JPH10205440A - Hollow piston and swash plate compressor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce inertial force and improve high speed performance and durability by threadedly connecting a hollow piston head slid inside a cylinder bore to a holder for a pair of shoes slid slidingly contacted with a swash plate. SOLUTION: A swash plate 4 is attached to a driving shaft 3 variably in its tilting angle interposing a spherical bush 8 attached to the driving shaft 3 movably in the axial direction. The swash plate 4 is bendbly connected to a rotor 9 fixed to the driving shaft 3. The swash plate 4 can thus be rotated together with the driving shaft 3. A shoe holder 52 is arranged for slidably holding a pair of shoes slid on the swash plate 4. The shoe holder 52 is threadedly connected to a hollow piston head 51 slid inside a cylinder bore 211. It is thus possible to reduce inertial force and improve high speed performance and durability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate type compressor, and more particularly to a hollow piston.

[0002]

2. Description of the Related Art The prior art will be described below. As shown in FIG. 3, in the case of the piston 15 used in the conventional swash plate type compressor 1, the material is metal, and the structure thereof is a solid piston head 151 sliding in the cylinder bore 211. And a shoe holding portion 152 that slidably holds a pair of shoes that are in sliding contact with the swash plate. The piston head 151 and the shoe holding portion 152 are integrally formed.

[0003] However, in such a conventional swash plate compressor, the high-speed performance of the piston is limited due to the heavy weight of the piston head, and the inertia force of the piston works in the direction of tilting the swash plate, so that the high-speed operation is performed. In the case of a variable displacement type swash plate compressor, the responsiveness of the variable displacement is deteriorated by the above-mentioned inertia force,
Problems arise in its controllability. Further, as shown in FIG. 3, even if the piston 15 is lightened simply by reducing the height of the piston head 151, the sealing area of the piston head 151 is reduced and the performance is deteriorated. Problems arise.

In view of the above problems, Japanese Utility Model Application Laid-Open No. 4-10994 has been proposed.
As disclosed in Japanese Patent Publication No. 81, the two members of the piston head and the shoe holding portion are not integrally molded, but are separately molded, and the piston head is formed into a hollow structure, and the two members are joined by welding. A variable displacement type swash plate type compressor having a hollow piston structure has been proposed.

[0005]

However, the hollow piston having the above-mentioned hollow structure has an economical problem that the manufacturing cost is high.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a hollow piston which can be manufactured at a low cost while reducing inertia force by reducing the weight of the piston, improving high speed performance and durability, and using the same. To provide a compressed swash plate type compressor.

[0007]

According to the first aspect of the present invention, a hollow piston head made of synthetic resin and sliding in a cylinder bore and a pair of shoes slidingly contacting a swash plate are slidable. And a shoe holding portion for holding the piston head, and wherein the piston head and the shoe holding portion are screwed to each other.

According to the second aspect of the present invention, a shoe holding portion made of synthetic resin and slidably holding a pair of hollow piston heads sliding in the cylinder bore and a pair of shoes slidingly contacting the swash plate. , And wherein the piston head and the shoe holder are press-fitted to each other.

According to the third aspect of the present invention, there is provided the hollow piston according to the first or second aspect, wherein the synthetic resin has self-lubricating properties.

According to a fourth aspect of the present invention, there is provided the housing, and the hollow piston according to any one of the first to third aspects, which is slidably inserted into a cylinder bore formed in the housing. A drive shaft rotatably provided in the housing, a swash plate mounted on the drive shaft, and a swash plate slidably held by a shoe holding portion of the hollow piston so as to sandwich the swash plate. A swash plate type compressor having a pair of shoes in sliding contact with each other is obtained.

According to a fifth aspect of the present invention, there is provided the swash plate type compressor according to the fourth aspect, wherein the swash plate is mounted at a variable inclination angle with respect to the drive shaft.

[0012]

Since the hollow piston head made of synthetic resin and the shoe holder are screwed or press-fitted to each other, it is necessary to join the piston head and the shoe holder by welding. Therefore, high-speed performance is improved by weight reduction by the hollow structure, and a hollow piston can be manufactured at low cost.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a longitudinal sectional view of a variable displacement swash plate type compressor according to a first embodiment of the present invention.

As shown in FIG. 1, a variable displacement type swash plate type compressor 1 of a single-headed piston type according to this embodiment has a housing 2.
, Drive shaft 3, swash plate 4, single-headed hollow piston 5
And a shoe 6.

The housing 2 includes a front housing 20
, Cylinder block 21 and cylinder head 22
It is composed of

The front housing 20 has a substantially funnel shape. The front housing 20 includes a radial needle bearing 200 and a thrust needle bearing 20.
1 and a shaft seal member 202 are provided.

The cylinder block 21 has a substantially cylindrical shape, and has one open end closed by a front housing 20 and the other open end closed by a cylinder head 22 with a valve plate device 24 interposed therebetween. The cylinder block 21 has a center hole 210 and a cylinder bore 21.
One. The center hole 210 is formed at the center of the cylinder block 21, and the radial needle bearing 212 is disposed therein. Cylinder bore 21
1 are formed at equal intervals so as to surround the center hole 210. A suction chamber 220 and a discharge chamber 221 are formed in the cylinder head 22.

The front housing 20 is fixed to the cylinder block 21 by bolts 25, and the cylinder head 22 is fixed to the valve plate device 24 by bolts 26.
The front housing 20, the cylinder block 21, and the cylinder head 22 are integrated with each other to form the housing 2. The bolt 25 extends in the vicinity of the inner peripheral wall surface of the cylinder block 21 in parallel with the center line of the cylinder bore 211 and is adjacent to the cylinder bore 2.
It passes through 11 spaces.

