JPS6241977A - Shoe for swash plate type compressor - Google Patents

Abstract

PURPOSE:To secure required dimensional accuracy while improve resistance to seizing by forming the plane-shaped sliding surface side of a shoe which is slidingly brought into contact with a swash plate, with a material having high resistance to seizing, even though having low machinability. CONSTITUTION:A first sliding member 4 having a plane shaped sliding surface 3 which is slidingly brought into contact with a swash plate 2, is combined in an integrated form with a second sliding member 5 having a projected semispherical surface 7 which is slidingly brought into contact with a piston, by means of a thermoset adhesive, etc., to constitute a shoe 1. The first sliding member 4 having a plane surface and which is easy to machine, is formed with a material such as a ceramic, a sintered hard alloy, etc. which has high resistance to seizing, even though having low machinability. And, the second sliding member 5 having the projected semispherical surface 7 and which is hard to machine, is formed by a material such as an iron group metal and the like which is easily machinable and has been used conventionally.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a swash plate type compressor shoe that interlocks a swash plate and a piston.

``Prior Art'' A swash plate compressor is equipped with a swash plate that is rotated by a rotating shaft in a cylinder block and a piston that is fitted into the cylinder block. It is something that moves people. Conventionally, a shoe and a ball have been used to interlock the swash plate and the piston, with one end surface of the shoe slidingly contacting the swash plate, and a concave hemispherical surface formed on the other end surface of the shoe. The swash plate and the piston are interlocked by interposing a ball between the concave hemispherical surface formed on the piston. Also, as for other chicos,
It is known that the delivery end surface is formed into a convex hemispherical surface, and this convex hemispherical surface is brought into direct sliding contact with the concave hemispherical surface of the piston.

"Problems to be Solved by the Invention" Conventionally known shingles have not caused any particular problems in general use, but with the increase in compression ratio of swash plate type comb l/asa in recent years, There is a growing demand for a shoe that has better seizure resistance than before.

In order to obtain a material with excellent seizure resistance, it is possible to change the material to a material with excellent seizure resistance, such as ceramic ink or cemented carbide, but these materials are generally extremely hard to heat. The fact that it has poor dimensional stability and cannot satisfy the required dimensional accuracy has been a major obstacle to its practical application.

``Means for Solving the Problems'' The present invention proposes that the burning resistance of the shoe is particularly problematic at the sliding contact surface with the swash plate, which has severe sliding conditions. This was done by focusing on the fact that the dynamic conditions are not so severe, and that the sliding surface with the swash plate is almost flat and can be machined relatively easily compared to the other concave or convex hemispherical surface. A swash plate compressor shoe 1 according to the invention includes a first sliding member and a second sliding member that are integrally connected to each other, and the first sliding member has a higher seizure resistance than the second sliding member. The second sliding member is made of a superior material and has a sliding surface that comes into contact with the swash plate, and the second sliding member is made of a material that has better workability than the first sliding member and is directly or It is characterized by having a hemispherical surface that freely slides into contact with the ball via the ball.

"Function" According to such a configuration, the sliding surface of the first sliding member, which has severe sliding conditions, which makes sliding contact with the swash plate has a planar shape that is relatively easy to process. It is possible to manufacture materials with excellent seizure resistance, such as ceramics and cemented carbide, even if the surface is poor, with the required dimensional accuracy.On the other hand, hemispherical surfaces that are relatively difficult to machine Regarding the second sliding member, since the sliding conditions are gentle, it is still possible to use materials with good workability, such as iron-based metals that have traditionally been used for shoes, even if they have relatively poor seizure resistance. It can be manufactured with required dimensional accuracy.

Therefore, the shoe formed by integrally bonding the first sliding member and the second sliding member to each other satisfies all the necessary dimensional accuracy as a whole, and also has good sliding contact with the swash plate, which has severe sliding conditions. Since the surface is made of a material with excellent seizure resistance, it is possible to obtain superior seizure resistance compared to the past.

``Embodiment'' The present invention will be described below with reference to the illustrated embodiment. In FIG. It is provided with a second sliding member 5 which is integrally connected to the first sliding member 4 and is interlocked with a piston (not shown), and has a generally hemispherical shape as a whole.

The first sliding member 4 is made of ceramic with excellent seizure resistance and is formed into a disk shape, and one flat sliding surface 3 is substantially flat or has a slight central portion. The second sliding member 5 is formed into a medium-height shape protruding from the top and is opposite to the sliding surface 3.
The abutting surface 6 is substantially planar. In addition, 1- ceramics include oxides, carbides, nitrides, or mixtures thereof, such as alumina, silicon carbide, silicon nitride, aluminum oxide, titanium carbide, poron carbide, zirconia, Isalon, etc. Further, as the other material of the first sliding member 4, cemented carbide can be used.

