JP3277600B2 - Variable capacity swash plate compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A conventional variable displacement type swash plate type compressor (hereinafter, referred to as a swash plate type compressor).
It is simply called a compressor. ) Is disclosed in
Japanese Unexamined Patent Application Publication No. 2000-205,099 is known. In this compressor, a cylinder bore is formed in a cylinder block, a suction chamber and a discharge chamber are formed in a housing, and the two are joined to form a crank chamber. In the crank chamber, the rotor is supported on the drive shaft so as to be synchronously rotatable, and the rotary drive body is rotatably and tiltably displaceable via a hinge mechanism between the rotor and the drive shaft via a sleeve. Supported. A rotary swash plate is fixed to the rotary driver, and the two constitute a swash plate. The hinge mechanism is
A mounting hole provided in a support arm protruding from the rotor,
The mounting hole includes a bearing that is swingably provided at least in the front-rear direction and has a guide hole penetrating therethrough, and a guide pin fixedly attached to the rotary driving body and loosely reciprocally fitted in the guide hole. The sleeve is provided so as to be slidable in the axial direction of the drive shaft, and the outer peripheral surface of the sleeve is maintained in cylindrical contact with the rotary drive by a pivot pin projecting in a direction perpendicular to the axis. A piston is engaged with the rotary swash plate via a pair of shoes for converting a swinging motion into a reciprocating motion, and each piston is accommodated in each cylinder bore. The cylinder block is provided with a communication hole that connects the crank chamber and the suction chamber, and the communication hole is opened and closed by a control valve.

In this compressor, when the swash plate rotates at a predetermined inclination angle with the driving of the drive shaft, the piston reciprocates in the cylinder bore. Thereby, the refrigerant gas is sucked into the cylinder bore from the suction chamber, and the refrigerant gas is compressed and discharged to the discharge chamber. The discharge capacity of the refrigerant gas discharged to the discharge chamber is controlled by adjusting the pressure in the crank chamber by the control valve.

During this time, in this compressor, the position of the fulcrum of the guide pin in the hinge mechanism and the position of the action point on the rotary swash plate are located on a fixed axis, so that no moment in the direction of reducing the capacity acts. Capacity control can be performed smoothly. Also, in this compressor, since the components of the hinge mechanism are easier to process than the conventional compressor,
The processing accuracy is improved, and the problems of reduced compression efficiency and abnormal noise can be solved.

[0005]

However, in the above-described compressor, the top clearance of the piston is increased between the minimum tilt angle and the maximum tilt angle of the rotary swash plate due to the structure of the hinge mechanism. Would. Therefore, depending on the setting of the offset angle between the guide pin and the swash plate,
Since the fluctuation range of the top clearance was wide, there was a case where the compression efficiency had a problem.

Accordingly, the present applicant has disclosed in Japanese Patent Application Laid-Open No. 4-2951.
No. 85 proposed a compressor capable of minimizing a fluctuation width of a top clearance accompanying a change in capacity by specifying an offset angle. However, in the proposed compressor, as shown in FIG. 5, although the maximum value of the top clearance TC during the period from the minimum capacity to the maximum capacity is lower than that of the conventional compressor, the fluctuation width of the top clearance TC is still small. It exists to some extent and is not yet satisfactory in terms of optimal compression efficiency.

According to the present invention, it is possible to smoothly control the capacity and to solve the problems of the reduction of the compression efficiency and the abnormal noise.
It is an object to be solved to make the fluctuation width of the top clearance due to the change in the capacity almost zero.

[0008]

In order to solve the above-mentioned problems, a compressor according to the present invention includes a crank chamber, a suction chamber, a discharge chamber, and cylinder bores connected thereto. Each of the pistons is accommodated so as to be able to reciprocate, and a rotor located in the crank chamber is supported on the drive shaft supported by the housing so as to be synchronously rotatable. displaceably pivotally supported, between the swash plate and the piston is interposed a pair of shoes for converting back and forth swinging motion of the swash plate to reciprocating motion of each piston, before Symbol hinge mechanism, A mounting hole provided in a support arm protruding from the rotor, a bearing provided in the mounting hole so as to be swingable at least in the front-rear direction, and a guide hole penetrating therethrough; Fits linearly A cam hole penetrating through the drive shaft, and the swash plate is supported by a pivot pin guided by the cam hole so as to be tiltable and slidable in the axial direction. The new means is adopted.

