JP3111696B2 - Refrigerant gas suction mechanism in piston type 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 refrigerant gas suction mechanism in a piston type compressor.

[0002]

2. Description of the Related Art Generally, an oscillating swash plate type piston compressor has a cylinder block in which a plurality of cylinder bores for accommodating pistons are formed in parallel with each other, and a crank chamber is formed by being joined to a front end surface of the cylinder block. The vehicle includes a front housing and a rear housing joined to a rear end surface of the cylinder block to define a suction chamber and a discharge chamber. Further, the compressor reciprocates the piston in the cylinder bore through a drive mechanism having a swinging swash plate provided in a crank chamber by rotation of a rotation shaft supported in a center hole of the cylinder block and the front housing. Thus, the refrigerant gas sucked from the suction chamber is compressed and discharged to the discharge chamber. More specifically, between the cylinder block and the rear housing, a valve plate penetrating the suction hole and the discharge hole,
A suction plate having a suction valve for opening and closing the suction hole is interposed on the cylinder bore side of the plate, and a discharge plate having a discharge valve for opening and closing the discharge hole is interposed on the rear housing side of the valve plate. When the piston is in the suction stroke, the suction valve of the suction plate is opened, and the refrigerant gas in the suction chamber is sucked from the suction hole of the valve plate into the working chamber for performing suction and compression in the cylinder bore. When the piston enters the compression stroke, the suction valve closes the suction hole, and when the pressure in the working chamber becomes equal to or higher than a predetermined pressure,
The discharge valve of the discharge plate is opened, and the compressed refrigerant gas in the working chamber is discharged from the discharge hole of the valve plate into the discharge chamber.

[0003]

In the above-mentioned piston type compressor, lubricating oil is mixed in the refrigerant gas, and the oil adheres to the gap between the contact portion between the flat suction valve and the valve plate. Therefore, when the suction valve is elastically deformed against its own elasticity to open the suction hole at the beginning of the suction stroke, the suction force of the oil makes it difficult for the suction valve to separate from the contact surface of the valve plate. Responsiveness of the inhalation operation deteriorates. Further, there is a problem that the suction pressure of the working chamber in each cylinder bore varies, which causes a power loss of the compressor.

In order to solve the above problems, the present applicant has proposed a novel refrigerant gas suction mechanism for a compressor different from the prior art. (See, for example, Japanese Patent Application No. Hei 4-16776.) In this suction mechanism, a valve housing chamber communicating with the suction chamber is provided at the center of the cylinder block and the rear housing. The working chambers are communicated with each other by conducting paths formed in the cylinder block. Further, a rotary valve that is rotated in synchronization with the reciprocating motion of the piston is accommodated in the valve accommodating chamber, and a suction passage that is always in communication with the suction chamber is formed in the center of the rotary valve. The outer peripheral surface of the rotary valve is provided with a suction guide groove in the circumferential direction that communicates with the conduction path only during the suction stroke and communicates with the suction passage.

Therefore, when the piston is in the suction stroke due to the rotation of the rotating shaft, the refrigerant gas is sucked from the suction chamber into the working chamber via the gas suction passage of the rotary valve, the suction guide groove, and the conduction path formed in the cylinder block. Therefore, the suction operation of the refrigerant gas is smoothly performed, and the above-described reduction in the responsiveness of the operation of the flat suction valve and the power loss can be solved.

However, in the above refrigerant gas suction mechanism, a suction chamber is formed at the center of the rear housing in correspondence with the rotary valve, and a discharge chamber is formed at the outer periphery thereof.
A new problem arises in that it is not easy to form a bleed passage for guiding the gas blown into the crank chamber through the gap between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder bore toward the suction chamber. That is, when the suction chamber is formed on the outer peripheral side of the rear housing as in the related art, the processing can be easily performed simply by forming a straight bleed passage in the cylinder block and the valve plate. However, when the suction chamber is located at the center of the rear housing, the bleed passage must also be formed in the partition in the rear housing that separates the suction chamber and the discharge chamber, which makes the processing troublesome. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to simply form a bleed passage for guiding gas from a crank chamber to a low pressure chamber such as a suction chamber. It is an object of the present invention to provide a refrigerant gas suction mechanism in a piston type compressor that can perform the above.

