JPH02267371A - Variable capacity swash plate compressor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a variable displacement swash plate compressor equipped with a double-ended piston.

[Prior Art] A variable capacity swash plate compressor having the cooling efficiency of a double-headed swash plate compressor is disclosed in JP-A-58-162782. In this compressor, the swash plate is supported so that it can rotate integrally with the rotating shaft and swing back and forth, and the inclination of this swash plate is controlled based on suction pressure information that reflects the cooling load. ing. However, since the center of oscillation of the swash plate is set at a fixed position on the rotation axis, the top dead center of the compression stroke of the double-headed piston fluctuates depending on the angle of inclination of the swash plate in both the front and rear compression chambers. Substantial compression and discharge cannot be performed in the compression action area on the small volume side where the inclination angle is close to both sides.

A variable displacement swash plate compressor that improved this drawback was developed in the Japanese Patent Application Publication No. 6
It is disclosed in Japanese Patent No. 3-147977. In this compressor, the center of swing of the swash plate is set at a radial position of the rotating shaft corresponding to the cylinder bore of the cylinder block that accommodates the double-headed piston, and the center of rotation 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 action area on the small capacity side where the swash plate inclination angle is close to the customer side.

The swash plate inclination is determined by the swash plate rocking force due to the pressure in both the front and rear cylinder bores and the swash plate rocking force in the control pressure chamber through the sliding control body and the swash plate that change the volume of the control pressure chamber connected to the discharge pressure region or the suction pressure region. It is controlled by opposing pressure, and the sliding control body is slidably supported on the rotating shaft. The force exerted on the rotating shaft by the swash plate, which oscillates due to this pressure opposition, is received by the guide hole on the rotating shaft side via the guide pin on the swash plate side, and the slanting force is stopped by the guide hole between the guide pin and the guide hole. The plate inclination angle is controlled. In this device, the swash plate is supported by a spherical support portion disposed at the end of the spool, which is movable along the axis of the rotating shaft as the sliding control body moves.

In addition, the swash plate is connected with a pin to a guide bush that is slidable along the rotation axis, so that the swash plate is movable and rotatably supported along the rotation axis in response to the movement of the sliding control body. There are also configurations that support it.

[Problems to be Solved by the Invention] In the conventional device, the swash plate has an integral structure in which the swash plate body and the rotational force transmitting portion protruding from the swash plate for transmitting the rotational driving force of the rotating shaft to the swash plate. It had a complicated shape. Therefore, there was a problem in that it was difficult to improve the processing accuracy of the spherical part corresponding to the spherical support part, the sliding surface with the shoe, etc.

In addition, when supporting the swash plate on the guide bush through a pin, it is necessary to install the pin inside the swash plate from the insertion hole side of the guide bush into which the rotating shaft is inserted, making assembly difficult. The disadvantage is that it is troublesome.

Furthermore, although the swash plate is generally made of iron-based materials to ensure the strength of the rotational force transmission part and to reduce costs, the shoes are also made of iron-based materials such as bearing steel. There is also the problem that sliding properties with the swash plate are poor, and problems such as seizure occur when the sliding parts are poorly lubricated or when the load is large.

The present invention has been made in view of the above problems, and includes:
The purpose of this is to make it easier to process the swash plate, improve the processing accuracy of parts such as the sliding surface with the shoe, and
A variable capacity slant that can prevent problems such as seizure from occurring even when the sliding parts of the swash plate are poorly lubricated or under high loads, and also improves work efficiency during assembly. Our objective is to provide a plate compressor.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, a rotating shaft is rotatably housed and supported in a cylinder block that accommodates a double-headed piston so as to be able to reciprocate, and the rotating shaft has a The swash plate that reciprocates the double-headed piston is supported so that it cannot rotate relative to the other but can swing back and forth around its peripheral edge.The center of the swash plate is set near the rear cylinder bore, and the swash plate that drives the double-headed piston reciprocally is supported so that it can swing back and forth around its periphery. In a variable displacement swash plate compressor, the reciprocating movement area of the double-headed piston is set above the rotation area of the center of movement, and the displacement can be adjusted by changing the piston stroke by changing the inclination of the swash plate. A swash plate body that engages with a shoe that transmits rotational oscillation motion to the double-headed piston as a reciprocating motion, and a rotational force transmission section that is connected via a guide pin to a connection section provided on the rotation shaft are separated. The swash plate was formed by fitting and fixing them together, and the sliding portion of the swash plate main body with the shoes was formed from a different type of bearing alloy.

