JP2011089495A - Swash plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swash plate promptly discharging hard foreign matter intruding between the sliding surfaces of the swash plate and shoes, preventing occurrence of dragging damage to the sliding surfaces of the swash plate, suppressing an increase in the rotating torque of the swash plate, reducing separation and abrasion of coating film layers as the sliding surfaces of the swash plate, and having superior seizure resistance. <P>SOLUTION: A swash plate compressor 1 includes the swash plate 3 and a plurality of hemispherical shoes 5 slid with the swash plate. The swash plate 3 is composed of disc-like bases 11 and soft coating film layers 12 coating the surfaces of the bases. The coating film layers 12 are made to serve as sliding surfaces 3A, 3B. Three of adjacent conical recessed portions 12A making a set are formed in the predetermined positions of the sliding surfaces 3A, 3B. When the foreign matter intrudes between the sliding surfaces 3A, 3B of the swash plate 3 and the shoes 5, the foreign matter is dragged by the shoes 5 and caught in the recessed portions 12A. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a swash plate, and more particularly to an improvement of a swash plate used in a swash plate compressor.

2. Description of the Related Art Conventionally, a swash plate rotated by a rotating shaft and a plurality of shoes provided between the swash plate and each piston are provided, and each piston is advanced and retracted through the shoe as the swash plate rotates. Such a swash plate compressor is well known (for example, Patent Document 1).
In such a conventional swash plate type compressor, it has been a problem to improve the sliding characteristics of the sliding surfaces of the shoe and the swash plate. For this reason, conventionally, the following proposal has been made regarding the shoe and the swash plate. . That is, as an improvement of the shoe, it has been proposed that the middle portion of the flat sliding surface is a medium-high shape that is slightly bulged from the outer peripheral side. When the sliding surface of the shoe has such a medium-high shape, an oil film of several μm is generated between the sliding surfaces of both members when the sliding surface of the shoe and the sliding surface of the swash plate slide. Thus, the frictional resistance of the sliding surfaces of both members can be reduced. On the other hand, as an improvement of the swash plate, it has been proposed to form a coating layer made of a resin layer or a soft metal plating layer on the surface of the sliding surface. Thus, by forming a soft coating layer on the surface of the sliding surface of the swash plate, it is intended that the seizure between the shoe and the swash plate can be suppressed even in a poorly lubricated situation.

JP-A-9-209918

By the way, the following problems are pointed out also in the above-described improvement of the shoe and the swash plate. That is, for example, when a hard foreign object having a diameter of about 0.5 mm enters between the sliding surfaces of the shoe and the swash plate, as shown in FIG. The film layer on the sliding surface of the swash plate is dragged by hard foreign matter, increasing the rotational torque of the swash plate and causing the sliding surface of the swash plate and shoe to seize. More specifically, the gap between the shoe and the swash plate becomes large at the position where the piston is at the bottom dead center where the piston is most retracted from the cylinder. It is thought that a hard foreign substance invades. When the shoe lands on the sliding surface of the swash plate with the subsequent rotation of the swash plate, foreign matter is sandwiched between the shoe and the swash plate, and the shoe is further loaded under compression. It is moved to the top dead center position of the swash plate. Therefore, as shown by a dotted line in FIG. 8, a drag is caused by a hard foreign substance on the sliding surface (coating layer) of the swash plate extending from the position of the bottom dead center to the position of the top dead center.
As described above, when a scratch is generated on the coating layer of the swash plate, the oil film between the sliding surfaces of the shoe and the swash plate is interrupted or no oil film is generated. For this reason, there is a drawback that the sliding layer which becomes the surface of the swash plate is worn and peeled, and as a result, both members are seized.

In view of the circumstances described above, the present invention includes a base material that is formed in a disc shape and has a pair of flat end surfaces, and a soft coating layer that is provided so as to cover both end surfaces of the base material. In the swash plate configured to slide with the shoe using the coating layer covering both end faces of the substrate as a sliding surface,
A recess is formed at a predetermined position on at least one of both end faces of the base material, and foreign matter that has entered between the sliding surface and the shoe is captured at the position of the recess.

  According to such a configuration, when a hard foreign matter enters between the sliding surface of the swash plate and the shoe, the hard foreign matter can be quickly captured at the position of the recess. As a result, it is possible to prevent dragging scratches on the sliding surface of the swash plate due to hard foreign matters, and to suppress an increase in torque when the swash plate is rotated. In addition, it is possible to reduce peeling and abrasion of the coating layer that becomes the sliding surface of the swash plate. Therefore, a swash plate with good seizure resistance can be provided.

