JPH05202849A - Variable displacement compressor - Google Patents

Abstract

PURPOSE:To exactly grasp the amount of the stroke to stabilize control of the displacement by controlling the pressure in a swash plate chamber by the relative relationship between the positions of a first opening and closing member coupled to the tilting of a swash plate, and a second opening and closing member positioned by a member signal. CONSTITUTION:When current flowing to a coil 40 is set at a constant value during controlling the displacement, a moving part 43 is stopped at a specified position in the axial direction by a balance between electromagnetic force and spring force. When a blowby gas leaks from a piston 11 under the condition, the pressure in a swash plate chamber 10 is raised, and a force acting on the backside of the piston pulls a piston support 24 through a connecting rod 33 to reduce the tilting angle of a swash plate 12. A sleeve 21 and a stroke rod 46 are interlocked with the tilting angle to be moved to the right. The large diameter part 461 of the rod 46 is then stabilized at a position at which a communication hole 45 of the moving part 43 is opened by a very small area in relation to the position of the moving part 43. Thus, the blowby gas is relieved to a suction chamber 8 through the communication hole 45, and the pressure in the swash plate chamber 10 is kept constant to stabilize the angle of the swash plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable capacity compressor,
Particularly, the present invention relates to a variable capacity compressor suitable for capacity control as a refrigerant compressor for an air conditioner.

[0002]

2. Description of the Related Art Capacity control in a conventional variable capacity compressor is performed by a swash plate chamber which is a pressure control space and a discharge chamber or a suction chamber which is another pressure space, as described in, for example, US Pat. No. 4,428,718. The chamber was opened and closed by a control valve that operates in response to the suction pressure of the compressor. That is, when the suction pressure of the compressor falls below a certain set value, the pressure in the swash plate chamber is increased by the control valve, the capacity of the compressor decreases and the suction pressure rises. Balance to maintain the set value. It is also possible to change the set value of the suction pressure from the outside by using electromagnetic force, etc., but in any case, the capacity of the compressor is always controlled to a certain set value. It was indirectly controlled through the.

[0003]

SUMMARY OF THE INVENTION In the above conventional technique,
Even if you try to control the suction pressure of the compressor to a certain set value, the compressor capacity at that time changes depending on the heat load of the refrigeration cycle and the rotation speed of the compressor. I cannot know exactly if I am driving. The technology shown in the above-mentioned U.S. Pat.No. 4,428,718 is proposed as a compressor for a car air conditioner.However, when it is attempted to control the engine speed in which the driving load changes depending on the compressor capacity, the compressor is used. Since the capacity cannot be accurately known, feedback information for control cannot be obtained, and accurate engine speed control cannot be performed.

Further, in the above conventional technique, when the swash plate tilt angle that determines the compressor capacity fluctuates from a predetermined position due to disturbance, first, the pressure balance of the refrigeration cycle changes due to the change of the swash plate tilt angle, Next, the control valve detects the change in the suction pressure and controls to restore the tilt angle of the swash plate to the original value, so that the generation of the restoring force is delayed. As a result, there is a risk that the tilt angle of the swash plate becomes unstable.

Further, in the above-mentioned conventional technique, a component such as a bellows or a diaphragm which is deformable or movable in response to the suction pressure of the compressor is required as a component of the control valve, which causes the following problems. First of all, in order to accurately control the pressure, it is necessary to manufacture the above-mentioned control bellows, diaphragm, etc. with high precision, and a special manufacturing technique is required, which causes a cost increase. Is. Second, since the control bellows, diaphragm and the like are formed of a thin film so as to be easily deformed in response to the ambient pressure, the airtightness and the strength must be guaranteed, so that the reliability of the variable capacity compressor is deteriorated. It is a factor.

An object of the present invention is to solve the above-mentioned drawbacks and to provide a variable displacement compressor capable of realizing stable displacement control with a simple structure while accurately grasping the stroke amount.

[0007]

To achieve the above object, a variable displacement compressor according to the present invention comprises a drive shaft bearing-supported by a housing and a cylinder block, and a drive plate fixed to the drive shaft. A swash plate which is regulated to rotate together with the drive plate and performs a tilting motion, a bearing supported so as to be rotatable relative to the swash plate, and a rotation angle of which is restrained by a rotation stop mechanism. And a plurality of cylinders arranged in parallel with the axis of the drive shaft in the circumferential direction, and a piston that reciprocates in each cylinder.
A first opening / closing member that moves in conjunction with the tilting movement of the swash plate, and a connecting rod that connects the piston and the piston support, and its position is set to be movable by a signal from the outside. The relative positional relationship with the second opening / closing member opens / closes the communication path that communicates the space in which the swash plate or the like is stored with another pressure space, and the pressure in the space in which the swash plate or the like is stored. Is to control.

A drive shaft supported by a housing and a cylinder block, a swash plate sleeve slidably mounted on the drive shaft, the fixed drive plate, and the drive shaft. On the other hand, a swash plate sleeve that is slidable in the axial direction and regulated in the rotation direction is incorporated, and a swash plate that is engaged with the swash plate sleeve by a slide pin so as to be tiltable. A piston support, which is supported by the swash plate so as to be rotatable relative to the swash plate, is constrained to rotate by a rotation-stopping mechanism, and performs a swinging motion corresponding to the tilt angle of the swash plate. And a plurality of cylinders arranged in the circumferential direction, pistons that reciprocate in the respective cylinders, and a connecting rod that connects the pistons to the piston support, and is connected to the swash plate sleeve. Combined and moved Due to the relative positional relationship between the first opening / closing member and the second opening / closing member whose position is set to be movable by a signal from the outside, the space in which the swash plate or the like is housed and the other pressure space The pressure in the space in which the swash plate or the like is housed is controlled by opening and closing the communication path that communicates with each other.

