JPH10274152A - Variable capacity type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize a tilting angle of a cam plate in the case of stopping by intervening a rotation regulation means which regulates relative rotation between a tilting angle decreasing spring and a driving shaft, between the tilting angle decreasing spring and a rotary support body or the driving shaft, which spring is wound around the driving shaft between the rotary support body and the cam plate. SOLUTION: A tilting angle decreasing spring 27 is wound around a driving shaft 16 between a rotary support body 22 and a cam plate 23. The tilting angle decreasing spring 27 is brought into contact with a front surface inner peripheral part of the cam plate 23, for energizing the cam plate 23 toward the side of a cylinder block along an axis L of the driving shaft 16. An end turn of the tilting angle decreasing spring 27 on the side of the rotary support body 22 is externally pushingly fitted to a spring washer 68 with proper pressure and fixed thereto. Relative rotation of the tilting angle decreasing spring 27 is prevented in respect to the driving shaft 16. It is thus possible to keep a positional relation to an end of the spring on the side of a cam plate 23 constant as previously set. A tilting angle of the cam plate 23 can be stabilized in the case of stopping, similarly to the case under operation.

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 applied to, for example, a vehicle air conditioning system and capable of changing a displacement by adjusting a tilt angle of a cam plate.

[0002]

2. Description of the Related Art As a compressor of this kind, for example, FIG.
To the clutchless type shown in FIG. That is, the cylinder bore 101, the crank chamber 102, the suction chamber 103, and the discharge chamber 104 are formed inside the housing 105. The piston 106 is the cylinder bore 101
Is housed in The drive shaft 107 is rotatably held by the housing 105 and passes through the crank chamber 102. The rotation support 108 is fixed on the drive shaft 107 in the crank chamber 102. The swash plate 109 is accommodated in the crank chamber 102, is slidably supported on the drive shaft 107 and is tiltably supported, and has a piston 10
6. The hinge mechanism 110 includes a support arm 111 provided on the rotary support 108 and a guide pin 112 provided on the swash plate 109.
The spherical portion 112a of the guide pin 112 is slidably fitted in the eleven guide holes 111a.

Accordingly, the swash plate 109 is provided on the rotating support 108.
The hinge mechanism 110 can rotate integrally with the drive shaft 107 via the hinge mechanism 110, and is guided by the hinge mechanism 110 between a maximum tilt position where the tilt angle is maximum and a minimum tilt position where the tilt angle is minimum, It is slidable while tilting on the drive shaft 107. The guide hole 11 of the hinge mechanism 110 is exaggerated as shown in the enlarged circle of FIG.
There is a slight clearance between 1a and the spherical portion 112a for smoothly moving the swash plate 109 and the like.

A supply passage 113 connects the discharge chamber 104 and the crank chamber 102, and a bleed passage 114 connects the crank chamber 10.
2 and the suction chamber 103 are connected. The capacity control valve 115 is interposed on the air supply passage 113. Same capacity control valve 115
Adjusts the opening degree of the air supply passage 113 so that the discharge chamber 1
The amount of the discharged refrigerant gas introduced from 04 into the crank chamber 102 is changed. Therefore, the pressure in the crank chamber 102 is adjusted in relation to the amount of refrigerant gas released through the bleed passage 114, and the difference between the pressure and the pressure in the cylinder bore 101 via the piston 106 is changed. As a result, the swash plate 109
Moves between the maximum tilt position and the minimum tilt position, the stroke of the piston 106 is changed, and the discharge capacity is changed.

[0005] The interrupter 121 is disposed inside the housing 105, and is connected to the swash plate 10 through a thrust bearing 122.
9 is in contact with a convex portion 109a formed on the inner peripheral portion of the rear surface. The swash plate 109 pushes the blocking body 121 via the protrusion 109 a and the thrust bearing 122 in accordance with the sliding movement to the minimum tilt position. Same swash plate 109
Is located at the minimum inclination position, the blocking body 121 is in contact with the positioning surface 124 formed on the housing 105 through the blocking surface 123, and the suction chamber 103 and the suction chamber 10
3 is disconnected from the suction passage 125 connecting the external refrigerant circuit to the external refrigerant circuit. In other words, the blocking body 121 is
When the connection between the air and the suction passage 125 is interrupted,
The further sliding movement of the swash plate 109 is restricted by the contact between the swash plate 109 and the positioning surface 124, and this restricted state is the minimum tilt position of the swash plate 109.

[0006] As described above, the circulation of the refrigerant on the external refrigerant circuit is prevented by the blocking body 121 blocking the suction of the refrigerant gas, so that the operation of the compressor, that is, the rotation of the drive shaft 107 can be performed even when cooling is unnecessary. Good to be continued. As a result, there is no need to interpose a clutch mechanism such as an electromagnetic clutch, which is expensive and heavy, between the drive shaft 107 and the vehicle engine 126, and the deterioration of the bodily sensation due to the on / off operation of the electromagnetic clutch is eliminated. There is good to be able to do.

An inclination reducing spring 116 formed of a compression coil spring is wound around the drive shaft 107 between the rotary support 108 and the swash plate 109 and urges the swash plate 109 toward the minimum inclination position. Therefore, even if the compressor is stopped due to the stop of the vehicle engine 126 and the pressure inside the compressor is equalized, the swash plate 109 is urged by the inclination reducing spring 116 and held at the minimum inclination position. 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 at the start is effectively mitigated.

Here, the inner peripheral portion of the front surface of the swash plate 109 to which the end turn portion 116a of the inclination reducing spring 116 is opposed is not a single plane due to manufacturing reasons. A plane 117 extending from the top dead center corresponding portion 109b side to the inner peripheral portion located at the top dead center,
Bottom dead center corresponding site 1 where piston 106 is located at bottom dead center
A plane 118 extending from the 09c side to the inner peripheral portion is constituted by a composite surface that intersects at an angle to the rotary support 108 side. The piston 106 shown in FIG. 6 is located at the top dead center, and the vicinity where the piston 106 is connected is near the swash plate 10.
9 is a top dead center corresponding part 109b, and a part located on the opposite side of the top dead center corresponding part 109b via the drive shaft 107 is a bottom dead center corresponding part 109c.

