JP2713759B2 - Variable displacement swash plate compressor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a variable displacement swash plate type compressor having a double-headed piston.

2. Description of the Related Art A variable displacement swash plate type compressor having a cooling efficiency of a double-headed piston type swash plate type compressor is disclosed in Japanese Patent Application Laid-Open No. 58-166272. In this compressor, a swash plate is supported so as to be rotatable integrally with the rotating shaft and swingable back and forth, and the inclination angle of the swash plate is controlled based on suction pressure information reflecting a cooling load. ing. However, since the swing center of the swash plate is set at a fixed position on the rotating shaft, the top dead center of the compression stroke of the double-headed piston fluctuates according to the inclination angle of the swash plate in both the front and rear compression chambers. Substantial compression and discharge cannot be performed in the compression operation region on the small capacity side where the inclination angle is close to zero.

A variable capacity swash plate type compressor with improved disadvantages is disclosed in
63-147977. In this compressor, the center of swing of the swash plate is set at the radial position of the rotation shaft corresponding to the cylinder bore of the cylinder block that houses the double-headed piston, and the position of the rotation center of the swash plate is variable. Therefore, the top dead center of the compression stroke in the cylinder bore on one side of the double-headed piston is defined at a fixed position, and substantial compression and discharge are performed even in the compression operation region on the small-capacity side where the swash plate tilt angle is close to zero.

The swash plate tilt angle is controlled by the pressure in the front and rear cylinder bores and the swash plate swinging power and the pressure in the control pressure chamber through a swash plate and a sliding control body that changes the volume of the control pressure chamber that is connected to the discharge compression area or the suction pressure area. It is controlled by opposition to pressure, and the sliding control body is slidably supported on the rotating shaft. The acting force applied to the rotating shaft by the swash plate that swings due to the pressure is received by the guide hole on the rotating shaft through the guide pin on the swash plate, and the swash plate tilt angle is determined by the guide relationship between the guide pin and the guide hole. It is controlled. In this apparatus, the swash plate is supported by a spherical support provided at an end of a spool provided movably along the axis of the rotating shaft with movement of the slide control body.

In addition, the swash plate is movably and rotatably supported along the rotation axis in accordance with the movement of the sliding control body. There is also a configuration that performs

[Problem to be Solved by the Invention] In the conventional device, the swash plate has a swash plate main body and a rotational force transmitting portion projecting from the swash plate for transmitting the rotational driving force of the rotating shaft to the swash plate. And had a complicated shape. For this reason, there is a problem that it is difficult to process the spherical portion corresponding to the spherical support portion and to enhance the processing accuracy of the sliding surface with the shoe. Further, when the swash plate is supported on the guide bush via the pin, the pin must be mounted inside the swash plate from the insertion hole side of the guide bush into which the rotating shaft is inserted. There is a disadvantage that there is. Further, in general, the swash plate is formed of an iron-based material in terms of securing the strength of the rotational force transmitting portion and cost, but since the shoe is also made of an iron-based material such as bearing steel, the swash plate is not used. Sliding properties with the swash plate are poor, and there is also a problem that a problem such as seizure occurs when lubrication of the sliding portion is poor or when a large load is applied.

The present invention has been made in view of the above-described problems, and an object of the present invention is to facilitate the processing of a swash plate, improve the processing accuracy of a portion such as a sliding surface with a shoe, and improve the swash plate. Variable displacement swash plate compressor that can prevent the occurrence of problems such as seizure even when the sliding part has poor lubrication or high load load, and can improve the workability during assembly. Is to provide.

[Means for Solving the Problems] In order to achieve the above object, according to the present invention, a rotary shaft is rotatably housed and supported in a cylinder block which houses a double-headed piston in a reciprocating manner. The swash plate that drives the double-headed piston reciprocally is supported so that it cannot rotate relatively and swings back and forth around its peripheral edge.The swing center position is set near the rear cylinder bore, and the swing caused by rotation of the rotating shaft is set. In a variable displacement swash plate type compressor in which a reciprocating region of the double-headed piston is set on a rotation region of a moving center, and a piston stroke is changed by changing a tilt angle of the swash plate to adjust a capacity, A swash plate main body that engages with a shoe that transmits rotational swinging motion to the double-headed piston as a reciprocating motion, and is connected via a guide pin to a connecting portion provided on the rotating shaft; The rotating force transmitting portion was formed separately, and the two were fitted and fixed to form a swash plate, and the sliding portion of the swash plate body with the shoe was formed of a copper-based bearing alloy.