Sectional drawing of the principal part which shows one Example of this invention. The front view of the sliding surface of the swash plate shown in FIG. Sectional drawing of the principal part which follows the III-III line | wire of FIG. Process drawing at the time of forming the recessed part of the swash plate shown in FIG. The figure which shows the installation range of the recessed part in the swash plate of FIG. The front view of the swash plate which shows 2nd Example of this invention. Sectional drawing of the principal part which follows the VII-VII line of the said FIG. The front view which shows the conventional swash plate and the drag | scratch which arises in it. The front view of the principal part which shows the other Example of this invention. The front view of the principal part which shows the other Example of this invention. The front view of the principal part which shows the other Example of this invention. Sectional drawing of the principal part of the swash plate which shows the other Example of this invention.

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows the internal structure of a swash plate compressor 1. The swash plate compressor 1 includes a rotary shaft 2 supported by a housing (not shown), a disk-like swash plate 3 attached to the rotary shaft 2, and a plurality of pistons that move forward and backward in a cylinder bore (not shown) of the housing. 4 and a plurality of shoes 5 provided so as to face the end portions of the pistons 4 and sandwiching the swash plate 3 therebetween.
The swash plate 3 is fixed obliquely with respect to the rotating shaft 2, or the inclination angle of the swash plate 3 can be changed. The flat sliding surfaces 3A, 3B on both the front and back sides of the swash plate 3 are sandwiched by two hemispherical shoes 5 for each piston 4, and the sliding surfaces 3A, 3A, 3B slides with the flat sliding surface 5A of each shoe 5.
As shown in a cross-sectional view of the main part in FIG. 3, the swash plate 3 is composed of a base material 11 made of a disk-shaped iron-based material and a soft film covering both the front and back end faces 11A and 11B of the base material 11. Layer 12. The coating layer 12 is made of a soft material such as a resin coating or a soft metal plating layer, and the coating layer 12 covering the both end surfaces 11A and 11B serves as the sliding surfaces 3A and 3B. It slides on the moving surface 5A.
In addition, conventionally known materials can be used for the base material 11 and the coating layer 12 of the swash plate 3. For example, as the base material 11, an iron-based material, high-strength brass, an aluminum-based material, and further, a thermal spray layer Or a layer provided with a sintered layer can be used. As the coating layer 12, a solid lubricant-containing resin coating, copper-based plating, tin plating, or the like can be used.

As shown in FIG. 1, a hemispherical concave sliding surface 4A is formed at the end of the piston 4 so as to face each other, and a hemispherical sliding surface 5B of the shoe 5 is fitted therein. ing. When the swash plate 3 is rotated in conjunction with the rotation of the rotary shaft 2, the sliding surface 5B of the shoe 5 swings with respect to the sliding surface 4A of the piston and the sliding surface 5A of the shoe 5 is inclined. Since it slides on the sliding surfaces 3 </ b> A and 3 </ b> B of the plate 3, the pair of shoes 5 converts the rotation of the swash plate 3 into the forward and backward movement of the piston 4. Thereby, each piston 4 is moved back and forth in a cylinder bore (not shown). In this case, in FIG. 1, the position of the piston 4 shown on the upper side of the rotating shaft 2 is the top dead center where the piston 4 is most advanced, while the position of the piston 4 shown on the lower side of the rotating shaft 2 is The piston 4 is at the bottom dead center with the most retracted position.
The swash plate compressor 1 having such a configuration is conventionally known, and further detailed description thereof is omitted.

In this embodiment, as shown in FIGS. 2 to 3, a plurality of conical recesses 11C are formed on the end surfaces 11A and 11B of the base material 11 in the swash plate 3, and the recesses 11C A foreign object is captured at a position.
That is, as shown in FIG. 2 to FIG. 4A, in this embodiment, first, a conical recess having a set of three adjacent to the front end surface 11A and the back end surface 11B of the base material 11 in sequence. 11C is formed. These concave portions 11C are formed in a conical shape in which the inner diameter of the opening is larger than the inner diameter of the bottom. Further, as shown in FIG. 5, the set of three recesses 11 </ b> C has a range in which the locus of the shoe 5 on the end surface 11 </ b> A of the base material 11 is from the bottom dead center to the top dead center on the compression side surface of the swash plate 3. The trajectory of the shoe 5 on the end surface 11B of the base material 11 is in the range of 30 ° on the side of the top dead center and 60 ° on the side of the bottom dead center in the circumferential direction centering on the intermediate position. The three concave portions 11C are provided in the radial direction of the swash plate 3 in a range of 30 degrees in the circumferential direction around the middle position of the range from the dead center to the bottom dead center. It arrange | positions so that it may mutually adjoin with respect to the sliding locus | trajectory of the shoes 5 adjacently. Thereby, when each shoe 5 slides on the sliding surface 3A of the swash plate 3, the entire area of the sliding surface 5A of each shoe 5 is overlapped and moved to the position of the three recesses 11C. (See FIG. 2).

