JPH10205445A - Variable displacement compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify assembling work by interposing an energizing means for energizing a cam plate to the minimum angle position between a rotation supporting body and the cam plate, and thereby equalizing the tilting angle of the cam plate during stoppage of operation to that during operation at the minimum angle position. SOLUTION: A tilting angle reducing spring 27 is arranged around a driving shaft 16 between a rotation supporting body 22 and a cam plate 23 as an energizing means. The tilting angle reducing spring 27 is abutted against an inner peripheral part of a front surface of the cam plate 23, for energizing the cam plate 23 to the side of a cylinder block 12 along an axis of the driving shaft 16. An inner peripheral part of the swash plate 23 is slid on the driving shaft 16 for reducing the tilting angle. The can plate 23 pushes a cut-off body 29 through its projection 23b and a thrust bearing 35. An cut-off surface 34 is abutted against a positioning surface 33, for regulating movement of the cam plate 23 and obtaining a minimum tilting angle. The tilting angle of the cam plate 23 during stoppage of operation is equalized to that during operation at the minimum angle position, so that assembling work is simplified.

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 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
Housed within. The drive shaft 107 is a housing 105
And is passed 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 is connected to the piston 106. The hinge mechanism 110 includes a support arm 111 provided on the rotary support 108 and the swash plate 10.
9, a spherical portion 112a of the guide pin 112 is slidably fitted in a guide hole 111a of the support arm 111.

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 shown as exaggerated 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. Accordingly, 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 10
9 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 in the housing 105 through the blocking surface 123, and the suction chamber 103 and the suction chamber 1
03 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 suction passage 125 and the suction passage 125 is cut off,
Further sliding movement of the swash plate 109 is restricted by the contact between the swash plate 109 and the positioning surface 124, and the 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.

[0007] Tilt reduction spring 1 comprising a coil spring
Reference numeral 16 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 tilt 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-up of the compressor is from the minimum discharge capacity state where the load torque is the smallest, and the shock at the start-up is effectively reduced.

[0008]

Here, the inner peripheral portion of the front surface of the swash plate 109 to which the end of the inclination-reducing spring 116 is opposed is not a single plane due to manufacturing reasons or the like.
A plane 11 extending from the top dead center corresponding portion 109b side to the inner peripheral portion at 09 to position the piston 106 at the top dead center.
7 and a plane 118 extending from the bottom dead center corresponding portion 109c to the inner peripheral portion where the piston 109 is located at the bottom dead center, and is formed by a composite surface that obliquely intersects the rotation support 108 side. . The piston 109 shown in FIG. 5 is located at the top dead center, and the vicinity where the piston 109 is connected is the top dead center corresponding portion 109b of the swash plate 109. A portion located on the opposite side via is a bottom dead center corresponding portion 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 line K11.
As shown in FIGS. 6 and 7, in the compressor, the line of intersection K11 is a line of contact between the swash plate 109 and the thrust bearing 122 which is the tilt center of the swash plate 109 when the swash plate 109 is at the minimum tilt position. T, more specifically, than an imaginary plane H including the abutment line T and parallel to the axis L of the drive shaft 107,
It exists at a position shifted toward the top dead center corresponding portion 109b.

Therefore, the inclination reducing spring 116 is provided for the swash plate 10.
9 is moved to the minimum tilt position and pushes the swash plate 109 toward the top dead center corresponding portion 109b side, and the tilting moment increases in the direction of increasing the tilt angle around the contact line T with respect to the swash plate 109. Activate M11. The hinge mechanism 110
, The clearance between the guide hole 111a and the spherical portion 112a 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.
When the swash plate 109 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 M12 is applied around the contact line T in a direction to decrease the tilt angle. The tilting moment M12 is larger than the tilting moment M11 exerted by the tilting 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 having the above-described configuration, 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 assembling the compressor, it deviates from the predetermined value during operation. For this reason, the swash plate 109 has to be assembled in consideration of these, and the operation has been troublesome.

The present invention has been made in view of the problems existing in the prior art described above, and an object of the present invention is to make the inclination of the cam plate at the minimum inclination position the same at the time of operation stop as at the time of operation. It is an object of the present invention to provide a variable displacement type compressor which can perform the following.

[0014]

In order to achieve the above object, according to the first aspect of the present invention, a biasing device for biasing the cam plate toward a minimum tilt position is provided between the rotary support and the cam plate. A variable displacement compressor in which means is interposed and the urging means applies a tilting moment in the direction of decreasing the inclination to the cam plate at the minimum inclination position.

