JPH04330385A - Swash plate type compressor - Google Patents

Abstract

PURPOSE:To reduce size and weight by forming a piston in a hollow shape in a manner to wrap a suction valve therewith and introducing a feedback refrigerant from a swash plate chamber and leading it out to the interior of a bore. CONSTITUTION:Hollow parts 25a communicating swash plate chambers 4 to the respective head parts of a piston 25 are formed, and suction ports 25b through which the hollow parts 25a are communicated with bores 1a and 2a are formed in a piston head. A valve chest is formed in a manner to surround the opening valve seat of each suction port 25b and floating type suction valves 26 and 27 are loosely mounted. Delivery ports 5b and 6b, through which the bores 1a and 2a are communicated to discharge chambers 11 and 12 by means of delivery valves 30 and 31, the opening of which is limited by retainers 28 and 29, are formed in valve sheets 5 and 6, respectively. A feedback refrigerant introduced in the swash plate chamber 4 is delivered in discharge chambers 11 and 12 through the hollow part 25a of the piston 25, the suction valves 26 and 27, the suction port 25b, the bores 1a and 2a, and the discharge ports 5b and 6b.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a swash plate compressor suitable for use in vehicle air conditioning.

0002

[Prior Art] As a conventional swash plate compressor,
The one described in JP-A-55809 is known. In this swash plate compressor, a pair of cylinder blocks are arranged opposite each other in the front and back, forming a swash plate chamber communicating with the return refrigerant suction port at the joint part, and each cylinder block has a valve plate at both outer ends. It is closed by the front and rear housings. A suction chamber and a discharge chamber are formed in each housing, and the discharge chamber on the rear side communicates with a discharge port that discharges the discharge refrigerant. A drive shaft is inserted into and supported in the common center shaft hole of each cylinder block, and a swash plate fixed to the drive shaft is rotatably housed in the swash plate chamber. In addition, the cylinder block is formed with multiple pairs of front and rear bores that are arranged in parallel around the drive shaft, and a double-headed piston that is moored to the swash plate via a shoe is inserted into each bore so that it can move freely in a straight line. There is. Each valve plate has a suction port that communicates with the suction chamber of each housing via a suction valve between each bore, and a discharge chamber of each housing via a discharge valve between each bore. A discharge port is formed which communicates with the discharge port. A plurality of suction passages are formed on the inner circumferential side of each cylinder block to communicate the swash plate chamber with the suction chamber of each housing, and on the outer circumferential side of each cylinder block, a plurality of suction passages are formed to communicate with the suction chamber of the front housing. A single discharge passage is formed that communicates the chamber with the discharge chamber of the rear housing.

In this swash plate compressor, return refrigerant is introduced into the swash plate chamber from the refrigeration circuit through the suction port, and the return refrigerant in the swash plate chamber is guided to the front and rear suction chambers through each suction passage. Since the piston moves directly within each bore via the swash plate due to the rotation of the drive shaft, the return refrigerant in each suction chamber is sucked into each bore that is in the process of expanding in volume through the suction port. Thereafter, the compressed refrigerant is discharged from each bore whose volume is being reduced through the respective discharge ports into the front and rear discharge chambers. The compressed refrigerant in the front discharge chamber is collected in the rear discharge chamber via the discharge passage, and the compressed refrigerant in the rear discharge chamber is discharged from the discharge port to the refrigeration circuit and circulated again to the refrigeration circuit.

0004

However, in the above general swash plate compressor, a plurality of bores, a swash plate chamber, and a plurality of suction passages are formed in the cylinder block, and the return refrigerant introduced into the swash plate chamber is transferred from the swash plate chamber. After being led to the suction chamber of each housing through each suction passage, the return refrigerant in each suction chamber is sucked into each bore, so the cylinder block is enlarged in diameter by the number of suction passages, and each Each housing has a suction chamber formed therein and is enlarged. At the same time, this swash plate compressor is heavy due to the large cylinder block and housing, and also due to the solid piston.

The problem to be solved by the present invention is to significantly reduce the size and weight while maintaining a predetermined compression efficiency.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the swash plate compressor of the present invention includes a suction valve included in the piston, and introduces return refrigerant from the swash plate chamber into each of the bores. A novel method is adopted in which the piston is formed into a hollow shape in order to be ejected.

