JPH037582Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a swash plate type compressor, in particular,
The present invention relates to an improvement in the structure of a valve part, and relates to one that is effective for compressing refrigerant in the cooling cycle of an air conditioner for an automobile, for example.

[Conventional technology]

A conventional swash plate type compressor of this type is described in Japanese Patent Application Laid-open No. 173576/1983.

In this swash plate type compressor, as shown in FIG. 3, a suction valve 5 is located at the head of a piston 4 that reciprocates in a cylinder 3 of a cylinder block 2 fitted in a casing 1, and a suction valve 5 is installed behind the piston. A discharge valve 6 is provided at the end of the cylinder 3 in the body of the cylinder block 2 to allow flow only from the inside of the cylinder to the outside. It is provided.

[Problem that the invention attempts to solve]

However, in such a swash plate type compressor, since the cylinder block 2 is fitted into a part of the end plate 7 in order to make the discharge valve 6 face the end of the cylinder 3, the stroke of the piston 4 is limited. There is a problem that the length is shortened by the amount of the fitting distance L, and conversely, the overall length is lengthened by the amount of the fitting distance L.

An object of the present invention is to provide a swash plate compressor whose overall length can be shortened.

[Means for solving problems]

The swash plate compressor according to the present invention is housed in a casing 11 and has a plurality of cylinders 1.
7 are arranged in the circumferential direction with equal phase difference and are bored parallel to the center line.
, a rotating shaft 14 supported on the center line of the cylinder block 16, a swash plate 15 fixed to the rotating shaft 14, and a swash plate 15 slidably fitted into each cylinder 17, 15 and respective pistons 26 linked to each other so as to reciprocate as the pistons rotate, and a suction valve having a suction valve passage 29 and a suction valve body 30 is provided at the head of each piston 26. A discharge valve having a discharge valve passage 23 and a discharge valve body 24 is provided at the end of each cylinder 17 to allow flow only from the rear to the end face of the piston. In the swash plate type compressor, the discharge valve passages 23 of the respective discharge valves are arranged and opened at positions spaced apart from the end face of the cylinder 17 toward the swash plate 15. At the same time, a communication passage 33 is provided in the head of each piston 26 to communicate the discharge valve passage 23 with the end surface of the piston 26. Arranged at a position facing the valve passage 23,
It includes a long groove 34 formed to maintain communication with the discharge valve passage 23 in the stroke range of the piston 26, and a recess 35 formed to have a large opening on the end surface of the piston 26, On the other hand, the surface of the casing 11 facing the piston 26 is characterized by protruding protrusions 36 that respectively fit into the recesses 35 of the communication passages 33 leaving appropriate gaps.

[Effect]

According to the above-mentioned means, since the discharge valve passage 23 is opened at a position away from the end face of the chamber in the cylinder 17, the discharge valve passage 23 is blocked by the head of the piston 26 during the compression stroke of the piston 26. There will be a period during which However, during this period, the refrigerant is guided to the discharge valve passage 23 by a communication passage 33 opened at the head of the piston 26. Since the long groove 35 is formed in the end of the communication passage 33 on the side of the discharge valve passage, and is long in the stroke direction, the period in which the communication passage 33 and the discharge valve passage 23 are blocked from communicating with each other is eliminated.

Furthermore, it is desirable that the volume of the space created by the end face inside the cylinder 17 chamber and the end face of the piston 26 at the final stage of the piston compression stroke is as small as possible from the viewpoint of the compression ratio. It tends to become larger.

However, a recess 35 is formed in the communication passage 33, and a protrusion 36 protruding from the end wall of the cylinder 17 is recessed into the recess 35, so that the volume of the space is suppressed to be small. Therefore, even though the communication passage 33 is provided at the head of the piston 26, the desired compression ratio can be ensured.

On the other hand, the refrigerant inside the cylinder 17 is discharged through the discharge valve passage 23.
It is desirable that the flow passage cross-sectional area of the communication passage 33 be as large as possible when guiding the water. According to the above-described means, when the convex part 36 is detached, the recessed part 35 is opened wide, so that the cross-sectional area of the communication passage 33 is set larger than that in the case where the communication passage 33 is formed thin as a whole. Therefore, the refrigerant is effectively guided to the discharge valve passage 23.

〔Example〕

FIG. 1 is a partially cutaway front view showing a swash plate type compressor which is an embodiment of the present invention, and FIG. 2 is a perspective view of a cylinder block.

