JP2000274351A - Variable capacity type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable capacity type compressor capable of preventing the pressure of a crank case from being excessively increased. SOLUTION: A capacity control valve 46 adjusts the introducing amount of discharge refrigerating gas high in pressure to a crank case 15 by letting the opening of a valve port 53 be adjusted by means of a valve element 52, and a discharge capacity is adjusted by changing the pressure of the crank case 15. The adjustment of the opening of the valve port 53 by means of the valve element 52 allows a solenoid rod 63 to be slid so as to be moved with respect to a stationary iron core 60. Therefore, a pressure acting part 91 integrally formed with the solenoid rod 63 changes a volume ratio between two pressure acting chambers 90a and 90b so as to let oil 'O' to be positively communicated with both the chambers 90a and 90b by way of a communicating path 93. As a result, the communication resistance of oil 'O' through a communication path 92 small in a passing through cross section, is given to the solenoid rod 63 as moving resistance. This constitution thereby allows the valve element 52 to gradually open the valve port 53 entirely at the time of suspending a compressor, and of starting a cut-out in acceleration, so that the pressure of the crank case will never be quickly increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement compressor which is used, for example, in a vehicle air conditioner to compress a refrigerant gas and change a discharge capacity.

[0002]

2. Description of the Related Art As this type of variable displacement compressor (hereinafter simply referred to as a compressor), for example, there is one as shown in FIG. That is, the housing 101 has a crankcase
102 is formed, and the drive shaft 103 is rotatably held. The lip seal 104 is interposed between the lip seal 104 and the housing 101 to seal the drive shaft 103.

[0003] The drive shaft 103 is an electromagnetic friction clutch.
It is operatively connected via 105 to a vehicle engine Eg as an external drive source. The friction clutch 105 includes a rotor 106 operatively connected to the vehicle engine Eg, an armature 107 fixed to the drive shaft 103 so as to be integrally rotatable, and an electromagnetic coil 10.
8 and The electromagnetic coil 108 attracts the armature 107 to the rotor 106 side by excitation, and
Is made possible to transmit power between the vehicle engine Eg and the drive shaft 103 (the friction clutch 105 is turned on). When the electromagnetic coil 108 is demagnetized in this state, the armature 107 is separated from the rotor 106, and the power transmission between the vehicle engine Eg and the drive shaft 103 is cut off (the friction clutch 105 is turned off).

The rotating support 109 is fixed to the drive shaft 103 in the crank chamber 102, and the rotating support 109 is
Is connected to a swash plate 110 via a hinge mechanism 111. The swash plate 110 is connected to the rotation support 109 via a hinge mechanism 111 so that the swash plate 110 can rotate integrally with the drive shaft 103 and can change the inclination angle of the drive shaft 103 with respect to the axis L. The minimum inclination angle defining section 112 is provided on the drive shaft 103,
The minimum inclination angle of the swash plate 110 is specified.

[0005] Cylinder bore 113, suction chamber 114 and discharge chamber
115 is formed in the housing 101. Piston 116
Are reciprocally accommodated in a cylinder bore 113 and connected to a swash plate 110. The valve / port forming body 117 provided in the housing 101 includes a cylinder bore 113 and a suction chamber 114 adjacent to each other, and a cylinder bore 113 and a discharge chamber 11 adjacent to each other.
4 and are divided respectively.

Then, the rotational movement of the drive shaft 103 is converted into a reciprocating movement of a piston 116 via a rotary support 109, a hinge mechanism 111 and a swash plate 110, and the suction port 117a of the valve / port forming body 117 and the suction valve are formed. Suction of the refrigerant gas from the suction chamber 114 into the cylinder bore 113 via the 117b, compression of the suction refrigerant gas, and discharge chamber of the compressed refrigerant gas via the discharge port 117c and the discharge valve 117d of the valve / port forming body 117. 115
The compression cycle of discharge to is repeated.

The drive shaft biasing spring 118 is interposed between the housing 101 and the drive shaft 103. Drive shaft biasing spring 118
Urges the drive shaft 103 toward the front of the axis L (to the left in the drawing) to absorb the manufacturing tolerance of each component at the time of assembling and suppress the play in the longitudinal direction of the axis L.

The bleed passage 119 is provided between the crank chamber 102 and the suction chamber 11.
4 and communicate. The air supply passage 120 communicates the discharge chamber 115 with the crank chamber 102. The capacity control valve 121 is formed of an electromagnetic valve, and is capable of adjusting the opening of the air supply passage 120. Capacity control valve
121 is the cabin temperature, cabin set temperature, friction clutch 10
5 is turned off or the vehicle engine Eg is stopped.

When the displacement control valve 121 adjusts the opening of the air supply passage 120, the amount of high-pressure discharge refrigerant gas introduced into the crank chamber 102 is adjusted.
From the relationship with the amount of refrigerant gas released to 114, the crankcase 1
02 pressure is changed. Accordingly, the difference between the pressure in the crank chamber 102 and the pressure in the cylinder bore 113 via the piston 116 is changed, and the inclination angle of the swash plate 110 is changed. As a result, the stroke amount of the piston 116 is changed, and the discharge capacity is adjusted.

In particular, the displacement control valve 121 fully opens the air supply passage 120 when the friction clutch 105 is turned off or the vehicle engine Eg is stopped. Therefore, the crankcase 10
2, the difference between the pressure of the cylinder bore 113 and the pressure of the cylinder bore 113 via the piston 116 increases, and the inclination angle of the swash plate 110 decreases. As a result, the compressor stops operating with the inclination angle of the swash plate 110 being minimized, so that the next startup is from the minimum discharge capacity state where the load torque is the smallest, and the shock generated at the startup is reduced.

[0011]

However, in the above prior art, for example, when the temperature of the passenger compartment is much higher than the set temperature, that is, when the demand for cooling the passenger compartment is high, the capacity control valve 121 is not used. As a result, the air supply passage 120 is completely closed,
The displacement of the compressor is adjusted to a maximum.

Here, it is assumed that the friction clutch 105 is turned off or the vehicle engine Eg is stopped and the compressor is stopped from the state where the compressor is operated at the maximum discharge capacity. Further, it is assumed that, during rapid acceleration of the vehicle, a control called “acceleration cut”, which does not respond to a cooling request, is executed to reduce the load on the vehicle engine Eg by minimizing the displacement of the compressor.

In such a case, the capacity control valve 121 is
In order to minimize the discharge capacity, the air supply passage 120 in the fully closed state is suddenly fully opened. Accordingly, the high-pressure refrigerant gas in the discharge chamber 115 is rapidly supplied to the crank chamber 102, and the bleed passage
The pressure in the crank chamber 102 rises excessively because 119 cannot completely escape the rapid inflow of the refrigerant gas. As a result, the pressure difference between the cylinder bore 113 and the crank chamber 102 is excessively increased.