When the swash plate 109 is moved to the minimum inclination position, the inclination reducing spring 116 is used to move the two flat surfaces 117 and 118.
At the intersection K of the swash plate 109. As shown in FIGS. 7 and 8, the line of intersection K in the compressor is a line of contact with the thrust bearing 122 which is the center of tilt of the swash plate 109 when the swash plate 109 is at the minimum tilt position. More specifically, it is located at a position shifted toward the top dead center corresponding portion 109b from an imaginary plane H including the contact line T and parallel to the axis L of the drive shaft 107.

Therefore, the inclination reducing spring 116 is provided for the swash plate 10.
9 is moved to the minimum tilt position, the swash plate 1
09 at the top dead center corresponding portion 109b side, and the swash plate 10
A tilting moment M1 is applied to the direction No. 9 in a direction in which the tilt angle increases around the contact line T. The clearance between the guide hole 111a and the spherical portion 112a in the hinge mechanism 110 allows a slight tilt of the swash plate 109 at the minimum tilt position. As a result, as shown in the enlarged circle of FIG.
Is pressed against the inner surface of the guide hole 111a toward the swash plate 109 (the right side in the drawing), the tilt angle of the swash plate 109 at the minimum tilt position is defined.

However, in the compressor having the above structure, during operation, a compression reaction force is applied to the swash plate 109 via the piston 106 near the top dead center, and the swash plate 109 is caused by the compression reaction force. , A tilting moment M2 is applied around the contact line T in a direction to decrease the tilt angle. The tilting moment M2 is larger than the tilting moment M1 exerted by the tilt angle reducing spring 116 described above. Therefore, the spherical portion 112a of the hinge mechanism 110 is positioned on the opposite side of the inner surface of the guide hole 111a from the stop of the compressor (the rotating support 10).
8), the tilt angle of the swash plate 109 at the minimum tilt position is defined.

That is, in the compressor shown in FIGS. 6 to 8, the inclination angle of the swash plate 109 at the minimum inclination position is different between when the operation is performed and when the operation is stopped. As a result, even when the tilt angle of the swash plate 109 at the minimum tilt position is set to a predetermined value at the time of manufacturing the compressor, it deviates from the predetermined value during operation. For this reason, the swash plate 109 must be assembled in consideration of the above, and the operation is troublesome.

Therefore, the present applicant has proposed a technique as shown in FIGS. 9 and 10 in order to solve the above problem. That is, when the swash plate 109 is at the minimum tilt position, the intersection line K is located
Both planes 117 and 118 are set so as to be shifted to the 9c side. Accordingly, the inclination decreasing spring 116 pushes the lower dead center corresponding portion 109c side of the swash plate 109 at the minimum inclination position, and the inclination decreasing direction with respect to the swash plate 109, that is, the inclination moment M2 described above. A tilting moment M1 in the same direction acts. As a result, even when the compressor is stopped, the inclination angle of the swash plate 109 at the minimum inclination position is the same as that at the time of operation.
Are defined in a state pressed against the rotation support 108 side on the inner surface of the guide hole 111a. Therefore, the inclination angle of the swash plate 109 at the minimum inclination position can be the same even when the operation is stopped as during the operation.

[0014]

However, in the compressor shown in FIGS.
07 with a little play, the drive shaft 1
Rotation relative to 07 is permitted. When the inclination decreasing spring 116 is rotated, the positional relationship between the spring end 116b and the intersection line K of the swash plate 109 at the minimum inclination position around the drive shaft 107 is changed. For example, when the inclination reducing spring 116 is rotated to the state shown in the drawing, the spring end 116b is located on the top dead center corresponding portion 109b side with respect to the intersection line K, and furthermore, the intersection line K at the end winding portion 116a. Free portion 116 from the abutting portion to the spring end 116b
c is longer. Accordingly, the inclination reducing spring 116 is
Not only is the lower dead center corresponding portion 109c side of the swash plate 109 pushed through the intersection line K, but also the free portion 116c jumps out of the intersection line K toward the swash plate 109 due to the bending of the end winding portion 116a. The swash plate 109 was also pushed on the top dead center corresponding portion 109b side. As a result, in addition to the tilting moment M1, the swash plate 109 at the minimum tilt position is
A tilting moment M3 in the tilt increasing direction is newly applied,
The spherical portion 112a of the hinge mechanism 110 has a guide hole 111a.
From the inner surface of the swash plate 109 at the minimum tilt position.
There was a slight deviation in the tilt angle from that during driving.

The present invention has been made in view of the problems existing in the prior art described above, and has as its object to provide a cam plate at a minimum tilt position and a spring end portion on the cam plate side in the tilt reduction spring. Is to provide a variable displacement compressor capable of maintaining a positional relationship with the compressor in a preset state.

[0016]

In order to achieve the above object, according to the first aspect of the present invention, the cam plate is urged toward the minimum tilt position on the drive shaft between the rotary support and the cam plate. A tilt-reducing spring formed of a coil spring is wound around the rotary shaft, and between the rotary shaft and the rotary support or the drive shaft, there is provided a rotation restricting means for restricting the relative rotation of the tilt-reducing spring with respect to the drive shaft. The rotation restricting means interposes the positional relationship between the cam plate at the minimum tilt position and the spring end on the cam plate side in the tilt reduction spring.
This is a variable displacement compressor that is maintained in a preset state.

According to the second aspect of the present invention, the rotary support or the drive shaft is provided with a spring seat that can be inserted into the tilt-reducing spring or can accommodate the tilt-reducing spring. The end turn on the side of the rotary support is press-fitted and fixed to the spring seat to constitute the rotation restricting means.

