JP3082466B2 - Single-head piston type variable displacement 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 single-head piston type variable displacement compressor.

[0002]

2. Description of the Related Art A conventional single-headed piston type compressor is disclosed in Japanese Patent Application Laid-Open No. Sho 60-175783.
This compressor has a cylindrical housing 40 as shown in FIG.
A piston 42 is reciprocally housed in a cylinder bore 41a formed in a cylinder block 41 integrally formed therein. A rotating shaft 44 is rotatably supported by the engine at the center of the cylinder block 41 and the front cover 43. A lug plate 45 is fitted and fixed to the rotating shaft 44 so as to be synchronously rotatable. further,
A rotary swing swash plate 47 is mounted on the rotary shaft 44 via a slider 46 so as to be able to swing back and forth in the front-rear direction. The lug plate 45 and the swash plate 47 are connected to the hinge mechanism 4.
8 are connected. The outer peripheral portion of the rotary swinging swash plate 47 has a piston 4 accommodated in the cylinder bore 41a.
The base 2 is moored via a shoe 49.

In the above-described compressor, when the rotating shaft 44 is rotated, the rotation swinging swash plate 47 is rotated at a predetermined inclination angle via the lug plate 45 and the hinge mechanism 48, so that the piston 42 is moved into the cylinder bore 41a. The refrigerant gas is reciprocated in the suction chamber and is compressed in the cylinder bore 1a and discharged to the discharge chamber.

The displacement of the compressor is adjusted via the piston 42 by the balance between the pressure in the crank chamber 50 acting on the back of the piston 42 and the suction pressure in the cylinder bore 41a acting on the front of the piston 42. This is performed by changing the piston stroke according to the magnitude of the bending moment acting on the swinging swash plate 47.

[0005] An electromagnetic clutch (not shown) is mounted on the rotating shaft 44 of the compressor. When the clutch is turned on, the rotating shaft 44 is rotated by the power of the engine, and the lug plate 45 is rotated. With the rotation swash plate 47
Is rotated to reciprocate the piston 42. To mitigate the shock when starting this compressor,
A coil spring 52 is interposed between the lug plate 45 and the slider 46 so as to bias and hold the rotary swinging swash plate 47 at a minimum inclination angle, that is, at a minimum capacity position.

On the other hand, the center hole 41 of the cylinder block 41
In b, a thrust bearing 53 and a disc spring 54 for urging the rear end face of the rotating shaft 44 to the front side are interposed between the stopper 55 and the thrust bearing 53. When the rotating shaft 44 receives a thrust load F on the rear side by the on operation of the electromagnetic clutch, the lug plate 45 is prevented from moving backward against the pressing force, that is, the top clearance of the piston 42 is reduced. It is reduced so that the piston 42 does not collide with the valve plate 56.

[0007]

In the conventional compressor, the inner end of the rotating shaft 44 is provided with a thrust bearing 53 and a disc spring 5.
4, the lubricating property of the bearing 53 is not a problem because the coolant gas in the crank chamber 50 enters due to the gap between the bearings 51 supporting the rotating shaft 44, but the structure is complicated and the assembly is troublesome. There was a problem that is. Further, since the thrust preload toward the front side largely varies due to a dimensional error of a portion where the disc spring 54 is interposed, there is a problem that it is very difficult to adjust the preload at the time of assembly.

In order to solve this problem, the present applicant first forms an engaging recess at the inner end of the rotating shaft, engages a sphere with the engaging recess, and moves the sphere forward by a coiled spring. We have proposed a support structure for the rotating shaft that pushes the shaft.

This conventional rotating shaft support structure has the advantage that the structure is simple and the manufacture and assembly can be easily performed. However, since the engaging recess of the rotating shaft and the sphere are in sliding contact,
Even if the crank chamber and the housing chamber of the sphere communicate with each other through the gap between the bearings that support the rotating shaft, the housing chamber is a dead end, so there is no gas flow, and the lubricity between the rotating shaft and the sphere is reduced. However, a new problem arises in that the sphere is worn and durability is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art, to simplify the structure and to facilitate the manufacture and assembly, and to provide the engagement recess of the rotating shaft and the slider with the engaging member. It is an object of the present invention to provide a single-headed piston type variable displacement compressor which can improve the lubrication of the sliding portion.