Further, a drive shaft supported by a frame and a cylinder block, an electric motor for rotating the drive shaft, and a slide shaft are slidably mounted in the closed container. A swash plate sleeve, the fixed drive plate, and a swash plate sleeve that is slidable in the axial direction with respect to the drive shaft and is regulated in the rotation direction.
A swash plate engaged with the swash plate sleeve by means of a sleeve pin for tilting movement, and a bearing supported so as to be rotatable relative to the swash plate and restrained from rotating by a rotation preventing mechanism. And a plurality of cylinders arranged in a circumferential direction in parallel with the axis of the drive shaft, a piston that reciprocates in each cylinder, and the piston. A connecting rod for connecting the piston support is housed, and the position is set to be movable by a first opening / closing member that moves by being engaged with the swash plate sleeve and a signal from the outside. Due to the relative positional relationship with the second opening / closing member, the communication path that communicates the space in which the swash plate or the like is stored with another pressure space is opened and closed, and the pressure in the space in which the swash plate or the like is stored is opened or closed. To control.

The second opening / closing member is made of a magnetic material, and its position is moved by passing a current through the coil based on a signal from the outside.

In addition to the space in which the swash plate is stored,
A pressure control space is provided.

Further, when the second opening / closing member is stationary at a certain set position, the space in which the swash plate or the like is housed is sucked at a low pressure by the first opening / closing member when the volume of the space increases. The communication with the chamber is communicated, and when the volume of the space is reduced, the communication with the suction chamber is blocked by the first opening / closing member that moves together with the space.

Further, when the second opening / closing member is stationary at a certain set position, the space in which the swash plate or the like is housed is discharged by the first opening / closing member at a high pressure when the volume of the space increases. The communication with the chamber is closed, and when the volume of the space decreases, the first opening / closing member communicates with the discharge chamber.

Further, the other pressure space is maintained at the suction pressure.

[0015]

In the variable displacement compressor, the volume of the space (hereinafter referred to as the pressure control space) in which the swash plate or the like is housed changes in association with the change in the stroke amount of the piston reciprocating motion. Therefore, by adopting a structure in which the first opening / closing member moves in association with a change in the stroke amount or a change in the volume of the pressure control space, there is a piston reciprocating motion corresponding to a position of the first opening / closing member. The stroke amount is uniquely determined.

With the above structure, the pressure control space and the other pressure space are communicated with each other by the first opening / closing member and the second opening / closing member.
The position of the first opening / closing member that is opened / closed according to the relative positional relationship with the opening / closing member of the first opening / closing member, and switches the opening / closing of the communication between the pressure control space and the other pressure space in correspondence with the position of the second opening / closing member, It is uniquely determined. Therefore, a certain stroke amount of the piston reciprocating motion in which opening / closing of communication between the pressure control space and another pressure space is switched corresponding to a certain position of the second opening / closing member is uniquely determined. That is, the pressure control space and other pressures are different depending on whether the actual stroke amount is smaller or larger than the predetermined stroke amount of the piston reciprocating motion uniquely determined corresponding to the position of the second opening / closing member. The communication state with the space will definitely switch. Here, when the actual stroke amount is smaller than the predetermined stroke amount, the actual stroke amount is increased by the structure for switching the communication state between the control space and another pressure space, and the predetermined stroke amount is increased. When the actual stroke amount is larger than that of, the actual stroke amount is reduced, so that the actual stroke amount finally becomes consistent with the predetermined stroke amount and becomes stable.
That is, the actual stroke amount that stabilizes during operation of the compressor is uniquely determined corresponding to the position of the second opening / closing member.

By the way, since the position of the second opening / closing member can be arbitrarily controlled by a signal from the outside, the actual stroke amount during operation of the compressor can be arbitrarily changed by a signal from the outside after all. It is possible to control. In such a variable capacity compressor, the control signal from the outside for capacity control directly corresponds to the capacity of the compressor, so that it is easy to know the capacity of the compressor accurately during operation. Further, since the communication between the pressure control space and another pressure space is directly opened / closed by the change in the piston stroke amount, that is, the swash plate tilt angle, a restoring force is generated quickly, and the swash plate tilt angle is stable. good. Further, the capacity can be controlled without using a part such as a bellows or a diaphragm that deforms or moves in response to the suction pressure of the compressor.

[0018]

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

1 to 7 show a first embodiment of the present invention. 1 and 2 are vertical sectional views showing the overall structure of a swash plate type variable displacement compressor for a car air conditioner according to a first embodiment of the present invention. FIG. 1 shows the maximum piston stroke amount, that is, the swash plate inclination. It shows the state that the turning angle is maximum,
FIG. 2 shows a state in which the piston stroke amount is minimum, that is, the swash plate tilt angle is minimum. 3 is a view showing a cross section taken along line I-I in FIG. 2, and FIG.
FIGS. 5 to 7 are partially enlarged views for explaining the principle of the capacity control when the tilt angle of the swash plate is an intermediate value between FIGS. 1 and 2.