[0008]

According to the present invention, in order to achieve the above object, in a piston type compressor, a valve accommodating chamber communicating with the suction chamber is provided in a housing and / or a cylinder block forming the suction chamber. The valve accommodating chamber communicates with the working chambers of the respective cylinder bores through respective conducting paths, and the valve accommodating chamber accommodates a rotary valve that is rotated in synchronization with the reciprocating motion of the piston. In addition to forming a suction passage that constantly communicates with the suction chamber, a suction guide groove that communicates with the working chamber during a suction stroke via a conduction path is formed in an outer peripheral surface of the rotary valve in a circumferential direction of the rotary valve. The rotary valve has a means for forming a bleed passage for guiding the refrigerant gas from the crank chamber to the low-pressure chamber.

[0009]

In the present invention, since the bleed passage is formed in the rotary valve, the refrigerant gas blow-by from the compression chamber in the cylinder bore into the crank chamber during the compression operation is guided to the low pressure chamber through the bleed passage formed in the rotary valve.

According to the present invention, since the bleed passage for communicating the clearance of the bearing with the low pressure chamber side such as the suction chamber may be formed in the rotary valve, the length thereof is shorter than that formed in the cylinder block. Becomes easier. Further, a curved bleed passage is easily formed in the rotary valve alone, and the processing operation can be performed very easily from this point.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in an oscillating swash plate type variable displacement compressor will be described with reference to FIGS.

A front housing 2 is joined and fixed to a front end surface of the cylinder block 1, and a crank chamber 3 is formed therein. A rear housing 4 is joined and fixed to the rear end surface of the cylinder block 1 via a valve plate 5, a discharge plate 6, and a retainer plate 7. In the rear housing 4, a suction chamber 8 is formed at the center and a discharge chamber 9 is formed at the outer periphery by a partition wall 4a formed inside. The valve plate 5 has a discharge hole 5a formed therein.
Is formed with a discharge valve 6a corresponding to the discharge hole 5a,
Further, a retainer 7a for regulating the open position of the discharge valve 6a is formed on the retainer plate 7.

A rotary shaft 10 is mounted on the cylinder block 1 and the front housing 2 by radial bearings 11,1.
2 and is rotatably supported by external power.
A rotary support 13 is fitted and fixed on the rotary shaft 10 so as to be located in the crank chamber 3. A thrust bearing 14 is interposed between the rotary support 13 and the front housing 2. Further, the rotating support 1
A long hole 13b is formed in the arm portion 13a protruding from the outer periphery of 3, and a rotary swash plate 16 is connected to the long hole 13b via a connecting pin 15 so as to be tiltable in the front-rear direction. A swinging swash plate 17 is rotatably supported on a boss 16 a of the rotating swash plate 16. A pin 19 engages with a sleeve 18 fitted on the rotating shaft 10 so as to reciprocate.
Boss portion 16a is rotatably connected. Further, the swing swash plate 17 is prevented from rotating by a guide rod 20 penetrating and fixed to the cylinder block 1 and the front housing 2, and is allowed to tilt in the front-rear direction.

Pistons 21 are respectively accommodated in cylinder bores 1 a formed at a plurality of positions (five in this embodiment) with respect to the cylinder block 1 in parallel with the rotation shaft 10. Are connected to the swinging swash plate 17 respectively. A spring receiver 23 is mounted on the rotating shaft 10, and a coiled spring 24 is interposed between the spring receiver 23 and the sleeve 18, and the inclination angle of the swash plate 17 always increases, The compression capacity is urged to increase. In this embodiment, a drive mechanism for the piston 21 is constituted by the rotary support 13, the rotary swash plate 16, the swinging swash plate 17, and the like.

