valve housing. In this case, the outer diameter dimension is equal to the effective diameter of the pressure receiving surface that exerts the discharge pressure of the compressor on the ball valve body.

For this reason, the discharge pressure of the compressor also acts on the end face on the discharge pressure introduction port side of the discharge pressure introduction hollow tube slidably fitted in the fitting hole. Since the outer diameter of the hollow tube is equal to the effective diameter of the pressure receiving surface of the ball valve body, the discharge pressure of the compressor acting on the end face on the discharge pressure inlet side of the discharge pressure introducing hollow tube is canceled, and the required The high pressure effect characteristics of

According to the control valve for a variable displacement type compressor according to the third aspect of the present invention, the discharge pressure introducing hollow tube is slidably fitted on the outer peripheral portion of the guide cylinder fixed to the valve housing. It is assumed that they are in agreement.

For this reason, the discharge pressure of the compressor does not act on the end face of the discharge pressure introducing hollow tube, and the required high pressure can be obtained without adjusting the effective diameter and the outer diameter of the discharge pressure introducing hollow tube. Influence characteristics are obtained.

According to the control valve for a variable displacement compressor according to the fourth aspect of the present invention, the valve urging means for urging the ball valve in the valve opening direction via the discharge pressure introducing hollow pipe. Was further provided.

Therefore, the vibration resistance of the ball valve body and the pressure responsive device is improved by the urging force of the valve body urging means for urging the ball valve body in the valve opening direction via the discharge pressure introducing hollow tube. In addition, a quiet and stable capacity control operation can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a variable displacement compressor incorporating a control valve according to the present invention.

FIG. 2 is a sectional view showing Embodiment 1 of the control valve for a variable displacement compressor according to the present invention.

FIG. 3 is a graph showing discharge pressure-suction pressure characteristics of a control valve for a variable displacement compressor according to the present invention.

FIG. 4 is a sectional view showing Embodiment 2 of the control valve for a variable displacement compressor according to the present invention.

FIG. 5 is a sectional view showing Embodiment 3 of a control valve for a variable displacement compressor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Swash plate type variable capacity compressor 2 Compressor housing 3 Crank chamber 4 Cylinder chamber 5 Piston 7 Drive shaft 9 Wobble plate 14 Suction port 15 Discharge port 23 Control valve receiving hole 24 Crank chamber pressure passage 25 Suction pressure passage 26 Discharge pressure passage REFERENCE SIGNS LIST 30 control valve 31 valve housing 32 crank chamber side passage 33 suction port side passage 34 valve chamber 37 ball valve body 38 valve seat 40 bellows device 44 compression coil spring 48 fitting hole 49 discharge pressure introduction hollow tubular body 50 compression coil spring 52 Guide cylinder 60 Diaphragm device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenta Nishimura 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Kenshi 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Ryo Matsubara 2-1-1 Toyota-cho, Kariya City, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Morio Kaneko 535 Sasai, Sayama City, Saitama Prefecture Sagimiya Manufacturing Co., Ltd. (72) Inventor Ichiro Ogawara 535 Sasai, Sayama-shi, Saitama Prefecture Sagimiya Manufacturing Co., Ltd. CC92 CC93 CC97

Claims (4)

[Claims] A valve housing having a communication passage communicating a suction port of the compressor with a crank chamber; a ball valve provided in the valve housing to open and close the communication passage; and closing the ball valve. A spring that urges the ball valve body in the valve direction, the ball valve body being directly connected to the ball valve body as an automatic centripetal ball, and a pressure that is applied with the suction pressure of a compressor to drive the ball valve body in the valve opening direction. A response device, slidably fitted to the valve housing, joined to the ball valve body at one end, and provided with an inlet for the compressor discharge pressure at the other end, and the compressor discharge pressure through an internal passage. And a discharge pressure introducing hollow pipe body that acts as a force in the valve opening direction on the back surface of the ball valve body. 2. The discharge pressure introducing hollow tube is slidably fitted in a fitting hole formed in the valve housing,
2. An effective diameter of a pressure receiving surface portion for exerting a discharge pressure of a compressor on the ball valve body, the outer diameter dimension being equal to the effective diameter of the ball valve body.
4. The control valve for a variable displacement compressor according to [1]. 3. The variable displacement capacity according to claim 1, wherein the discharge pressure introducing hollow tube is slidably fitted on an outer peripheral portion of a guide cylinder fixed to the valve housing. Control valve for compressor. 4. The valve body biasing means for biasing the ball valve body in the valve opening direction via the discharge pressure introducing hollow tube body according to claim 1, further comprising: Control valve for variable displacement compressor.