For this reason, the swash plate 110 having the minimum inclination angle is used.
(Shown by a two-dot chain line in FIG. 9) is a minimum inclination angle defining portion.
The rotating support 109 is strongly pushed to the rear side via the hinge mechanism 111. As a result, the driving shaft 103 receives a strong moving force toward the rear side of the axis L, and slides against the urging force of the driving shaft urging spring 118.

When the drive shaft 103 slides in the direction of the axis L, the sliding position with the lip seal 104 may deviate from a predetermined position called a contact line.
Foreign matter such as sludge often adheres to portions of the outer peripheral surface of the drive shaft 103 that deviate from the contact lines. For this reason, the lip seal 104 has a problem in that sludge is caught between the lip seal 104 and the drive shaft 103, thereby deteriorating the shaft sealing performance and causing problems such as gas leakage.

In addition, especially when the friction clutch 105 is off, in other words, the vehicle engine Eg and the drive shaft 10
When the power transmission with the drive shaft 103 is interrupted, the armature 107 fixed to the drive shaft 103 moves toward the rotor 106 when the drive shaft 103 slides rearward on the axis L. The clearance between the rotor 106 and the armature 107 in the off state of the friction clutch 105 is very small (for example, 0.5 mm
) Is set to Therefore, the clearance between the rotor 106 and the armature 107 easily disappears due to the sliding movement of the drive shaft 103 to the rear side of the axis L, and the armature 107 slides on the rotor 106 in a rotating state, thereby causing a difference. There is a problem that noise and vibration are generated, and power transmission is allowed.

In particular, in the case of acceleration cutting, the driving shaft 103
Slides rearward along the axis L, the drive shaft 102
In contrast, the rotating support 109, the hinge mechanism 111, and the swash plate 110
The piston 116 connected through the
It slides rearward in the inside of 113, and its dead center tends to shift to the valve / port forming body 117 side. Therefore, the piston
When the piston 116 is located at the top dead center, it collides with the valve / port formation body 117, and the collision causes vibration or noise, or the piston 116 or the valve / port formation body 117
This causes problems such as breakage.

In order to prevent the slide movement of the drive shaft 103, a measure to increase the urging force of the drive shaft urging spring 118 may be considered. However, the durability of the thrust bearing 122 which receives the large load is considered. And a new problem that power loss increases.

The present invention has been made in view of the problems existing in the above prior art, and an object thereof is to provide a variable displacement compressor capable of preventing an excessive rise in the pressure of a crank chamber. Is to provide.

[0020]

According to the first aspect of the present invention, there is provided a variable displacement compressor which is applied to a refrigeration circuit and compresses a refrigerant gas. A drive shaft is rotatably held so as to form a cylinder bore and pass through a crank chamber.In the crank chamber, a cam plate is connected to the drive shaft so as to be integrally rotatable and change an inclination angle,
A piston connected to a cam plate is reciprocally housed in the cylinder bore, and a valve / port forming body having a suction port, a suction valve, a discharge port, and a discharge valve in the housing closes the cylinder bore with the piston. Mounted between the housing and the drive shaft,
A drive shaft biasing member that biases the drive shaft along the axis in a direction in which the piston separates from the valve / port formation body is interposed, and the crank chamber and the discharge pressure region are communicated via an air supply passage. The crank chamber and the suction pressure area are always communicated via a bleed passage, and a capacity control valve that changes the pressure in the crank chamber by adjusting at least one of the supply passage and the bleed passage by external control. Wherein the displacement control valve is configured to change the inclination angle of the cam plate in accordance with the difference between the pressure in the crank chamber and the pressure in the cylinder bore through the piston to adjust the discharge displacement. When the displacement control valve adjusts the opening degree of at least one of the air supply passage or the bleed passage so that the displacement control valve increases the pressure in the crank chamber, the damper means may perform a sudden change in the opening degree. It is characterized in that it is configured to stop.

In this configuration, the displacement control valve regulates the pressure in the crank chamber by external control, thereby regulating the displacement of the compressor. Therefore, for example, when the compressor is stopped, it is possible to reduce the load torque by positively minimizing the discharge capacity to reduce the shock generated at the next start. It is also possible to minimize the discharge capacity without responding to cooling requirements. If these displacement controls are performed, for example, from a state where the compressor is operating at the maximum discharge displacement, in the related art, the pressure in the crank chamber is rapidly increased and tends to increase excessively.

However, in the present invention, the damper means is provided in the displacement control valve, and the damper means adjusts the opening degree of at least one of the air supply passage or the bleed passage so that the displacement control valve increases the pressure in the crank chamber. In this case, the sudden change of the opening is prevented. Therefore, it is possible to prevent the pressure in the crank chamber from increasing sharply, and it is possible to prevent the pressure in the crank chamber from increasing excessively and the difference from the pressure in the cylinder bore from increasing excessively. As a result, it is possible to prevent a phenomenon that the drive shaft slides in the axial direction against the urging force of the drive shaft urging member.

According to a second aspect of the present invention, in the variable displacement compressor according to the first aspect, the displacement control valve is configured to adjust at least an opening degree of an air supply passage.

In this configuration, a high discharge pressure is used for controlling the pressure in the crank chamber. For example, when the displacement control valve opens and closes only the bleed passage to adjust the pressure in the crank chamber, that is, when the discharge pressure is higher than the discharge pressure. In this case, the pressure in the crank chamber can be quickly increased as compared with the case where a low pressure is handled. Therefore, when the compressor is stopped, the discharge capacity can be quickly minimized, and the next start-up of the compressor immediately after the stop can be started from the minimum discharge capacity. From another point of view, compared with the case where the displacement control valve controls only the bleed passage to adjust the discharge displacement, the problem that the pressure in the crank chamber rises excessively easily occurs. The effect is produced more effectively.

According to a third aspect of the present invention, in the variable displacement compressor according to the first or second aspect, the electromagnetic force capable of interrupting power transmission between the drive shaft and an external drive source for rotating the drive shaft. A friction clutch is provided, and the friction clutch is rotatably supported by the housing and operatively connected to an external drive source, and is fixed to the drive shaft so as to be integrally rotatable and is disposed to face the rotor. And an electromagnetic coil that attracts the armature to the rotor side by excitation and fastens the two to enable power transmission.

In this configuration, when the power transmission by the friction clutch is cut off, the load torque is reduced by positively minimizing the discharge capacity of the compressor, and the shock generated at the next startup of the compressor is reduced. A configuration is also possible. Then, for example, when the compressor is stopped by shutting off the power transmission in the friction clutch from a state where the compressor is operated at the maximum discharge capacity, at least the supply passage or the bleed passage in order to minimize the discharge capacity. One of the opening adjustments is about to be performed. Even in such a case, claim 1
As in the invention of the first aspect, the damper means prevents an excessive increase in the pressure in the crank chamber, and for example, it is possible to prevent the clearance between the rotor and the armature from disappearing due to the sliding movement of the drive shaft. In other words, by providing the friction clutch between the external drive source, when the power transmission by the friction clutch is interrupted, a peculiar problem due to an excessive rise in the pressure of the crank chamber is likely to occur, and the provision of the damper means Is more effectively achieved.