In the compressor of the present invention, it is preferable that a sleeve for maintaining surface contact between the swash plate and the drive shaft is interposed between the swash plate and the drive shaft.

[0010]

In the compressor of the present invention, the pivot pin is guided by the cam hole penetrating the drive shaft, whereby the swash plate is supported so as to be tiltable and slidable in the axial direction. Thus, the top point of the top clearance from the minimum capacity to the maximum capacity can be lowered, and the fluctuation range of the top clearance can be made almost zero.

In the compressor of the present invention, when a sleeve is interposed between the swash plate and the drive shaft, the sleeve slides in the axial direction while maintaining surface contact with the drive shaft, and the swash plate is Swings due to the displacement of the tilt angle while maintaining the surface contact.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In this compressor, as shown in FIGS. 1 and 2, a cylinder block 1 having a plurality of cylinder bores 1a is disposed at a central portion, and a front end of the cylinder block 1 forms a closed crank chamber 2 and is formed by a front housing 3. The rear end is closed by a rear housing 6 via a valve plate 4 and a retainer 5. Rear housing 6
Is provided with a suction chamber 7 and a discharge chamber 8 which communicate with the cylinder bore 1a.

A drive shaft 9 is supported by the front housing 3 via a shaft sealing device 3a and a radial bearing 3a. The drive shaft 9 is provided in the center shaft hole 1b of the cylinder block 1.
Is fitted through a radial bearing 1c. A rotor 10 is supported on the drive shaft 9 so as to be able to rotate synchronously in the crank chamber 2, and a thrust bearing 3 c is interposed between the rotor 10 and the front housing 3. Rotor 10
, A rotation drive body 11 is supported via a hinge mechanism K.

In the hinge mechanism K, a mounting hole 12a is provided through a support arm 12 projecting rearward in the axial direction from the rotor 10, and a race 13 having a spherical inner surface is fixed to the mounting hole 12a by a circlip 14. The race 13 is provided with an engaging bearing 15 so as to be swingable. A guide hole 15a is formed through the bearing 15, and one end of a guide pin 16 is supported in the guide hole 15a so as to be able to linearly move. The other end of the guide pin 16 is fixed to the rotation driving body 11.

A rotary swash plate 17 is fixed behind the rotary driver 11 by screwing, and the rotary driver 11 and the rotary swash plate 17 constitute a swash plate in the present invention. A plurality of pairs of hemispherical shoes 18, 18 are slidably abutted on both surfaces of the rotating swash plate 17, and a neck of a piston 19 is rotatably engaged with the hemispherical surface of each pair of shoes 18, 18. ing. Each piston 19 is accommodated in the cylinder bore 1a, and is reciprocable in the cylinder bore 1a according to the inclination angle of the rotary swash plate 17. These pistons 1
9 is formed hollow except for the neck,
A projection 19a is provided on the piston head so as to be aligned with the discharge port 4a of the valve plate 4.

The drive shaft 9 has a cam hole 9a formed at right angles to the axis. The cam hole 9a has a profile in which the action point position Q on the rotary swash plate 17 is constant regardless of the tilt angle displacement of the rotary swash plate 17. A sleeve 20 slidable through the length of the cam hole 9 a is fitted into the drive shaft 9.
It is urged away from zero. This sleeve 20
As shown in FIGS. 3 and 4, a flat surface 20a that fits with the rotary driving body 11 is formed at both ends of the cam hole 9a on the opening side.
And the escape hole 2 corresponding to the variation width of the profile of the cam hole 9a.
0b is penetrated.

The rotary driving body 11 has a right angle to the inclined line L in a plane including the inclined line L determined by the top dead center position (action point position Q) and the bottom dead center position of the rotary swash plate 17. Press-in hole 11a
The press-fit hole 11a has a sleeve 2
A pivot pin 22 that is slidably inserted into the cam hole 9a of the drive shaft 9 through the 0 escape hole 20b is press-fitted. In this way, as shown in FIGS.
2 is slidably guided in the cam hole 9a, and is supported so as to be tiltable and slidable in the axial direction.

