JPH11173263A - Swash plate compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve both of the coating performance and the productivity by using aluminum as a base material of a swash plate, and forming a coating film of a solid lubricant comprising at least one of molybdenum disulfide, tungsten disulfide and graphite on a sliding contact face with a shoe by the transferal method. SOLUTION: A base is selectively coarsened, for example, by the shot blast as the pretreatment of a sliding contact face 3a of a swash plate for enhancing the adhesion strength of a coating of a solid lubricant in advance. Then the coating of the solid lubricant comprising, for example, at least one of molybdenum disulfide, tungsten disulfide and graphite is formed on the sliding contact face 3a of the swash plate 3 after the pretreatment by a transferal method. Accordingly the coating of the solid lubricant formed on the sliding contact face 3a of the swash plate 3 to be engaged with a shoe 7 is superior not only in the lubricating performance, but also the cost efficiency and the productivity such as the yield of a coating material and the control of a film thickness can be improved by the coating by the transferal method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate type compressor, and more particularly to an improvement in surface treatment applied to a swash plate.

[0002]

2. Description of the Related Art For example, in a double-headed swash plate type compressor mainly used for vehicle air conditioning, a drive shaft is rotatably supported by a pair of cylinder blocks, and a swash plate is formed in a joint area between the two cylinder blocks. And is integrally rotatably connected to the drive shaft in the swash plate chamber. A double-headed piston is co-inserted into the bore arranged in alignment with both cylinder blocks, and each piston is linked to the swash plate via a shoe. And the compression of the refrigerant gas is performed.

On the other hand, in a single-head type swash plate type compressor, a swash plate chamber (crank chamber) is formed by a housing that covers an inner end side of a cylinder block, and a swash plate mounted on a drive shaft in the swash plate chamber has a shoe. And the swash plate can be tilted around a fulcrum in the compressor of the variable displacement type, and the gas pressure acting on both end faces of the piston based on a change in the crank chamber pressure. Is controlled so as to control the inclination displacement of the swash plate, that is, the piston stroke.

In such swash plate compressors, aluminum alloys have become the mainstream for swash plates and pistons in addition to cylinder blocks due to the need for ever-reduced weight reduction for vehicle compartment air conditioning. Therefore, for the sliding surface of the swash plate, which is subjected to severe sliding conditions, with the shoe and the sliding surface of the piston with the bore, anti-wear and anti-seizure measures have been studied for some time. Formation of a fluororesin film and formation of a solid lubricant film on a sliding surface of a swash plate are known.

[0005]

However, the double-headed piston has a recess extending over the outer periphery of the swash plate.
The rotational moment acting on the piston through the shoe, that is, the rotation of the piston, is suppressed by the interference surface for preventing rotation provided in the concave portion coming into contact with the outer peripheral surface of the swash plate. The rotation of the piston in the shape of the piston is also suppressed by the interference surface provided at the base end for preventing rotation coming into contact with the inner wall surface of the housing forming the swash plate chamber. For this reason, under the same condition as non-lubrication as seen at the start of the compressor, there is a concern that seizure may occur on the interference surface of the piston and the outer peripheral surface of the swash plate, and an attempt is made to form a lubricious coating on the sliding surface. ing. However, the practice of coating on a swash plate, for example, the spraying method, is extremely poor in yield of the coating material and the adhesion strength of the coating to the sliding surface is low, so that not only seizure resistance but also durability should be satisfied. Is not good.

An object of the present invention is to improve the reliability of a compressor by improving a swash plate which is excellent in productivity as well as film performance.

[0007]

According to a first aspect of the present invention, there is provided a swash plate compressor comprising: a plurality of bores arranged in a cylinder block; a piston inserted into the bore; A swash plate compressor having a swash plate rotating with a drive shaft and linked to the piston via a shoe, wherein the swash plate is made of an aluminum alloy, and a molybdenum disulfide is provided on a sliding surface with the shoe. A coating of a solid lubricant composed of at least one of tungsten, tungsten disulfide and graphite is formed by a transfer method.

Therefore, the solid lubricant film formed on the sliding contact surface of the swash plate engaging with the shoe not only exhibits excellent lubrication performance, but also yields the coating material by the transfer method. This is extremely advantageous from the viewpoints of both economy and productivity, such as control of film thickness and film thickness. Claim 2
If the solid lubricant film is similarly formed on the outer peripheral surface of the swash plate in contact with the interference surface for preventing rotation of the piston by the transfer method as in the described invention, a better resistance to the piston can be obtained. Seizure can be ensured.