1 to 7, a radial needle roller bearing 19 for rotatably supporting one end of a main shaft 13 is arranged at the center of a cylindrical cylinder block 2, and an end portion of the cylinder block 2 is provided at the end thereof. The front housing 1 having a radial needle roller bearing 18 rotatably supporting the other end of the main shaft 13 in the center thereof is arranged and fixed via an O-ring 36, and inside the cylinder block 2 and the front housing 1. A swash plate chamber 10 (pressure control space) is formed. The cylinder block 2 is formed with a plurality of cylinder bores 201 arranged in parallel to the axis of the main shaft 13 and in the circumferential direction around the main shaft 13. The spindle 13 is
The bearing is rotatably supported by the radial needle roller bearings 18 and 19 provided on the center of the cylinder block 2 and the center of the cylinder block 2 and the front housing 1. The drive plate 14 is fixed. Drive plate 1
4 is formed with a concave spherical surface portion 141.
A shoe 16 having a shape in which a flat surface portion is provided on a part of a sphere having the same radius is abutted on 41 so as to be rotatable around the spherical center of the spherical surface portion 141. The flat portion of the shoe 16 is the swash plate 1.
The flat portion 121 provided on the second contacting member 2 is slidably abutted. At this time, the concave spherical surface portion 141 of the drive plate 14
The spherical center of is set to be at a constant distance from the flat surface portion 121 of the swash plate 12. Further, as shown in FIG. 3, flat surface portions 142 and 143 are provided on both sides of the spherical surface portion 141 of the drive plate 14, and the ear portions 122 and 123 of the swash plate 12 are inserted so as to sandwich the flat surface portions 142 and 143. There is. As shown in FIG. 4, the drive plate 14 is further provided with a cylindrical surface portion 144 having a central axis of the axis passing through the spherical center of the spherical surface portion 141, and the swash plate 1 parallel to the flat surface portion 121.
A stopper 20 attached to the slide contact member 2 is slidably abutted.

As a result, when the main shaft 13 and the drive plate 14 rotate clockwise as viewed from the left of FIGS. 1 and 2, a rotational force is applied from the flat surface portion 142 of the drive plate 14 to the swash plate ear portion 122, and The plate 12 rotates. A swash plate sleeve 15 is incorporated in the main shaft 13 so as to be slidable in the axial direction with respect to the main shaft 13. The swash plate sleeve 15 and the swash plate 12 are attached to the swash plate sleeve 15 by a swash plate sleeve pin 17. A swash plate 12 is rotatably connected around a swash plate sleeve pin 17. Therefore, as the main shaft 13 rotates, the drive plate 14, the swash plate 12, and the swash plate sleeve 15 rotate together.

A support sleeve 21 is rotatably inserted into the swash plate sleeve 15 via a radial needle roller bearing 22.
A sliding key 23 fixed to the center of the cylinder block 2
Due to this, the rotation is restricted, and the main shaft 13 is restrained so as to be slidable only in the axial direction.

The support sleeve 21 has a plurality of groove portions 211 on the outer periphery of one end thereof, which are inclined only in one direction of the central axis (inclined toward the left side of FIGS. 1 and 2 toward the central axis). The groove portion 211 of the support sleeve 21 is formed on the inner circumference of the outer ring 25 having a ring shape.
The same number of groove portions 251 that are inclined in the opposite direction are formed. A plurality of spheres 26 are inserted in each of the pair of the groove portion 211 and the groove portion 251. This plurality of spheres 26
Is held on a common plane by contacting only one side with a ring-shaped flat portion 271 formed on the end surface of the holding member 27. A convex spherical surface portion 272 is provided on the outer periphery of the holding member 27.
Are formed, and are in contact with the concave spherical surface portion 252 formed on the outer ring 25 with a spherical pair. A piston support 24 is fixed to the outer circumference of the outer ring 25. With these configurations, the piston support 24 is constrained with respect to the support sleeve 21 so as to be prevented from rotating and performing only a swinging motion.

The piston support 24 and the swash plate 12 are provided with a thrust needle roller bearing 29 sandwiched between them, so that the piston support 24 and the swash plate 12 are maintained parallel to each other. However, at that time, a preload in the direction of close contact is given by a preload spring 32 incorporated between the support sleeve 21 and the swash plate sleeve 15 via a thrust needle roller bearing 30.

The piston support 24 is formed with a plurality of concave spherical surface portions 241 on the same circumference, and the spherical surface portions 331, 3 are provided at both ends of each concave spherical surface portion 241.
One end of a connecting rod 33 having 32 is attached rotatably around the spherical center of the spherical surface portion 241. A piston 11 is attached to the other end of the connecting rod 33 so as to be rotatable around the spherical center of the concave spherical surface portion 111. The plurality of pistons 11 are incorporated so that they can reciprocate in the plurality of cylinder bores 201, respectively, with the piston rings 34 and 35 attached.

A suction valve plate 5, a cylinder head 4, a discharge valve plate 6, a discharge valve retainer 7, and a rear cover 3 are attached to the rear of the cylinder block 2 (on the right side in the drawing), and these parts are a drive plate 14 and a slanted plate. The front housing 1 arranged so as to surround the plate 12, the piston support 24 and the like are integrally fixed by a bolt (not shown) or the like. The airtightness at the joint between the front housing 1 and the cylinder block 2 is maintained by the O-ring 36, and the airtightness at the joint between the rear cover 3 and the cylinder block 2 is maintained by the O-ring 37. The cylinder head 4 has a suction port 401 and a discharge port 402 corresponding to each cylinder bore 201.
And a suction chamber 8 provided at the center of the rear cover 3.
It communicates with (another pressure space) and a discharge chamber 9 provided outside thereof. The rear cover 3 is provided with a suction port 301 and a discharge port 302, which communicate with the suction chamber 8 and the discharge chamber 9, respectively.