According to the third aspect of the present invention, the contact position of the cam plate at the minimum inclination position with the inclination decreasing spring is shifted toward the bottom dead center corresponding portion with respect to the contact position with the minimum inclination position defining means. Is set.

According to a fourth aspect of the present invention, there is provided a refrigerant circulation preventing means capable of preventing refrigerant circulation on the external refrigerant circuit. According to the fifth aspect of the present invention, the drive shaft is operatively connected to an external drive source without a clutch mechanism.

(Operation) In the first aspect of the present invention, the rotation restricting means is interposed between the inclination reducing spring and the rotating support or the drive shaft, and the inclination reducing spring rotates relative to the drive shaft. Regulate what you do. Therefore, the positional relationship between the cam plate at the minimum tilt position and the spring end on the cam plate side in the tilt reduction spring can be maintained in a preset state.

According to the second aspect of the present invention, the end turn on the side of the rotary support is press-fitted and fixed to the spring seat, whereby the relative rotation of the inclination reducing spring with respect to the drive shaft is regulated. Here, during operation of the compressor, a compression reaction force is applied to the cam plate via the piston near the top dead center. A tilting moment is applied to the cam plate at the minimum tilt position around the contact portion with the minimum tilt position defining means in a direction to decrease the tilt angle due to the compression reaction force.

When the compressor stops, the cam plate is moved to the minimum tilt position by the tilt reducing spring. Therefore, the next start of the compressor is from the minimum discharge capacity state where the load torque is the smallest, and the shock at the start is effectively reduced.

In the third aspect of the present invention, the inclination decreasing spring is
The cam plate is brought into contact with the cam plate at a position shifted toward the bottom dead center corresponding portion side from the contact position with the minimum inclination position defining means. Therefore, the inclination-reducing spring pushes the lower-dead-center-corresponding portion of the cam plate at the minimum inclination position to decrease the inclination angle with respect to the cam plate, that is, the same as the tilting moment caused by the compression reaction force. A tilting moment is exerted in the direction about the contact position with the minimum tilt position defining means.
As a result, the inclination angle of the cam plate at the minimum inclination position can be the same at the time of operation stop as at the time of operation.

According to the fourth aspect of the present invention, when cooling is not required or when frost is likely to occur in the evaporator on the external refrigerant circuit, the refrigerant circulation on the external refrigerant circuit is prevented by the refrigerant circulation preventing means. . Therefore, the operation of the compressor, that is, the rotation of the drive shaft may be continued, and in the invention of claim 5, the drive shaft is connected to the external drive source without via the clutch mechanism.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention embodied in a clutchless type variable displacement compressor will be described below.

As shown in FIGS. 1 and 2, the front housing 11 is fixedly joined to the front end of the cylinder block 12. The rear housing 13 is fixedly joined to the rear end of the cylinder block 12 via a valve forming body 14. The front housing 11, the cylinder block 12, and the rear housing 13 form a housing of the compressor. The crank chamber 15 is defined by being surrounded by the front housing 11 and the cylinder block 12. The drive shaft 16 is rotatably supported between the front housing 11 and the cylinder block 12 so as to pass through the crank chamber 15. The pulley 17 is rotatably supported on a front wall surface of the front housing 11 via an angular bearing 18. The pulley 17 is connected to a protruding end of the drive shaft 16 from the front housing 11, and is connected to a vehicle engine 20 as an external drive source via a belt 19 wrapped around the outer periphery of the pulley 17. They are directly connected without going through the clutch mechanism.

The lip seal 21 is interposed between the front end of the drive shaft 16 and the front housing 11 and seals the drive shaft 16. The rotating support 22 is provided in the crankcase 1.
5 is fixed to the drive shaft 16. The swash plate 23 serving as a cam plate is housed in the crank chamber 15, and the drive shaft 16 is inserted through an insertion hole 23 a provided through the center of the swash plate 23. The swash plate 23 is supported by the drive shaft 16 and is slidable and tiltable in the direction of the axis L of the drive shaft 16. The hinge mechanism 24 includes the rotation support 2
2 and the swash plate 23.

The support arm 25 constituting the hinge mechanism 24 is provided to project from the outer periphery of the rear surface of the rotary support 22. Guide pin 26 also constituting hinge mechanism 24
Is planted on the front surface of the swash plate 23. Guide pin 2
6 is slidably fitted into a guide hole 25 a formed in the support arm 25. The swash plate 23 can rotate integrally with the drive shaft 16 via the rotation support 22 and the hinge mechanism 24. The swash plate 23 is slidable while tilting on the drive shaft 16 by a slide guide relationship between the guide hole 25a and the spherical portion 26a and a slide support action by the drive shaft 16.

The inclination reducing spring 27 is composed of a compression coil spring, and is wound around the drive shaft 16 between the rotary support 22 and the swash plate 23. The end turn 27a on the swash plate 23 side of the inclination reducing spring 27 is open-ended. The inclination decreasing spring 27 is in contact with the inner peripheral portion of the front surface of the swash plate 23 and urges the swash plate 23 along the axis L of the drive shaft 16 toward the cylinder block 12.

The accommodation hole 28 extends through the center of the cylinder block 12 in the direction of the axis L of the drive shaft 16. The blocking body 29 having a closed cylindrical shape is slidably accommodated in the accommodation hole 28. Inlet passage opening spring 30
Are housed in the housing holes 28 and urge the blocking body 29 toward the swash plate 23 side.

The rear end of the drive shaft 16 is inserted into a blocking body 29. The radial bearing 31 is interposed between the rear end of the drive shaft 16 and the inner peripheral surface of the blocking body 29. The radial bearing 31 is slidable with respect to the drive shaft 16 in the direction of the axis L together with the blocking body 29.

The suction passage 32 is formed at the center of the rear housing 13 and the valve body 14. Inhalation passage 3
2 is connected to the accommodation hole 28, and a positioning surface 33 is formed around the opening that appears on the front side of the valve forming body 14. The blocking surface 34 is formed on the distal end surface of the blocking member 29, and is moved toward and away from the positioning surface 33 by the movement of the blocking member 29. When the blocking surface 34 comes into contact with the positioning surface 33 in the annular region, the communication between the suction passage 32 and the inner space of the housing hole 28 is blocked by the sealing action between the two.