[Operation] With the above configuration, in the swash plate compressor of the present invention,
Even if the entire swash plate has a complicated shape, the shape of each individual swash plate becomes simple and processing becomes easy, and it becomes easy to increase the processing accuracy of a portion such as a sliding surface with a shoe. The copper-based bearing alloy used for the material of the sliding part with the shoe has good compatibility with the iron-based material such as bearing steel used as the material of the shoe. Even when a load is applied, sliding with the shoe is performed smoothly. When the swash plate is supported by the guide bush via the pin, the pin is inserted into the guide bush from outside the torque transmitting portion, and then the swash plate body is fitted to the torque transmitting portion. By fixing, the swash plate is assembled to the guide bush.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG.
The front housing 2 and the rear housing 3 are joined and fixed to both front and rear end surfaces of the front housing 2. A swash plate chamber 4 is formed in the cylinder block 1, and a plurality of sets (five in this embodiment) of cylinder bores 5a and 5b are formed on the front side and the rear side of the swash plate chamber 4 so as to face each other. The double-headed piston 6 is accommodated in the reciprocating motions 5a and 5b. Front housing 2 and cylinder block 1
The rotary shaft 7 is rotatably supported via a front shaft portion 7a, and a rear shaft portion 7b is connected and fixed to the inner end side of the front shaft portion 7a via connecting bodies 8, 9 as connecting portions. In addition, guide holes 8a, 9a are formed in the coupling bodies 8, 9. Rear shaft 7b
A guide bush 10 is slidably fitted to the shaft, and a pressing spring 11 is interposed between the tip of the rear shaft portion 7b and the inner end of the guide bush 10.

A pair of shaft pins 12 project from the base end of the guide bush 10 projecting into the swash plate chamber 4 in a state orthogonal to the rear shaft portion 7b.
A swash plate 13 is rotatably supported on the guide bush 10 via a shaft pin 12. The swash plate 13 is a shoe 14 for transmitting the rotational swinging motion to the double-headed piston 6 as a reciprocating motion.
A swash plate main body 15 that engages with a connecting body provided on the rotating shaft 7
A torque transmitting portion 17 connected to the guides 8 and 9 via a guide pin 16 is formed separately. Swash plate body 15 is a shoe
The sliding part 15a other than the sliding part 15a is formed of an iron-based material, and the sliding part 15a
Is formed of a copper-based bearing alloy. The sliding part 15a is made by sintering and spraying a copper bearing alloy such as JIS LBC6 on the surface of the iron base material.
It is formed by joining or the like.

The rotational force transmitting portion 17 is entirely formed of an iron-based material, and has an annular fitting protrusion 17a having an outer diameter substantially the same as the fitting hole 15b formed in the swash plate body 15, and a fitting protrusion 17a. And a fitting piece 17b formed so as to protrude to the opposite side, and the fitting projection 17a is fitted into the fitting hole 15b of the swash plate body 15 to form the swash plate 13. ing. The shaft pin 12 is fitted into a pair of through holes 18 formed in the fitting projection 17a. Mating piece
A fitting hole 17c is formed in 17b, and as shown in FIG. 2, a fitting piece 17b is inserted between the two connecting members 8, 9, and
The guide pin 16 penetrating through the fitting hole 17c is communicated with the guide holes 8a, 9a of the linking bodies 8, 9 in a state of being fitted thereto, whereby the swash plate 13 rotates together with the rotary shaft 7 in the swash plate chamber 4. .

The rotating shaft 7, the swash plate 13, and the guide bush 10 are connected to each other with a guide relationship between the guide pin 16 and the guide holes 8a, 9a and a rotatable relationship of the swash plate 13 with respect to the guide bush 10. Thus, the swash plate 13 can swing with the sliding of the guide bush 10, and the center of swing C is set to the swash plate.
13 are set on the peripheral side. Each double-headed piston 6 and swash plate
13 is engaged via a shoe 14 and the double-headed piston 6
Reciprocate back and forth with the rotation of the swash plate 13.