According to a fourth aspect of the present invention, in the variable displacement compressor according to any one of the first to third aspects, the capacity control valve includes a valve body that opens and closes at least one of the air supply passage or the bleed passage. A valve body driving unit that moves the valve body under external control, wherein the damper means is configured by a movement resistance applying means for applying a movement resistance to the valve body moving in a direction to increase the pressure in the crank chamber. It is characterized by being.

In this configuration, when the opening degree of at least one of the air supply passage and the bleed passage is adjusted so that the valve body increases the pressure of the crank chamber, the valve body is given movement resistance by the movement resistance applying means. Is done. Therefore, the opening degree of at least one of the air supply passage and the bleed passage by the valve body is moderately adjusted, and it is possible to prevent the pressure in the crank chamber from rapidly increasing.

According to a fifth aspect of the present invention, in the variable displacement compressor according to the fourth aspect, the moving resistance imparting means includes a pressure acting portion provided integrally with the valve body and the pressure acting portion. The two fluid pressure chambers are formed in the space before and after the valve body in the movement direction of the valve body, and a communication path communicating the two fluid pressure chambers is formed, and the valve body moves in a direction to increase the pressure of the crank chamber. Sometimes, the pressure acting portion changes the volume ratio of the two fluid pressure chambers, thereby providing a movement resistance to the valve body by resistance generated by the flow of fluid through the communication passage between the two chambers. Features.

In this configuration, when the opening degree of one of the air supply passage or the bleed passage is adjusted by the valve body driving section so that the valve body increases the pressure in the crank chamber, the valve body is provided integrally with the valve body. The pressure acting portion changes the volume ratio of the two fluid pressure chambers. Therefore, between the two fluid pressure chambers,
The resistance is generated by the fluid flowing through the communication passage having a small cross-sectional area, and the valve body is provided with the movement resistance via the pressure acting portion. As a result, the degree of opening adjustment of one of the air supply passage and the bleed passage by the valve body is gently performed, and it is possible to prevent the pressure in the crank chamber from rapidly increasing.

According to a sixth aspect of the present invention, in the variable displacement compressor according to any one of the first to third aspects, the capacity control valve includes a valve body that opens and closes at least one of the air supply passage and the bleed passage. A valve drive unit that moves the valve body by external control, wherein the damper means adjusts at least one of the air supply passage and the bleed passage so that the displacement control valve increases the pressure in the crank chamber. In this case, the valve body driving section is controlled so as to change the moving force applied to the valve body in a stepwise manner, so that a sudden change in the opening degree is prevented.

In this configuration, when adjusting the opening of at least one of the air supply passage and the bleed passage so as to increase the pressure in the crank chamber, the damper means changes the moving force applied to the valve body in a stepwise manner. To control the valve body drive unit. Therefore, at least one of the air supply passage and the bleed passage is not suddenly changed to the target opening degree, and it is possible to prevent the pressure in the crank chamber from rapidly increasing.

According to a seventh aspect of the present invention, in the variable displacement compressor according to any one of the first to third aspects, the capacity control valve includes a valve body that opens and closes at least one of the air supply passage or the bleed passage. A valve drive unit that moves the valve body by external control, wherein the damper means adjusts at least one of the air supply passage and the bleed passage so that the displacement control valve increases the pressure in the crank chamber. In such a case, the valve body driving unit is controlled so as to continuously change the moving force applied to the valve body, thereby preventing a rapid change in the opening degree.

In this configuration, when adjusting the opening of at least one of the air supply passage and the bleed passage so as to increase the pressure in the crank chamber, the damper means continuously changes the moving force applied to the valve body. To control the valve body drive unit. Therefore, at least one of the air supply passage and the bleed passage is not suddenly changed to the target opening degree, and it is possible to prevent the pressure in the crank chamber from rapidly increasing.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment of the present invention is described below with reference to a variable displacement compressor used in a vehicle air conditioner.
The fourth to fourth embodiments will be described. In the second to fourth embodiments, only differences from the first embodiment will be described, and the same members will be denoted by the same reference numerals and description thereof will be omitted.

(First Embodiment) As shown in FIG. 1, a front housing 11 is joined and fixed to a front end of a cylinder block 12 as a center housing. The rear housing 13 is joined and fixed to the rear end of the cylinder block 12 via a valve / port forming body 14. The front housing 11, the cylinder block 12, and the rear housing 13 constitute a compressor housing. In addition, let the left of FIG. 1 be the front of a compressor, and let the right be the back.

The valve / port forming body 14 has a suction valve forming plate 14b on the front side of the port forming plate 14a, a discharge valve forming plate 14c on the rear side, and a retainer forming plate 14d on the rear side of the discharge valve forming plate 14c. Are respectively polymerized.

The crank chamber 15 is provided in the front housing 1
1 and a cylinder block 12. The drive shaft 16 is disposed so as to pass through the crank chamber 15, and is rotatably supported between the front housing 11 and the cylinder block 12.

The front end of the drive shaft 16 is supported by the front housing 11 via a radial bearing 17. The accommodation hole 12a is provided through the center of the cylinder block 12. The rear end side of the drive shaft 16 has an accommodation hole 12a.
And is supported via a radial bearing 18. The spring seat 21 is made of a circlip,
2a is fitted and fixed to the inner peripheral surface (cylinder block 12). The thrust bearing 19 and the drive shaft biasing spring 20 as a drive shaft biasing member are interposed between the rear end face of the drive shaft 16 and the spring seat 21 in the accommodation hole 12a. The drive shaft biasing spring 20 is a coil spring, and biases the drive shaft 16 toward the front of the axis L. The transmission of the rotational force of the drive shaft 16 to the drive shaft biasing spring 20 is interrupted by the interposition of the thrust bearing 19.

The front end of the drive shaft 16 projects outside through the front wall of the front housing 11. A lip seal 22 is used as a shaft sealing device for the drive shaft 16, and the lip seal 22 is interposed between the front end of the drive shaft 16 and the front housing 11. The lip seal 22 is connected to the drive shaft 16 by a lip ring 22a.
The drive shaft 16 is sealed by pressing against the outer peripheral surface of the drive shaft 16.

The electromagnetic friction clutch 23 is interposed between the vehicle engine Eg as an external drive source and the drive shaft 16. That is, the rotor 24 of the friction clutch 23
Is rotatably supported on the outer wall surface of the front housing 11 via an angular bearing 25. A belt 26 from the vehicle engine Eg is wound around the outer periphery of the rotor 24. The hub 27 is fixed to the front end of the drive shaft 16 and elastically supports the armature 28 on the outer peripheral side. The armature 28 includes a drive shaft biasing spring 20.
And opposite to the rotor 24. The electromagnetic coil 29 is supported on the outer wall surface of the front housing 11 and is arranged in the rotor 24.