According to the third aspect of the present invention, when the surface of the coating formed on the sliding contact surface of the swash plate is roughened, fine irregularities on the surface of the substrate where plastic deformation has occurred are obtained. The so-called anchor effect into which the strongly-pressed coating material bites enhances the adhesion strength of the coating, and in addition to the lower layer of the coating formed on the sliding contact surface and the outer peripheral surface of the swash plate, as in the invention of claim 4. In the case of tin-based plating, even if the coating is partially missing, this plating layer functions as a lubricating layer by preventing the exposure of the aluminum base material, so superior durability is guaranteed. Is done. Further, if the coating formed on the sliding surface of the swash plate is finished by grinding as in the invention according to claim 5, extremely high film surface accuracy (flatness) can be obtained simultaneously with the adjustment of the film thickness.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a swash plate type compressor, FIG. 2 (a) is a perspective view showing a double-headed piston, FIG.
(B) is a longitudinal sectional view showing an interference surface for preventing rotation formed on the piston, and shows a pair of cylinder blocks 1A, 1B.
The drive shaft 2 is rotatably supported by B, and the swash plate 3 is accommodated in a swash plate chamber 4 formed in the joint area of the cylinder blocks 1A and 1B, and is connected to the drive shaft 2 so as to be integrally rotatable. . A double-headed piston 6 is co-inserted into a bore 5 arranged in alignment with both cylinder blocks 1A and 1B, and each piston 6 is provided with a sliding contact surface 3a of the swash plate 3 via shoes 7 and 7. The rotation of the swash plate 3 is converted into a linear movement of the piston 6 by linking the swash plate 3a, and the refrigerant gas is compressed.

In this embodiment, the shoe 7 is made of an iron-based metal, and the cylinder blocks 1A and 1B, the swash plate 3 and the piston 6 are made of an aluminum-based metal, for example, a hypereutectic aluminum-silicon alloy. The piston 6 has sliding contact surfaces 6a, 6a fitted into the bore 5 with a required fitting length at both ends thereof, and the swash plate 3
Have semi-spherical seats 6c, 6c, which are axially opposed to each other and engage with each of the shoes 7, 7, and are provided axially symmetrically in the recess 6b. The interference surfaces 6d, 6d provided for preventing rotation are brought into contact with the outer peripheral surface 3b of the swash plate 3, so that the rotational moment acting on the piston 6 via the shoe 7, that is, the rotation of the piston 6, is suppressed. I have.

FIG. 3 is a longitudinal sectional view of a variable displacement swash plate type compressor, FIG. 4 (a) is a front view showing a single-headed piston,
FIG. 4B is a side view showing an interference surface formed on the piston for preventing rotation. The front end of the cylinder block 10 is closed by a front housing 11, and the rear end of the cylinder block 10 is interposed via a valve plate 12. And are closed by a rear housing 13 and are fastened together by through bolts. Cylinder block 10 and front housing 11
A drive shaft 15 extending in the axial direction is accommodated in the crank chamber 14 formed by the above and is rotatably supported by a radial bearing. And cylinder block 1
0 has a plurality of bores 16 at positions surrounding the drive shaft 15.
Each bore 16 has a single-headed piston 1.
7 are reciprocally fitted.

In the crank chamber 14, a rotor 20 is coupled to the drive shaft 15 so as to be synchronously rotatable between the drive shaft 15 and the front housing 11 through a thrust bearing, and a swash plate 18 is fitted behind the rotor 20. I have. And the swash plate 1
8 is constantly urged rearward by a pressing spring 21 interposed between the rotor 8 and the rotor 20. The swash plate 18 is formed with a smooth sliding contact surface 18a on the outer peripheral side of both end surfaces.
a is in contact with shoes 19, 19, each of which is a hemispherical seat 17 of a piston 17.
c, 17c. Further, a relative hinge mechanism K is provided between the swash plate 18 and the rotor 20, and the swash plate 18 fitted to the drive shaft 15 through the bent through hole 18a is a piston. 17 is configured to be able to be displaced at an angle while keeping the top dead center position immobile.

Also in this embodiment, the cylinder block 10, the swash plate 18 and the piston 17 are made of an aluminum-based metal, for example, a hypereutectic aluminum silicon alloy, and the piston 17 has a required fitting length at the tip. And a concave portion 17b straddling the swash plate 18 at the base end, and a large radius of curvature is provided on the rear side of the concave portion 17b so that the inner wall surface 14a of the crank chamber 14 has a large radius of curvature. An interference surface 17d for preventing rotation is provided.