[0007]

In the swash plate compressor of the present invention, return refrigerant is introduced into the swash plate chamber from the refrigeration circuit through the suction port, and the return refrigerant in the swash plate chamber is guided into the hollow portion of the piston. Since the piston moves directly within each bore via the swash plate due to rotation of the drive shaft, the return refrigerant within the piston is sucked into each bore via the suction valve included in the piston. Thereafter, the return refrigerant is compressed within each bore and discharged into the front or rear discharge chamber. The compressed refrigerant in the discharge chamber on the rear side or the front side is discharged into the refrigeration circuit from the discharge port.

Therefore, in this swash plate compressor, each bore and the swash plate chamber are formed in the cylinder block, and there is no need to form a suction passage as in the conventional case, so the cylinder block is compressed by the amount of the conventional suction passage. The cylinder block is made smaller. Since the return refrigerant introduced into the swash plate chamber is directly sucked from the swash plate chamber into each bore through the hollow part of the piston, each housing does not require a suction chamber, and each housing can also be made smaller. At the same time, the weight of this swash plate compressor is reduced by the small cylinder block and housing, and the weight is further reduced by the hollow piston.

[0009]

Embodiments Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. In this swash plate compressor, as shown in FIG. 1, a pair of cylinder blocks 1 and 2 are arranged opposite each other in the front and back, and a swash plate chamber 4 that communicates with a return refrigerant suction port 3 is formed at the joint portion. Each cylinder block 1, 2 has its both outer ends closed by a front housing 7 and a rear housing 8 via valve plates 5, 6, respectively. Discharge chambers 11 and 12 are formed in the center of both the front housing 7 and the rear housing 8.

A radial bearing 1 is installed between each cylinder block 1 and 2 in the common center shaft hole of each cylinder block 1 and 2.
4, 15 and the drive shaft 18 via rubber seals 16, 17.
The drive shaft 18 passes through the through hole 5c of the front valve plate 5 and is supported by the front housing 7 via a radial bearing 19 and a shaft sealing device 20. A swash plate 23 is fixed to the drive shaft 18 so as to be rotatable within the swash plate chamber 4, and this swash plate 23 is supported by each cylinder block 1, 2 via thrust bearings 21, 22. Further, each cylinder block 1, 2 is formed with a plurality of pairs of front and rear bores 1a, 2a arranged in parallel around the drive shaft 18, and each bore 1a, 2a has a pair of shoes 24 on a swash plate 23;
A double-headed piston 25, which is moored via a piston 24, is inserted so as to be movable in a linear manner.

The characteristic configuration of this swash plate compressor is as follows:
The piston 25 has a hollow portion 25a formed at each head thereof that communicates with the swash plate chamber 4, and the piston head has an intake port 25b that communicates the hollow portion 25a with the bores 1a and 2a.
is bored therein, and floating type suction valves 26 and 27 are freely installed in a valve chamber surrounding the open valve seat of the suction port 25b.

Each valve plate 5, 6 has a discharge valve 30 whose opening degree is limited by retainers 28, 29 between each bore 1a, 2a.
, 31 are formed to communicate with the discharge chambers 11, 12 through discharge ports 5b, 6b. This swash plate compressor has
Return refrigerant is introduced into the swash plate chamber 4 from a refrigeration circuit (not shown) through the suction port 3, and the return refrigerant in the swash plate chamber 4 is introduced into the piston 2.
5 into the hollow part 25a. The rotation of the drive shaft 18 causes the piston 25 to move through the swash plate 23 to each bore 1a,
2a, the return refrigerant in the hollow part 25a of the piston 25 floats the suction valves 26 and 27 from their valve seats to open the suction port 25b, and enters each bore 1a and 2 in the process of expanding their volume.
It is inhaled into a. After this, the suction valves 26 and 27 are seated on their valve seats, as the pressure within each bore 1a and 2a is increased by the forward movement of the piston 25, and the suction port 25b is closed. The compressed refrigerant is then discharged from the bores 1a, 2a, which are in the process of volume reduction, into the front and rear discharge chambers 11, 12 via the discharge ports 5b, 6b of the valve plates 5, 6, respectively. The compressed refrigerant in the front discharge chamber 11 is collected in the rear discharge chamber 12 through a discharge passage (not shown), and
The compressed refrigerant in 2 is circulated again to the refrigeration circuit from a discharge port (not shown).