According to the second aspect of the present invention, by setting the contact position between the urging means and the cam plate, the urging means exerts a tilting moment in the direction of decreasing the inclination on the cam plate at the minimum inclination position. The contact position of the urging means in the cam plate is set so as to be shifted to a position corresponding to the bottom dead center with respect to a contact portion between the cam plate and the minimum inclination position defining means.

According to a third 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 fourth aspect of the present invention, the drive shaft is operatively connected to an external drive source without a clutch mechanism.

(Function) In the first aspect of the present invention, for example, between the relative movement portions of the hinge mechanism, the cam plate smoothly moves between the maximum tilt position and the minimum tilt position. Clearance exists. The clearance allows the cam plate at the minimum tilt position to be slightly tilted about the contact portion with the minimum tilt position defining means.

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.

While the operation of the compressor is stopped, the cam plate is urged by the urging means to place the cam plate at the minimum inclination position. For example, in the second aspect of the present invention, the urging means is in contact with the cam plate at a position shifted to a position corresponding to the bottom dead center from a contact portion with the minimum inclination position defining means. Therefore, the biasing means pushes the lower dead center corresponding portion side of the cam plate at the minimum tilt position to reduce the tilt angle with respect to the cam plate, that is, the tilting moment caused by the compression reaction force and In the same direction, a tilting moment is exerted around the contact portion with the minimum tilt position defining means.
As a result, the inclination angle of the cam plate at the minimum inclination position is the same even when the operation is stopped as during the operation.

According to the third aspect of the present invention, for example, when cooling is unnecessary 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 prevention means. . Therefore, the operation of the compressor, that is, the rotation of the drive shaft may be continued. In the invention of claim 4, the drive shaft is connected to an external drive source without interposing a clutch mechanism.

[0021]

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 an end of the drive shaft 16 protruding from the front housing 11 and has a belt 19 wound around the outer periphery thereof.
And is directly connected to the vehicle engine 20 as an external drive source without using a clutch mechanism such as an electromagnetic clutch.

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. A swash plate 23 serving as a cam plate is housed in the crank chamber 15, and a drive shaft 16 is provided with an insertion hole 23 formed through the center of the swash plate 23.
a is inserted. 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 is interposed between the rotary support 22 and the swash plate 23.

The support arm 25 constituting the hinge mechanism 24 is provided on the outer periphery of the rear surface of the rotary support 22 so as to project therefrom. 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 as a biasing means is formed of a coil spring, and is wound around the drive shaft 16 between the rotary support 22 and the swash plate 23. The inclination decreasing spring 26 is in contact with the inner peripheral portion of the front surface of the swash plate 23 and
With the axis L of the drive shaft 16 facing the cylinder block 12 side.
Energize along.

The accommodation hole 28 is provided at 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 3
0 is housed in the housing hole 28 and urges 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.

An 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 of the swash plate 23 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 29,
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.
Housed within. The swash plate 23 anchors a piston 37 at its outer peripheral portion via a shoe 38,
The rotational movement of the swash plate 23 is converted into a reciprocating linear movement of the piston 37.

The suction chamber 39 and the discharge chamber 40 are separately formed in the rear housing 13. A suction port 41, 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
Each is formed on the valve body 14. Then, the refrigerant gas in the suction chamber 39 is moved by the reciprocating operation of the piston 37 through the suction port 41 and the suction valve 42 to the cylinder bore 3.
It is inhaled into 6. The refrigerant gas flowing into the cylinder bore 36 is discharged into the discharge chamber 40 via 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 in 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 opened in the valve chamber 52. The valve element 54 is housed in the valve chamber 52 and can be connected to and separated from the port 53. Open spring 55
Is housed in the valve chamber 52 and urges the valve body 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. The bellows 58 is housed in the pressure-sensitive chamber 56 and is operatively connected to the valve body 54 via a rod 59.

The movable iron core 60 is disposed on the opposite side to 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 to 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.