Now, the most characteristic surface treatment of the swash plate of the present invention will be described below. In addition, the swash plate 8 linked to the double-headed piston 6 and the swash plate 18 linked to the single-headed piston 17 shown in both embodiments are formed by an interference surface 6d for preventing the piston 6 from rotating. While the outer peripheral surface of the swash plate 18 is different from the outer peripheral surface 3b of FIG. Therefore, although there is no particular need for surface treatment on the outer peripheral surface of the swash plate 18, there is essentially no change in the surface treatment of the sliding surfaces 3a, 18a with the shoes 7, 19,
Only the surface treatment of the swash plate 3 will be described.

First, the sliding surface 3a of the swash plate workpiece 3W is selectively roughened by, for example, shot blasting as a pretreatment for increasing the adhesion strength of a coating made of a solid lubricant. The roughness is adjusted to 0.4 μmRz or more. And, regardless of the presence or absence of rough surface processing, the sliding contact surface 3a of the swash plate workpiece 3W (including the outer peripheral surface 3b if necessary).
Is also subjected to a base plating mainly composed of tin as a selective pretreatment, but the surface roughness adjusted by the above roughening proceeds to about 1.2 μm Rz by the base plating. In addition, it is also possible to form the base material to some extent roughened at the time of cutting, and to omit these pretreatments.

Here, a transfer method (pad transfer) for forming a solid lubricant film on the sliding contact surface 3a of the swash plate workpiece 3W that has been subjected to the above pretreatment will be described below. FIG. 5 is a schematic view showing a transfer device 70, in which a coating material C containing an uncured thermosetting resin such as a solid lubricant made of, for example, molybdenum disulfide and graphite and a polyamideimide resin is stored. The storage tank 72 is a slide table which is slidably in contact with the opening edge of the lower end of the storage tank 71 and is horizontally movable in the direction of the arrow. On the slide table 72, an annular surface having a surface area substantially matching the sliding contact surface 3a is provided. The material holding groove 72a is indented. And the storage tank 71
A cylindrical transfer pad 73 made of synthetic rubber is vertically movably arranged at a standby position at a predetermined distance in the moving direction of the slide table 72 from the standby position to the center position of the storage tank 71. The stroke of the slide table 72 is set so that the material holding groove 72a can reciprocate.

The transfer pad 3 is formed so that the lower end surface 73b of the swash plate work 3W excluding the escape hole 73a with respect to the boss portion slightly fills the material holding groove 72a while bending slightly. The transfer pad 73 is indicated by an arrow. As shown in the figure, a horizontal reciprocating movement between adjacent transfer positions and a vertical movement at both positions are possible. Below the transfer pad 73 at the transfer position, there is provided an abutment 74 having a positioning concave portion 74a which is aligned with the boss portion of the swash plate workpiece 3W. Although not shown, the abutment 74 is provided separately. It is configured to be able to reciprocate with the container.

Therefore, the slide table 72 is moved to the left from the standby position shown in the drawing, so that the material holding groove 72a is positioned at the center of the storage tank 71, that is, the lower end of the storage tank 71 is indicated by the outline circle of the material holding groove 72a. By aligning with the opening edge, the coating material C in the storage tank 71 is automatically introduced into the material holding groove 72a. After the slide table 72 is returned from this state to the standby position (moves to the right) and the transfer pad 73 in the standby position is lowered, the material holding groove 7
The coating material C is attached to the lower end surface 73b of the transfer pad 73 which has entered the inside 2a and has been slightly bent.

Transfer pad 73 to which coating material C is applied
Is moved to a transfer position aligned with the abutment 74 by rightward movement following the ascending, and is further lowered to the lower end face 73b.
Is pressed against the sliding contact surface 3a of the swash plate work 3W positioned on the support 74, the coating material C on the lower end surface 73b is transferred and is covered (transferred) on the sliding contact surface 3a. You. In addition,
The swash plate workpiece 3W that has been covered is once dried in a dryer together with the support 74 as necessary, and the above-described process is repeated to adjust the film thickness. It is needless to say again that a similar coating is formed on the opposite sliding contact surface 3a, and then the adhered film is formed through the firing step.

Next, a transfer method (roll transfer) for forming a solid lubricant film on the outer peripheral surface 3b of the swash plate work 3W will be described. FIG. 6A is a schematic diagram illustrating a transfer device, and FIG. 6B is a schematic diagram illustrating a relationship between a swash plate work and a roller row. The transfer device 80 includes a storage tank 82 in which a coating material C including a solid lubricant made of, for example, molybdenum disulfide and graphite and an uncured thermosetting resin such as a polyamideimide resin is stored, and a coating material C in the storage tank 82. A metal roller 83 having a part of the outer peripheral edge immersed therein, a comma roller 84 disposed with a predetermined gap between the metal roller 83, and a large roller that matches the rotation locus of the outer peripheral surface 3b of the swash plate workpiece 3W. The transfer roller 85 made of synthetic rubber whose diameter part 85a is arranged in contact with the metal roller 83, the work holder 86 for rotatably holding the swash plate work 3W, and the above-mentioned roller rows 83 and 85 are driven to rotate in the direction of the arrow. And a drive mechanism 81.

