JP2947243B2 - Piston structure in 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 piston structure in a swash plate type compressor for sucking, compressing, and discharging refrigerant gas by converting the rotational motion of a drive shaft into a reciprocating motion of a piston via a swash plate. is there.

[0002]

2. Description of the Related Art Conventionally, as a swash plate type compressor of this type,
When the swash plate is rotated, that is, when the piston is reciprocated in the cylinder bore, the piston may slightly rotate and the piston may come into contact with the swash plate. If they come into contact with each other, noise may be generated at the time of contact, or a problem may occur in that the contact portion between the piston and the swash plate is worn.

In order to prevent the contact between the piston and the swash plate by restricting the fine rotation of the piston, the present applicant has proposed the following swash plate type compressor (Japanese Utility Model Application Laid-Open No. 62-133).
No. 973).

[0004] That is, as shown in FIG.
Are formed by a neck 22, a flat portion 23 having a height H is formed above the neck 22. A groove for fitting the flat portion 23 of the piston 20 and guiding the piston in the axial direction is provided in a cylinder bore (not shown) for accommodating the piston 20 reciprocally.
It is formed at a depth obtained by adding the clearance H with the flat portion 23 to the height H of the flat portion 23. Even when the swash plate is rotated to reciprocate the piston 20 in the cylinder bore, the flat portion 23 of the piston 20 and the groove formed in the cylinder bore are in an engagement relationship.
The number 0 restricts the fine rotation of the swash plate before the swash plate comes into contact with the swash plate. Therefore, contact between the piston 20 and the outer periphery of the swash plate is prevented.

[0005]

However, in the cylinder bore of the swash plate type compressor, the height H of the flat portion 23 formed on the piston 20 and the depth corresponding to the clearance H between the flat portion 23 and the flat portion 23 are added. Because the groove is formed in
The thickness from the peripheral wall of the cylinder bore to the outer periphery of the cylinder block is reduced. As a result, the strength of the cylinder block is reduced by the reduced thickness. Then, in order to replenish the reduced strength, it is necessary to increase the thickness from the peripheral wall of the cylinder bore to the outer periphery of the cylinder block.

Therefore, in order to increase the wall thickness, the outer circumference of the cylinder block must be increased. As a result, the size of the compressor is increased, and there is a problem that a space for mounting the compressor is limited. In particular, the problem is serious for a swash plate type compressor using a single-headed piston requiring compactness.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a piston structure of a swash plate type compressor capable of suppressing an increase in the outer periphery of a housing.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, both surfaces of a swash plate that rotates integrally with a drive shaft and a cylinder bore are reciprocally movable within a housing. In a swash plate compressor configured to convert the rotational motion of the swash plate into reciprocating motion of the piston through a shoe interposed between the piston and a neck portion of the swash plate,
A piston head that slides the piston in a cylinder bore
And a single-headed piston consisting of a neck formed continuously with the head
Configure Te, the neck 該片headed piston, anti from said head
The gist is that a fine rotation restricting piece extending from the neck portion to both sides from the neck portion and capable of contacting the housing is provided at the opposite end .

[0009] According to the invention of claim 2, the above-mentioned claim 1 is provided.
In the invention, the housing has an inner wall surface facing the neck of the piston, and the fine rotation restricting piece extends along the inner wall surface and is provided so as to be able to contact the inner wall surface. The gist is that.

[0010]

According to the first aspect of the present invention, when the swash plate rotates with the rotation of the drive shaft, the piston reciprocates in the cylinder bore. At this time, the piston tries to finely rotate and fine rotation restriction member and the housing provided on both sides of the neck of the piston is not contacting the abutment to order, the swash plate periphery and the piston. Therefore, wear and noise due to contact between the swash plate and the piston do not occur.

According to the second aspect of the present invention, in addition to the function of the first aspect, the fine rotation restricting piece is aligned with the inner wall of the housing and extends along the inner wall. Therefore, the housing does not require a structure for fitting with the fine rotation restricting piece.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a swash plate type compressor for a vehicle according to an embodiment of the present invention; FIG.

As shown in FIG. 3, a front housing 2 and a rear housing 3 are connected to the front and rear of the cylinder block 1 by connecting means (not shown). A housing is formed by the cylinder block 1, the front and rear housings 2, 3 and connecting means, etc., which constitute the exterior of the compressor. When the front housing 2 and the rear housing 3 are connected to the cylinder block 1, the crank chamber 2a, the suction chamber 3a, and the discharge chamber 3
b is formed. A cylinder bore 1a is formed in the cylinder block 1 so as to connect the crank chamber 2a, the suction chamber 3a and the discharge chamber 3b in the rear housing 3 to each other.

A drive shaft 4 is rotatably supported by the cylinder block 1 and the front housing 2. In the front housing 2, a rotation support 5 is fixed to the drive shaft 4, and a long hole 5 a is provided in a front end side thereof. Further, a spherical bush 6 is slidably supported on the drive shaft 4, and a swash plate 7 is tilted toward the drive shaft 4 on the bush 6.

A connecting piece 7a is fixed to the front surface of the swash plate 7 (the left side in the figure), and a pin 7b is fixedly attached to the tip of the connecting piece 7a. The pin 7b is engaged with a long hole 5a provided in the rotary support 5, and the swash plate 7 can be tilted by a sliding relationship between the long hole 5a of the rotary support 5 and the pin 7b.