The rear cover 3 is also provided with an opening at the rear of the suction chamber 8, and a coil case 38 made of a magnetic material is inserted from the rear and fixed by a bolt (not shown). The airtightness in the opening is maintained by the O-ring 39. A coil 40 for controlling is incorporated inside the coil case 38, and a stator 381 in the central portion of the coil case 38 can be magnetized by passing an electric current through the coil 40. Rear Caba 3
In addition, a boss portion 303 extending from the insertion portion of the coil case 38 toward the cylinder head 4 is formed,
A guide hole 41 formed coaxially with the coil case 38 penetrates through the center thereof. Suction chamber 8 of boss 303
A first connecting hole 42 provided in a part of the boss 303 communicates between the outer periphery facing the inner periphery of the guide hole 41 at the center. At the tip of the boss 303, airtightness is maintained by the tip being in close contact with the cylinder head 4. Guide hole 41 to coil 4
A cylindrical movable element 43 (second opening / closing member) formed of a magnetic material is slidably inserted in the axial direction toward the center of 0, and the inner peripheral surface of the movable element 43 and the guide hole 41. The gap between and is very small, and the airtightness in the gap is almost maintained. A spring 44 is incorporated between the mover 43 and the stator 381, and gives a force to move the mover 43 to the left in FIG. 1 or 2. When a current is passed through the coil 40 in this state, the mover 43 is attracted to the stator 381 by an electromagnetic force, and the mover 43 is attracted to the stator 381.
However, it will stop at a position balanced with the leftward force of the spring 44. That is, for a certain current value of the current flowing through the coil 40, the position of the mover 43 is unique between the position in FIG. 1 where the left end contacts the cylinder head 4 and the position in FIG. 2 where the right end contacts the stator 381. Will be decided. A connecting groove 431 is formed on the outer periphery of the mover 43 in a part of the axial direction thereof, so that the first connecting hole 4 is always formed regardless of the position of the mover 43.
It communicates with 2. The mover 43 also has a second communication hole 4 that opens from the inner peripheral surface of the cylinder to the communication groove 431 on the outer circumference.
5 is formed.

A third communication hole 403, a fourth communication hole 501, and a fifth communication hole 202 are formed in the cylinder head 4, the suction valve plate 5, and the cylinder block 2 coaxially with the guide hole 41, respectively. The stroke rod 46 (first opening / closing member) is penetrated and incorporated in them. The stroke rod 46 has a stepped cylindrical shape, and the large diameter portion 461 at the right end thereof is inserted into the cylindrical inner peripheral surface of the mover 43 so as to be slidable in the axial direction.
The gap between the large diameter portion 461 of the stroke rod 46 and the inner peripheral surface of the cylinder of the mover 43 is very small, and the airtightness in the gap portion is almost maintained. On the other hand, the small diameter portion 462 of the stroke rod 46 has a cylindrical inner peripheral surface of the mover 43 into which the stroke rod 46 is inserted, a third communication hole 403, a fourth communication hole 501,
There is a sufficient gap with the fifth communication hole 202,
The support sleeve 21 arranged in the swash plate chamber 10 at the left end is connected by a pin 47. Therefore, the outer peripheral portion of the small-diameter portion 462 of the stroke rod 46, that is, the left end side of the large-diameter portion 461 in the drawing is always in communication with the swash plate chamber 10. When the tilt angle of the swash plate 12 changes, the large diameter portion 461 of the stroke rod 46 moves on the inner peripheral surface of the cylinder of the mover 43 in conjunction with the support sleeve 21 that moves in the axial direction in conjunction with this. It is configured to move in the axial direction.

With the above-described compression mechanism structure, the magnet clutch 2 is driven by the engine (not shown).
When the main shaft 13 of the compressor is driven via 8, the drive plate 14 and the swash plate 12 rotate, and the main shaft 1 which is the rotating shaft.
3, the piston support 24 swings.
As a result, the piston 11 reciprocates in the cylinder bore 201, and the refrigerant returned from the refrigeration cycle (not shown) receives the suction chamber 8 formed in the rear cover 3 from the suction port 301, the suction port 401 of the cylinder head 4, and the suction port. Valve plate 5
After being sucked into the cylinder bore 201 via the
The discharge port 40 of the cylinder head 4 is compressed by 1.
2. After being discharged through the discharge valve plate 6, it is discharged into the discharge chamber 9 formed in the rear cover 3, and is discharged from the discharge port 302 to a refrigeration cycle (not shown).