The center hole 1b of the cylinder block 1, the center hole 5b of the valve plate 5, the center hole 6b of the discharge plate 6, the center hole 7b of the retainer plate 7, and the inner peripheral surface 4b of the partition 4a of the rear housing 4. A cylindrical valve storage chamber 25 communicating with the suction chamber 8 is formed. The valve chamber 25 and the working chamber 30 in each of the cylinder bores 1a are connected to each other by a plurality of conducting paths 1c formed in the cylinder block 1.
A cylindrical rotary valve 26 for sucking refrigerant gas is rotatably stored in the valve storage chamber 25. The engagement hole 2 formed in the front end face of the rotary valve 26
6a has an engagement projection 10a formed on the rear end face of the rotating shaft 10.
Are fitted, and are connected to the rotating shaft 10 by a key 27 so as to be able to rotate synchronously. The rear end surface of the rotary valve 26 is restricted in position so that it cannot move rearward by a step 4c formed on the inner peripheral surface of the partition wall 4a.

A suction passage 28 communicating with the suction chamber 8 is formed at an axial center of the rotary valve 26, and an outer peripheral surface thereof is always in communication with an inner end of the suction passage 28.
A suction guide groove 29 is formed which can communicate with the plurality of conducting paths 1c in the suction stroke. Then, the rotating shaft 10 is rotated, and the swinging swash plate 17 is swung back and forth through the rotating support 13, the connecting pin 15 and the rotating swash plate 16 in a state where the rotation is prevented, and the piston rod 22 is moved. The plurality of pistons 21 are sequentially reciprocated at different timings. Then, when the rotary valve 26 is rotated by the rotating shaft 10 and the piston 21 shifts to the suction stroke, the front end face 31 of the suction guide groove 29 is formed in the cylinder block 1 with respect to the valve rotation direction in FIG. 1c in the opening direction. As a result, the suction passage 8, the guide groove 29, and the conduction passage 1 of the rotary valve 26 extend from the suction chamber 8.
The refrigerant gas is sucked into the working chamber 30 in the cylinder bore 1a through c.

At the end of the suction stroke, the rear end face 32 of the suction guide groove 29 in the direction of rotation of the valve is
c in the direction in which it closes the working chamber 30 in the cylinder bore.
The suction of the refrigerant gas into the interior is stopped. Furthermore, the rotating shaft 1
When the piston 21 is shifted to the discharge stroke by rotating the rotary valve 26 and the rotary valve 26, the conduction path 1c is kept closed by the outer peripheral surface of the rotary valve 26. Then, the refrigerant gas compressed in the working chamber 30 is discharged to the discharge chamber 9 by opening the discharge valve 6a from a discharge hole 5a formed in the valve plate 5.

Next, the essential part of the present invention will be described. In the rotary valve 26, a bleed passage 33 is formed linearly from the front end surface to the inner wall surface of the suction guide groove 29. The crank chamber 3 and the suction guide groove 29 are communicated with each other by a gap g between the bleed passage 33 and the bearing 12 supporting the rotary shaft 10.
The gas blow-by into the crank chamber 3 from the working chamber 30 in the cylinder bore 1a flows from the crank chamber 3 to the gap g.
And it is guided into the suction guide groove 29 through the bleed passage 33.

As shown in FIG.
Further, an air supply passage 34 that connects the discharge chamber 9 and the crank chamber 3 is formed in the valve plate 5. This air supply passage 3
In the middle of 4, an external capacity control valve 35 is interposed. When the bleed passage 34 is opened by the control valve 35, high-pressure gas flows from the discharge chamber 9 through the supply passage 34 to the crank chamber 3.
Supplied within. As a result, the differential pressure between the crank chamber pressure and the suction pressure acting on the back surface and the working surface of the piston 21 increases, and the stroke of the piston 21 decreases, and the swing swash plate 17 about the connecting pin 15 The discharge capacity is reduced by changing the inclination angle. A pressure control valve (not shown) that is opened and closed by internal pressure may be used as the control valve 35.

In the above embodiment, the rotary valve 2
6, a linear bleed passage 33 that connects the accommodation chamber of the bearing 12 and the suction guide groove 29 is formed. Therefore, the length of the bleed passage 33 is extremely short as compared with the case where the cylinder block 1 is formed. Very easy to do.

Since the blow-by gas is introduced into the suction guide groove 29 through the gap g between the bearings 12, the bearing 12 can be lubricated by mist-like oil contained in the gas.