The annular thrust bearing 35 is
The swash plate 23 is interposed between a pair of projections 23 b formed at the center of the rear surface of the swash plate 23 and the rear end surface of the blocking body 29, and is slidably supported on the drive shaft 16. The thrust bearing 35 is urged by the suction passage opening spring 30 and is always held between the swash plate 23 and the blocking body 29.

The inner peripheral portion of the swash plate 23 has a drive shaft 16.
The inclination angle is reduced as the upper side slides toward the cylinder block 12. At the same time, the swash plate 23
Pushes the blocking body 29 via the convex portion 23b and the thrust bearing 35. Accordingly, the blocking body 29 is moved toward the positioning surface 33 against the urging force of the suction passage opening spring 30. When the blocking body 29 comes into contact with the positioning surface 33 with the blocking surface 34, further sliding movement of the swash plate 23 is restricted. In this state, the inclination angle of the swash plate 23 is a minimum inclination angle slightly larger than 0 °. FIG.
This shows a state where the swash plate 23 is moved and arranged at the minimum inclination position.
In a state where the blocking body 29 is in contact with the valve forming body 14, the blocking body 29, the valve forming body 14, and the thrust bearing 35 serve as minimum inclination position defining means. In the present embodiment, it is assumed that the cam plate 23 is brought into contact with the minimum tilt angle defining means 35 in this state.

The inclination angle of the swash plate 23 increases as the inner peripheral portion slides on the drive shaft 16 toward the rotary support 22. Interlocking body 29
By the urging force of the released suction passage opening spring 30
The blocking surface 34 is moved to a side away from the positioning surface 33. The inclination restricting portion 22 a is formed on the rear surface of the rotary support 22. When the swash plate 23 comes into contact with the inclination-angle restricting projection 22a, further sliding movement and inclination are restricted. In this state, the inclination angle of the swash plate 23 becomes maximum.
FIG. 1 shows a state where the swash plate 23 is moved and arranged at the maximum tilt position.

The cylinder bore 36 is provided in the cylinder block 12
(Only one is shown in the drawing), and the same number of single-headed pistons 37 are provided in each cylinder bore 36.
Is housed in The swash plate 23 anchors a piston 37 via a shoe 38 at an outer peripheral portion of the swash plate 23. Rotational movement of the swash plate 23 is converted into reciprocating linear movement of the piston 37.

The suction chamber 39 and the discharge chamber 40 are formed separately in the rear housing 13. Suction port 4
1. A suction valve 42 for opening and closing the suction port 41, a discharge port 43, and a discharge valve 44 for opening and closing the discharge port 43 are formed on the valve body 14, respectively. Then, the refrigerant gas in the suction chamber 39 is sucked into the cylinder bore 36 through the suction port 41 and the suction valve 42 by the reciprocating operation of the piston 37. The refrigerant gas flowing into the cylinder bore 36 is discharged to the discharge chamber 40 through the discharge port 43 and the discharge valve 44 by the forward movement of the piston 37. The opening of the discharge valve 44 is defined by a retainer 45 fixed on the valve body 14 by polymerization.

The thrust bearing 46 is provided on the rotating support 2.
2 and the front housing 11.
The thrust bearing 46 includes the piston 37 and the swash plate 2.
3 to receive the compression reaction force applied to the rotary support 22 during the compression of the refrigerant.

The suction chamber 39 is connected to the housing hole 28 through the opening 47. Then, when the blocking body 29 comes into contact with the positioning surface 33 with its blocking surface 34, the opening 47 is blocked from the suction passage 32.

The passage 48 is formed at the axis of the drive shaft 16. The pressure release port 49 extends through the peripheral surface of the blocking body 29. The crank chamber 15 and the inner space of the housing hole 28
8 and the pressure relief port 49.

The air supply passage 50 is provided between the discharge chamber 40 and the crank chamber 1.
5, and a capacity control valve 51 is interposed on the passage 50. That is, the valve chamber 52 of the same capacity control valve 51
Constitutes a part of the air supply passage 50. The port 53 is formed in the valve chamber 52 with an opening. The valve element 54 is housed in the valve chamber 52 and can be connected to and separated from the port 53. The opening spring 55 is housed in the valve chamber 52 and urges the valve element 54 in a direction to open the port 53.

The pressure sensing chamber 56 is formed so as to be adjacent to the valve chamber 52. The pressure-sensitive passage 57 is connected to the pressure-sensitive chamber 56 and the suction passage 32.
And connect. Bellows 58 is housed in pressure-sensitive chamber 56,
It is operatively connected to the valve body 54 via a rod 59.

The movable iron core 60 is disposed on the opposite side of the bellows 58 with respect to the valve element 54, and is connected to the valve element 5 via a rod 61.
4 is operatively connected. The fixed iron core 62 is a movable iron core 60.
The solenoid 63 is arranged so as to surround the movable iron core 60 and the fixed iron core 62. When a predetermined current is supplied to the solenoid 63, an attraction force corresponding to the input current value is generated between the iron cores 60 and 62.
This suction force is transmitted to the valve element 54 via the rod 61 as a force in the direction in which the opening of the port 53 decreases.

On the other hand, the bellows 58 is displaced in accordance with the fluctuation of the suction pressure introduced from the suction passage 32 into the pressure-sensitive chamber 56 via the pressure-sensitive passage 57. The bellows 58 responds to the suction pressure when the solenoid 63 is excited, and its displacement is transmitted to the valve body 54 via the rod 59.