The capacitance control is performed by adjusting the value of the current flowing through the coil 40, the principle of which will be described below. 5 to 7 show the case where all the current values flowing in the coil 40 are set to a certain constant value. As described above, the mover 43 (second opening / closing member) has an electromagnetic force and a spring force. Due to the equilibrium of the above, the robot stays at the same position during its axial movement range. In this state, if the tilt angle of the swash plate 12 is such that the large diameter portion 461 of the stroke rod 46 (first opening / closing member) that moves in conjunction with this, is at the position shown in FIG. Consider a case where the tilt angle is such that the second communication hole 45 formed in the mover 43 (second opening / closing member) is stopped at a position that closes the inner peripheral side opening. At this time, the swash plate chamber 10 (pressure control space) is closed as a result of the second communication hole 45 being closed and the communication with the suction chamber 8 (other pressure space) that is a low pressure chamber is cut off to become a sealed space, and the piston rings 34, 35 The pressure increases due to blow-by gas leaking from the back side of each piston 11 (swash plate chamber 10
The force pushing the (side surface) increases, so that the piston support 24 is attached to the rear cover 3 via the connecting rod 33.
The resultant force of the pulling force in the direction (the action position is on the rotation axis of the main shaft 13) increases. As a result, the tilt angle of the piston support 24 and the swash plate 12 parallel to the piston support 24 decreases, the support sleeve 21 moves in the right direction in the figure in association with the tilt angle, and further, the support sleeve 21 moves in conjunction with the support sleeve 21. Stroke rod 46 moves to the right in the figure. That is, FIGS.
The large diameter portion 461 of the stroke rod 46 (first opening / closing member) is not stable at the position of FIG. 5 with respect to the position of the mover 43 (second opening / closing member) of FIG. Move to the right as shown. At this time, the volume of the swash plate chamber 10 (pressure control space) increases as the stroke amount of each piston 11 decreases. Next, the tilting angle of the swash plate 12 moves the large diameter portion 461 of the stroke rod 46 (first opening / closing member) which moves in conjunction with this, to the position shown in FIG. 6, that is, the large diameter portion 461 moves the movable element. Consider a case where the tilt angle is such that the second communication hole 45 of 43 (second opening / closing member) is stopped at a position where it is sufficiently opened on the inner peripheral surface. In this case, the swash plate chamber 10 (pressure control space) has a third communication hole 403 and a fourth communication hole 403.
Between the communication hole 501 and the fifth communication hole 202 and the small diameter portion 462 of the stroke rod 46, and the second communication hole 45, the communication groove 431, and the first communication hole 42 in the low pressure chamber. Communicating with a suction chamber 8 (other pressure space),
The pressure accumulated in the swash plate chamber 10 (pressure control space) is shown in FIG.
Intake chamber 8 (other pressure space) as indicated by the dashed arrow inside
The pressure in the swash plate chamber 10 (pressure control space) is sufficiently reduced and the force pushing the back side of each piston 11 is reduced to pull the piston support 24 toward the rear cover 3 via the connecting rod 33. The total force of is reduced. As a result, the tilt angle of the piston support 24 and the swash plate 12 parallel to the piston support 24 increases, the support sleeve 21 moves in the left direction in the figure in association with the tilt angle, and further interlocks with the support sleeve 21. Stroke rod 46 (first
Open / close member) moves to the left in the figure. That is, the large diameter portion 461 of the stroke rod 46 (first opening / closing member) is not stable at the position of FIG. 6 with respect to the position of the mover 43 (second opening / closing member) of FIGS. Move to the left as indicated by the solid arrow. At this time, the swash plate chamber 10
The volume of the (pressure control space) decreases as the stroke amount of each piston 11 increases. As described above, the large diameter portion 4
61 will be stable in the position of FIG. 7 between the positions of FIG. 5 and FIG. The position of the large diameter portion 461 of FIG.
This is a position where the second communication hole 45 of the (second opening / closing member) is opened in a small area on the inner peripheral surface, and the piston rings 34, 35 are provided in the swash plate chamber 10 (pressure control space) due to the passage resistance of the opening. The blow-by gas leaking from the portion accumulates and has a pressure that holds the swash plate 12 at a tilt angle corresponding to the position of the large diameter portion 461. At this time, the piston ring 3
The blow-by gas amount leaking from the swash plate chamber 10 to the swash plate chamber 10 (pressure control space) and the minute opening of the second communication hole 45 from the swash plate chamber 10 (pressure control space) to the one-dot chain line arrow in FIG. Thus, the amount of gas leaking into the suction chamber 8 (other pressure space) is equal, the pressure in the swash plate chamber 10 (pressure control space) is kept constant, and the tilt angle of the swash plate 12 is stabilized. In the vicinity of the position shown in FIG. 7, even if the movement of the large diameter portion 461 is small, the ratio of the opening area of the second communication hole 45 changes abruptly, so the low pressure chamber 8 (another pressure space The amount of gas leaked to) also changes rapidly. Therefore, even if the blow-by gas amount changes due to operating conditions or the like, the mover 43
The large-diameter portion 461 with respect to a certain position of the (second opening / closing member)
The stable position, that is, the tilting angle at which the swash plate 12 stabilizes is almost unchanged and is uniquely determined. As described above, the position of the mover 43 (second opening / closing member) is uniquely determined with respect to the value of the current flowing through the coil 40.
It is possible to control the tilt angle of the swash plate 12, that is, the compressor capacity to a predetermined value by the value of the current flowing through.

In FIG. 1, the current value flowing through the coil is zero or less than a certain lower limit value, and the mover 43 (second opening / closing member) is moved to the left end by the force of the spring 44 and pressed against the cylinder head 4. The state is shown. At this time, in the present embodiment, even if the swash plate sleeve 15 comes into contact with the stepped portion of the main shaft 13 and the tilt angle of the swash plate 12 becomes maximum, the large diameter portion 461 of the stroke rod 46 (first opening / closing member). Is configured not to close the second communication hole 45 of the mover 43 (second opening / closing member).
Since the pressure in the (pressure control space) drops sufficiently, the swash plate 1
The tilt angle of 2 is maintained at the maximum. Also, FIG.
In the figure, the current value flowing through the coil is equal to or higher than a certain upper limit value, and the movable element 43 (second opening / closing member) is moved to the right end by the electromagnetic force and is pressed against the stator 381. At this time, in this embodiment, the support sleeve 2
Even if 1 contacts the cylinder block 2 and the tilt angle of the swash plate 12 is minimized, the large diameter portion 46 of the stroke rod 46 is
No. 1 has a structure in which the movable element 43 (the second opening / closing member does not open the second communication hole 45 and the pressure in the swash plate chamber 10 (pressure control space) rises sufficiently, so that the swash plate 12 tilts. The angle is kept at a minimum.