[Function] With the above configuration, in the swash plate compressor of the present invention, even if the swash plate as a whole has a complicated shape, each individual piece has a simple shape and is easy to process, and the sliding movement between the shoes and the swash plate is simple. It becomes easy to improve the processing accuracy of parts such as surfaces. The copper-based bearing alloy used as the material for the sliding part of the shoe has good sliding compatibility with the ferrous material such as bearing steel used as the material for the shoe, and can handle high loads when the sliding part is poorly lubricated. Smooth sliding with the Shinny even under load. In addition, when adopting a configuration in which the swash plate is supported by the guide bush through pins,
The swash plate is assembled to the kite bush by fitting the pin into the guide bushing from the outside of the rotational force transmission part and then fitting and fixing the swash plate main body to the rotational force transmission part.

[Example] An example embodying the present invention will be described below with reference to FIGS. 1 to 4. As shown in FIG. 1, a front housing 2 and a rear housing 3 are joined and fixed to both front and rear end surfaces of a cylinder block 1.

A swash plate chamber 4 is formed in the cylinder block 1, and on the front and rear sides of the swash plate chamber 4, a plurality of pairs (5 pairs in this embodiment) of cylinder bores 5a, 5 are arranged facing each other.
b is formed, and a double-headed piston 6 is accommodated in both cylinder bores 5a and 5b so as to be able to reciprocate. A rotary shaft 7 is rotatably supported by the front housing 2 and the cylinder block 1 via a front shaft portion 7a, and a rear shaft portion 7b is connected to connecting bodies 8, 9 as connecting portions on the inner end side of the front shaft portion 7a. The guide holes 8a and 9a are formed in the connecting body 89. A guide bushing 10 is slidably fitted into the rear shaft portion 7b, and a pressure spring 11 is interposed between the tip of the rear shaft portion 7b and the inner end of the guide bushing 10.

A pair of shaft pins 12 are protruded from the base end of the guide bushing 10 protruding into the swash plate chamber 4 in a state perpendicular to the rear shaft portion 7b.
It is rotatably supported. The swash plate 13 has a swash plate main body 15 that engages with a shoe 14 that transmits its rotational oscillation motion to the double-ended piston 6 as a reciprocating motion, and a guide pin 16 that engages with a shoe 14 that transmits its rotational oscillation motion to the double-headed piston 6 as a reciprocating motion. A rotational force transmitting section 17 connected via a rotary force transmitting section 17 is formed separately. The swash plate main body 15 is made of iron-based material except for the sliding portion 15a with respect to the shoe 14, and the sliding portion 15a is made of a copper-based bearing alloy. The sliding part 15a has a JIS standard on the surface of the iron base material.
It is formed by sintering, thermal spraying, joining, etc. a copper-based bearing alloy such as LBC6.

The rotational force transmitting part 17 is entirely made of iron-based material, and is fitted with an annular fitting protrusion 1.7a having an outer diameter that is approximately the same as the fitting hole 15b formed in the swash plate main body 15. It has a protrusion 17a and a fitting piece 17b formed to protrude to the opposite side, and the fitting protrusion 17a is fitted into the fitting hole 15b of the swash plate main body 15 to form the swash plate 13. It looks like this. The shaft pin 12 is fitted into a pair of through holes 18 formed in the fitting protrusion 17a. The fitting piece 17b has a fitting hole 1.
7c is formed, and as shown in FIG. 2, the fitting piece 17b is inserted between the two connecting bodies 8 and 9, and the guide pin 16 or the connecting body 8.9 passes through the fitting hole 17c. The swash plate 13 is inserted into the guide holes 8a, 9a of the swash plate 13 so as to fit into the guide holes 8a, 9a of the swash plate 13, thereby rotating the swash plate 13 together with the rotating shaft 7 within the swash plate chamber 4.

The rotating shaft 7, the swash plate 13, and the guide bush 10 are connected to each other through a guiding relationship between the guide pin 16 and the guide holes 8a, 9a, and a rotatable relationship between the swash plate 13 and the guide bush 10. As a result, the swash plate 13 can swing as the guide bush 10 slides, and the center C of this swing is set on the peripheral edge side of the swash plate 13. Each double-headed piston 6 and the swash plate 13 engage with each other via a shoe 14, and the double-headed piston 6 reciprocates back and forth as the swash plate 13 rotates.