The cylinder block 1 is formed with a radial conduction path 1d for communicating each cylinder bore with the central shaft hole 1b. A mounting bracket 24 is fixed to the inner end of the drive shaft 9 via a washer 23.
Are press-fitted into the rotary valve 25 so as not to rotate relatively. The rotary valve 25 is rotatably housed in the central shaft hole 1 b of the cylinder block 1, and a thrust bearing 26 is interposed between the rear end and the rear housing 6. The rotary valve 25 is formed with a suction passage 25a for communicating the suction chamber 7 of the rear housing 6 with the conduction path 1d of the cylinder bore 1a in the suction stroke, and the peripheral surface of the rotation valve 25 bypasses gas leaked from the suction passage 25a. Leak gas bypass groove 25b
Are formed.

A discharge valve 26 for blocking the discharge port 4a is interposed between the valve plate 4 and the retainer 5, and a control valve (not shown) for adjusting the pressure of the crank chamber 2 is provided in the rear housing 3. I have. In this compressor, the rotor 10 rotates with the driving of the drive shaft 9 and the hinge mechanism K
The rotation driving body 11 rotates via the pivot pin 22 and the rotation swash plate 17 rotates. Thereby, each piston 19 reciprocates in the cylinder bore 1a via the shoe 18.
At the same time, since the rotary valve 25 rotates, the refrigerant gas is sucked from the suction chamber 7 into the cylinder bore 1a if the suction passage 25a communicates with the cylinder bore 1a in the suction stroke via the conduction path 1d. Then, the refrigerant gas in the cylinder bore 1a is compressed by the forward movement of the piston 19, and the compressed refrigerant gas is pushed to open the discharge valve 26 and discharged to the discharge chamber 8. During this time, the leak gas existing on the peripheral surface of the rotary valve 25 is bypassed from the leak gas bypass groove 25b to the cylinder bore 1a.

The discharge capacity of the refrigerant gas discharged to the discharge chamber 8 is controlled by adjusting the pressure in the crank chamber 2 by a control valve. That is, if the control valve increases the pressure in the crank chamber 2 from the state shown in FIG. 1, the back pressure acting on the piston 19 increases, so that the bearing 15 moves relative to the race 13 in the mounting hole 12 a of the support arm 12. While swinging backward, the guide pin 16 moves to a position close to the drive shaft 9 in the guide hole 15a of the bearing 15, and the sleeve 2
0 retracts until it buckles against the spring 21 and contacts the stopper 27. As a result, the rotary driving body 11 swings forward with the pivot pin 22 while retreating because the pivot pin 22 is slid and guided rearward along the cam hole 9a of the drive shaft 9.
Therefore, as shown in FIG. 2, the inclination angle of the rotary swash plate 17 is reduced, the stroke of the piston 19 is shortened, and the discharge capacity is reduced.

Conversely, when the pressure in the crank chamber 2 is reduced by the control valve from the state shown in FIG. 2, the back pressure acting on the piston 19 is reduced, so that the bearing 15 races in the mounting hole 12a of the support arm 12. 13, the guide pin 16 moves to a position far from the drive shaft 9 in the guide hole 15 a of the bearing 15, and the sleeve 20 moves forward against the spring 21. Thereby, the rotation driving body 11
Since the pivot pin 22 slides forward along the cam hole 9a of the drive shaft 9, the pivot pin 22 moves forward until it comes into contact with the rotor 10, and swings backward with the pivot pin 22. Therefore, as shown in FIG. 1, the inclination angle of the rotary swash plate 17 increases, the stroke of the piston 19 is extended, and the discharge capacity increases.