In the compressor having the above-described structure, the suction passage 32 serving as a passage for introducing the refrigerant gas into the suction chamber 39 and the discharge chamber 4
An external refrigerant circuit 71 connects the discharge flange 67 that discharges refrigerant gas from zero. The condenser 72, the expansion valve 73, and the evaporator 74 are interposed on the external refrigerant circuit 71. Evaporator temperature sensor 81, cabin temperature sensor 8
2. The air conditioner switch 83 and the cabin temperature setting device 84
It is connected to the control computer 85.

When the air conditioner switch 83 is turned on, the control computer 85 outputs, for example, a vehicle temperature sensor 82.
When the vehicle temperature detected by the above is equal to or higher than the set temperature set via the vehicle temperature setting device 84, the solenoid 63 is commanded to be excited. Then, a predetermined current is supplied to the solenoid 63, and an attraction force corresponding to the input current value is generated between the iron cores 60 and 62. This suction force is transmitted to the valve element 54 via the rod 61 as a force in the direction in which the opening of the port 53 decreases, against the urging force of the opening spring 55. On the other hand, the bellows 58 is displaced in accordance with a change in the suction pressure introduced from the suction passage 32 into the pressure-sensitive chamber 56 via the pressure-sensitive passage 57. Then, the bellows 58 operates in response to the suction pressure when the solenoid 63 is excited, and the displacement is transmitted to the valve body 54 via the rod 59. The valve opening of the displacement control valve 51 is determined by the balance between the excitation and demagnetization of the solenoid 63, the urging force from the bellows 58, and the urging force of the opening spring 55.

When the cooling load is large, for example, the difference between the compartment temperature detected by the compartment temperature sensor 82 and the temperature set by the compartment temperature setting device 84 is large. The control computer 85 controls the input current value to the solenoid 63 so as to change the set suction pressure based on the difference between the vehicle interior temperature and the set temperature. The control computer 85 increases the input current value as the difference between the cabin temperature and the set temperature increases. Therefore,
The suction force between the fixed iron core 62 and the movable iron core 60 is increased, and the urging force acting on the valve body 54 in the direction of decreasing the opening of the port 53 is increased. Then, the port 53 is opened and closed by the valve body 54 at a lower suction pressure. Therefore, the capacity control valve 51 is operated so as to maintain a lower suction pressure by increasing the input current value.

When the opening of the port 53 is reduced, the amount of refrigerant gas flowing from the discharge chamber 40 into the crank chamber 15 via the air supply passage 50 is reduced. On the other hand, the refrigerant gas in the crank chamber 15 flows out to the suction chamber 39 via the passage 48 and the pressure release port 49. For this reason, the crankcase 1
The pressure of 5 drops. When the cooling load is large, the suction pressure of the cylinder bore 36 is also high, and the crank chamber 15
And the pressure of the cylinder bore 36 becomes smaller.
Therefore, the swash plate 23 is moved to the maximum tilt position.

When the port 53 is closed, the supply of the high-pressure refrigerant gas from the discharge chamber 40 to the crank chamber 15 is not performed. Then, the pressure in the crank chamber 15 becomes substantially the same as the pressure in the suction chamber 39, and the swash plate 23 is moved to the maximum tilt position.

Conversely, when the cooling load is small, for example, the difference between the cabin temperature and the set temperature is small. The control computer 85 instructs the input current value to decrease as the difference between the cabin temperature and the set temperature decreases. For this reason, the suction force between the fixed iron core 62 and the movable iron core 60 is weak, and the valve body 5
The urging force applied to the port 4 in the direction of decreasing the opening of the port 53 decreases. Then, at a higher suction pressure, the valve body 5
4, the port 53 is opened and closed. Therefore, the capacity control valve 51 operates to maintain a higher suction pressure by reducing the input current value.

When the opening of the port 53 increases, the amount of refrigerant gas flowing from the discharge chamber 40 into the crank chamber 15 increases, and the pressure in the crank chamber 15 increases. When the cooling load is small, the suction pressure of the cylinder bore 36 is low, and the difference between the pressure in the crank chamber 15 and the pressure in the cylinder bore 36 increases. Accordingly, the swash plate 23 is moved to the minimum tilt position.

As the cooling load is approached, the temperature in the evaporator 74 approaches the temperature at which frost occurs. When the value detected by the evaporator temperature sensor 81 becomes equal to or lower than the frost determination temperature, the control computer 85 demagnetizes the solenoid 63. The frost determination temperature reflects a situation in which frost is likely to occur in the evaporator 74. When the air conditioner switch 83 is switched to the off state, the control computer 85 demagnetizes the solenoid 63.

When the solenoid 63 is demagnetized, the valve 54
Opens the port 53 to the maximum by the urging force of the opening spring 55. For this reason, a large amount of the high-pressure refrigerant gas in the discharge chamber 40 is supplied to the crank chamber 15 through the air supply passage 50, and the pressure in the crank chamber 15 increases. When the pressure in the crank chamber 15 increases, the swash plate 23 is moved to the minimum tilt position.

As described above, the opening / closing operation of the capacity control valve 51 is changed according to the magnitude of the input current value to the solenoid 63. When the input current value increases, the switching operation is performed at a low suction pressure, and when the input current value decreases, the opening and closing operation is performed at a high suction pressure. The compressor changes the inclination angle of the swash plate 23 to maintain the set suction pressure, and changes the discharge capacity. That is, the displacement control valve 51 has a role of changing the set suction pressure by changing the input current value and a role of performing the minimum displacement operation regardless of the suction pressure. By providing such a capacity control valve 51, the compressor plays a role of changing the refrigeration capacity of the refrigeration circuit.

When the swash plate 23 is disposed at the minimum inclination position,
The blocking body 29 is brought into contact with the positioning surface 33 with the blocking surface 34 interlockingly, and the connection between the suction passage 32 and the suction chamber 39 is cut off. In this state, the flow of the refrigerant gas from the external refrigerant circuit 71 into the suction chamber 39 is prevented. Since the minimum inclination angle of the swash plate 23 is not 0 °, the refrigerant gas is discharged from the cylinder bore 36 to the discharge chamber 39. Refrigerant gas discharged from the cylinder bore 36 to the discharge chamber 40 is supplied to the air supply passage 48, the crank chamber 15, the passage 48, and the discharge port from the pressure difference between the discharge chamber 40, the crank chamber 15, and the suction chamber 39. 49, accommodation hole 28, suction chamber 39, cylinder bore 3
6. The lubricating oil circulating inside the discharge chamber 40 and flowing together with the refrigerant gas lubricates each sliding portion in the compressor.