[0011]

According to the first aspect of the present invention,
In order to achieve the above object, in a single-head piston type variable displacement compressor, a recess is formed in a rear end surface of a rotating shaft, a slider is housed in the recess, and the slider is further moved toward the rotating shaft. The coil spring to be pressed is housed in the cylinder block, and the cylinder block communicates with the housing chamber of the slider and the high-pressure chamber through a communication passage, and the clearance of the bearing supporting the rotary shaft, the housing chamber, and the communication passage. A means for forming an air supply passage communicating the high-pressure chamber and the crank chamber is adopted.

According to a second aspect of the present invention, in order to achieve the above object, in a single-head piston type variable displacement compressor, a recess is formed in a rear end surface of the rotating shaft, and a slider is housed in the recess. Further, a coil spring that presses the slider toward the rotating shaft is housed in a cylinder block, and a bearing that supports the rotating shaft by communicating the housing of the sphere and the low-pressure chamber through a communication passage with the cylinder block. Means for forming a bleed passage that connects the crank chamber and the low-pressure chamber by the gap, the accommodation chamber, and the communication passage.

[0013]

According to a first aspect of the present invention, there is provided a bearing for supporting a rotating shaft by communicating a housing of a slider engaged with an engaging recess formed in a rear end surface of the rotating shaft with a high pressure chamber. Since the gap, the accommodating chamber, and the communication passage serve as an air supply passage for guiding the refrigerant gas from the high-pressure chamber to the crank chamber, the sliding portion between the engaging recess of the rotary shaft and the slider has a crankshaft from the high-pressure chamber. Gas is supplied to the chamber for movement. For this reason, the lubricity of the sliding portion is improved.

According to the second aspect of the present invention, the low pressure chamber communicates with the housing chamber of the slider engaged with the engagement recess formed in the rear end face of the rotary shaft to support the rotary shaft. Since the bleed passage for guiding the refrigerant gas from the crank chamber to the low-pressure chamber is formed by the clearance between the bearings and the housing chamber and the communication passage, the sliding portion between the engagement recess of the rotary shaft and the slider is moved from the crank chamber to the sliding portion. Gas moving to the low pressure chamber through the bleed passage is supplied. For this reason, the lubricity of the sliding portion is improved.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention;
An embodiment will be described with reference to FIGS.

As shown in FIG. 1, a front housing 2 is joined and fixed to the front end face of the center housing 1. A rear housing 3 is joined and fixed to a rear end surface of the center housing 1 via a valve plate 4. The center housing 1 has a cylinder bore 1
The cylinder block 1b in which a is formed at a plurality of locations is integrally formed. A rotary shaft 6 is rotatably supported in bearings 7 and 8 in a crank chamber 5 formed in the center housing 1. The cylinder bore 1
The piston 9 is fitted in a. The rotating shaft 6
The lug plate 10 is fitted and fixed to the. Similarly, a slider 11 having a spherical surface is supported on the rotating shaft 6 so as to be able to reciprocate in the front-rear direction. The slider 11 is urged toward the cylinder block 1 b by a coil spring 12. A rotating support 13 is supported by the slider 11 so as to be rotatable along the spherical surface. The rotary support 13 is connected to the lug plate 10 via a hinge mechanism K so as to be swingable in the front-rear direction.

As shown in FIGS. 2 and 3, the hinge mechanism K has a pair of left and right support arms 14, 14 protruding in the front-rear direction near the outer periphery of the lug plate 10, and a pair of support arms 14, 14, respectively. It is composed of connecting pins 15, 15 having engaged spherical portions 15a, 15a, and bearing portions 16, 16 having insertion holes 16a for reciprocatingly inserting rod portions 15b, 15b of the connecting pins 15, 15. ing.

As shown in FIG. 1, a rotary swinging swash plate 17 is fitted and fixed to an outer peripheral portion of the rotary support 13. The rotary swinging swash plate 17 is inserted into a recess 18 formed at the base end of the piston 9 and a pair of front and rear shoes 19, 1 is inserted.
It is moored to the piston 9 via 9.

A suction chamber 21 and a discharge chamber 22 are formed in the rear housing 3 by a partition wall 20. A suction valve plate 23 having a suction valve 23a formed on the front surface of the valve plate 4, and a discharge valve plate 24 having a discharge valve 24a formed on the rear surface of the plate 4. A retainer 2 for regulating the open position of the discharge valve 23a is provided on the rear surface of the discharge valve plate 24.
5 are joined and fixed to the valve plate 4 by bolts 26 and nuts 27.