Further, as described above, when a set of three recesses 11C is formed on each end face 11A, 11B of the base material 11, the entire area of both end faces 11A, 11B of the base material 11 is made of a resin coating or a soft metal plating layer. It coat | covers so that it may become the same thickness with the coating layer 12 (refer Fig.4 (a) and FIG.4 (b)).
Then, as shown in FIG. 3 and FIG. 4B, the concave portion 11C formed in the base material 11 is filled with the coating layer 12, but the concave portion 11C of the base material 11 has a conical shape following the shape thereof. The recess 12A is exposed and formed. That is, by covering the both end surfaces 11A and 11B of the base material 11 with the coating layer 12, a set of three recesses 12A is formed on each end surface 11A and 11B (FIG. 2). In this embodiment, the inner diameter of the opening of the recess 11C is set to 0.1 to 5 mm, and the depth d of the recess 11C is set to 0.005 to 1 mm. Further, the thickness t of the coating layer 12 is preferably 10 to 30 μm or more. Further, the inner diameter of the opening of the recess 12A and the depth of the recess 12A are substantially the same as those of the recess 11C in this embodiment, but it is of course possible to set them freely according to the situation. For example, the depth of the concave portion 12A may be smaller than the thickness t of the coating layer 12, and the sum of the thickness t of the coating layer 12 and the depth d of the concave portion 11C (only in a portion overlapping with the concave portion 11C ( The upper limit of t + d) may be larger than the thickness t of the coating layer 12.
In this way, a set of three recesses 12A is exposed on both sliding surfaces 3A and 3B of the swash plate 3.

  As described above, the swash plate 3 according to the present embodiment includes the plurality of recesses 12A for capturing foreign matter on both sliding surfaces 3A and 3B. When a hard foreign substance enters between the sliding surface 5A of each shoe 5 and the foreign substance is dragged by the shoe 5 and passes through the position of each concave part 12A, it is early by any of the concave parts 12A. And is accommodated therein (FIG. 3). At this time, as described above, the set of three recesses 12A are arranged adjacent to each other in the radial direction of the swash plate 3 and so as to overlap each other. Is reliably captured by any of the recesses 12A and accommodated therein (FIG. 3). Alternatively, when a hard foreign matter adheres to the oil film of the lubricating oil formed on the sliding surfaces 3A and 3B of the swash plate 3, the foreign matter is not dragged by the shoe 5 as described above. It rolls together with the lubricating oil and is discharged directly to the outside of the sliding surfaces 3A and 3B by centrifugal force, or is captured and accommodated in the recess 12A.

As described above, according to the swash plate 3 of the present embodiment, even if a foreign object enters between the sliding surfaces 3A and 3B of the swash plate 3 and the sliding surface 5A of the shoe 5, The foreign matter can be captured quickly and efficiently by 12A. Therefore, near the top dead center of the compression side sliding surface 3A and the bottom dead center of the anti-compression side sliding surface 3B in the coating layer 12 where the surface pressure increases as a sliding condition due to foreign matter. As a result, it is possible to prevent the oil film of the lubricating oil from being continuously maintained between the swash plate 3 and the shoe 5. Therefore, it is possible to reduce peeling and overwear of the coating layer 12 which is the sliding surfaces 3A and 3B of the swash plate 3. In addition, since the oil film between the swash plate 3 and the shoe 5 is not interrupted due to the foreign matter, it is possible to prevent the rotational torque from increasing due to the entry of the foreign matter.
Thus, according to the present embodiment, it is possible to provide the swash plate 3 having better sliding characteristics than the conventional one and the swash plate compressor 1 having the swash plate.