As described above, in this swash plate compressor, the cylinder blocks 1 and 2 are formed with the bores 1a and 2a and the swash plate chamber 4, and no suction passage is formed as in the conventional case. The diameter is reduced by the amount of the suction passage, and the cylinder blocks 1 and 2 are made smaller. and,
The return refrigerant introduced into the swash plate chamber 4 is transferred from the swash plate chamber 4 to the piston 2.
Since the air is sucked directly into each of the bores 1a and 2a through the hollow portion 25a of the housing 7 and 8, a suction chamber is not required in each of the housings 7 and 8, and each of the housings 7 and 8 is also miniaturized. At the same time, with this swash plate type compressor, the cylinder blocks 1 and 2 are smaller.
The weight is reduced by the housings 7 and 8, and the weight is further reduced by the hollow piston 25. Therefore, this swash plate compressor can be significantly reduced in size and weight while maintaining a predetermined compression efficiency.

Furthermore, in this swash plate compressor, the piston 2
Since 5 is hollow, the inertial force of the reciprocating movement of the piston 25 is reduced, and vibration can also be reduced. Furthermore, in this swash plate compressor, a hollow piston 25
contains floating type suction valves 26 and 27, and the return refrigerant is introduced from the swash plate chamber 4 and led out into each bore 1a and 2a to form a suction passage, so the bore volume is smaller than that of the conventional one. If it is the same, the return refrigerant can be introduced into the hollow part 25a of the piston 25 more easily than the conventional method in which the return refrigerant is caused to flow over a long distance in a restricted suction passage and then sucked, and the compression efficiency is improved. can be improved. At the same time, in this swash plate compressor, since the suction passage is shorter than the conventional one, the refrigerant gas is less likely to be warmed up before being sucked into the bores 1a and 2a, and low-temperature refrigerant can be compressed. Therefore, in this swash plate compressor, relatively low temperature discharged refrigerant is circulated through the refrigeration circuit, the load on the refrigeration circuit is small, and cooling capacity can be suitably maintained. In fact, when we compared the compression efficiency of this swash plate type compressor and the conventional type mentioned above under the condition that the bore volume and outer diameter dimensions were the same, this swash plate type compressor had a compression rate of about 68% compared to the conventional type. While the efficiency was about 7
A compression efficiency of 1% could be obtained.

In the swash plate compressor of the present invention, as shown in FIG. 2, oil holes 25c may be formed in the piston 25 to communicate the hollow portions 25a with the receiving surfaces of the shoes 24. In this case, mist-like lubricating oil in the return refrigerant introduced into the hollow part 25a is supplied to each shoe 24,
It becomes possible to suitably slide the piston 25 and the shoe 24.

[0016]

As described in detail above, in the swash plate compressor of the present invention, the piston includes a suction valve, and the piston is hollow in order to introduce the return refrigerant from the swash plate chamber and lead it out into each bore. , it is possible to significantly reduce the size and weight while maintaining a predetermined compression capacity.

In addition, in this swash plate compressor, the hollow shape of the piston makes it possible to reduce vibration, and the return refrigerant can be sucked into each bore at an extremely short distance from the swash plate chamber with low resistance. It is also possible to improve compression efficiency and reduce the load on the refrigeration circuit. Therefore, with this swash plate compressor, with extremely suitable mounting characteristics,
A discharged refrigerant having a relatively low temperature is circulated through the refrigeration circuit, so the load on the refrigeration circuit is small, and the cooling capacity can be suitably maintained.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a swash plate compressor according to an embodiment.

FIG. 2 is a sectional view of a main part of a swash plate compressor according to another embodiment.

[Explanation of symbols]

1, 2...Cylinder block 1a,
2a...Bore 3...Suction port
4... Swash plate chambers 11, 12... Discharge chamber
5, 6... Valve plate 7, 8... Housing 18... Drive shaft 23... Swash plate
24...Shoe 25...Piston
25a...Hollow parts 26, 27
…Suction valve

Claims (1)

[Claims] 1. A cylinder block in which a plurality of bores are formed and a swash plate chamber communicating with an inlet, each having a discharge chamber, and both outer ends of the cylinder block are closed through valve plates. a drive shaft inserted into and supported by the central shaft hole of the cylinder block, a swash plate fixed to the drive shaft and rotatably housed in the swash plate chamber, and a shoe mounted on the swash plate. and a double-headed piston that is moored through the piston and moves directly in each of the bores, sucks return refrigerant from the suction port into each of the bores through the swash plate chamber, and compresses refrigerant from within each of the bores. In the swash plate compressor that discharges into each discharge chamber, the piston includes a suction valve and is formed in a hollow shape so as to introduce return refrigerant from the swash plate chamber and lead it out into each of the bores. A swash plate compressor.