When the electromagnetic coil 29 is energized by energization while the vehicle engine Eg is activated, an attractive force based on an electromagnetic force is applied between the armature 28 and the rotor 24. Accordingly, the armature 28 moves against the elastic force of the hub 27 and presses against the rotor 24, so that the friction clutch 23 is turned on. In this ON state, the driving force of the vehicle engine Eg is applied to the belt 26 and the friction clutch 23.
To the drive shaft 16 (FIG. 1). When the electromagnetic coil 29 is demagnetized from this state, the armature 28 is separated from the rotor 24 by the elastic force of the hub 27, and the friction clutch 23 is turned off. In this off state, transmission of the driving force from the vehicle engine Eg to the drive shaft 16 is interrupted (FIG. 4).

The rotary support 30 is fixed to the drive shaft 16 in the crank chamber 15. The swash plate 31 as a cam plate can be tilted to the drive shaft 16 and
6 is slidably supported in the direction of the axis L.
The hinge mechanism 32 is interposed between the rotation support 30 and the swash plate 31. The swash plate 31 can rotate integrally with the drive shaft 16 and can change the inclination angle with respect to the axis L by hinge connection to the rotation support 30 via a hinge mechanism 32.

The minimum tilt angle defining section 34 is provided between the swash plate 31 and the cylinder block 12 on the drive shaft 16. The minimum tilt angle defining portion 34 is formed by externally fixing a ring-shaped member to the outer peripheral surface of the drive shaft 16. As shown by a two-dot chain line in FIG. 1, the minimum inclination angle of the swash plate 31 is defined by contact with the minimum inclination angle defining part 34. As shown by the solid line in FIG. 1, the maximum inclination angle of the swash plate 31 is defined by the contact with the rotating support 30.

The cylinder bore 33 is provided for the cylinder block 12
Is formed. The single-headed piston 35 is housed in a cylinder bore 33. The front and rear sides of the cylinder bore 33 are closed by the distal end surface of the piston 35 and the front surface of the valve / port forming body 14. The piston 35 is moored on the outer peripheral portion of the swash plate 31 via a shoe 36. The rotational movement of the drive shaft 16 is controlled by the rotation support 30, the hinge mechanism 32,
Through the swash plate 31 and the shoe 36, the reciprocating motion of the piston 35 in the cylinder bore 33 is converted.

The suction chamber 37 serving as a suction pressure area is defined in the center of the rear housing 13. The discharge chamber 38 as a discharge pressure region is defined in the rear housing 13 on the outer peripheral side of the suction chamber 37. The suction chamber 37 and the discharge chamber 38 are respectively provided with the valve / port forming body 14.
Is adjacent to the cylinder bore 33. The suction port 39 and the discharge port 40 are formed on the port forming plate 14 a of the valve / port forming body 14 so as to correspond to the cylinder bore 33. The suction valve 41 is provided on the suction valve forming plate 14.
At b, it is formed corresponding to the suction port 39.
The discharge valve 42 is formed corresponding to the discharge port 40 on the discharge valve forming plate 14c. The retainer 43 is formed on the retainer forming plate 14d so as to correspond to the discharge valve 42. The retainer 43 regulates the maximum opening of the discharge valve 42.

The refrigerant gas in the suction chamber 37 is sucked into the cylinder bore 33 through the suction port 39 and the suction valve 41 by moving from the top dead center side of the piston 35 to the bottom dead center side. The refrigerant gas sucked into the cylinder bore 33 is
The piston 35 is compressed to a predetermined pressure by moving from the bottom dead center side to the top dead center side.
The liquid is discharged to the discharge chamber 38 through the discharge chamber 2.

The supply passage 44 is provided between the discharge chamber 38 and the crank chamber 1.
5 is communicated. The bleed passage 45 always connects the crank chamber 15 and the suction chamber 37. The capacity control valve 46 is interposed on the air supply passage 44. Then, the capacity control valve 46 adjusts the opening degree of the air supply passage 44, so that the amount of the high-pressure discharge refrigerant gas introduced into the crank chamber 15 is adjusted, and the refrigerant gas is introduced into the refrigerant gas suction chamber 37 through the bleed passage 45. From the amount of escape
The pressure in the crank chamber 15 is changed. Therefore, the piston 3 between the pressure in the crank chamber 15 and the pressure in the cylinder bore 33
5 is changed, and the inclination angle of the swash plate 31 is changed. As a result, the stroke amount of the piston 35 is changed, and the discharge capacity is adjusted.

Next, the capacity control valve 46 will be described in detail. As shown in FIG. 2, the valve chamber 51 is defined on the air supply passage 44. The valve body 52 is housed in the valve chamber 51. The valve hole 53 is opened in the valve chamber 51 so as to face the valve body 52. The forcible opening spring 54 is connected to the valve chamber 51.
And urges the valve body 52 in a direction to open the valve hole 53. The valve chamber 51 and the valve hole 53 constitute a part of the air supply passage 44.

The pressure sensing chamber 55 is formed so as to be adjacent to the valve chamber 51. The pressure sensing chamber 55 is always in communication with the suction chamber 37 via the pressure detection passage 47. The bellows 56 as a pressure-sensitive member is housed in the pressure-sensitive chamber 55. Setting spring 5
7 is arranged in the bellows 56. Setting spring 57
Is for setting the initial length of the bellows 56. The pressure sensing rod 58 is formed integrally with the valve body 52 and operatively connects the bellows 56 and the valve body 52.

The plunger chamber 59 is adjacent to the valve chamber 51 on the side opposite to the pressure-sensitive chamber 55, and a fixed iron core 60 is fitted into the upper opening so as to be separated from the valve chamber 51. The movable iron core 61 is housed in the plunger chamber 59. The follower spring 62 is housed in the plunger chamber 59 and urges the movable iron core 61 toward the valve body 52. The rod guide hole 65 extends through the fixed iron core 60 and communicates the valve chamber 51 with the plunger chamber 59. The solenoid rod 63 is formed integrally with the valve body 74 and is inserted into the rod guide hole 65. The end of the solenoid rod 63 on the movable iron core 61 side is in contact with the movable iron core 61 by the urging force of the forcible opening spring 54 and the follower spring 62. Therefore, the valve element 52 and the movable iron core 61 are operatively connected via the solenoid rod 63. The electromagnetic coil 64 is disposed outside the fixed core 60 and the movable core 61 so as to straddle the two cores 60, 61. The fixed iron core 60, the movable iron core 61,
The electromagnetic coil 64 and the solenoid rod 63 form an electromagnetic configuration of the displacement control valve 46 and constitute a valve body driving unit.

As shown in FIG. 1, in the variable displacement compressor (hereinafter simply referred to as a compressor) having the above configuration, the suction chamber 37 and the discharge chamber 38 are connected by an external refrigerant circuit 71. . The external refrigerant circuit 71 includes a condenser 72, an expansion valve 73, and an evaporator 74. The external refrigerant circuit 71 and the compressor constitute a refrigeration circuit of the vehicle air conditioner.