In the state where the air conditioner switch 83 is on and the swash plate 23 is at the minimum tilt position, for example, when the cabin temperature rises and the cooling load increases, the vehicle temperature detected by the cabin temperature sensor 82 The room temperature exceeds the temperature set in the vehicle room temperature setting device 84. The control computer 85
The solenoid 63 is excited based on the displacement of the compartment temperature, and the air supply passage 50 is closed. Therefore, the crankcase 1
The pressure of 5 is reduced based on the pressure released through the passage 48 and the pressure release port 49. Due to this pressure reduction, the suction passage opening spring 30 extends from the contracted state in FIG. Then, the movement of the blocking body 29 separates the blocking surface 34 from the positioning surface 33, and the introduction of the refrigerant gas from the suction passage 32 into the suction chamber 39 is allowed.

When the vehicle engine 20 stops, the operation of the compressor also stops, that is, the rotation of the swash plate 23 also stops, and the power supply to the solenoid 63 of the displacement control valve 51 also stops. Therefore, the solenoid 63 is demagnetized, the air supply passage 50 is opened, and the swash plate 23 is disposed at the minimum inclination position. If the operation stop state of the compressor continues, the pressure in the compressor becomes uniform, but the swash plate 23 is held at the minimum tilt position by the biasing force of the tilt reduction spring 27. Therefore, when the operation of the compressor is started by starting the vehicle engine 20, the swash plate 23
Start rotation from the minimum tilt state with the lowest load torque,
There is almost no shock when starting the compressor.

As shown in an enlarged circle in FIG. 3, the guide hole 25a and the spherical portion 26 of the hinge mechanism 24 are exaggerated.
There is some clearance between a and c. The clearance is such that the swash plate 23 at the minimum inclination position is
Contact line between 3b and thrust bearing 35 (contact position)
It is allowed to be slightly tilted about T.

Here, during operation of the compressor, a compression reaction force is applied to the swash plate 23 via the piston 37 near the top dead center, and the inclination angle is applied to the swash plate 23 due to the compression reaction force. Is tilted around the contact line T in a direction to reduce Therefore, the inclination angle of the swash plate 23 at the minimum inclination position is
The spherical portion 26a of the hinge mechanism 24 is defined in a state where the spherical portion 26a is pressed against the rotary support 22 on the inner surface of the guide hole 25a.

In the present embodiment, the swash plate 23 and the inclination-reducing spring 27 are arranged so that the inclination angle of the swash plate 23 at the minimum inclination position is the same as when the operation is stopped.
Abutment position is set.

That is, as shown in FIGS. 3 and 4, the swash plate 23 with which the end turn 27a of the inclination reducing spring 27 is opposed.
The inner peripheral portion of the front surface of the swash plate 23 is not a single plane for convenience of manufacture and the like, but is a plane extending from the top dead center corresponding portion 23c side of the swash plate 23 at the top dead center to the inner peripheral portion. 64 and a flat surface 65 extending from the bottom dead center corresponding part 23d side to the inner peripheral part where the piston 37 is located at the bottom dead center,
It is composed of a composite surface that is inclined toward the rotary support 22 and intersects at the intersection line K. The insertion hole 23a penetrates the center of the intersection line K, and therefore, the intersection line K exists in two places around the opening of the insertion hole 23a. 1 and 2
Is located at the top dead center, and the piston 3
7 is connected to the top dead center corresponding portion 23c of the swash plate 23.
The part located on the opposite side to the top dead center corresponding part 23c via the drive shaft 16 is the bottom dead center corresponding part 23d. When the drive shaft 16 is rotated by 180 ° from the state shown in the drawing, the swash plate 23 faces the piston 37 shown in the figure with the bottom dead center corresponding portion 23d, and the piston 37 is located at the bottom dead center.

The intersection line K between the two flat surfaces 64 and 65 is
3 is in the minimum tilt position, the contact line T with the thrust bearing 35 which is the center of tilt of the swash plate 23 is smaller than the contact line T.
More specifically, it is set at a position shifted to the lower dead center corresponding portion 23d side from an imaginary plane H including the contact line T and parallel to the drive shaft 16. Then, the end winding portion 2 of the inclination reducing spring 27
7a is in contact with the swash plate 23 at the intersection line K when the swash plate 23 is moved to the minimum tilt position. Therefore, the inclination-reducing spring 27 moves the swash plate 2 at the minimum inclination position.
3, the bottom dead center corresponding portion 23d is pushed, and a tilting moment M1 is applied to the swash plate 23 in the direction of decreasing the tilting angle, that is, in the same direction as the tilting moment M2 described above. As a result, even when the compressor is stopped, as in the case of operation, the inclination of the swash plate 23 at the minimum inclination position is such that the spherical portion 26a of the hinge mechanism 24 is pressed against the rotary support 22 on the inner surface of the guide hole 25a. Stipulated.

However, as described in detail in the prior art, depending on the positional relationship around the drive shaft 16 between the intersection line K of the swash plate 23 at the minimum tilt position and the spring end 27b of the tilt reduction spring 27, the same. The free portion 27c of the inclination reducing spring 27 protrudes more than the intersection line K and pushes the upper dead center corresponding portion 23c side of the swash plate 23. Accordingly, in addition to the tilting moment M1, a tilting moment M3 in the direction of increasing the tilting angle is newly applied to the swash plate 23, and the spherical portion 26a of the hinge mechanism 24 rises from the inner surface of the guide hole 25a, and the minimum. The inclination of the swash plate 23 at the inclination position is slightly different from that during operation.