Therefore, when the drive mechanism 81 is activated and the roller rows 83 and 85 are rotated, the coating material C adhered to the outer peripheral surface of the metal roller 83 comes into contact after the film thickness is adjusted by the comma roller 84. The transfer roller 85 is transferred to the large-diameter portion 85a. In this state, the swash plate work 3 </ b> W that rotates in the same manner is transferred to the transfer roller 85 via the work holder 86.
, The coating material C is transferred again and is coated (transferred) on the outer peripheral surface 3b of the swash plate workpiece 3W. The swash plate work 3W, which has been separated from the transfer roller 85 after being covered, is removed from the work holder 86, and after the solvent in the coating material C is removed in the drying step, the swash plate work 3W is further subjected to a baking step, whereby the outer peripheral surface is removed. An adherent coating is formed on 3b.

[0023]

As described above in detail, according to the first to fifth aspects of the present invention, the solid lubricant film formed on the sliding contact surface of the swash plate for the swash plate type compressor has excellent lubrication performance. In addition to exhibiting the effect, the coating by the transfer method is extremely advantageous from the viewpoints of both economy and productivity such as control of the yield and thickness of the coating material.

In the case where the base material of the coating formed on the sliding contact surface of the swash plate is roughened as in the invention according to the third aspect, a so-called anchor in which the coating material bites into the irregularities on the surface of the base material. According to the effect, the adhesion strength of the coating is improved, and further, as in the invention according to claim 4, an undercoat mainly made of tin is applied to the lower layer of the coating formed on the sliding contact surface and the outer peripheral surface of the swash plate. Thus, better durability is guaranteed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a double-headed swash plate type compressor according to an embodiment of the present invention.

FIGS. 2A and 2B are double-headed pistons used in the compressor, in which FIG. 2A is a perspective view showing the entirety thereof, and FIG. 2B is a longitudinal sectional view showing an interference surface for preventing rotation.

FIG. 3 is a longitudinal sectional view of the single-head swash plate type compressor according to the embodiment of the present invention.

FIG. 4 is a single-headed piston used in the compressor, wherein (a) is a front view and (b) is a side view showing an interference surface for preventing rotation.

FIG. 5 is a schematic diagram illustrating a transfer device for a swash plate sliding contact surface.

FIGS. 6A and 6B are schematic views illustrating a transfer device on an outer peripheral surface of a swash plate, in which FIG. 6A is a schematic diagram illustrating an outline of the transfer device, and FIG.

[Explanation of symbols]

1A and 1B are cylinder blocks, 2 is a drive shaft, 3 is a swash plate, 3b is an outer peripheral surface, 5 is a bore, 6 is a piston, and 6d is an interference surface for preventing rotation.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI F04B 27/08 A (72) Inventor Seiji Katayama 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Takayuki Kato 2-1-1, Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Hayato Ikeda 2-1-1, Toyota-cho, Kariya City, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Masaaki Taga 2-1-1 Toyota-cho, Kariya City, Aichi Prefecture Inside Toyota Industries Corporation

Claims (5)

[Claims] 1. A swash plate compression system comprising: a plurality of bores juxtaposed in a cylinder block; a piston fitted into the bore; and a swash plate rotating with a drive shaft and linked to the piston via a shoe. In the machine, the swash plate is made of an aluminum alloy as a base material, and a coating of a solid lubricant composed of at least one of molybdenum disulfide, tungsten disulfide, and graphite is formed on a sliding surface with the shoe by a transfer method. A swash plate compressor. 2. A solid lubricant film is formed on an outer peripheral surface of said swash plate which comes into contact with an interference surface for preventing rotation of said piston by a transfer method.
The swash plate compressor as described. 3. The swash plate type compressor according to claim 1, wherein a surface of the solid lubricant film formed on the sliding contact surface of the swash plate is roughened. . 4. The undercoat mainly composed of tin is applied to a lower layer of the solid lubricant film formed on a sliding contact surface and an outer peripheral surface of the swash plate. Or 3
The swash plate compressor as described. 5. The swash plate type according to claim 1, wherein the precision of the solid lubricant film formed on the sliding contact surface of the swash plate is adjusted by grinding. Compressor.