JP2001003858A - Swash plate type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the amount of wearing between a shoe and a swash plate. SOLUTION: This compressor is provided with a swash plate rotated by a rotating shaft in a cylinder block having a cylinder bore, a piston slidably fitted in the cylinder bore, and a shoe 10 laid between sliding surfaces of the piston and the swash plate. The shoe 10 has a flat surface 10a slidably contacted with the swash plate, a hemispherical convex surface 10d slidably contacted with the piston, and a flange portion 10b including the flat surface 10a and outwardly extending over the hemispherical convex surface 10d. The flat surface 10a has a gently tilting surface 10c continuing to the flange portion 10b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a swash plate type compressor generally used for an air conditioner for a vehicle, and more particularly to a swash plate type compressor having a shoe interposed between a piston and a swash plate. Belongs to.

[0002]

2. Description of the Related Art As prior art 1, Japanese Patent Laid-Open No. 59-6857.
Japanese Patent Application Laid-Open No. 6-204, discloses a swash plate compressor including a swash plate that is disposed in a cylinder bore and is rotated by a rotating shaft.

As shown in FIGS. 4 and 5, this swash plate type compressor has a swash plate 205 provided in a cylinder block 201.
And a piston 204 connected to the swash plate 205 so as to reciprocate in the direction of the rotation shaft 202 in the cylinder bore 207 in accordance with the rotation of the swash plate 205, and is fitted and held between the swash plate 205 and the piston 204. It has a shoe 203 and a ball 208.

One side of the contact between the shoe 203 and the swash plate 205 has a substantially flat central portion, and the other side has a spherical concave surface to fit and hold a part of the ball 208. Further, a part of the ball 208 is fitted and held in a spherical concave portion inside the piston 204.

As prior art 2, Japanese Patent Application Laid-Open No. 62-41980
As shown in FIG. 6 and FIG. 7, the publication discloses a cylinder block 301 having a plurality of cylinder bores 306 provided in parallel with an axis, and a swash plate 305 rotated by a rotation shaft 302 in the cylinder block 301. And a piston 307 slidably fitted in the cylinder bore 306
A swash plate type compressor including a swash plate type compressor and a shoe 312 for reciprocating a piston 307 by rotation of a swash plate 305 is disclosed.

The shoe 312 is made of a base material having a flat surface 314 sliding on a smooth flat surface and a spherical surface 313 sliding on a concave spherical surface 307a of the piston 307.
Reference numeral 3 denotes a surface of the soft thin layer 315 formed on the base material.

[0007]

Since the compressor according to the prior art 1 is composed of two members, the shoe 203 and the ball 208, there is a problem that the assembling work and the configuration are complicated.

In the compressor of the prior art 2, the shoe 3
Since the flat portion 314 has a contact area smaller than the radius of the shoe 312, there is no effect of reducing the surface pressure between the swash plate 305 and the shoe 312.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a swash plate compressor capable of reducing the surface pressure of a shoe provided between a piston provided in a cylinder bore of a cylinder block and a sliding surface of a swash plate. is there.

[0010]

According to the present invention, a cylinder block having a plurality of cylinder bores, a swash plate rotated by a rotating shaft in the cylinder block, and slidably fitted in the cylinder bore. Piston
A swash plate compressor having a piston interposed between the piston and a sliding contact surface of the swash plate, wherein the shoe slides on the sliding contact surface of the swash plate. A flat surface that comes into contact, a hemispherical convex curved surface that slides on the sliding contact surface of the piston, and a flange portion that includes the flat surface and extends outward from the hemispherical convex curved surface, wherein the flat surface is the flange. And a swash plate compressor having an inclined surface connected to the swash plate.

Further, according to the present invention, there is provided a cylinder block having a plurality of cylinder bores, a swash plate rotated by a rotation shaft in the cylinder block, and a piston slidably fitted in the cylinder bore. And a shoe interposed between the piston and a sliding surface of the swash plate. In the swash plate compressor in which the piston reciprocates by rotation of the swash plate, the shoe slides on the swash plate. A convex curved surface slidingly contacting the surface, a hemispherical convex curved surface slidingly contacting the sliding contact surface of the piston, and a flange portion including the convex curved surface and extending outward from the hemispherical convex curved surface; Is connected to the flange portion and has a larger radius of curvature than the hemispherical convex curved surface, thereby obtaining a swash plate type compressor.