For example, when the inclination reducing spring 27 is in the state shown in FIGS. 5 (a) and 5 (d), the end turn part 27a is in contact with the intersection K near the spring end 27b, and the free part 27c Has become shorter. In this state, the free portion 27
c hardly jumps out of the intersection line K toward the swash plate 23, and there is no need to worry about the above-described problem of the related art.
Rotating the inclination reducing spring 27 relative to the drive shaft 16,
The positional relationship between the spring end 27b and the intersection line K around the drive shaft 16 is shown in FIG. 5 (a) through FIG.
When the state is changed to the state of (c), the free portion 27c becomes longer. However, since the spring end 27b is located on the side corresponding to the bottom dead center 23d with respect to the intersection line K, even if the free portion 27c protrudes more than the intersection line K and pushes the swash plate 23, it is the same. The swash plate 23 is on the side corresponding to the bottom dead center 23d. Therefore, the tilting moment M3 is not applied to the swash plate 23.

However, by rotating the inclination reducing spring 27,
When the positional relationship between the spring end 27b and the intersection line K around the drive shaft 16 is changed from the state shown in FIG. 5D through the state shown in FIG. 5E to the state shown in FIG. The end portion 27b is on the side of the top dead center corresponding portion 23c with respect to the intersection line K, and the free portion 27c becomes longer. Therefore, the free portion 27
c gradually jumps out of the intersection line K toward the swash plate 23 side,
In particular, the positional relationship between the two 27b and K is shown in FIG.
In the state between (f), the free portion 27c is moved to the swash plate 23.
Is pressed against the top dead center corresponding portion 23c, and a tilting moment M3 is applied to the swash plate 23 so as to oppose the tilting moment M1.

In other words, in order to avoid a situation in which the tilt-reducing spring 27 exerts a tilting moment M3 on the swash plate 23 at the minimum tilt position, the spring end portion 27b of the tilt-reducing spring 27 and the minimum tilt position are required. Is required to satisfy at least one of the following two conditions with respect to the intersection line K of the swash plate 23 around the drive shaft 16. Spring end 27
b does not exist on the top dead center corresponding portion 23c side with respect to the intersection line K (specifically, a virtual plane including the intersection line K and parallel to the axis L). In the end winding portion 27a, a free portion 27c from a contact portion with the intersection line K to a spring end portion 27b is not long.

In this embodiment, as shown in FIG. 4, the positional relationship between the intersection line K of the swash plate 23 at the minimum tilt position and the spring end 27b of the tilt reduction spring 27 around the drive shaft 16 is shown. By setting both of the above-mentioned conditions to be satisfied, and fixing a part of the inclination decreasing spring 27 to the drive shaft 16, a suitable positional relationship between the two 27b and K is maintained. As shown in FIGS. 1 to 3, a spring seat portion 68 for fixing the inclination reduction spring 27 to the drive shaft 16 includes:
Drive shaft 16 located between rotary support 22 and swash plate 23
Are configured to have a large diameter. The large diameter portion is ensured by forming a portion of the drive shaft 16 to which the rotary support 22 is fixed on the swash plate 23 side slightly longer. End turn 2 on the rotation support 22 side of the inclination reducing spring 27
7d is inserted into the spring seat portion 68 with an appropriate pressure and fixed to the outside so that the tilt angle reducing spring 27 cannot rotate relative to the drive shaft 16.

Accordingly, the spherical portion 26a of the hinge mechanism 24
Is reliably pressed against the inner surface of the guide hole 25a on the side of the rotary support 22, and there is no fear that the spherical portion 26a will rise from the inner surface of the guide hole 25a.
It is possible to prevent a slight shift in the tilt angle from that during driving.

The present embodiment having the above configuration has the following effects. (1) The intersection line K between the planes 64 and 65 is set at a position shifted from the virtual plane H toward the bottom dead center corresponding portion 23d when the swash plate 23 is at the minimum inclination position. Therefore, the inclination angle of the swash plate 23 at the minimum inclination position can be made the same at the time of operation stop as at the time of operation. Therefore, it becomes easy to set the minimum inclination angle of the swash plate 23 at the time of manufacturing the compressor,
The work can be simplified. This reduces the cost of the compressor,
Furthermore, it leads to improvement of the capacitance accuracy.

(2) The inclination decreasing spring 27 is fixed to the drive shaft 16 and cannot rotate relative to the drive shaft 16. Therefore, in a state where the swash plate 23 is at the minimum tilt position, the positional relationship between the spring end 27b and the intersection line K around the drive shaft 16 is reliably maintained at a preset suitable state. As a result, the above-described effect (1) can be reliably achieved.

(3) The inclination-reducing spring 27 has a spring seat 68
Is fixed by press-fitting. Therefore, both 2
It is not necessary to interpose a special fixing tool for fixing the 7, 68, and the assembling work is simplified.

(4) The shut-off body 29 can prevent the circulation of the refrigerant on the external refrigerant circuit 71 by shutting off the suction of the refrigerant gas from the external refrigerant circuit 71. Therefore, the operation of the compressor may be continued even when cooling is unnecessary, and no expensive and heavy clutch mechanism such as an electromagnetic clutch is interposed between the drive shaft 16 and the vehicle engine 20. As a result, the deterioration of the bodily sensation due to the on / off operation of the electromagnetic clutch is eliminated.

(5) The blocker 29 interlocks with the minimum inclination position of the swash plate 23 to prevent the circulation of the refrigerant on the external refrigerant circuit 71. Therefore, the compressor has a minimum discharge capacity and requires a small driving torque, so that a power loss when the refrigerant circulation is prevented can be reduced.

(6) The minimum discharge capacity operation for the clutchless type compressor is not limited to simply minimizing the discharge capacity. For example, the above-described optimization of the internal circulation of the refrigerant gas (more It is necessary to consider the balance between the internal circulation of the lubricating oil) and the reduction of the power loss. That is, delicate setting of the minimum inclination angle of the swash plate 23 becomes important. Therefore, in the present embodiment embodied in the clutchless type compressor, it is particularly effective to exhibit the effect.