The drive shaft 3 is rotatably supported by the front housing 20 and the cylinder block 21 via radial needle bearings 200 and 212, and is located at the center of the housing 2. The tip of the drive shaft 3
Projecting from the front end of the front housing 20 to the outside of the compressor, this portion is connected to this portion via an electromagnetic clutch (not shown).
For example, a force from an engine (not shown) is transmitted.

The swash plate 4 is provided with a spherical bush 8 mounted on the drive shaft 3 so as to be movable in the axial direction thereof.
Is mounted on the drive shaft 3 so that the inclination angle with respect to the drive shaft 3 is variable.
The swash plate 4 is flexibly connected to a rotor 9 fixed to the drive shaft 3, whereby the swash plate 4 rotates together with the drive shaft 3. Further, a coil spring 10 mounted on the drive shaft 3 is interposed between the swash plate 4 and the rotor 9, and the swash plate 4 is urged by the coil spring 10 so that the inclination angle becomes smaller. I have.

The single-headed hollow piston 5 has a hollow piston head 51 that slides in a cylinder bore 211 and a shoe holder 52 that slidably holds a pair of shoes 6 that are in sliding contact with the swash plate 4. The piston head 51 and the shoe holder 52 are screwed together. Piston head 51
Is a self-lubricating synthetic resin, and the material of the shoe holding portion 52 is an aluminum alloy.

Accordingly, the weight of the hollow piston 5 is reduced because the piston head 51 is hollow and made of synthetic resin, and the inertial force of the piston head 51 acting in the direction of tilting the swash plate 4 is reduced. It will be smaller by the amount
The durability during high-speed operation is improved. In particular, in the case of a variable displacement compressor, the response of the variable displacement is improved, and the controllability is also improved.

In this embodiment, since the piston head 51 and the shoe holding portion 52 are screwed together, a comparison is made with a conventional hollow piston in which the piston head and the shoe holding portion are welded together. Thus, an excellent effect that it can be manufactured at low cost can be obtained.

Next, a second embodiment of the present invention will be described in detail with reference to FIG. FIG. 2 is a longitudinal sectional view of a variable displacement swash plate type compressor according to a second embodiment of the present invention.

As shown in FIG. 2, a variable displacement swash plate type compressor 1 of the single-headed piston type according to the present embodiment has a housing 2.
, Drive shaft 3, swash plate 4, single-headed hollow piston 5
And a shoe 6. This embodiment is the same as the first embodiment except that the method of coupling the piston head 51 and the shoe holding portion 52 is different. Therefore, in the present embodiment, the description of the portions other than the above-described combining method is omitted.

The hollow piston 5 has a cylinder bore 211
It has a hollow piston head 51 that slides inside, and a shoe holder 52 that slidably holds a pair of shoes 6 that slide on the swash plate 4. Are press-fitted to each other. The material of the piston head 51 is a self-lubricating synthetic resin, and the material of the shoe holding portion 52 is an aluminum alloy.

Therefore, similarly to the first embodiment, the weight of the hollow piston 5 is reduced because the piston head 51 is hollow and made of synthetic resin, and the piston acting in the direction of tilting the swash plate 4 is reduced. Since the inertial force of the head 51 is reduced by the reduced weight, the durability during high-speed operation is improved. Particularly in the case of a variable displacement compressor, the response of variable displacement is improved and the controllability is also improved, as in the first embodiment.

Further, in this embodiment, since the piston head 51 and the shoe holding portion 52 are press-fitted and connected to each other, compared with the conventional welding connection between the piston head and the shoe holding portion in the case of a hollow piston. As in the first embodiment, an excellent effect that it can be manufactured at low cost can be obtained.

[0029]

According to the present invention, the weight of the hollow piston can be reduced by screwing or press-fitting the two members of the hollow piston head made of synthetic resin and the shoe holder. As a result, the inertia force acting on the swash plate of the hollow piston can be reduced, so that the durability at the time of high-speed operation is improved, and in particular, the response of variable displacement in the case of a variable displacement swash plate compressor is improved. Therefore, the controllability can be improved.

Further, according to the present invention, since the method of connecting the two members of the hollow piston head made of synthetic resin and the shoe holding portion is screwed or press-fitted, the conventional welding method is used. It can be manufactured at a lower cost than coupling.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a swash plate type compressor according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a swash plate type compressor according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of an example of a conventional swash plate type compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Variable capacity swash plate compressor 2 Housing 3 Drive shaft 4 Swash plate 5 Hollow piston 6 Shoe 8 Spherical bush 9 Rotor 10 Coil spring 20 Front housing 21 Cylinder block 22 Cylinder head 24 Valve plate device 51 Piston head 52 Shoe holding part 220 suction chamber 221 discharge chamber 211 cylinder bore

Claims (5)

[Claims] 1. A piston head having a hollow piston head made of synthetic resin and sliding in a cylinder bore, and a shoe holding portion slidably holding a pair of shoes slidingly contacting a swash plate. A hollow piston, wherein the part and the shoe holding part are screwed to each other. 2. A piston head having a hollow piston head made of a synthetic resin and sliding in a cylinder bore, and a shoe holding portion slidably holding a pair of shoes slidably contacting a swash plate. A hollow piston, wherein the part and the shoe holding part are press-fitted to each other. 3. The hollow piston according to claim 1, wherein the synthetic resin has a self-lubricating property. 4. A housing and a slidably inserted cylinder bore formed in the housing.
And a drive shaft rotatably provided in the housing, a swash plate mounted on the drive shaft, and slidable on a shoe holding portion of the hollow piston. A swash plate compressor having a pair of shoes that are held and slidably contact the swash plate so as to sandwich the swash plate. 5. The swash plate compressor according to claim 4, wherein said swash plate is mounted at a variable inclination angle with respect to said drive shaft.