The compressor having the above-described structure includes a suction passage 32 serving as a passage for introducing refrigerant gas into the suction chamber 39 and a 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 operates, 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 pressure in the crank chamber 15 decreases. When the cooling load is large, the suction pressure in the cylinder bore 36 is also high, and the crank chamber 1
5 and the pressure in the cylinder bore 36 are reduced. 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. 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 in 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 inclination position, for example, when the vehicle interior temperature rises and the cooling load increases, the vehicle detected by the vehicle interior 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. And the blocking body 2
By the movement of 9, the blocking surface 34 and the positioning surface 33 are separated from each other, and the introduction of the refrigerant gas from the suction passage 32 to 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 the enlarged circle of FIG. 3, the guide hole 25a of the hinge mechanism 24 and the spherical portion 26 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 part)
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 applied 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 contact position between the inclination-reducing spring 27 and the swash plate 23 is set so that the inclination of the swash plate 23 at the minimum inclination position is the same as when the operation is stopped. Is set.

That is, as shown in FIGS. 3 and 4, the inner peripheral portion of the front surface of the swash plate 23 to which the end portion of the inclination reducing spring 27 is opposed is not a single plane, but is formed by the same inclination for convenience of manufacture. A flat surface 64 extending from the top dead center corresponding portion 23c side to the inner peripheral portion to position the piston 37 at the top dead center on the plate 23;
Bottom dead center corresponding portion 23 for positioning piston 37 at bottom dead center
A plane 65 extending from the d side to the inner peripheral portion is constituted by a composite surface which is inclined toward the rotary support 22 and intersects at the intersection line K11. Note that the piston 37 shown in FIGS.
Is located at the top dead center, the vicinity where the piston 37 is connected is a top dead center corresponding portion 23c of the swash plate 23, and is located on the opposite side to the top dead center corresponding portion 23c via the drive shaft 16. The site is the bottom dead center corresponding site 23d. Accordingly, when the drive shaft 16 is rotated by 180 ° from the state shown in the drawing, the swash plate 23 moves to the piston 3 of FIG.
7, the piston 37 is located at the bottom dead center.

The difference between the swash plate 23 of the present embodiment and the swash plate 109 of the prior art is that the spring seat 68 corresponding to the inclination reducing spring 27 has a semicircle around the opening of the insertion hole 23a on the plane 64. The point is that it is concavely formed in an arc shape and both ends thereof are open to the flat surface 65. Therefore, the spring seat surface 68a
The spring seat 68 is formed at a position one step lower than the plane 64. The intersection line K1 between the spring seating surface 68a and the plane 65 is more detailed than the contact line T with the thrust bearing 35 which is the tilt center of the swash plate 23 when the swash plate 23 is at the minimum tilt position. Drive shaft 1 including the contact line T
It is located at a position shifted from the virtual plane H parallel to 6 toward the bottom dead center corresponding portion 23d. And the same inclination decreasing spring 27
When the swash plate 23 is moved to the minimum tilt position, the swash plate 23 comes into contact with the swash plate 23 at the intersection line K1 between the spring seat surface 68 and the flat surface 65.

Accordingly, the inclination reducing spring 27 pushes the bottom dead center corresponding portion 23d side of the swash plate 23 at the minimum inclination position,
With respect to the swash plate 23, the tilting moment M moves in the direction of decreasing the tilting angle, that is, in the same direction as the aforementioned tilting moment M1.
Act on 2. As a result, even when the compressor is stopped, the inclination angle of the swash plate 23 at the minimum inclination position is similar to that at the time of operation because the spherical portion 26a of the hinge mechanism 24 presses the inner surface of the guide hole 25a against the rotary support 22 side. It is specified in the specified state.

The present embodiment having the above configuration has the following effects. (1) 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 is easy to set the minimum inclination angle of the swash plate 23 when assembling the compressor, and the assembling work can be simplified. This will reduce the labor of the operator, reduce the cost of the compressor,
Furthermore, it leads to improvement of the capacitance accuracy.

(2) The object is achieved by setting the contact position between the inclination reducing spring 27 and the swash plate 23. In particular, in the present embodiment, for setting the contact position, for example, the swash plate 23 having a configuration in which the spring seat portion 68 is recessed in the conventional swash plate 109 is used. Therefore, it is only necessary to add a step of forming the spring seat 68 to the existing swash plate manufacturing process. As a result, further cost reduction of the compressor can be achieved. Further, the swash plate 23 is reduced in weight by the thickness of the spring seat 68 as compared with the swash plate 109 of the conventional compressor. This leads to a reduction in the weight of the compressor.

(3) The shut-off body 29 blocks the suction of the refrigerant gas from the external refrigerant circuit 71, whereby the circulation of the refrigerant on the external refrigerant circuit 71 can be prevented. 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.

(4) The blocking body 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.