Side plates 19, 20 and valve forming plates 21, 22 are interposed between the cylinder block 1 and the front and rear housings 2, 3. In the front and rear housings 2, 3, suction chambers 23, 24 and discharge chambers 25, 26 are formed. Front suction chamber 23
Is connected to the swash plate chamber 4 via the suction passage 27 and is connected to the front compression chamber Pf via the suction hole 19a of the front side plate 19 and the suction valve 21a. The front side discharge chamber 25 is provided with a discharge hole 19b of the front side plate 19.
And a discharge valve 28 connected to the front compression chamber Pf. The rear suction chamber 24 communicates with the swash plate chamber 4 via a suction passage 29 and is connected to the rear compression chamber Pr via a suction hole 20a on the side plate 20 and a suction valve 22a. The rear discharge chamber 26 is provided with a discharge hole 20b on the side plate 20.
And a discharge valve 30 connected to the rear compression chamber Pr. In addition, the cylinder block 1 has an inlet 31a connecting the suction pipe line 31 and the swash plate chamber 4 constituting an external refrigerant gas circuit (not shown), and a discharge connecting the external refrigerant gas circuit and the discharge chambers 25 and 26. A passage 32 is formed.

A sliding control body 33 having a bottomed cylindrical shape and having a flange portion 33a at the rear end is slidably fitted in the rear side suction chamber 24 in the front-rear direction, and a part of the rear side suction chamber 24 is formed by the flange portion 33a. It is partitioned and formed in the control pressure chamber 24a. Sliding control body 3
The cylindrical portion 33b is supported by the guide bush 10 via a thrust bearing 34 and a radial bearing 35 so as to be relatively rotatable. As a result, the pressure in the control pressure chamber 24a is converted into the swash plate oscillating power generated by the pressure in the front compression chamber Pf and the pressure in the rear compression chamber Pr via the sliding control body 33, the guide bush 10, and the swash plate 13. Oppose. The control pressure chamber 24a, the rear discharge chamber 26, and the suction line 31 are connected to a capacity control valve mechanism (not shown), and the displacement of the sliding control body 33 before and after is controlled by a change in suction pressure in the suction line 31. It is supposed to be. That is, the control pressure chamber 24a is switched to a high pressure equivalent to the discharge pressure or a low pressure equivalent to the suction pressure by opening and closing a valve in the capacity control valve mechanism based on the suction pressure in the suction pipe line 31, and the swash plate 13 is moved in FIG. And a tiltable minimum position (not shown).

Refrigerant gas in the suction pipe line 31 constituting the external refrigerant gas circuit enters the swash plate chamber 4 from the inlet 31a with the reciprocation of the double-headed piston 6, and the front side suction passage 27 and the rear side suction passage.
29, the air is sucked into the front-side compression chamber Pf and the rear-side compression chamber Pr through the front-side suction chamber 23 and the rear-side suction chamber 24, respectively, and receives a compression action. Then, the discharge chamber 2 passes through the discharge holes 19b and 20b opened and closed by the discharge valves 28 and 30 from both the compression chambers Pf and Pr.
The refrigerant gas discharged to 5, 26 is sent out to the external refrigerant gas circuit via the discharge passage 32. In this case, the inclination center C of the swash plate 13 is set on the peripheral side of the swash plate 13 and is set closer to the rear cylinder bore 5b, so that the compression stroke of the double-headed piston 6 in the front compression chamber Pf is reduced. Although the point varies according to the inclination angle of the swash plate 13, the top dead center of the compression stroke of the double-headed piston 6 in the rear compression chamber Pr is defined at the fixed position shown in FIG.

When attaching the swash plate 13 to the guide bush 10, the shaft pin 12 is inserted into the through hole 18 from the outside of the fitting projection 17a of the rotational force transmitting unit 17, and in this state, the swash plate body 15 is inserted into the fitting projection 17a. Mating hole 15b
Is fitted. The fitting hole 15b of the swash plate body 15 and the rotational force transmitting portion 17
Are fitted (press-fitted) into the fitting projections 17a, and are assembled so that they rotate and move completely integrally. Shaft pin for torque transmitting part 17 or guide bush 10
The assembled state of 12 may be any state in which the swash plate 13 is rotatable about the shaft pin 12, and any one of the three types shown in the following table is adopted. When No1 combination is used, shaft pin 1
After the swash plate body 15 is pressed into the fitting projection 17a after the fitting 2 is inserted into the fitting projection 17a, if the through hole 18 is deformed and the space between the shaft pin 12 and the rotational force transmitting unit 17 is tight. (Press-fitting).