A horizontal conical engaging recess 6a is formed in the rear end surface of the rotary shaft 6, and a sphere 28 as a slider is accommodated in the recess 6a. Also, the cylinder block 1b
Of the sphere 28 and the bolt 26
A coiled spring 29 is interposed between the head and the head. The spring 29 applies a preload F ₂₉ toward the front side to the rotating shaft 6 via the spherical body 28, and generates a rearward thrust load F by an electromagnetic clutch (not shown) acting on the rotating shaft 6. The movement of the rotating shaft 6 is prevented.

The cylinder block 1b is provided with a communication passage 30 for connecting the housing chamber 1d for housing the spherical body 28 and the cylinder bore 1a. This communication passage 3
One end of 0 is communicated with a discharge hole 4 b formed in the valve plate 4 by cutting out a part of the suction valve plate 23. An air supply passage 31 that connects the inside of the cylinder bore 1a and the crank chamber 5 is formed by the communication passage 30, the housing chamber 1d, the gap g between the bearing 8, and the like. A throttle 30a is formed in the middle of the communication passage 30 as shown in FIG.
An appropriate amount of refrigerant gas is supplied to the crank chamber 5 from the internal compression chamber. During the suction stroke of the piston 9, the gas in the suction chamber 21 is drawn into the bore 1a from the suction hole 4a formed in the valve plate 4, but the throttle 30a
Through the air supply passage 31 from the crank chamber 5
No gas flows into the interior.

Further, a capacity control valve 32 is provided in the rear housing 3. A bleed passage 33 communicating from the crank chamber 5 to the suction chamber 21 by the capacity control valve 32.
(See FIG. 4). Then, the stroke of the piston 9 is changed by adjusting the differential pressure between the crank chamber pressure acting before and after the piston 9 and the suction chamber pressure,
By controlling the tilt angle of the rotary swing swash plate 17, the discharge capacity is adjusted.

Next, the operation of the variable displacement compressor configured as described above will be described. When the compressor is stopped, the rotary swash plate 17 is moved rearward by the spring 12 together with the slider 11 and the rotary support 13 as shown by a two-dot chain line in FIG. 1, and the tilt angle of the rotary swash plate 17 is minimized. The minimum capacity is available. When an electromagnetic clutch (not shown) is turned on in this state, the rotating shaft 6 is rotated by the power of the engine. At this time, the rotating shaft 6 receives a rearward thrust load F by an electromagnetic clutch (not shown). This load F is applied to the rotation shaft 6 to the front side by the coil spring 29.
Since pre smaller than heavy F ₂₉ granted to, does not like the rotating shaft 6 and the lug plate 10 is moved rearward. Therefore, no vibration or noise is generated, and the top clearance of the piston 9 is not reduced.

The rotation of the rotary shaft 6 causes the lug plate 1
The rotation support 13 and the swash plate 17 are rotated in the minimum tilt state via the support arm 14, the connecting pin 15, and the bearing portion 16. As a result, the piston 9 is moved to the cylinder bore 1a.
The refrigerant gas is reciprocated inside, and compresses the refrigerant gas drawn into the cylinder bore 1 a from the suction chamber 21, and then discharges it to the discharge chamber 22.

When the compressor is started, the bleed passage 33 is opened by the capacity control valve 32 and the rise in the pressure in the crank chamber 5 is suppressed, so that the crank chamber pressure and the suction pressure acting on the back and front of the pin strike 9 are reduced. Is small, the stroke of the piston 9 increases, and the compression capacity increases.

In the compression stroke of the piston 9, the refrigerant gas compressed in the cylinder bore 1 a is led to the crank chamber 5 through the air supply passage 31. At this time, the gas is a sphere 2
8, the sliding surfaces of the sphere 28 and the engaging recess 6a are reliably lubricated by the lubricating oil contained in the gas.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, in the above-described compressor, the capacity control valve 34 is provided in the middle of the passage 31A without passing the air supply passage 31A communicating the discharge chamber 22 and the crank chamber 5 with the housing chamber 1d of the sphere 28. Intervening. A bleed passage 33 communicating the crank chamber 5 and the suction chamber 21 passes through the housing chamber 1d of the sphere 28. The bleed passage 33 is provided with a throttle 33a.
Is provided.

Accordingly, the sliding portion between the spherical body 28 housed in the housing chamber 1d and the engaging recess 6a is lubricated by the refrigerant gas flowing from the crank chamber 5 to the suction chamber 21 through the air extraction passage 33 by the bleed passage 33. can do.

The present invention is not limited to the above embodiment, but can be embodied as follows. (1) In the above embodiment, the sphere 28 is used as the slider, but this shape is changed to, for example, a conical shape, a hemispherical shape, or the like.