(5) For the clutchless type compressor, the minimum displacement operation does not mean simply minimizing the discharge capacity. For example, the above-mentioned optimization of the internal circulation of the refrigerant gas (more lubrication) It is necessary to consider the trade-off between circulating oil and reducing power loss. That is,
The 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) In changing the inclination angle of the swash plate 23, in the above embodiment, the pressure of the crank chamber 15 is adjusted by adjusting the amount of refrigerant gas discharged from the discharge chamber 40 to the crank chamber 15. Was. Change this to crankcase 1
5 and the discharge chamber 40 are always in communication. And the capacity control valve is arranged on the bleed passage (47, 48 or 49),
The amount of refrigerant gas that escapes from the crank chamber 15 to the suction chamber 39 is adjusted by the same capacity control valve, so that the crank chamber 15
May be adjusted.

(2) The spring seat 68 is not provided on the swash plate 23,
The imaginary plane H is changed by changing the position of the convex portion 23b of the swash plate 23.
Is shifted to the top dead center corresponding portion 23c side, and as a result, the intersection line K
11 is arranged so as to be shifted toward the bottom dead center corresponding portion 23d with respect to the virtual plane H.

(3) Implementation in a variable displacement compressor with a clutch. To describe the technical idea that can be grasped from the above-described embodiment, by setting the contact position between the cam plate 23 and the minimum tilt position defining means 35,
The biasing means 27 is configured to apply a tilting moment M2 in the direction of decreasing the inclination to the cam plate 23 at the minimum inclination position, and the contact portion between the cam plate 23 and the minimum inclination position defining means 35 is the same cam. The cam plate 23 is set so as to be shifted toward the top dead center corresponding portion 23c with respect to the contact position between the plate 23 and the urging means 27.
Can be made the same at the time of operation stop as at the time of operation.

[0068]

According to the first and second aspects of the present invention, the inclination of the cam plate at the minimum inclination position can be the same even when the operation is stopped as during the operation. Therefore, it is easy to set the minimum inclination angle of the cam plate when assembling the compressor, and the assembling work can be simplified. This leads to a reduction in operator's labor, a reduction in cost of the compressor, and an improvement in capacity accuracy.

According to the third aspect of the present invention, it is possible to prevent the circulation of the refrigerant on the external refrigerant circuit. According to the fourth aspect of the present invention, an expensive and heavy material is required between the drive shaft and the external drive source. Do not interpose a clutch mechanism such as an electromagnetic clutch. 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 a diagram showing a minimum capacity state.

FIG. 3 is a diagram illustrating a main part.

FIG. 4 is a partially enlarged front view of a swash plate near an insertion hole.

FIG. 5 is a longitudinal sectional view of a conventional compressor, showing a minimum capacity state.

FIG. 6 is a diagram illustrating a main part.

FIG. 7 is a partially enlarged front view of a swash plate.

[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... A tilt-reducing spring as biasing means, 29. Thrust bearing, 36: cylinder bore, 37: piston, L: axis of drive shaft.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takeshi Takeshi 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation

Claims (4)

[Claims] 1. A piston is housed 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, and the drive shaft is also mounted on the drive shaft. The cam plate is supported so that it can slide and tilt in the axial direction of the drive shaft, a piston is connected to the cam plate, and a hinge mechanism is interposed between the rotating support and the cam plate. The cam plate is rotatable integrally with the drive shaft via a rotary support and a hinge mechanism, and is guided by the hinge mechanism to provide a maximum tilt position for maximizing its own tilt angle and a minimum tilt position for minimizing its tilt angle. The cam plate is slid while tilting on the drive shaft, and the minimum tilt position of the cam plate is determined by the contact with the minimum tilt position determining means. A biasing means for biasing the cam plate toward the minimum tilt position is interposed between the rotating support and the cam plate, and the biasing means is biased against the cam plate at the minimum tilt position. Is a variable displacement compressor configured to exert a tilting moment in the direction of decreasing the tilt angle. 2. The apparatus according to claim 1, wherein said urging means applies a tilting moment in a direction of decreasing the inclination to said cam plate at a minimum inclination position by setting a contact position between said urging means and said cam plate. 2. The variable capacitor according to claim 1, wherein a contact position of the urging means in the cam plate is set to be shifted to a position corresponding to the bottom dead center with respect to a contact portion between the cam plate and the minimum inclination position defining means. Type compressor. 3. 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. 4. The variable displacement compressor according to claim 3, wherein the drive shaft is operatively connected to an external drive source without a clutch mechanism.