An air conditioner switch 80 which is a main switch of the vehicle air conditioner, a compartment temperature sensor 81 for detecting the temperature in the compartment of the vehicle, a compartment temperature setting device 82 for the occupant to set the temperature in the compartment, And accelerator opening sensor 8
3 are respectively connected to the control computer C.
The control computer C is interposed on a power supply line between the electromagnetic coils 29 and 64 of the friction clutch 23 and the capacity control valve 46 and a power source S such as a vehicle battery. The control computer C turns on / off the air conditioner switch 80,
The cabin temperature and the cabin temperature setting device 8 from the cabin temperature sensor 81
The power supply from the power source S to each of the electromagnetic coils 29 and 64 is controlled based on the set temperature from 2 and an external signal such as the accelerator opening from the accelerator opening sensor 83.

In general, when the operation of the vehicle engine Eg is stopped (specifically, when an ignition key (not shown) is operated to the accessory off position), most of the power supply to the electric components of the vehicle is performed. And this is no exception for vehicle air conditioners. Therefore, when the operation of the vehicle engine Eg is stopped, the power supply line between each of the electromagnetic coils 29 and 64 and the power supply S is cut off on the upstream side of the control computer C, and the power supply S is disconnected from each of the electromagnetic coils 29 and 6.
4 is stopped.

Next, the operation of the capacity control valve 46 will be described. When the temperature detected by the cabin temperature sensor 81 becomes equal to or higher than the set temperature of the cabin temperature setter 82 under the ON condition of the air conditioner switch 80 in the operating state of the vehicle engine Eg, the control computer C sends an electromagnetic signal A current is input to the coil 29. Therefore, the friction clutch 23
Is turned on to start the compressor.

In this state, the bellows 56 of the capacity control valve 46
Tries to expand and contract in response to the suction pressure of the pressure-sensitive chamber 55, and the expansion and contraction of the bellows 56 applies a load to the valve body 52 via the pressure-sensitive rod 58 in a direction to open or close the valve hole 53. You. Further, the control computer C determines an input current value to the electromagnetic coil 64 of the capacity control valve 46 based on the compartment temperature from the compartment temperature sensor 81 and the set temperature from the compartment temperature setting device 82. Control computer C
Causes the current of the determined value to be input from the power supply S to the electromagnetic coil 64. When a current is input to the electromagnetic coil 64, an attractive force (electromagnetic force) corresponding to the input current value is generated between the fixed iron core 60 and the movable iron core 61. This suction force is applied to the valve hole 53.
Is applied to the valve body 52 as a load in a direction to decrease the opening of the valve body 52.

As described above, the degree of opening of the valve hole 53 by the valve body 52 depends on the load applied by the expansion and contraction of the bellows 56, the load applied by the attraction force between the fixed iron core 60 and the movable iron core 61, and It is determined by the total force such as the load applied by the urging forces of the springs 54 and 62.

For example, the control computer C increases the input current value to the electromagnetic coil 64 of the capacity control valve 46 as the difference between the cabin temperature and the set temperature increases, that is, as the cooling demand of the cabin increases. Accordingly, the suction force between the fixed iron core 60 and the movable iron core 61 is increased, and the load in the direction of decreasing the opening of the valve hole 53 applied to the valve body 52 is increased. Accordingly, the capacity control valve 46 sets the target suction pressure (set suction pressure) low, and operates the valve body 52 by the bellows 56 to open and close the valve hole 53 so as to maintain the set suction pressure. That is, the capacity control valve 4
6 adjusts the displacement of the compressor so as to maintain a lower suction pressure by increasing the input current value to the electromagnetic coil 64.

When the opening degree of the valve hole 53 (the air supply passage 44) is reduced, the flow rate of the refrigerant gas supplied from the discharge chamber 38 to the crank chamber 15 is reduced. When the amount of the refrigerant gas supplied to the crank chamber 15 decreases, the pressure of the crank chamber 15 gradually decreases due to the escape of the refrigerant gas to the suction chamber 37 through the bleed passage 45. Therefore, the difference between the pressure in the crank chamber 15 and the pressure in the cylinder bore 33 via the piston 35 is reduced, and the inclination angle of the swash plate 31 is increased. As a result, the stroke amount of the piston 35 increases, and the displacement of the compressor increases.

Conversely, the control computer C reduces the input current value to the electromagnetic coil 64 of the capacity control valve 46 as the difference between the cabin temperature and the set temperature is smaller, that is, as the demand for cooling the cabin is lower. . For this reason, the attraction force between the fixed iron core 60 and the movable iron core 61 is weakened, and the load in the direction of decreasing the opening of the valve hole 53 applied to the valve body 52 is reduced. Therefore, the capacity control valve 46 sets the set suction pressure high, and operates the valve body 52 by the bellows 56 to open and close the valve hole 53 so as to maintain the set suction pressure. That is, the capacity control valve 46 is
By reducing the input current value to the compressor, the displacement of the compressor is adjusted so as to maintain a higher suction pressure.

As the opening of the valve hole 53 (the supply passage 44) increases, the flow rate of the refrigerant gas supplied from the discharge chamber 38 to the crank chamber 15 increases. When the amount of the refrigerant gas supplied to the crank chamber 15 increases, the pressure in the crank chamber 15 gradually increases because the bleed passage 45 cannot escape the increased amount. Therefore, the difference between the pressure in the crank chamber 15 and the pressure in the cylinder bore 33 via the piston 35 increases. As a result, the inclination angle of the swash plate 31 is reduced, the stroke amount of the piston 35 is reduced, and the displacement of the compressor is reduced.

Next, a characteristic configuration of the present embodiment will be described. As shown in FIG. 2 and FIG.
Numeral 0 is formed in the fixed iron core 60 in the middle of the rod guide hole 65 and hermetically accommodates oil O as a fluid. The pressure acting portion 91 is formed by externally fixing a ring-shaped member to a portion of the solenoid rod 63 located in the pressure acting space 90. Pressure acting section 91
The upper and lower two pressure action chambers 90a,
90b. The outer diameter of the pressure acting portion 91 is slightly smaller than the inner diameter of the pressure acting space 90, and a region of this difference in diameter communicates the two pressure acting chambers 90 a and 90 b as a communication passage 92.

When the solenoid rod 63 slides up and down with respect to the fixed iron core 60 from the state shown in FIG. 2 to the state shown in FIG. 3 or vice versa, a pressure acting portion 91 integrated with the solenoid rod 63 is formed. Changes the volume ratio of the two pressure action chambers 90a and 90b, and the oil O through the communication passage 92 between both chambers 90a and 90b.
Aggressive distribution of Therefore, the flow resistance of the oil O generated in the communication passage 92 having the small passage cross-sectional area is given to the solenoid rod 63 via the pressure acting portion 91 as the movement resistance. The fluid damper configuration including the pressure action space 90, the pressure action chambers 90a and 90b, the pressure action portion 91, and the communication passage 92 constitutes a movement resistance applying means as a damper means.