In this embodiment, the swash plate type compressor includes a casing 11, and the casing 11 is constructed by a pair of end plates 13, 13 attached to both left and right ends of a main body 12 formed in a substantially cylindrical shape. A shaft 14 rotatably driven by an automobile engine or the like is provided within the casing body 12 and supported by a cylinder block to be described later, and a swash plate 15 is fixed to the center of the shaft 14.

A pair of cylinder blocks 16 as shown in FIG. 2 are inserted into the casing body 12 from the left and right end openings and are fitted so as to butt against each other. The cylinder block 16 is integrally molded into a substantially cylindrical shape, and a plurality of cylinders 17 are bored in the solid portion of the cylinder block 16, arranged in the circumferential direction with equal phase differences and parallel to the center. Long grooves 18 having a generally fan-shaped cross section are provided between adjacent cylinders on the outer circumference of the cylinder block 16 in parallel to the center, and these long grooves 18 cooperate with the inner circumferential surface of the casing body 12 to form communication channels. 19 respectively. Although not shown, each communication path 19 is connected to an output port of this compressor.

A seal ring portion 20 is formed at the opposite end of the cylinder block 16, and this seal ring portion is fitted onto the inner periphery of the casing body 12 with a seal member 21 sandwiched therebetween. Therefore, this seal ring portion 20 serves as a blind plate at one end of each communication path 19. Seal ring part 20
An end plate 13 is brought into contact with the end face of the end plate 13, and a sealing member 22 is sandwiched between the two end plates 20 and 13. Therefore, the length of each cylinder 17 makes maximum use of the entire length of the cylinder block 16.

The cylinder block 16 has a seal ring portion 20.
Discharge valve passages 23, which constitute a discharge valve together with the valve body, are bored in the vicinity and at a position apart from the end face, corresponding to each cylinder 17, so as to communicate between the inside of the cylinder 17 and the communication passage 19. There is. The discharge valve passage 23 is provided with a discharge valve body 24, which is a reed valve or the like made of a plate spring material, and is fixed to the side of the long groove 18 of the cylinder block. This discharge valve is configured to allow flow only from the cylinder 17 to the communication path 19.

A sealing member 25 is sandwiched between the abutting end surfaces of the pair of cylinder blocks 16 to prevent leakage between the cylinder 17 and the communication passage 19. Each cylinder 17 communicates with an input port (not shown) of the compressor at the center of the cylinder block 16.

A piston 26 is slidably fitted into each of the cylinders 7, and the pistons fitted into the pair of abutting cylinders are integrally connected at the rear. The piston 26 is connected to the end face of the swash plate 15 by a ball 27 and a shoe 28, and is configured to reciprocate within the cylinder 17 as the swash plate 15 rotates.

A suction valve passage 29, which together with the valve body constitutes a suction valve, is bored in the head of the piston 26 so as to communicate between the end surface of the piston and the rear part of the piston. A suction valve body 30 made of a lead made of a plate spring material or the like is provided at the opening of the piston end face of the suction valve passage 29 and fastened with a bolt 31 screwed into the end face. This suction valve body 30 is configured to allow flow only from the rear portion of the piston 26 to the end face thereof. Fastening bolt 31 of this suction valve body 30
In order to escape the head of the bolt, an escape hole 32 is provided in the end plate 13 at a location facing the bolt.

A passage 33 is provided inside the head of the piston 26 to communicate the discharge valve passage 23 with an end surface of the piston head. A long groove 34 is provided at the end of the communication passage 33 facing the discharge valve passage 23.
A long groove 34 is cut in the outer circumference of the piston 26 in the stroke direction.
The communication passage 33 is set to maintain communication with the discharge valve passage 23 within a predetermined stroke range.

Further, a recess 35 is formed at the end of the communication passage 33 on the side of the end surface of the piston head so as to open largely at the end surface. On the other hand, a protrusion 36 is screwed onto a bolt 37 and protrudes from a position facing the recess 35 in the end plate 13, so that the protrusion 36 can be inserted into the recess 35 leaving an appropriate gap. It is formed to be slightly smaller than the recess 35.

Next, the action will be explained.

When the piston 26 is moved away from the end plate 13 as the swash plate 15 is rotated by the drive shaft 14, the refrigerant that has been supplied into the cylinder 17 through the cylinder block 16 is disposed on the piston 26. Suction valve passage 29 and suction valve body 30
The air is sucked into the chamber between the end surface of the end plate 13 and the head of the piston 26 in the cylinder 17 through the air.

As the rotation of the swash plate 15 progresses and the piston 26 moves in a direction approaching the end plate 13, the suction valve body 30 is closed and the discharge valve 24 is opened. As a result, the refrigerant sucked into the chamber is compressed by the piston 26 and discharged into the communication path 19 through the communication path 33 and the discharge valve path 23, which are opened at the head of the piston 26.