[0012]

According to the swash plate compressor of the present invention, the piston reciprocating in the cylinder bore and the shoe interposed between the swash plate have a large contact area with the swash plate against the gas compression reaction force. I do. Therefore, smooth sliding and a reduction in the amount of wear are achieved due to a decrease in surface pressure generated there. Further, a large contact area between the shoe and the swash plate can be secured, and as a result, the amount of wear is reduced. Further, since the flange portion and the shoe are integrally formed, the configuration is simplified.

[0013]

FIG. 1 shows a swash plate type compressor according to a first embodiment of the present invention. This compressor is a piston-type variable displacement compressor included in a refrigeration circuit of an automotive air conditioner, and is installed with its axis horizontal as shown in the figure.

This compressor comprises a cylinder block 1a having a plurality of cylinder bores 5, and a cylinder block 1a.
And a rotatable rotating shaft 2 extending in the axial direction at the center. One end of the rotating shaft 2 is exposed to the outside through a front housing 3 fixed to one end in the axial direction of the cylinder block 1a, and an external power source (not shown) can be appropriately detached therefrom via an electromagnetic clutch 4. Connected.

In the cylinder block 1a, an odd number, for example, five cylinder bores 5 are formed around the axis. Pistons 6 are fitted into these cylinder bores 5 so as to be slidable in the axial direction. These pistons 6
Is connected to the rotating shaft 2 via a known crank mechanism 7,
The cylinder reciprocates in the cylinder bore 5 according to the rotation of the rotating shaft 2.

The reciprocating stroke of the piston 6 is variable by the operation of the crank mechanism 7. A swash plate 11 rotated by the rotation shaft 2 is provided in the cylinder block 1a. A pair of shoes 10 is interposed between the piston 6 and the sliding surface of the swash plate 11. The pair of shoes 10 is a piston connecting portion 6a formed in the piston 6 in a concave shape.
It is fitted in. The piston connecting portion 6a is located outside the cylinder bore 5 and inside the cylinder block 1a. In this compressor, the piston 6 is reciprocated by the rotation of the swash plate 11.

The shoe 10, as shown in detail in FIG.
A flat surface 10a slidingly in contact with the sliding contact surface of the swash plate 11, a hemispherical convex curved surface 10d sliding in contact with a hemispherical concave sliding contact surface 6b formed on the inner surface of the piston connecting portion 6a of the piston 6, and a flat surface 10a; And a flange portion 10b extending outward from the substantially hemispherical convex curved surface 10d. Flat surface 10
a has a gentle inclined surface 10c connected to the flange portion 10b.

The radius of the flat surface 10a is a hemispherical convex curved surface 10d.
Can be set smaller or larger for the radius of. However, when a large compression load is generated, the contact area can be increased by making the radius larger than the hemispherical convex curved surface 10d, and the surface pressure can be reduced.

The shoe 10 slides with a large contact area with the swash plate 11 against the gas compression reaction force. Therefore, smooth sliding and a reduction in the amount of wear are achieved due to a decrease in surface pressure generated there.

A cylinder head 8 is fixed to the other axial end of the cylinder block 1a via a valve mechanism 9. The valve mechanism 9 includes discharge holes 12 formed corresponding to each cylinder 5.
The discharge valve 13 and the suction valve 14, which are leaf valves, face the b and the suction hole 12a.

The cylinder head 8 has a central discharge chamber 15
And a suction chamber 16 extending therearound. The discharge chamber 15 is connected to the high pressure side of the refrigeration circuit through a discharge port 17 and supplies high pressure gas to the condenser. The suction chamber 15 is connected to the low pressure side of the refrigeration circuit through a suction path including a gas passage and a suction port 19, and receives the return gas from the evaporator.

When the piston 6 reciprocates in the cylinder 5 according to the rotation of the rotary shaft 2, the refrigerant gas in the suction chamber 16 is sucked into the cylinder 5 through the suction hole 12a and the suction valve 14, and is discharged into the discharge hole 12b. It is discharged into the discharge chamber 15 via the discharge valve 13. Furthermore, the discharge port 1
Refrigerant gas is supplied to the high pressure side of the refrigeration circuit through 9.