Next, FIG. 8 shows a second embodiment of the present invention. The second embodiment is an example in which the present invention is applied to a closed type single swash plate type variable capacity compressor, and FIG. 8 is a side sectional view showing the entire structure at the maximum capacity. Main shaft 13a is rotor 49
It is directly driven by an electric motor 48a composed of a, a stator 50a, and the like. The basic structure of the compression mechanism part is the same as that of the first embodiment, but the feature of the second embodiment is that the main shaft 13a is arranged vertically and the following points.

The small diameter portion 462a of the stroke rod 46a (first opening / closing member) is incorporated in the central portion of the main shaft 13a so as to be slidable in the axial direction, and is a pin penetrating an elongated hole 131a provided in the main shaft 13a. It is also connected to the swash plate sleeve 15a by 47a. Therefore, the stroke rod 46a moves in the axial direction together with the swash plate sleeve 15a as the swash plate tilt angle changes, but also rotates together with the swash plate sleeve 15a as the main shaft 13a rotates.

The cover-3a divides the upper surface of the cylinder head 4a into a central suction chamber 8a and an outer discharge chamber 9a, and a boss portion extending toward the cylinder head 4a at the central portion of the suction chamber 8a. 303a is formed, and the guide hole 41a penetrates therethrough so as to be coaxial with the rotation axis of the main shaft 13a. A mover 43a (second opening / closing member) similar to that of the first embodiment is incorporated in the guide hole 41a so as to be slidable in the axial direction.

The large diameter portion 461a of the stroke rod 46a is inserted into the inner peripheral surface of the cylinder of the mover 43a. In the case of the second embodiment, both of them slide relatively in the axial direction. The main shaft 13a also rotates relative to the main shaft 13a.

Radial plain bearings 18a and 19a are mounted in the central portions of the frame 1a and the cylinder block 2a, respectively, to support the main shaft 13a and to provide airtightness in the minute bearing clearances. There is. A swash plate chamber 10a (pressure control space) is formed by these components.

The communication path that connects the swash plate chamber 10a (pressure control space) and the suction chamber 8a, which is another pressure space, has a sixth communication hole 203a formed in the cylinder block 2a, a recess 204a, and a fourth communication hole. Hole 501a and third communication hole 4
03a and the small diameter portion 462a of the stroke rod.
, A second communication hole 45a formed in the mover 43a and a communication groove 431a, a coil case 38a and a cover.
3a, a gap between the mounting portion 3a and its mounting portion, and a first communication hole 42a formed in the cover 3a. The closed container 51a for accommodating all of the above components is composed of a cylinder chamber 52a, a bottom chamber 53a, and a lid chamber 54a. It is divided into The upper space 55a communicates with the suction chamber 8a through a suction hole 304a formed in the cover-3a and has a low pressure, and the lower space 56a is connected to the discharge chamber 9a by a discharge hole 305a formed in the cover-3a. It has been contacted and the pressure is high. If the swash plate chamber 10a is included, there are three pressure spaces other than the compression chambers corresponding to the pistons.

When the main shaft 13a is rotated by the electric motor 48a, the refrigerant flows in through the suction port 57a by the reciprocating motion of the piston 11a, is compressed, and then flows out through the discharge port 58a, as in the first embodiment. At that time, the lubricating oil separated from the refrigerant in the high pressure chamber collects at the bottom of the closed container 51a, but passes through the oil supply passage 131a formed inside the main shaft 13a and the oil supply pipe 59a attached to the lower end of the main shaft 13a. First, it is supplied to the radial plain bearing 18a. After lubricating the radial plain bearing 18a, the lubricating oil that has been reduced in pressure by the passage resistance of the bearing gap and reached the swash plate chamber 10a lubricates the thrust needle roller bearing 31a and collects at the bottom of the swash plate chamber 10a. After that, the weight projection 145a of the drive plate 14a is rotated to splash oil on the other sliding portions, and finally returns to the suction chamber 8a through the communication passage for controlling the pressure of the swash plate chamber 10a. The cooling medium flows again and the circulation in the closed container 51a is repeated.

The capacitance control is performed by adjusting the value of the current flowing through the coil 40a as in the first embodiment, and the principle is also the same as in the first embodiment. However, the part to which the stroke rod 46a, which is the first opening / closing member, is directly connected is different from the case of the first embodiment, but this may be any part that moves in conjunction with the volume change of the pressure control space. It can be configured by interlocking this with the first opening / closing member.

As described above, since the tilt angle of the swash plate, that is, the compressor capacity is uniquely determined by the current value flowing in the coil, the compressor capacity can be known from the current value flowing in the coil. The current value to be sent can be used as a control signal for the entire refrigeration cycle. Especially when applied to a vehicle air conditioner, the value of the current flowing in the coil can be used as an engine control signal whose load varies depending on the capacity of the compressor, and therefore, for example, it is shown in FIG. It is not necessary to attach a device (position detector 56) for detecting the compressor capacity as described above. In addition, when adjusting the pressure in the swash plate chamber to stabilize the variation in the swash plate tilt angle, the pressure communication path is directly opened and closed by the swash plate tilt angle variation itself. The responsiveness of the restoring force generation to the fluctuation of the angle is good, and the stability is excellent. In addition, it does not require special parts such as bellows and diaphragms that deform or move in response to the ambient pressure value, and is inexpensive and highly reliable.