Between the cylinder block 1 and both the front and rear housings 2.3 are a side plate 19.20 and a valvuloplasty plate) 21.
22 is interposed. A suction chamber 23.24 and a discharge chamber 25.26 are formed in both the front and rear housings 2.3. The front side suction chamber 23 communicates with the swash plate chamber 4 via the suction passage 27, and also communicates with the front side plate 1.
It is connected to the front side compression chamber Pf via the suction hole 19a of No. 9 and the suction valve 21a. The front discharge chamber 25 is connected to the front compression chamber Pf via the discharge hole 19b of the front side plate 19 and the discharge valve 28. The rear suction chamber 24 communicates with the swash plate chamber 4 via a suction passage 29, and also communicates with the swash plate chamber 4 through a suction hole 20 on the side plate 20.
a and a suction valve 22a to the rear compression chamber Pr. The rear side discharge chamber 26 is connected to the rear side compression chamber Pr via the discharge hole 20b on the side plate 20 and the discharge valve 30.
It is connected to the. The cylinder block 1 also has an inlet 31a that connects the swash plate chamber 4 with a suction pipe 31 constituting an external refrigerant gas circuit (not shown), and a discharge that connects the external refrigerant gas circuit and the discharge chambers 25 and 26. A passage 32 is formed.

A sliding control body 33, which has a cylindrical shape with a bottom and has a flange portion 33a at the rear end, is fitted into the rear suction chamber 24 so as to be slidable in the front-rear direction. It is divided into a control pressure chamber 24a.

The sliding control body 33 has a cylindrical portion 33b 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 transmitted through the sliding control body 33, the guide bush 10, and the swash plate 13 to the swash plate rocking force generated by the pressure in the front side compression chamber Pf and the pressure in the rear side compression chamber Pr. to counter. The control pressure chamber 24a, the rear side discharge chamber 26, and the suction pipe line 31 are connected to a capacity control valve mechanism (not shown), and the longitudinal displacement of the sliding part 611 body 33 causes the suction pipe line 3
It is controlled by fluctuations in suction pressure within 1. That is, by opening and closing a valve in the capacity control valve mechanism based on the suction pressure in the suction pipe M31, the control pressure chamber 24a is controlled to be switched to a high pressure equivalent to the discharge pressure or a low pressure equivalent to the suction pressure, and the swash plate 13
is swingably arranged between a maximum inclination position shown in FIG. 1 and a minimum inclination position not shown.

The refrigerant gas in the suction pipe 31 constituting the external refrigerant gas circuit enters the swash plate chamber 4 from the inlet 31a as the double-headed piston 6 reciprocates, and passes through the front suction passage 27, the rear suction passage 29, and the front suction passage. Chamber 23 and rear suction chamber 24
The air is sucked into the front side compression chamber Pf and the rear side compression chamber Pr through respectively, and is subjected to compression action. And both compression chambers Pf.

Discharge hole 19 opened and closed by discharge valve 28.30 from Pr
The refrigerant gas discharged into the discharge chamber 25, 26 through the discharge passages 32 and 20b is sent to the external refrigerant gas circuit through the discharge passage 32. In this case, the inclination center C of the swash plate 13 is set on the peripheral edge side of the swash plate 13, and is also set closer to the rear cylinder bore 5b, so that the front compression chamber Pf
The compression stroke top dead center of the double-headed piston 6 in the rear side compression chamber Pr varies depending on the inclination angle of the swash plate 13, but the compression stroke top dead center of the double-headed piston 6 in the rear side compression chamber Pr is defined at the fixed position shown in FIG. .

When assembling the swash plate 13 to the guide bush 10, insert the shaft pin 12 into the through hole 18 from the outside of the fitting protrusion 17a of the rotational force transmitting part 17, and in this state insert the swash plate main body into the fitting protrusion 17a. No. 15 fitting holes 15b are fitted. The fitting hole 15b of the swash plate main body 15 and the fitting protrusion 17a of the rotational force transmission part 17 are tightly fitted (press-fitted), and the two are assembled so that they rotate and move completely as one unit. The state of assembly of the shaft pin 12 to the part 17 or the guide bush 10 is as follows.
It is only necessary that the swash plate 13 be able to rotate around the shaft pin 12, and any of the three methods shown in the following table may be adopted.

When the No. 1 combination is adopted, after the shaft pin 12 is fitted into the fitting protrusion 17a, when the swash plate main body 15 is not press-fitted into the fitting projection 17a, the through hole 18 is deformed and the shaft pin 12 is inserted. It is also possible to make the space between the rotary force transmitting portion 17 and the rotational force transmitting portion 17 equivalent to a tight fit (press fit).