As the rotation of the swash plate 15 further progresses, the piston 26 moves to the suction stroke, the discharge valve body 24 is closed, the suction valve body 30 is opened, and the refrigerant is sucked in as described above.

In this embodiment, the pistons in each cylinder of both cylinder blocks in the abutting state alternately repeat suction and discharge strokes.

By the way, since the discharge valve passage 23 is opened at a position away from the end face of the chamber of the cylinder 17, there is a period during the compression stroke of the piston 26 in which the discharge valve passage 23 is closed by the head of the piston 26. . Therefore, the refrigerant during this period is guided to the discharge valve passage 23 by a communication passage 33 established at the head of the piston 26. Since the long groove 35 is formed in the end of the communication passage 33 on the side of the discharge valve passageway in the stroke direction, the communication cutoff period between the communication passageway 33 and the discharge valve passageway 23 is eliminated.

Furthermore, it is desirable that the volume of the space created by the end face inside the cylinder 17 chamber and the end face of the piston 26 at the final stage of the piston compression stroke is as small as possible from the viewpoint of the compression ratio. It tends to become larger.

However, in this embodiment, a recess 35 is formed in the communication passage 33, and a protrusion 36 protruding from the end wall of the cylinder 17 is recessed into the recess 35, so that the volume of the space is suppressed to be small. be done. Therefore, even though the communication passage 33 is provided at the head of the piston 26, the desired compression ratio can be ensured.

On the other hand, the refrigerant inside the cylinder 17 is discharged through the discharge valve passage 23.
It is desirable that the flow passage cross-sectional area of the communication passage 33 be as large as possible when guiding the water. In this embodiment, when the convex part 36 is removed, the concave part 35 is opened to a large extent, so that the cross-sectional area of the communication passage 33 becomes large, and the refrigerant is effectively guided to the discharge valve passage 23.

[Effect of idea]

As explained above, according to the present invention, by providing a communication passage in the piston head, all the fluid in the cylinder chamber can be guided to the discharge valve passage, so that the discharge valve passage can be moved away from the end face of the cylinder chamber. The piston can be provided at any position, and the entire length of the cylinder can be effectively used as the stroke of the piston, and the overall length can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing a swash plate compressor according to an embodiment of the present invention, and FIG. 2 is a perspective view of a cylinder block. FIG. 3 is an enlarged partial sectional view showing a conventional example. 11... Casing, 12... Casing body, 13... End plate, 14... Drive shaft,
15... Swash plate, 16... Cylinder block, 17
...Cylinder, 18...Long groove, 19...Connection path,
20... Seal ring part, 21, 22, 25...
Seal member, 23...Discharge valve path, 24...Discharge valve body, 26...Piston, 27...Ball, 28...
...Show, 29...Suction valve path, 30...Suction valve body, 31...Tightening bolt, 32...Escape hole, 33
... Communication passage, 34 ... Long groove, 35 ... Recess, 3
6...Protrusion, 37...Bolt.

Claims (1)

[Claims for Utility Model Registration] A plurality of cylinders 1 installed in a casing 11
7 are arranged in the circumferential direction with equal phase difference and are bored parallel to the center line.
, a rotating shaft 14 supported on the center line of the cylinder block 16, a swash plate 15 fixed to the rotating shaft 14, and a swash plate 15 slidably fitted into each cylinder 17, 15 and each piston 26 linked to reciprocate as the piston rotates, and a suction valve having a suction valve passage 29 and a suction valve body 30 is provided at the head of each piston 26, and the suction valve has a suction valve passage 29 and a suction valve body 30. A discharge valve having a discharge valve passage 23 and a discharge valve body 24 is provided at the end of each cylinder 17 to allow flow only from the rear to the piston end face. In the swash plate type compressor, the discharge valve passages 23 of the respective discharge valves are arranged and opened at positions spaced apart from the end surface of the cylinder 17 toward the swash plate 15. At the same time, a communication passage 33 is provided in the head of each piston 26 to communicate the discharge valve passage 23 with the end surface of the piston 26. Arranged at a position facing the valve passage 23,
It includes a long groove 34 formed to maintain communication with the discharge valve passage 23 in the stroke range of the piston 26, and a recess 35 formed to have a large opening on the end surface of the piston 26, On the other hand, on the surface of the casing 11 facing the piston 26, protrusions 36 are provided to project into the recesses 35 of the communication passages 33, leaving appropriate gaps. Plate type compressor.