Next, another embodiment of the present invention will be described with reference to FIGS. In this embodiment, one end opening 41a of the bleed passage 41 opens to the gap g side of the bearing 12 and the other end opening 41
b is formed so as to be located at a predetermined position on the outer peripheral surface of the rotary valve 26, that is, immediately after the rear end surface 32 of the suction guide groove 29. When the rotation of the rotary valve 26 causes the opening 41b of the bleed passage 41 to temporarily communicate with the working chamber 30 in the cylinder bore 1a immediately after the end of the suction stroke through the conduction path 1c, the gas in the crank chamber 3 is removed from the working chamber 30.
To lead to.

In this embodiment, since the working chamber 30 immediately after the end of the suction stroke is a closed space, the refrigerant gas blow-by to the crank chamber 3 can be supplied to the working chamber 30 again, and the blow-by gas can be recovered. Along with
Since the blow-by gas is not returned to the suction chamber 8 or the suction guide groove 29, even if the amount of gas supplied from the discharge chamber 9 to the crank chamber 3 through the air supply passage 34 is reduced, the crank chamber pressure can be increased. The volume efficiency does not decrease because the chamber pressure is increased.

Further, the rotary valve 26 can be easily machined even if it is a bent bleed passage 41. The present invention is not limited to the above embodiment, but can be embodied as follows.

(1) As shown in FIG.
3 and 41 are formed in a groove shape on the outer periphery of the rotary valve 26. (2) The valve chamber 25 is formed only on the cylinder block 1 side or only on the rear housing 4 side.

(3) The present invention is embodied in a fixed displacement piston type compressor.

[0027]

As described above in detail, according to the present invention, the rotary valve is provided with a bleed passage for guiding the refrigerant gas from the crank chamber to the low-pressure chamber, so that the gas flows from the crank chamber to the low-pressure chamber such as the suction chamber. There is an effect that formation of a bleed passage for guiding the air can be easily performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment in which the present invention is embodied in an oscillating swash plate type variable displacement compressor.

FIG. 2 is a perspective view of a rotary valve.

FIG. 3 is a cross-sectional view showing a housed state of a rotary valve.

FIG. 4 is a perspective view of a rotary valve showing another embodiment of the present invention.

FIG. 5 is a cross-sectional view showing an assembly structure of the rotary valve according to the embodiment of FIG. 4;

FIG. 6 is a perspective view of a rotary valve showing another embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 cylinder block, 1a cylinder bore, 1c conduction path, 2 front housing, 3 crankcase, 4
Rear housing, 4a partition, 5 valve plate, 8
Suction chamber as low pressure chamber, 9 discharge chamber, 10 rotating shaft,
Reference Signs List 13 rotary support member forming drive mechanism, 16 rotating swash plate forming drive mechanism, 17 swinging swash plate forming drive mechanism, 21 piston, 25 valve housing chamber, 26 rotary valve, 28 suction passage, 29 suction guide Groove, 30
Working chamber, 31, 32 End face, 33, 41 Bleed passage.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeyuki Hidaka 2-1-1, Toyota-cho, Kariya-shi, Aichi Pref. Inside Toyota Industries Corporation (58) Field surveyed (Int. Cl. ⁷ , DB name) F04B 27 / 08 F04B 27/14

Claims (1)

(57) [Claims] A cylinder block having a plurality of cylinder bores accommodating a piston; a plurality of housings joined to the cylinder block to form a suction chamber, a discharge chamber, and a crank chamber; Piston type compression configured to compress the refrigerant gas sucked from the suction chamber and discharge it to the discharge chamber by reciprocating the piston in the cylinder bore through the drive mechanism by the rotation of the rotation shaft supported by the housing. In a machine, a valve accommodating chamber communicating with the suction chamber is provided in a housing and / or a cylinder block forming the suction chamber,
The valve accommodating chamber and the working chamber of each of the cylinder bores communicate with each other by a conduction path, and the valve accommodating chamber accommodates a rotary valve that is rotated in synchronization with the reciprocating motion of the piston. In addition to forming a suction passage that constantly communicates with the suction chamber, a suction guide groove that communicates with the working chamber during a suction stroke through a conduction path is formed in the outer peripheral surface of the rotary valve in a circumferential direction of the rotary valve. A refrigerant gas suction mechanism in a piston type compressor in which a rotary valve has a bleed passage for guiding refrigerant gas from a crank chamber to a low pressure chamber.