During this movement, the compressor uses a drive shaft 9
The pivot pin 22 is slidably guided by the cam hole 9a penetrating the swash plate, whereby the rotary swash plate 17 is supported so as to be tiltable and slidable in the axial direction. The maximum value of the clearance decreases, and the fluctuation width of the top clearance is almost zero. Further, in this compressor, the sleeve 20 slides in the axial direction while maintaining the surface contact with the drive shaft 9, and the rotary driving body 11 maintains the surface contact with the two flat surfaces 20 a of the sleeve 20 while displacing the inclination angle. As a result, the driving force of the drive shaft 9 is suitably transmitted to the rotary driver 11, and the rotary driver 11 is also smoothly rocked.

Further, in this compressor, the guide pins 16
Of the fulcrum position P and the fulcrum position P on the rotary swash plate 17 that receives a compression reaction force from the piston 19 corresponding to the top dead center are located on a fixed axis. Therefore, in this compressor, the bending moment does not act, and the displacement control can be performed smoothly. Also, in this compressor, when a long hole is formed in the rotor in a direction perpendicular to the axis, as in a hinge mechanism of a conventional compressor, and a pin fixed to a swash plate is inserted into the long hole. As compared with the above, since the processing of the components of the hinge mechanism K is easier, the processing accuracy is improved, and the reduction in compression efficiency and the problem of abnormal noise can be solved.

In addition, in this compressor, the weight is reduced by the hollow piston 19, and the protrusion 19a of the piston head is aligned with the discharge port 4a of the valve plate 4, so that the cylinder bore 1a The amount of residual gas inside is reduced. The rotary valve 25 is rotatable synchronously with the drive shaft 9.
Is provided, the suction efficiency is improved as compared with a general flapper valve.

[0025]

As described above in detail, in the compressor of the present invention, the hinge mechanism having the bearing and the guide pin is adopted, and the pivot pin is guided in the cam hole penetrating the drive shaft. Since the swash plate is supported so that it can be tilted and slidable in the axial direction, the capacity can be smoothly controlled, the compression efficiency can be reduced and abnormal noise can be solved, and the fluctuation width of the top clearance due to the capacity change Can be close to zero.

Therefore, this compressor can ensure the optimum compression efficiency.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a compressor according to an embodiment at a maximum capacity.

FIG. 2 is a longitudinal sectional view of the compressor according to the embodiment at the time of a minimum capacity.

FIG. 3 is a perspective view of a main part of the compressor of the embodiment.

FIG. 4 is a sectional view of a main part of the compressor of the embodiment.

FIG. 5 is a curve diagram showing a relationship between a tilt angle of a swash plate and a top clearance in a conventional compressor.

[Explanation of symbols]

1: Cylinder block 3, 6: Housing 2:
Crank chamber 7 ... Suction chamber 8 ... Discharge chamber 1a
... Cylinder bore 19 ... Piston 9 ... Drive shaft 10
... rotor K ... hinge mechanism 12 ... support arm 12
a: mounting hole 15: bearing 15a: guide hole 16
… Guide pins 11, 17… Swash plate (11… Rotary driving body, 17… Rotating swash plate) 18… Shoe 9a… Cam hole 22
... Axis pin 20 ... Sleeve

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F04B 27/10 F04B 27/14

Claims (2)

(57) [Claims] 1. A crank chamber, a suction chamber, a discharge chamber, and cylinder bores connected to these are defined, and a piston is reciprocally housed in each of the cylinder bores. The rotor located in the crank chamber is supported so as to be able to rotate synchronously, a swash plate is pivotally supported between the rotor and a hinge mechanism via a hinge mechanism so that the inclination angle can be displaced, and between the swash plate and the piston. a pair of shoes for converting back and forth swinging motion of the swash plate to reciprocating motion of each piston is interposed, prior Symbol hinge mechanism includes a mounting hole provided in the support arm projecting from the rotor, the mounting hole A variable capacity swash plate type compression system comprising: a bearing which is swingably provided at least in the front-rear direction and has a guide hole formed therethrough; and a guide pin which is fixed to the swash plate and is inserted in the guide hole so as to be able to move directly. At the machine A cam hole is provided in the drive shaft, and the swash plate is supported by a pivot pin guided by the cam hole so as to be tiltable and slidable in the axial direction. Compressor. 2. The variable displacement type swash plate type compressor according to claim 1, wherein a sleeve is provided between the swash plate and the drive shaft to maintain surface contact with the swash plate.