(2) Although not shown, a spring receiver is interposed between the coil spring 29 and the sphere 28.

[0031]

As described above in detail, according to the present invention, the slider is housed in the recess at the rear end face of the rotating shaft, and the coil spring for pressing the slider toward the rotating shaft is housed in the cylinder block. The cylinder block communicates the housing chamber of the slider with the high-pressure chamber or the low-pressure chamber through a communication path to support a rotating shaft. The housing chamber and the communication path provide a high-pressure chamber or a low-pressure chamber and a crank. Since the air supply passage or bleed passage communicating the chamber is formed, the structure is simple, manufacturing and assembly can be easily performed, and lubrication of the sliding portion between the engaging recess of the rotating shaft and the slider is achieved. There is an effect that the property can be improved.

[Brief description of the drawings]

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

FIG. 2 is a plan sectional view showing the vicinity of a hinge mechanism.

FIG. 3 is a vertical cross-sectional view near a hinge mechanism.

FIG. 4 is a circuit diagram showing a relationship between a cylinder bore, a crank chamber, and a suction chamber.

FIG. 5 is a circuit diagram showing a relationship between a discharge chamber, a crank chamber, and a suction chamber according to a second embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a conventional compressor.

[Explanation of symbols]

1 center housing, 1a cylinder bore, 1b cylinder block, 1d accommodation room, 2 front housing, 3 rear housing, 5 crankcase, 6 rotating shafts,
6a recess, 9 piston, 10 lug plate, 11
Slider, 13 rotating support, 14 support arm,
15 connecting pin, 16 bearing, 17 rotation swash plate, 2
1 suction chamber as low pressure chamber, 22 discharge chamber as high pressure chamber, 28 sphere as slider, 29 coil spring, 3
0 communication passage, 31 air supply passage, 33 bleed passage, K hinge mechanism.

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

Claims (2)

(57) [Claims] 1. A cylinder block in which a plurality of cylinder bores for accommodating a single-headed piston are formed in a housing in parallel with each other, and a crank chamber is provided in one of the housings to support a rotating shaft. A rotary support is fitted and fixed, and a rotary swing swash plate is mounted on the rotary support via a hinge mechanism so as to be capable of reciprocating swing in the front-rear direction. The plate is moved back and forth to reciprocate the single-headed piston in the cylinder bore, so that the refrigerant gas sucked from the suction chamber is compressed in the cylinder bore and discharged to the discharge chamber, and a crank chamber acting on the back of the piston By changing the reciprocating stroke of the piston by the differential pressure between the pressure and the suction pressure acting on the front face, and changing the inclination angle of the rotary swing swash plate,
In a single-headed piston type variable displacement compressor in which a discharge capacity is adjusted, a recess is formed in a rear end surface of the rotating shaft, a slider is housed in the recess, and the slider is further rotated by a rotating shaft. A coil spring that presses toward the side is accommodated in a cylinder block, and the accommodation space of the slider and the high-pressure chamber communicate with each other through a communication passage in the cylinder block, and a clearance of a bearing that supports a rotating shaft, the accommodation chamber, and the communication space. A single-head piston type variable displacement compressor in which an air supply passage connecting the high pressure chamber and the crank chamber is formed by a passage. 2. A cylinder block in which a plurality of cylinder bores for accommodating a single-headed piston are formed in a housing in parallel with each other, and a crank chamber is provided in one of the housings to support a rotating shaft. A rotary support is fitted and fixed, and a rotary swing swash plate is mounted on the rotary support via a hinge mechanism so as to be capable of reciprocating swing in the front-rear direction. The plate is moved back and forth to reciprocate the single-headed piston in the cylinder bore, so that the refrigerant gas sucked from the suction chamber is compressed in the cylinder bore and discharged to the discharge chamber, and a crank chamber acting on the back of the piston By changing the reciprocating stroke of the piston by the differential pressure between the pressure and the suction pressure acting on the front face, and changing the inclination angle of the rotary swing swash plate,
In a single-headed piston type variable displacement compressor in which a discharge capacity is adjusted, a recess is formed in a rear end surface of the rotating shaft, a slider is housed in the recess, and the slider is further rotated by a rotating shaft. A coil spring that presses to the side is accommodated in a cylinder block, and the cylinder block communicates with the housing chamber of the sphere and the low-pressure chamber through a communication passage, and a gap between bearings that supports a rotating shaft, an accommodation chamber, and the communication passage. A single-headed piston variable displacement compressor that has a bleed passage that connects the crank chamber and the low-pressure chamber.