FIG. 3 shows a shoe 101 of a second embodiment having a shoe shape different from the shape of the shoe 10 shown in the first embodiment.

The shoe 101 includes a convex curved surface 101a slidingly contacting the sliding contact surface of the swash plate 11, a hemispherical convex curved surface 101d slidingly contacting the sliding contact surface 6b of the piston 6, and a convex curved surface 101a. Flange part 1 extending outward
01b.

The convex curved surface 101a is connected to the flange portion 101b and has a larger radius of curvature than the hemispherical convex curved surface 101d. Note that, as compared with the flat surface 10a shown in the first embodiment, the convex curved surface 101a has a portion that protrudes in a curved shape at the maximum protrudes by about 10 to 30 micrometers from the flat surface 10a.

In the case of the shoe 101, the convex curved surface 101a
Are formed with a large radius of the sliding contact surface with the swash plate 11. Thus, a wedge-shaped space S is formed between the swash plate 11 and the shoe 101.
Is configured. An oil film is formed in the wedge-shaped space S, and the wear resistance is improved. In this case, the swash plate 11 and the shoe 101 are shown in FIG.
Therefore, the area around the flange portion 101b is not a gentle slope but a small curved surface.

Also in the configuration of the shoe 101 of the second embodiment, the shoe 101 interposed between the piston 6 and the swash plate 11 reciprocating in the cylinder bore 5 has a large inclination against the gas compression reaction force. It slides with a contact area with the plate 11. Therefore, smooth sliding and a reduction in the amount of wear are achieved due to a decrease in surface pressure generated there.

[0028]

As described above, according to the present invention,
A flange portion is formed on the shoe to form a hemispherical convex curved surface and an inclined surface or a convex curved surface, so that the shoe can be integrated, simplifying the configuration, and ensuring a large contact area between the shoe and the swash plate. A reduction in pressure results in a reduction in wear.

Further, when the convex curved surface is formed so that the surface in contact with the swash plate has a large radius, a wedge-shaped space is formed between the swash plate and the shoe. Abrasion is improved.

[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 side view showing details of a shoe shown in FIG. 1;

FIG. 3 is a side view showing a second embodiment of the shoe in the swash plate type compressor according to the present invention.

FIG. 4 is a longitudinal sectional view of a swash plate type compressor according to the related art 1.

FIG. 5 is a side view showing the shoe shown in FIG. 4;

FIG. 6 is a longitudinal sectional view of a swash plate type compressor according to the related art 2.

FIG. 7 is a sectional view showing the shoe shown in FIG. 6;

[Explanation of symbols]

 1a, 201, 301 Cylinder block 5, 207, 306 Cylinder bore 2, 202, 302 Rotating shaft 3 Front housing 6, 204, 307 Piston 6a Piston connecting part 7 Crank mechanism 8 Cylinder head 10, 203, 312 Shoe 10a Flat surface 10b, 101b Flange portion 10c Inclined surface 10d Hemispherical convex curved surface 11,205,305 Swash plate 101a Convex curved surface 208 Ball 313 Spherical surface

Claims (2)

[Claims] A cylinder block having a plurality of cylinder bores, a swash plate rotated by a rotation shaft in the cylinder block, a piston slidably fitted in the cylinder bore, the piston and the swash plate And a shoe interposed between the sliding surfaces of the swash plate, wherein the rotation of the swash plate causes the piston to reciprocate. A hemispherical convex curved surface that is in sliding contact with the sliding surface of the piston; and a flange portion that includes the flat surface and extends outward from the hemispherical convex curved surface, wherein the flat surface is connected to the flange portion. A swash plate type compressor having a surface. 2. A cylinder block having a plurality of cylinder bores, a swash plate rotated by a rotating shaft in the cylinder block, a piston slidably fitted in the cylinder bore, and the piston and the swash plate. And a shoe interposed between the swash plate and the sliding surface of the plate, wherein the swash plate rotates the piston in a reciprocating motion. A hemispherical convex curved surface that slides on the sliding surface of the piston;
A flange portion including the convex curved surface and extending outward from the hemispheric convex curved surface, wherein the convex curved surface is connected to the flange portion and has a larger radius of curvature than the hemispheric convex curved surface. A swash plate compressor.