On the other hand, the second sliding member 5 is formed into a hemispherical shape using a ferrous metal conventionally used for shoes, and its convex hemispherical surface 7 is brought into sliding contact with a portal-shaped spherical surface of a piston (not shown). , this second sliding member 5 is directly interlocked with the screws. Further, the abutment surface 8 for the first sliding member 4 on the opposite side to the convex hemispherical surface 7 is formed into a substantially flat surface.

In addition, 5UJ-2, 5I5C, 34 are listed as iron-based metals.
5G, 555C, etc. can be used, and it goes without saying that other materials for the second sliding member 5 can be used, such as various materials conventionally used for shoes.

In this embodiment, the abutment surface 6 of the first sliding member 4 is
The first sliding member 4 and the second sliding member 5 are integrally joined by abutting the abutting surface 8 of the second sliding fJJ member 5 and bonding them together with a thermosetting adhesive. are doing.

In this embodiment having the configuration described in -1- below, since the second sliding member 4 on the piston side is manufactured from a ferrous metal conventionally used in shoes, it is natural that the convex hemispherical surface 7 is It is possible to ensure the same dimensional accuracy and seizure resistance as before. The first sliding member 4, which is in sliding contact with the swash plate 2 and has severe sliding conditions, is molded from ceramic with excellent ML hardening properties, and the sliding surface 3, which requires high dimensional accuracy, is as described in 1-1. As it can be formed substantially flat or in a medium-height shape with a slightly protruding center, it is relatively easy to obtain the required dimensional accuracy even with materials that are difficult to work with, such as ceramics. .

Therefore, in the above shoe 1, the sliding surface 3 and the convex hemispherical surface 7 can have the same appropriate dimensions and legal accuracy as conventional ones, and the sliding surface 3, which has severe sliding conditions, is larger than the conventional one. Since it has seizure resistance, superior seizure resistance can be obtained compared to conventional shoes.

2 and 3 respectively show other embodiments of the present invention. In the embodiment shown in FIG. A cylindrical, rectangular, or square-shaped retaining protrusion 10 is formed protrudingly directed toward the
An engagement hole 11 into which the engagement protrusion 10 is fitted into the sliding member 5
The first sliding member 4 and the second sliding member 5 are connected by engaging the engaging projection lO and the engaging hole 11. Further, in the embodiment shown in FIG. 3, a fitting hole 12 is formed in the end surface of the second sliding member 5 on the side of the first sliding member 4, and
One side of the sliding member 4 is press-fitted into the fitting hole 12 and connected. The rest of the structure is the same as that in FIG. 1, and the same or equivalent parts as in FIG. 1 are designated by the same reference numerals as in FIG. 1.

In addition, in the embodiments shown in FIGS. 2 and 3, the retaining protrusion 10
The positions of the first sliding member 4 and the second sliding member 5 may be reversed, or the positions of the first sliding member 4 and the second sliding member 5 may be reversed. Of course, an adhesive may also be used when bonding the sliding member 5.

In addition, in the embodiments described in -■-, the convex hemispherical surface 7 is formed on the second sliding member 5, but it is made into a concave hemispherical surface,
A ball may be interposed between the concave hemispherical surface and the piston to interlock the second sliding member 5 and the piston.

Next, the effects of the present invention will be explained based on the test results shown in FIG. In this test, the dimensional change in the axial direction of the entire shoe was measured.
Shoes B and C according to the present invention manufactured using 5G are comparative materials, and B has the entire shoe made of the same ceramic as the first sliding member 4 of product A of the present invention. C is a conventionally commonly used integral type shoe in which the entire shoe is made of 5UJ-2 and hardened.

At this time, the surface roughness Rz of each of shoes A and C in which the convex hemispherical surface 7 is made of iron-based metal is 1.5 p.
-m, the roundness was 3 JLm, and virtually the same small value was obtained for both shoes A and C, but the surface roughness Rz and roundness of the shoe B, whose convex hemispherical surface was made of ceramic, were They were large at 3.0 gm and 40 gm, respectively, and it was actually difficult to reduce them to less than that.

As is clear from the test results in Figure 4, the dimensional change in the axial direction is large for comparative material B, which is made entirely of ceramic, and such a large dimensional change causes play between the swash plate and the piston. This makes practical use virtually impossible. The reason why such a large dimensional change occurs in comparison material B, which is generally made of hard and wear-resistant ceramic, is that the convex hemispherical surface has poor roundness, which causes uneven contact on the sliding surface between the shoe and the piston. This is thought to be due to the occurrence of abnormal wear on each other locally, and it is also thought that the large surface roughness promotes an increase in the amount of change.