Next, the characteristic operation of this embodiment will be described. When the air conditioner switch 80 is turned off in the operation state of the compressor, the control computer C stops the power supply to the electromagnetic coil 29 to turn off the friction clutch 23, and turns off the electromagnetic coil 64 of the displacement control valve 46.
Is stopped at an input current value of zero.

In the control computer C, the accelerator is greatly depressed by the driver in the operating state of the compressor in order to accelerate the vehicle rapidly.
When the accelerator opening detected by the above becomes larger than a predetermined value, the power supply control of the capacity control valve 46 to the electromagnetic coil 64 is stopped at an input current value of zero for a predetermined time (hereinafter referred to as acceleration cut).

Further, when the vehicle engine Eg is stopped in the operating state of the compressor, each electromagnetic coil 2
The power supply lines to 9, 64 are cut off upstream of the control computer C.

As described above, when the friction clutch 23 is turned off or the vehicle engine Eg is stopped, the displacement control valve 46 is stopped.
Is stopped at an input current value of zero, the suction force between the fixed iron core 60 and the movable iron core 61 disappears, and the set suction pressure is fixed at the maximum value.
Accordingly, the displacement control valve 46 fully opens the air supply passage 44, and the compressor minimizes the inclination angle of the swash plate 31. As a result, the next start of the compressor is from the minimum discharge capacity state where the load torque is the smallest, and the shock generated at the start is reduced.

Further, the capacity control valve 4 is controlled by the acceleration cut.
When the power supply control to the electromagnetic coil 64 is stopped at an input current value of zero, the set suction pressure is fixed to the maximum value in the same manner as when the compressor is stopped. Accordingly, the displacement control valve 46 fully opens the air supply passage 44, and the compressor minimizes the inclination angle of the swash plate 31. As a result, the compressor has a minimum discharge capacity with a small load torque, the load on the vehicle engine Eg is reduced, and a sharp acceleration of the vehicle can be obtained.

Now, when the above-described stop of the compressor and the acceleration cut are performed from the operating state at the maximum discharge capacity, the valve hole 53 of the capacity control valve 46 is fully closed (FIG. 3).
The valve body 52 at the point (a) attempts to fully open the valve hole 53 (FIG. 2). That is, the sliding movement of the solenoid rod 63 with respect to the fixed iron core 60 tends to be performed rapidly.

However, depending on the sliding movement of the solenoid rod 63 with respect to the fixed iron core 60, both pressure action chambers 9
The resistance generated by the flow of the oil O through the communication passage 92 between 0a and 90b is applied to the valve body 52 as the movement resistance via the pressure acting portion 91 and the solenoid rod 63. Accordingly, as shown in the time chart of FIG. 5, the valve body 52 gradually opens the valve hole 53 gradually from the stop of the compressor or the start of the acceleration cut, and the pressure in the crank chamber 15 is rapidly increased. Therefore, the pressure in the crank chamber 15 is not excessively increased.

As described above, excessive expansion of the differential pressure between the crank chamber 15 and the cylinder bore 33 is prevented, and the swash plate 31 having the minimum inclination angle is pressed against the minimum inclination angle defining portion 34 with excessive force. And the rotation support 30 is not strongly pulled through the hinge mechanism 32. Therefore, the phenomenon that the drive shaft 16 slides rearward on the axis L against the biasing force of the drive shaft biasing spring 20 does not occur.

The present embodiment having the above configuration has the following effects. (1) Due to the above-described fluid damper configurations 90 to 92, it is possible to prevent the difference between the pressure in the crank chamber 15 and the pressure in the crank chamber 15 from becoming excessively large, and the drive shaft 16 resists the urging force of the drive shaft urging spring 20. Sliding movement to the rear of the axis L can be prevented. Therefore, the following effects are obtained.

(1-1) The relative sliding movement between the lip seal 22 and the drive shaft 16 can be prevented. Therefore,
The sliding position between the lip ring 22a of the lip seal 22 and the drive shaft 16 does not largely deviate from a predetermined contact line on the drive shaft 16. For this reason, it is possible to prevent foreign matter, such as sludge, attached to portions other than the contact line from being caught between the sliding contact surfaces of the lip ring 22a and the drive shaft 16. Therefore, lip seal 2
2 is prevented from deteriorating at an early stage or causing gas leakage, which leads to improvement in the durability of the compressor.

(1-2) The armature 28 of the friction clutch 23 is moved toward and away from the rotor 24 in the longitudinal direction of the axis L. Therefore, when the frictional clutch 23 is in the off state, if the drive shaft 16 slides rearward on the axis L,
Even though no suction force is generated between the rotor 24 and the armature 28, a situation may occur in which a predetermined clearance (FIG. 4) cannot be secured between the rotor 24 and the armature 28. However, as described above, the sliding movement of the drive shaft 16 to the rear side of the axis L is prevented, a predetermined clearance can be secured between the rotor 24 and the armature 28, and the friction clutch 23 is turned off. There is no possibility that both 24 and 28 remain in contact. Therefore, no sliding occurs between the rotor 24 and the armature 28,
The transmission of power between the motors 4 and 28 can be reliably shut off, and generation of abnormal noise and vibration and heat generation due to sliding of the motors 24 and 28 can be prevented.

(1-3) The piston 35 is mounted on the rotating support 3
0, the hinge mechanism 32, the swash plate 31, and the shoe 36 are connected to the drive shaft 16. Therefore, as described above, the fact that the sliding movement of the drive shaft 16 to the rear side of the axis L can be prevented leads to the prevention of the piston 35 sliding to the valve / port forming body 14 side. as a result,
At the time of the acceleration cut, when the piston 35 is located at the top dead center, it is possible to prevent the front end surface from colliding with the valve / port forming body 14, and it is possible to suppress the generation of vibration and noise. Further, the piston 35 and the valve / port forming body 1
The damage of both 35 and 14 due to the collision with 4 is also avoided,
As a result, the durability of the compressor is improved.

(2) The capacity control valve 46 opens and closes the air supply passage 44 so that the high-pressure discharge refrigerant gas is supplied to the crank chamber 15.
To adjust the discharge capacity of the compressor. Therefore, for example, the bleed passage 45 is opened and closed, and the crank chamber 1 is opened.
By adjusting the amount of refrigerant gas (lower pressure than the discharged refrigerant gas) flowing out of the compressor 5 to the suction chamber 37, the crank chamber 15 can be quickly pressurized as compared with a configuration in which the discharge capacity of the compressor is adjusted. Therefore, if the compressor is stopped,
The discharge capacity can be minimized quickly, and the next start-up of the compressor immediately after the stop can be started from the minimum discharge capacity. From another point of view, compared to the case where the displacement control valve 46 opens and closes only the bleed passage 45 to adjust the discharge displacement, the problem that the pressure in the crank chamber 15 is excessively increased easily occurs, and the suction chamber pressure control is performed. The effect provided by providing the valve 91 is more effectively achieved.

(3) The fluid damper structures 90 to 92 exhibit the above-described damper function even when the power supply line to the compressor is interrupted upstream of the control computer C (when the vehicle engine Eg is stopped). be able to.