After the swash plate 13 is divided into the swash plate body 15 and the rotational force transmitting portion 17 as described above, the swash plate 13 is formed by fitting and fixing the two, so that the shape of the entire swash plate is complicated. Despite this, the shape of each of the divided parts is not so complicated, making it easier to process and
The processing accuracy of the sliding surface with 14, etc. is improved. Also, swash plate body 15
The sliding part 15a is made by sintering a copper-based bearing alloy on the surface of an iron-based base material,
It is formed by thermal spraying, joining, etc.
Since the shape is not complicated, sintering can be easily performed.

In addition, since the sliding portion 15a of the swash plate body 15 is formed of a copper-based bearing alloy such as JIS LBC6, which has good sliding compatibility with an iron-based material such as bearing steel, which is a material of the shoe 14, poor lubrication. The swash plate 13 and the shoe 14 slide smoothly even when the load is high or when the load is high, and the double-headed piston 6 is always reciprocated smoothly.

Note that the present invention is not limited to the above-described embodiment.For example, when connecting the coupling bodies 8 and 9 and the rotational force transmitting unit 17, a fitting hole is formed in the coupling bodies 8 and 9 and Piece 1
A guide hole is formed on the 7b side and the two are connected by the guide pin 16, or the guide hole 36 is formed on the rotating shaft 7 side as shown in FIG.
One connecting member 36 having a may be provided, and two fitting pieces 17b may be provided on the rotational force transmitting portion 17 side.
Also, instead of connecting the swash plate 13 and the guide bush 10 with the shaft pin 12, a spherical bearing is formed on the guide bush and the swash plate 13 is formed.
Is applied to a structure with a spherical bearing
The present invention may be applied to the structure disclosed in JP-A-63-147977.

[Effects of the Invention] As described above in detail, according to the present invention, a swash plate main body having a sliding surface with a shoe and a torque transmitting portion to which rotation of a rotating shaft is transmitted are formed separately. After that, the two are fitted and fixed to form a swash plate, which facilitates the processing of the sliding surface, etc., and improves the processing accuracy. In addition, the sliding portion of the swash plate is compatible with the material of the shoe. The bearing is made of a good copper-based bearing alloy, so that problems such as seizures are reliably prevented even when lubrication is poor or under high load, the reciprocating motion of the piston is always performed smoothly and the sliding part , The durability and reliability of the compressor as a whole can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of the compressor, FIG. 2 is a sectional view taken along line AA of FIG. 1, FIG. 3 is an exploded perspective view of a swash plate, and FIG. FIG. 5 is a cross-sectional view showing the state, and FIG. Cylinder block 1, cylinder bores 5a, 5b, double-headed piston 6, rotary shaft 7, connecting bodies 8, 9, 36 as connecting parts, guide holes 8a, 9a, 36a, guide bush 10, shaft pin 12, swash plate 1
3, shoe 14, swash plate body 15, sliding portion 15a, fitting hole 15b, guide pin 16, rotational force transmitting portion 17, fitting protrusion 17a, fitting piece 17
b, hole 18.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Keiichiro Otsu 3-65, Midorigaoka, Toyota-shi, Aichi Prefecture Inside Daitoyo Kogyo Co., Ltd. (72) Inventor Tatsuhiko Fukuoka 3-65, Midorigaoka, Toyota-shi, Aichi Prefecture Inside Daitoyo Kogyo Co., Ltd. (56) References JP 7-41902 (JP, Y2)

Claims (1)

(57) [Claims] A rotary shaft is rotatably accommodated and supported in a cylinder block which accommodates a double-headed piston in a reciprocally movable manner, and a swash plate for reciprocating the double-headed piston is relatively non-rotatable on the rotary shaft and is located on a peripheral side thereof. The center of rotation is set near the rear cylinder bore, and the reciprocating area of the double-headed piston is set on the rotation area of the center of rotation accompanying rotation of the rotating shaft. And
In a variable displacement type swash plate type compressor in which the displacement can be adjusted by changing the piston stroke by changing the inclination angle of the swash plate, a shoe that engages with the double-headed piston to transmit the rotational swinging motion of the swash plate to the double-headed piston is engaged. A swash plate body is formed by separately forming a swash plate main body and a rotational force transmitting portion connected via a guide pin to a connecting portion provided on a rotating shaft, and the two are fitted and fixed. A variable displacement type swash plate compressor in which a sliding portion of a swash plate body with a shoe is formed of a copper-based bearing alloy.