On the other hand, the product A of the present invention also uses ceramic for the first sliding member 4, but as described above, the sliding surface 3
Since it is relatively easy to process, it does not cause local uneven contact like the convex hemispherical surface mentioned above, and even if the surface roughness is rough, it is small compared to the overall dimensional change, so as a result, conventional The amount of dimensional change is the same as C.

Next, FIGS. 5a and 5b show the results of measuring the seizure resistance of shoes A and C, which have small dimensional changes, respectively. In the test shown in Fig. 5a, one drop of lubricating oil was first supplied, and after that, the shul was brought into pressure contact with the Alsil alloy swash plate 2 under a load of 12 kg, and the shul and the swash plate 2 were The time taken to reach seizure was measured with a relative sliding speed of 5 ml sec.

In addition, the test in FIG. 5b shows that 4(lKH
The test was started with the shutter pressed against the swash plate 2 under a load of 1, and the load was increased by 40 kg at each required time, and the load at which seizure occurred was measured.

At this time, the relative sliding speed between shoe 1 and swash plate 2 is 15n+
/sec.

As shown in the test results in Figures 5a and 5b,
Product A of the present invention has superior seizure resistance in all tests compared to conventional shoe C.

Furthermore, Fig. 6 shows that the void occupancy rate in the sliding contact surface 3, that is, the proportion occupied by pores in the ceramic's median surface area, was varied under the same test conditions as in Fig. 5b for product A of the present invention. This figure shows the results of measuring changes in seizure resistance during the test.

As shown in the test results in the same figure, the void occupancy rate is 10
% or less, and in particular, when it is 4% or less, better seizure resistance is obtained compared to Comparative Material C. Furthermore, as can be understood from the test results in Figure 6, Figures 5a and 5
The test shown in Figure b was conducted with the void occupancy rate of product A of the present invention being about 3%.

"Effects of the Invention" As described above, according to the present invention, it is possible to use a material with excellent seizure resistance and to ensure the required dimensional accuracy, so the seizure resistance is more reliable than in the past. This has the effect that it can be improved.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing one embodiment of the present invention, Figures 2 and 3 are
The figures are cross-sectional views showing other embodiments of the present invention, Figure 4 is a diagram showing the test results of measuring the amount of dimensional change in the axial direction of the shoe, and Figures 5a and 5b are tests related to seizure resistance, respectively. A diagram showing the results, FIG. 6 is a diagram showing the test results of measuring the influence of ceramic void occupancy on seizure resistance. l... Shoe 2... Swash plate 3... Sliding surface 4... First sliding member 5... Second sliding member 6.8... Abutment surface 7... Convex shaped hemisphere IO
... Retaining protrusion 11 ... Engagement hole 12 ...
Fitting hole Figure 1 Figure 2 Figure 3 Figure 58 Figure 4 Door Figure 5b Figure 6

Claims (7)

[Claims] (1) A swash plate that is interposed between a swash plate rotated by a rotating shaft in a cylinder block and a piston that is slidably fitted into the cylinder block, and that causes the piston to reciprocate in accordance with the rotation of the swash plate. A shoe for a plate compressor, the shoe comprising a first sliding member and a second sliding member that are integrally connected to each other, the first sliding member having a higher seizure resistance than the second sliding member. The second sliding member is made of a material that has better workability than the first sliding member and has a sliding surface that comes into contact with the swash plate. A shoe for a swash plate type compressor, characterized by comprising a hemispherical surface that is slidably in contact with the shaft through the hemispherical surface. (2) The shoe for a swash plate type compressor according to claim 1, wherein the first sliding member and the second sliding member are bonded together with an adhesive. (3) An engagement protrusion is formed in one of the first sliding member and the second sliding member, and an engagement hole into which the engagement protrusion is fitted is formed in the other, and the engagement protrusion and the engagement hole are formed in the other. Claim 1, characterized in that both sliding members are coupled by engagement with
The shoe for a swash plate compressor according to item 1 or 2. (4) A fitting hole is formed in one of the first sliding member and the second sliding member, and the other sliding member is fitted into the fitting hole to connect both sliding members. A swash plate compressor shoe according to claim 1 or 2, characterized in that: (5) A shoe for a swash plate compressor according to any one of claims 1 to 4, wherein the first sliding member is made of ceramic. (6) A shoe for a swash plate compressor according to claim 5, wherein the ceramic has a void occupancy of 4% or less. (7) A shoe for a swash plate type compressor according to any one of claims 1 to 6, wherein the second sliding member is made of a ferrous metal.