(4) For example, the electromagnetic 6 of the capacity control valve 46
0, 61, 63, 64 The configuration in which the suction force generated between the fixed iron core 60 and the movable iron core 61 is applied to the valve body 52 as a load in the direction of increasing the opening degree of the valve hole 53 by changing the configuration. Does not depart from the spirit of the present invention. That is, the larger the input current value to the electromagnetic coil 64, the higher the set suction pressure is set. In this case, in particular, in order to change the discharge capacity to the minimum when the vehicle engine Eg is stopped, in other words,
To maximize the set suction pressure, the electromagnetic coil 64
A special configuration is required so that the power supply line between the power supply S and the power supply S is not interrupted on the upstream side of the control computer C, and a large structural change is required for the existing vehicle power supply system.

However, the capacity control valve 46 of the present embodiment is
The configuration is such that the set suction pressure is set higher as the input current value to the electromagnetic coil 64 decreases. Therefore, when the set suction pressure is set to the maximum value, the control computer C stops supplying power to the electromagnetic coil 64. This is because when the vehicle engine Eg stops, the power supply line between the electromagnetic coil 64 and the power supply S is supplied from the control computer C. Also results in the same condition as being shut off upstream. Therefore, a configuration in which the discharge capacity is minimized when the vehicle engine Eg is stopped can be achieved without forcing a structural change to the existing vehicle power supply system.

(Second Embodiment) As shown in FIG. 6, in this embodiment, the plunger chamber 59 also serves as the pressure action space 90, and the plunger chamber 59 contains oil O in a sealed manner. The pressure acting portion 91 also serves as the movable iron core 61 that is operated integrally with the valve body 52. The communication passage 92 extends through the movable iron core 61, and the two pressure action chambers 90 defined above and below the movable iron core 61 in the plunger chamber 59.
a, 90b. When the movable iron core 61 (valve element 52) moves in the vertical direction, the two pressure action chambers 90 move.
The resistance generated by the flow of the oil O through the communication passage 92 having a small passage cross-sectional area between the movable iron 6 and
The movement resistance is applied to the valve body 52 via the solenoid rod 1 and the solenoid rod 63.

In this embodiment, the same operation and effect as those of the first embodiment are obtained. In addition, the plunger chamber 59 is used as the pressure action space 90, and the movable core 6 is used as the pressure action part 91.
Since each of them uses the fluid damper, the fluid damper configuration can be applied to the compressor without increasing the number of parts.

(Third Embodiment) In the present embodiment,
The control computer C (FIG. 1) controls the displacement control valve 46 by damper control to constitute a damper means. That is, the control computer C is programmed to gradually decrease the current value input to the electromagnetic coil 64 (FIG. 2) of the capacity control valve 46 to the target value when increasing the set suction pressure. . That is, the control computer C
When increasing the set suction pressure, the electromagnetic configurations 60, 61,
The load applied to the valve body 52 by 63 and 64 in the direction of opening the valve hole 53 is reduced stepwise.

For example, in the time chart of FIG. 7, when the set suction pressure of the displacement control valve 46 is at the lowest value, the friction clutch 23 is turned off or the acceleration cut is started, and the set suction pressure becomes the highest value. Until the change to. In this case, the control computer C increases and changes the set suction pressure in three steps.
By changing the current value input to the three stages, the change from the lowest value to the highest value is prevented from being suddenly performed.

Therefore, the valve body 52 does not suddenly and fully open the valve hole 53 in the fully closed state (or an opening degree close to the fully closed state), and the pressure in the crank chamber 15 does not suddenly increase. In addition, it is possible to prevent the pressure in the crank chamber 15 from excessively increasing. As a result, except when the vehicle engine Eg is stopped (when the vehicle engine Eg is stopped, the power supply line to the electromagnetic coil 64 of the capacity control valve 46 is cut off at the same time on the upstream side of the control computer C). The same effect as (1) of the first embodiment is obtained.

In the present embodiment having the above-described structure, the displacement control valve 46 is configured to perform a damper-like operation under the control of the control computer C. Therefore,
Only when the set suction pressure is increased, that is, only when the pressure in the crank chamber 15 is excessively increased, the valve hole 5
3 can be gradually increased. In other words, when the set suction pressure is lowered, a damper-like action can be prevented from being exerted, and the opening degree of the valve hole 53 can be promptly changed at this time. Therefore, the responsiveness of the increase in the displacement of the compressor is improved, and the vehicle air conditioner can respond quickly to a large cooling request.

(Fourth Embodiment) In the present embodiment,
As in the third embodiment, the control computer C (FIG. 1) controls the displacement control valve 46 by damper control to constitute damper means. That is, the control computer C
Is programmed to continuously reduce the current value input to the electromagnetic coil 64 (FIG. 2) of the capacity control valve 46 to a target value when the set suction pressure is increased.
That is, when increasing the set suction pressure, the control computer C uses the electromagnetic components 60, 61, 63, and 64 to control the valve element 5.
2, the load in the direction of opening the valve hole 53 is continuously reduced.

For example, in the time chart of FIG. 8, when the set suction pressure of the capacity control valve 46 is at the lowest value, the friction clutch 23 is turned off or the acceleration cut is started, and the set suction pressure becomes the highest value. Until the change to. In this case, the control computer C continuously increases and changes the set suction pressure.
By continuously lowering the current value input to, the change from the lowest value to the highest value is prevented from being suddenly performed. Therefore, the valve body 52 does not suddenly and fully open the valve hole 53 in the fully closed state (or an opening degree close to the fully closed state), and the pressure in the crank chamber 15 does not suddenly increase. 15 can be prevented from excessively increasing. As a result, the same effects as (1) of the first embodiment are obtained except when the vehicle engine Eg is stopped.

In the present embodiment or the third embodiment, if the power supply system of the vehicle is changed so that the power supply line is not interrupted on the upstream side of the control computer C even when the vehicle engine Eg is stopped, for example, Alternatively, if a power storage function is added between the power supply S and the control computer C, the set suction pressure by the control computer C can be changed continuously or stepwise even when the vehicle engine Eg is stopped.

In the present embodiment having the above-described structure, the capacity control valve 46 is configured to perform a damper-like operation under the control of the control computer C. Therefore,
When the set suction pressure is lowered, a damper-like action can be prevented from being exhibited, and the opening degree of the valve hole 53 can be promptly changed at this time. As a result, the responsiveness of the increase in the displacement of the compressor is enhanced, and the vehicle air conditioner can respond quickly to a large cooling request.

The present invention can be implemented in the following modes without departing from the spirit of the present invention. In the third or fourth embodiment, the set suction pressure is changed stepwise or continuously only when the set suction pressure is changed from the lowest value to the highest value. In this way, when the other set suction pressure is increased, the discharge capacity can be rapidly reduced, and the cooling feeling of the vehicle air conditioner is improved.