In the first and second embodiments, the swash plate chambers 10 and 10 are used as pressure control spaces for changing the pressure in order to generate the force for adjusting the tilt angle of the swash plate.
Although a is used, any other space may be configured as the pressure control space as long as the volume changes in association with the change in the tilt angle of the swash plate. For example, 2-24
In the one-sided swash plate type variable displacement compressor shown in FIG. 1 of Japanese Patent No. 081 publication, a space (control chamber 3) formed on the side of the magnet clutch of the swash plate chamber (working chamber 5) in which the swash plate is stored.
4) and the double-headed swash plate type variable displacement compressor shown in FIG. 1 of Japanese Patent Laid-Open No. 1-237363, the space (control pressure chamber 20) formed in the rear cover (rear housing 13).
0) can be used as the pressure control space. Also,
In the first and second embodiments, when adjusting the tilt angle of the swash plate, the positions of the movable elements 43 and 43a, which are the second opening / closing members of the pressure communication path, are adjusted by the electromagnetic force of the coils 40 and 40a. However, this may be performed by a general linear actuator using a servo motor or the like or other positioning device. Further, in order to change the pressure in the pressure control space, the first opening / closing member (stroke rods 46 and 46a in the first and second embodiments) and the second opening / closing member
Other pressure spaces that open and close communication with the pressure control space by the relative position of the opening / closing member (movers 43 and 43a in the first and second embodiments) are the first and second embodiments. Even if the low pressure chambers such as the suction chambers 8 and 8a are used as in the embodiment described above or the high pressure chambers such as the discharge chambers 9 and 9a are used instead of the low pressure chambers, both the low pressure chamber and the high pressure chamber are simultaneously You may use. At this time, when the other pressure space is a low pressure chamber as in the first and second embodiments, the communication is opened and closed in correspondence with the increase and decrease of the volume of the pressure control space. When the pressure space is a high-pressure chamber, the structure may be such that the communication is closed or opened in correspondence with the increase and decrease of the pressure control space volume.

[0042]

As described above, according to the present invention, the stroke amount of the variable displacement compressor that changes the stroke amount of the piston that reciprocates in the axial direction by adjusting the tilt angle of the swash plate. Since it is possible to realize stable capacity control with a simple configuration while accurately grasping the above, it is possible to provide a variable capacity compressor that can perform advanced system control and has high reliability at low cost.

[0043]

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a variable capacity compressor for a car air conditioner according to a first embodiment of the present invention at a maximum capacity.

FIG. 2 is a vertical sectional view of the first embodiment of the present invention at the minimum capacity.

3 is a cross-sectional view taken along the line I-I of FIG.

4 is a sectional view taken along line II-II of FIG.

FIG. 5 is a partially enlarged view for explaining the principle of capacity control in the first embodiment.

FIG. 6 is a partial enlarged view for explaining the principle of capacity control in the first embodiment.

FIG. 7 is a partial enlarged view for explaining the principle of capacity control in the first embodiment.

FIG. 8 is a vertical cross-sectional view of the hermetic variable displacement compressor according to the second embodiment of the present invention at the maximum capacity.

[Explanation of symbols]

1 ... Front housing 1a ... Frame, 2 and 2a ...
Cylinder block, 3 ... Rear cover, 3a ... Upper cover,
4, 4a ... Cylinder head, 5, 5a ... Suction valve plate, 6,
6a ... Discharge valve plate, 7, 7a ... Discharge valve retainer, 8, 8a ... Suction chamber, 9, 9a ... Discharge chamber 10, 10a ... Swash plate chamber, 1
1, 11a ... Piston, 12, 12a ... Swash plate, 13, 1
3a ... spindle, 14, 14a ... drive plate, 15,
15a ... swash plate sleeve, 16, 16a ... shoe, 17,
17a ... Swash plate sleeve pin, 18, 19 ... Radial needle roller bearing, 18a, 19a ... Radial plain bearing, 20 ...
Stoppers 21, 21a ... Support sleeves 22, 22
2a ... Radial needle roller bearing, 23, 23a ... Sliding key, 24, 24a ... Piston support, 25, 25a ...
Outer ring, 26, 26a ... Ball, 27, 27a ... Holding member, 2
8 ... Magnet clutch, 29, 29a, 30, 30
a, 31, 31a ... Thrust needle roller bearings, 32, 32
a ... preload spring, 33, 33a ... connecting rod,
34, 34a, 35, 35a ... Piston ring, 36,
37, 37a ... O-ring, 38, 38a ... Coil case, 39 ... O-ring, 40, 40a ... Control coil, 4
1, 41a ... Guide hole, 42, 42a ... First communication hole, 43, 43a ... Mover, 44, 44a ... Spring, 45, 45a ... Second communication hole, 46, 46a ... Stroke rod, 47, 47a ... pin, 48a ... electric motor, 49a ... rotor, 50a ... stator, 51a ... closed container, 52a ... cylinder chamber, 53a ... bottom chamber, 54
a ... Lid chamber, 55a ... Upper space, 56a ... Lower space, 57a ... Suction port, 58a ... Discharge port, 59a ... Oil supply pipe, 60a ... Counter weight, 111 ... Piston concave spherical surface part, 121 ... Swash plate flat surface part, 122 , 123 ... swash plate ears, 131a ... oblong hole, 132a ... oil supply passage, 141 ... drive plate concave spherical surface portion, 142, 143 ... drive plate flat surface portion, 144 ... drive plate cylindrical surface portion, 1
45a ... Drive plate weight part projections, 201, 2
01a ... Cylinder bore, 202 ... Fifth communication hole, 203
a: sixth connecting hole, 204a: cylinder block recess,
211 ... Support sleeve groove portion, 241 ... Piston support concave spherical surface portion, 251, ... Outer ring groove portion, 252 ... Outer ring concave spherical surface portion, 271 ... Holding member flat surface portion, 272 ... Holding member convex spherical surface portion, 301 ... Exit, 303 ... Rear cover boss, 303a ... Upper cover boss, 304a ...
Suction hole, 305a ... Discharge hole, 331, 332 ... Connecting rod spherical surface part, 381, 381a ... Stator, 40
1, 401a ... Intake port, 402, 402a ... Discharge port, 403, 403a ... Third communication hole, 431, 43
1a ... Connecting groove, 461, 461a ... Stroke rod large diameter portion, 462, 462a ... Stroke rod small diameter portion, 5
01, 501a ... Fourth communication hole.