A single-ended piston 8 is accommodated in a cylinder bore 1a formed in the cylinder block 1 so as to be able to reciprocate. A pair of support concave portions 8b are formed inside the neck portion 8a of the single-headed piston 8 in a state where the concave portions face each other.
As shown in FIGS. 2 and 3, a substantially rectangular plate-shaped fine rotation restricting piece 8c is integrally formed on both sides of the neck 8a.
The upper surface 8d of the fine rotation restricting piece 8c is lower than the uppermost portion M of the single-headed piston 8, and when the single-headed piston 8 is housed in the cylinder bore 1a, the cylinder bore 1a
They are formed at positions that come in contact with the inner wall surface of the cylinder block 1 except the inner wall.

As shown in FIG. 3, a hemispherical shoe 9 is interposed between both sides of the swash plate 7 and the support recess 8b of the single-headed piston 8, and the swash plate 7 is rotated. When this occurs, the rotational movement is converted into reciprocating motion of the single-headed piston 8 via the shoe 9, and the single-headed piston 8 moves back and forth in the cylinder bore 1a.

As a result, the refrigerant gas sucked from the suction chamber 3a into the cylinder bore 1a is compressed while the discharge chamber 3b is compressed.
To be discharged to And crankcase 2
The stroke of the single-headed piston 8 changes in accordance with the pressure difference between the pressure in the cylinder head 1a and the suction pressure in the cylinder bore 1a through the single-headed piston 8, and the swash plate angle of the swash plate 7, which affects the compression capacity, changes. The pressure in the crank chamber 2a is controlled by an electromagnetic control valve mechanism 10 in the cylinder block 1.

Next, the operation of the swash plate type compressor formed as described above will be described. When the drive shaft 4 is driven, the swash plate 7 is rotated accordingly. Then, the rotational motion is further converted into a forward and backward motion of the single-headed piston 8 in the cylinder bore 1a. At this time, the single-headed piston 8 is connected to the cylinder bore 1
When you try to clockwise or counter-clockwise direction fine-rotated in the direction in the a. However, the fine rotation restriction member 8c of single-headed piston 8 is to become in a state of contact with the inner wall of the cylinder block 1, single-headed piston 8 is fine rotation even when moving back and forth in the cylinder bore 1a is restricted.

Therefore, the single-headed piston 8 and the outer periphery of the swash plate 7 do not come into contact with each other, so that noise at the time of contact and wear of the swash plate 7 and the piston 8 can be prevented. Further, the fine rotation restricting piece 8 formed integrally with the neck 8a of the single-headed piston 8
Since the upper surface 8d of c is formed at a position lower than the uppermost portion M of the single-headed piston 8, it is not necessary to form a concave groove on the inner wall of the cylinder block 1 as in the related art. As a result, it is not necessary to raise a part of the outer periphery of the cylinder block 1 to adjust the thickness between the outer periphery of the cylinder block 1 and the inner wall of the cylinder bore 1a, so that the outer diameter of the cylinder block 1 can be made much smaller than before. Therefore, the entire swash plate compressor can be reduced in size, and the degree of freedom in designing a vehicle can be increased.

It should be noted that the present invention is not limited to the above embodiment, and may be configured as follows, for example, without departing from the spirit of the invention .

( 1 ) In the above embodiment, the fine rotation restricting piece 8c is formed in a substantially rectangular plate shape, but this shape may be formed by, for example, a rod-shaped protrusion.

[0023]

As described in detail above, according to the first aspect of the present invention, it is possible to suppress an increase in the size of the outer periphery of the housing. According to the invention of claim 2, in addition to the effect of the invention of claim 1, there is no need to form a structure for fitting the fine rotation restricting piece to the inner periphery of the housing, which is simple and strong. The compressor can be excellent in quality.

[Brief description of the drawings]

FIG. 1 is a perspective view of a single-headed piston showing an embodiment embodying the present invention.

FIG. 2 is a front sectional view showing a state in which a single-headed piston is accommodated in a cylinder bore.

FIG. 3 is a side sectional view showing a configuration of a swinging swash plate type compressor.

FIG. 4 is a perspective view of a single-headed piston of a conventional piston.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cylinder block which comprises a housing, 1a ... Cylinder bore, 2 ... Front housing which comprises a housing, 3 ... Rear housing which comprises a housing, 4 ...
Drive shaft, 7: swash plate, 8: single-headed piston as piston, 8a: neck, 9: shoe, 8c: fine rotation restricting piece.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F04B 27/08 F04B 39/00 107

Claims (2)

(57) [Claims] 1. A shoe interposed between both surfaces of a swash plate that rotates integrally with a drive shaft in a housing and a neck of a piston reciprocally disposed in a cylinder bore. In a swash plate type compressor configured to convert a rotary motion of a swash plate into a reciprocating motion of the piston, a piston head that slides the piston in a cylinder bore.
And a single-headed piston consisting of a neck formed continuously with the head
Configure Te, the neck 該片headed piston, anti from said head
A piston structure in a swash plate type compressor provided with a fine rotation restricting piece that extends to both sides from the neck at the opposite end and that can contact the housing. 2. The housing has an inner wall surface facing the neck of the piston, and the fine rotation restricting piece extends along the inner wall surface and is provided so as to be able to contact the inner wall surface. A piston structure in the swash plate compressor according to claim 1.