In each of the above embodiments, the capacity control valve 46
Are pressure sensitive (56, 58 etc.) and electromagnetic (60, 6
1, 63, 64 etc.) to operate the valve body 52,
Although the configuration is such that the air supply passage 44 is opened and closed, this is changed. For example, as in the prior art of FIG. 9, the valve body 52 is operated only by the electromagnetic configuration to open and close the air supply passage 44. thing.

The capacity control valve 46 is configured to adjust the discharge capacity by opening and closing both the air supply passage 44 and the bleed passage 45. In this case, it is important that the bleed passage 45 is not completely closed, that is, that the bleed passage 45 is always in communication.

The capacity control valve 46 is configured to adjust the discharge capacity by opening and closing only the bleed passage 45. Also in this case, it is important that the bleed passage 45 is always in communication.

(1) The present invention is embodied in a wobble type variable displacement compressor. In describing the technical idea that can be grasped from the above-described embodiment, the valve element driving section is composed of electromagnetic components 60, 61, 63, and 64, and the valve element is arranged so that the opening degree of the valve hole 53 increases as the input current value decreases. The variable displacement compressor according to any one of claims 4 to 7, wherein the variable displacement compressor is configured to move the first compressor.

In this way, in order to maximize the pressure in the crank chamber 15, the input current value to the displacement control valve 46 (electromagnetic coil 64) may be set to zero, and when the vehicle engine Eg is stopped. In addition, there is no need for a special configuration in which the power supply line between the capacity control valve 46 and the power supply S is not interrupted upstream of the control computer C.

[0096]

According to the present embodiment having the above-described structure, the provision of the damper means can prevent an excessive increase in the pressure in the crank chamber, and can prevent an excessive difference between the pressure in the crank chamber and the pressure in the cylinder bore. The enlargement can be prevented, and the slide of the drive shaft against the urging force of the drive shaft urging member can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a variable displacement compressor.

FIG. 2 is a vertical sectional view of a displacement control valve.

FIG. 3 is an enlarged sectional view of a main part for explaining the operation of the displacement control valve.

FIG. 4 is a diagram illustrating an off state of a friction clutch.

FIG. 5 is a time chart showing operation characteristics of the displacement control valve.

FIG. 6 is an enlarged sectional view of a main part of a displacement control valve according to a second embodiment.

FIG. 7 is a time chart showing operation characteristics of the capacity control valve according to the third embodiment.

FIG. 8 is a time chart showing operation characteristics of the capacity control valve according to the fourth embodiment.

FIG. 9 is a longitudinal sectional view of a conventional variable displacement compressor.

[Explanation of symbols]

11 front housing constituting the housing, 12
... Cylinder block, 13 ... Rear housing, 14 ... Valve / port forming body, 15 ... Crank chamber, 16
.., A drive shaft, 20 a drive shaft biasing spring as a drive shaft biasing member, 31 a swash plate as a cam plate, 33 a cylinder bore, 35 a piston, 37 a suction chamber, 38 a discharge forming a discharge pressure region. Chamber, 39 ... suction port, 40 ... discharge port, 41 ... suction valve, 42 ... discharge valve, 44 ... air supply passage, 45 ... bleed passage, 46 ... capacity control valve, 90 ... pressure action space constituting damper means, 90a: a pressure acting chamber; 90b: a pressure acting chamber; 91: a pressure acting portion; 92: a communication passage.

Claims (7)

[Claims] 1. A variable displacement compressor applied to a refrigeration circuit for compressing refrigerant gas, wherein a crank chamber and a cylinder bore are formed in a housing, and a drive shaft rotates so as to pass through the crank chamber. A cam plate is connected to the drive shaft in the crank chamber so that the cam plate is integrally rotatable and the inclination angle is changeable; a piston connected to the cam plate is reciprocally housed in the cylinder bore; A valve / port forming body having a suction port, a suction valve, a discharge port, and a discharge valve is mounted on the housing so as to close the cylinder bore with the piston, and a piston is provided between the housing and the drive shaft. A drive shaft biasing member that biases the drive shaft along the axis in a direction away from the port forming body is interposed, and the crank chamber and the discharge pressure The crank chamber and the suction pressure area are communicated via a bleed passage, and the opening degree of at least one of the supply passage and the bleed passage is adjusted by external control. A displacement control valve that changes the pressure in the crank chamber by changing the inclination angle of the cam plate in accordance with the difference between the pressure in the crank chamber and the pressure in the cylinder bore through the piston. In the variable displacement compressor, the displacement control valve includes a damper unit, and the damper unit changes the opening degree of at least one of the air supply passage or the bleed passage so that the displacement control valve increases the pressure in the crank chamber. A variable displacement compressor having a configuration for preventing a sudden change in the opening. 2. The variable displacement compressor according to claim 1, wherein the displacement control valve is configured to adjust at least an opening degree of an air supply passage. 3. An electromagnetic friction clutch capable of interrupting power transmission is disposed between the drive shaft and an external drive source that rotationally drives the drive shaft. The friction clutch is rotatable by a housing. A rotor supported and operatively connected to an external drive source, an armature fixed to the drive shaft so as to be integrally rotatable and arranged opposite to the rotor, and the armature is attracted to the rotor by excitation to fasten the two together; 3. The variable displacement compressor according to claim 1, further comprising an electromagnetic coil capable of transmitting power. 4. The capacity control valve includes: a valve body that opens and closes at least one of the air supply passage and the bleed passage; and a valve body drive unit that moves the valve body by external control. The variable displacement compressor according to any one of claims 1 to 3, wherein the variable displacement compressor includes a moving resistance applying unit that applies a moving resistance to a valve body that moves in a direction to increase the pressure of the crank chamber. 5. The moving resistance applying means, comprising: a pressure acting portion provided integrally with the valve body; and two fluids partitioned by the pressure acting portion into spaces before and after the valve body in the moving direction. A pressure chamber, and a communication passage communicating the two fluid pressure chambers. When the valve element moves in a direction to increase the pressure of the crank chamber, the pressure acting portion changes the volume ratio of the two fluid pressure chambers. The variable displacement compressor according to claim 4, wherein the valve body is provided with a movement resistance by a resistance generated by a fluid flowing through the communication passage between the two chambers. 6. The capacity control valve includes: a valve body that opens and closes at least one of the air supply passage or the bleed air passage; and a valve body drive unit that moves the valve body under external control. When adjusting the opening degree of at least one of the air supply passage or the bleed passage so that the displacement control valve increases the pressure of the crank chamber, the valve body drive unit is configured to change the moving force applied to the valve body in a stepwise manner. The variable displacement compressor according to any one of claims 1 to 3, wherein a sudden change in the opening is prevented by controlling. 7. The capacity control valve includes: a valve body that opens and closes at least one of the air supply passage or the bleed passage; and a valve body drive unit that moves the valve body by external control. When adjusting the opening degree of at least one of the air supply passage or the bleed passage so that the displacement control valve increases the pressure of the crank chamber, the valve body driving unit is configured to continuously change the moving force applied to the valve body. The variable displacement compressor according to any one of claims 1 to 3, wherein a sudden change in the opening is prevented by controlling.