Claims (8)

[Claims] 1. A drive shaft bearing-supported by a housing and a cylinder block, a drive plate fixed to the drive shaft, and a swash plate restricted to rotate together with the drive plate and performing a tilting motion. A piston support which is supported by the swash plate so as to be rotatable relative to the swash plate, and whose rotation is restrained by a rotation stop mechanism to perform a swinging motion corresponding to the tilt angle of the swash plate; and an axis line of the drive shaft. The tilting of the swash plate includes a plurality of cylinders arranged in parallel in the circumferential direction, a piston that reciprocates in each cylinder, and a connecting rod that connects the piston and the piston support. Due to the relative positional relationship between the first opening / closing member that moves in conjunction with the movement and the second opening / closing member whose position is set to be movable by a signal from the outside, the swash plate or the like is stored. Variable displacement compressor, characterized by controlling the pressure of the storage spaces of the swash plate or the like performs the opening and closing of the communication passage for communicating the space and the other pressure space. 2. A drive shaft bearing-supported by a housing and a cylinder block, a swash plate sleeve slidably mounted on the drive shaft, and the fixed drive plate.
And a swash plate sleeve that is slidable in the axial direction with respect to the drive shaft and is regulated in the rotation direction, and is incorporated in the swash plate sleeve by means of a sleeve pin. A combined swash plate, a piston support which is rotatably supported by the swash plate relative to the swash plate, and whose rotation is restrained by a rotation stop mechanism to perform a swinging motion corresponding to the tilt angle of the swash plate; A plurality of cylinders arranged parallel to the axis of the drive shaft and in the circumferential direction; pistons that reciprocate in the respective cylinders; and a connecting rod that connects the pistons and the piston support, The swash plate or the like is formed by the relative positional relationship between the first opening / closing member that moves by being engaged with the swash plate sleeve and the second opening / closing member whose position is set to be movable by a signal from the outside. Of stored space and other pressure space Variable displacement compressor, characterized by controlling the pressure of the storage spaces of the swash plate or the like performs the opening and closing of the communication path communicating the. 3. A drive shaft supported by a frame and a cylinder block, an electric motor for rotationally driving the drive shaft, and a slide shaft slidably incorporated in the closed container. A swash plate sleeve, the fixed drive plate, a swash plate sleeve that is slidable in the axial direction with respect to the drive shaft and is regulated in the rotation direction, and the swash plate. A swash plate engaged with a sleeve by a sleeve pin so as to be tiltable, and a bearing rotatably supported relative to the swash plate and restrained from rotating by a detent mechanism to correspond to the tilt angle of the swash plate. Piston support for oscillating motion, a plurality of cylinders arranged parallel to the axis of the drive shaft and in the circumferential direction, pistons that reciprocate in each cylinder, and the piston and the piston support. -Connecting unit that connects And a second opening / closing member which is moved by being engaged with the swash plate sleeve and whose position is set to be movable by a signal from the outside. A variable capacity compression characterized by controlling the pressure in the space accommodated in the swash plate by opening / closing a communication path that communicates the space accommodated in the swash plate with another pressure space according to the positional relationship. Machine. 4. The second opening / closing member is made of a magnetic material, and the position of the second opening / closing member is moved by passing an electric current through a coil based on a signal from the outside. Variable capacity compressor. 5. The variable capacity compressor according to claim 1, wherein a pressure control space is provided in addition to the space in which the swash plate is stored. 6. The low-pressure suction by the first opening / closing member when the space of the swash plate or the like when the second opening / closing member is stationary at a set position is increased by the first opening / closing member. Any of claims 1 to 5, wherein communication with the chamber is communicated, and when the volume of the space decreases, the first opening / closing member that moves in conjunction with the space interrupts communication with the suction chamber. Variable capacity compressor described in. 7. A space for accommodating a swash plate or the like when the second opening / closing member is stationary at a certain set position is used to discharge high pressure by the first opening / closing member when the volume of the space increases. The variable capacity compressor according to claim 1, wherein communication with the chamber is blocked, and when the volume of the space is reduced, the first opening / closing member communicates with the discharge chamber. 8. The variable displacement compressor according to claim 1, wherein the other pressure space is maintained at a suction pressure.