In this way, the swash plate 13 is connected to the swash plate main body 15 and the rotational force transmitting portion 17.
The swash plate 13 is formed by dividing the swash plate into two parts and then fitting and fixing the two parts.Although the shape of the swash plate as a whole is complex, the shape of the individual parts is not so much. Since it is not complicated, machining becomes easy and the machining accuracy of the sliding surface with the shoe 14, etc. is improved. Furthermore, the sliding portion 15a of the swash plate body 15 is formed by sintering, spraying, bonding, etc. a copper-based bearing alloy on the surface of an iron base material, but since the shape of the swash plate body 15 is not complicated, Easy to perform sintering process.

In addition, the sliding portion 15a of the swash plate body 15 is made of JIS L, which has good sliding compatibility with ferrous materials such as bearing steel, which is the material of the shoe 14.
Since it is made of a copper-based bearing alloy such as BC6, the swash plate 13 and the shoe 14 can smoothly slide even during poor lubrication or high loads, and the double-headed piston 6 always reciprocates smoothly. .

Note that the present invention is not limited to the above embodiments,
For example, when connecting the connecting body 8.9 and the rotational force transmitting part 17, a fitting hole is formed on the connecting body 8.9 side and a guide hole is formed on the fitting piece 17b side, and the guide pin 16 connects the two. Alternatively, as shown in FIG. 5, one connecting body 36 having a guide hole 36a on the rotating shaft 7 side may be provided, and two fitting pieces 17b may be provided on the rotational force transmitting portion 171FI. , Also, the swash plate 13 and the guide bush 10
Instead of connecting the swash plate 13 with the shaft pin 12, a spherical bearing part is formed on the guide bushing and the swash plate 13 is supported by the spherical bearing part. It may also be applied to objects with different configurations.

[Effects of the Invention] As detailed above, according to the present invention, the swash plate main body having a sliding surface with the shoe and the rotational force transmitting portion to which rotation of the rotating shaft is transmitted are formed separately. After that, the two are fitted and fixed to form the swash plate, making it easier to process the sliding surfaces etc. and improving the machining accuracy.Moreover, the sliding part of the swash plate has good sliding compatibility with the material of the shoe. Since it is made of a copper-based bearing alloy with good lubrication, it reliably prevents problems such as seizure even when there is poor lubrication or high loads, and the reciprocating movement of the piston is always performed smoothly and the sliding parts The durability of
The durability and reliability of the compressor as a whole can be improved.

[Brief explanation of drawings]

Figure 1 is a longitudinal sectional view of the compressor, Figure 2 is a sectional view taken along line A-A in Figure 1, Figure 3 is an exploded perspective view of the swash plate, and Figure 4 shows the swash plate assembled to the guide bushing. FIG. 5 is an exploded perspective view of essential parts of a modified example. Cylinder block 1, cylinder bores 5a, 5b, double-ended piston 6, rotating shaft 7, connecting bodies 8, 9.3 as connecting parts
6. Guide holes 8a, 9a, 36a, guide bush 10
, shaft pin 12, swash plate 13, shoe 14, swash plate main body 15,
Sliding portion 15a, fitting hole 15b, guide bin 16, rotational force transmitting portion 17, fitting protrusion 17a, fitting piece 17b, through hole 18
゜Patent applicant: Toyota Industries Corporation, Daitoyo Kogyo Co., Ltd.

Claims (1)

[Claims] 1. A rotary shaft is rotatably housed and supported within a cylinder block that reciprocably accommodates a double-headed piston, and a swash plate that drives the double-headed piston to reciprocate is attached to the rotary shaft so that it is not relatively rotatable and moves back and forth around its periphery. The swash plate is supported so as to be swingable, and its swing center position is set near the rear cylinder bore, and the reciprocating region of the double-headed piston is set above the rotation region of the swing center due to rotation of the rotating shaft. In a variable capacity swash plate type compressor, the capacity can be adjusted by changing the piston stroke by changing the inclination of the swash plate, the swash plate engaging with a shoe that transmits the rotational rocking motion of the swash plate to the double-ended piston as a reciprocating motion. The main body and the rotational force transmitting part connected to the connecting part provided on the rotating shaft via a guide pin are formed separately, and the two are fitted and fixed to form a swash plate, and the swash plate is formed. A variable capacity swash plate compressor in which the sliding part between the shoe and the plate body is made of copper-based bearing alloy.