The present invention can be practiced in the following modes without departing from the spirit of the present invention. (1) A boss portion as a spring seat portion is protruded around the drive shaft 16 on the inner peripheral portion of the rear surface of the rotary support 22, and the end turn portion 27d of the inclination reducing spring 27 is press-fitted and fixed to the outer peripheral portion of the boss portion. To do.

(2) An annular groove as a spring seat portion is recessed around the drive shaft 16 in the inner peripheral portion of the rear surface of the rotary support 22, and a seat on the rotary support 22 side of the inclination reducing spring 27 is provided in the annular groove. Press-fit the winding part.

(3) In changing the inclination angle of the swash plate 23, in the above embodiment, the pressure of the crank chamber 15 is regulated by adjusting the amount of refrigerant gas discharged from the discharge chamber 40 to the crank chamber 15. Had gone. Change this,
The crank chamber 15 and the discharge chamber 40 are always in communication. Then, the displacement control valve is disposed on the bleed passage (47, 48 or 49), and the amount of refrigerant gas released from the crank chamber 15 to the suction chamber 39 is adjusted by the displacement control valve so that the pressure in the crank chamber 15 is reduced. Pressure adjustment may be performed.

(4) Implementation in a variable displacement compressor with a clutch.

[0079]

According to the first aspect of the present invention, by providing the rotation restricting means, the positional relationship between the cam plate at the minimum tilt position and the spring end on the cam plate side in the tilt reduction spring is provided. , Can be maintained in a preset state. Therefore, for example, if this positional relationship is appropriately set in the invention of claim 3, the inclination angle of the cam plate at the minimum inclination position can be reliably set to the same as that during the operation even when the operation is stopped.

According to the second aspect of the present invention, the inclination-reducing spring can be fixed to the spring seat without any special fixing tool, and the assembling work is simplified. According to the invention of claim 4, it is possible to prevent the circulation of the refrigerant on the external refrigerant circuit, and according to the invention of claim 5, an expensive and heavy electromagnetic clutch is provided between the drive shaft and the external drive source. Do not interpose a clutch mechanism such as As a result, the deterioration of the bodily sensation due to the on / off operation of the electromagnetic clutch is eliminated.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing a minimum discharge capacity state.

FIG. 3 is an explanatory view showing a main part.

FIG. 4 is an enlarged front view showing the vicinity of an insertion hole when the swash plate is at a minimum tilt position;

FIGS. 5A to 5F are explanatory views showing examples in which the positional relationship between a swash plate at a minimum tilt position and a spring end of a tilt reduction spring is variously changed.

FIG. 6 is a longitudinal sectional view of a conventional compressor, showing a minimum discharge capacity state.

FIG. 7 is an explanatory view showing a main part.

FIG. 8 is an enlarged front view showing the vicinity of the insertion hole when the swash plate is at the minimum inclination position.

FIG. 9 is an explanatory diagram showing a conventional technique proposed by the present applicant.

FIG. 10 shows a state in which the swash plate is in the minimum inclination position.
The front view which expands and shows the vicinity of an insertion hole.

[Explanation of symbols]

11 front housing constituting the housing, 12
... the same cylinder block, 13 ... the rear housing, 14 ... the valve forming body which constitutes the minimum tilt angle defining means, 16
.., A drive shaft, 22... A rotating support, 23... A swash plate as a cam plate, 24. A hinge mechanism, 27.
9: a blocking member constituting minimum inclination defining means; 35, a thrust bearing; 36, a cylinder bore; 37, a piston; 68, a spring seat constituting rotation control means;

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Koji Kawamura 2-1, 1-1, Toyotamachi, Kariya, Aichi Prefecture Inside Toyota Industries Corporation

Claims (5)

[Claims] 1. A piston is accommodated in a cylinder bore formed in a housing, a drive shaft is rotatably held in the housing, and a rotation support is fixed on the drive shaft.
Similarly, a cam plate is supported on the drive shaft so as to be slidable and tiltable in the axial direction of the drive shaft, and a piston is connected to the cam plate. A hinge mechanism is interposed, and the cam plate is rotatable integrally with the drive shaft via the rotation support and the hinge mechanism, and the guide of the hinge mechanism minimizes the maximum tilt position that maximizes the tilt angle of itself and the tilt angle. The cam plate is slid while being tilted on the drive shaft between the minimum tilt position and the minimum tilt position of the cam plate, the variable displacement compressor having a configuration defined by contact with the minimum tilt position determining means. Between the rotary support and the cam plate, a drive shaft is provided with an inclination-reducing spring composed of a coil spring that biases the cam plate toward the minimum inclination position. A rotation restricting means is provided between the inclination reducing spring and the rotation support or the drive shaft to restrict the relative rotation of the inclination reducing spring from the driving shaft. A variable displacement compressor in which a positional relationship between a cam plate at a minimum tilt position and a spring end on a cam plate side in a tilt reducing spring is maintained in a preset state. 2. The rotary support or the drive shaft is provided with a spring seat that can be inserted into the tilt-reducing spring or that can accommodate the tilt-reducing spring. 2. The variable displacement compressor according to claim 1, wherein the rotation restricting means is formed by press-fitting and fixing a winding portion to a spring seat portion. 3. The cam plate at the minimum inclination position, wherein the contact position with the inclination-reducing spring is set to be shifted toward the bottom dead center corresponding portion side with respect to the contact position with the minimum inclination position defining means. Item 3. The variable displacement compressor according to any one of Items 1 and 2. 4. The variable displacement compressor according to claim 1, further comprising a refrigerant circulation preventing means capable of preventing refrigerant circulation on the external refrigerant circuit. 5. The variable displacement compressor according to claim 4, wherein the drive shaft is operatively connected to an external drive source without a clutch mechanism.