Next, FIGS. 6 to 7 show a second embodiment of the present invention. In the first embodiment described above, the recess 12A is formed by exposing the coating layer 12 which is the sliding surfaces 3A and 3B following the recess 11C provided in the substrate 11, but in this second embodiment, Is a flat surface in which the recessed portion 11C of the substrate 11 is completely filled with the coating layer 12 and the filled portion is flush with the surroundings. That is, in the second embodiment, since the concave portion 12A in the first embodiment is also filled with the coating layer 12, the concave portion 11C of the substrate 11 is the coating layer that is the sliding surfaces 3A, 3B. When 12 is viewed from the front, the entire area is flat.
By comprising in this way, the coating layer 12 of the position of each recessed part 11C in the base material 11 is formed about twice as thick as the coating layer 12 of another area | region. Other configurations are the same as those in the first embodiment.
In such a second embodiment, when a foreign object enters between the sliding surfaces 3A, 3B of the swash plate 3 and the sliding surface 5A of the shoe 5, the foreign object that is dragged and moved by the shoe 5 is It is embedded and captured in the coating layer 12 at the position of the recess 11C (FIG. 7). Therefore, also in the second embodiment, the same operation and effect as the first embodiment can be obtained.

In each of the above-described embodiments, a conical concave portion having a large diameter on the opening side is disclosed as the concave portion 11C of the base material 11. However, instead of the conical concave portion, the shape shown in FIGS. A recess may be used. That is, the circular bottomed hole having the same inner diameter shown in FIG. 9, the elliptical bottomed hole shown in FIG. 10, and the square bottomed hole shown in FIG. You may form as.
Further, the cross-sectional shape of the recess 11C of the base material 11 may be V-shaped or U-shaped.
Further, the concave portion 11C of the base material 11 may be a linear or curved groove extending in the radial direction on the end surfaces 11A and 11B of the base material 11, and is V-shaped over the radial direction of the end surfaces 11A and 11B. Either U-shaped or X-shaped grooves may be formed as the recesses 11C. Then, such a groove as a concave portion is also completely filled with a coating layer 12 as shown in FIG. 7, and foreign matter is buried therein.
Note that the cross-sectional shape of the recess 11C of the substrate 11 and the cross-sectional shape of the recess 12A of the coating layer 12 covering the recess 11C do not necessarily have to match. That is, for example, as shown in FIG. 12, the concave portion 11C of the base material 11 is formed in a conical shape in which the cross-sectional shape of each corner is square as in the first embodiment, while the coating layer 12 covering the concave portion 11C is formed. The recess 12A may have a smooth arc shape at the corners.
Furthermore, a plurality of concentric or spiral circumferential grooves may be formed on at least one of the sliding surfaces 3A and 3B of the coating layer 12, and ridges may be formed between adjacent grooves. good. Thereby, initial conformability under boundary lubrication to dry conditions can be improved.

DESCRIPTION OF SYMBOLS 1 ... Swash plate type compressor 2 ... Rotary shaft 3 ... Swash plate 3A, 3B ... Sliding surface 4 ... Piston 5 ... Shoe 11 ... Base material 11A, 11B ... End face 11C ... Concave part 12 ... Coating layer

Claims (6)

A coating layer that is formed in a disc shape and has a pair of flat end surfaces, and a soft coating layer that covers both end surfaces of the substrate, and covers both end surfaces of the substrate. In the swash plate configured to slide with the shoe as a sliding surface,
A slant formed by forming a recess at a predetermined position on at least one of both end faces of the base material, and capturing foreign matter that has entered between the sliding surface and the shoe at the position of the recess. Board.   The location of the coating layer covering the recess of the substrate is formed as a capture recess following the shape of the recess of the substrate, and the foreign matter is captured by the recess of the coating layer. The swash plate according to claim 1.   The concave portion of the base material is completely filled with a coating layer, and has a flat surface similar to the periphery thereof, and the foreign matter is embedded and captured in the coating layer at the position of the concave portion. The swash plate according to claim 1.   A plurality of the recesses are provided within a range of 30 ° on the top dead center side and 60 ° on the bottom dead center side, centering on an intermediate position between the bottom dead center and the top dead center in the circumferential direction of the end face. The swash plate according to any one of claims 1 to 3.   5. The swash plate according to claim 4, wherein the concave portion of the base material is formed of any one of a linear groove, a U-shaped groove, a V-shaped groove, and an X-shaped groove formed in a radial direction. .   The swash plate according to claim 4, wherein the concave portion of the base material is a conical, circular, elliptical, or rectangular concave portion.

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