JP2007270994A - Sliding member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sliding member having surface layers formed on one face and on the other face, the surface layers on both faces enduring for an equalized period. <P>SOLUTION: A swash plate 6 of a swash plate compressor 1 should have different sliding properties required for both faces. The surface layer 9 on one face (the face on the side of pushing a piston 4 for compressing refrigerant gas) of the swash plate 6 is formed with a PAI-base resin coating having high non-seizure property. The surface layer 10 on the other face (the face on the side of pulling the piston 4 for sucking the refrigerant gas) of the swash plate 6 is formed with a PBI-base resin coating having high wear resistance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sliding member in which surface layers having different sliding characteristics are provided on one surface and the other surface.

For example, a swash plate compressor used in a car air conditioner has a structure in which a gas refrigerant is sucked into a cylinder and compressed by reciprocating a piston in the cylinder with a rotating swash plate. The swash plate of this swash plate compressor slides on both sides at a high speed on a shoe which is a mating member attached to the piston. In particular, when it is desired to rapidly cool the interior of the vehicle, the operating state of the swash plate compressor is high speed and high load, and the swash plate is placed under severe sliding conditions, and the surface is suddenly damaged and seized. For this reason, the surface layer excellent in non-seizure property is provided on both surfaces of the swash plate (see, for example, Patent Document 1 and Patent Document 2).
JP 2003-278742 A JP 2005-187617 A

The swash plate disclosed in Patent Document 1 is made of a single metal such as Fe, Cu, Al, or both surfaces of a swash plate substrate made of Fe-based alloy, Cu-based alloy, Al-based alloy, etc. A surface layer made of a thermosetting resin is provided. In addition, the swash plate disclosed in Patent Document 2 is a solid material such as MoS ₂ which is contained in fluorine resin particles such as PTFE (polytetrafluoroethylene) and, if necessary, on both front and back surfaces of a steel plate swash plate substrate. A surface layer made of a lubricant and a binder resin such as polyamideimide is provided.

  As described above, the swash plates shown in Patent Document 1 and Patent Document 2 both have a surface layer formed using the same material on both sides. That is, a thrust load for compressing the refrigerant gas by the piston (compression stroke) acts on one surface of the swash plate, and the other surface for sucking the refrigerant gas into the cylinder (suction stroke). Thrust load is applied. In this way, the load acting on both sides of the swash plate is the same type of load (thrust load) even if there is a large or small difference, so of the thrust load acting on both sides, the larger one If the composition component of the surface layer is determined so as to exhibit sufficient non-seizure properties, the surface layer is excellent in non-seizure properties on both sides, and the swash plate can be used for a long time.

However, according to the inventor's experiment, in the conventional swash plate in which the surface layer of the same composition component is formed on both sides, the surface layer on the side where the acting thrust load is small is worn early and cannot be used. Produced.
Thus, when the surface layer made of the same material is formed on both surfaces, the sliding member that the surface layer on one surface cannot withstand early use is not limited to the swash plate of the swash plate compressor described above, There are others.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sliding member in which the service life of both surface layers can be balanced as much as possible in a sliding member having a surface layer formed on one surface and the other surface. Is to provide.

  The present inventor conducted a number of experiments in order to investigate the cause of the difference in the service life of the surface layers provided on both sides of the swash plate of the swash plate compressor. In other words, in the past, both sides of the swash plate differed in size from the shoe existing between the pistons, but both slide at a high speed while receiving a thrust load. It has been said that if both surface layers have excellent non-seizure properties, the service life of the swash plate can be extended. However, as a result of experiments, the inventor of the present invention requires non-seizure on one side of the swash plate, and of course the remaining one side requires a certain degree of non-seizure, but withstands wear rather than seizure. It turns out that is more important.

The present invention is based on such an experiment by the inventors, and is characterized in that surface layers having different sliding characteristics are provided on one surface and the other surface of the sliding member (claim 1).
In the current state of the art, as a material for forming the surface layer, there is no material that exhibits a plurality of sliding characteristics, for example, excellent characteristics in both non-seizure property and wear resistance. For this reason, if the surface layer has excellent anti-seizure properties, wear resistance must be sacrificed. Conversely, if the surface layer has excellent wear resistance, non-seizure properties are sacrificed. However, according to the present invention, the sliding characteristics required for the surface layer formed on one surface and the other surface of the sliding member are investigated, and the surface layer having the sliding characteristics required for each is obtained. Further, it is possible to prevent the difference in the service life between the surface layers on both sides as much as possible. That is, the service life of the surface layers on both sides can be balanced as much as possible.

  In the present invention, of the surface layers provided on one surface and the other surface of the sliding member, one surface layer is excellent in non-seizure property, and the other surface layer is excellent in wear resistance. (Claim 2). In the present invention, one of the surface layers on both sides of the sliding member can be formed of a resin material and the other can be formed of a metal material. Further, in the present invention, it can be used as a swash plate of a swash plate compressor.

  Hereinafter, an embodiment in which the present invention is applied to a swash plate of a swash plate compressor will be described with reference to the drawings. As shown in FIG. 3, the swash plate compressor 1 houses the piston 4 in a plurality of cylinder bores 3 (only one is shown) formed in the cylinder block 2, and reciprocates the piston 4 on the drive shaft 5. The swash plate 6 is fixed. Both sides of the swash plate 6 are brought into sliding contact with a metal shoe 7 attached to the piston 4.

  In the swash plate compressor 1, when the drive shaft 5 is driven to rotate and the swash plate 6 integrated therewith is rotated, the piston 4 reciprocates in the cylinder bore 3 as the swash plate 6 rotates. Due to the reciprocating movement of the piston 4, the refrigerant gas is sucked into the cylinder bore 3 and then compressed and discharged from the cylinder bore 3.

  Such a swash plate compressor 1 is used, for example, as a compressor for a car air conditioner. In car air conditioners, driving is frequently stopped, so the compressor 1 is often in an oil-free operation. In addition, the compressor 1 is forced to operate at high speed and high load when rapidly cooling the interior of a car left under the hot sun. Therefore, considering that the swash plate 6 slides at a high speed and a high load with respect to the shoe 7 in an oil-free state, both sides of the swash plate 6 have front and back surfaces of the iron base 8 as shown in FIG. Surface layers 9 and 10 for improving sliding properties are attached to both surfaces (one surface and the other surface).

  The surface layers 9 and 10 on both sides of the swash plate 6 have different sliding characteristics. That is, the swash plate 6 slides on the both surfaces of the shoe 7 at a high speed while receiving a thrust load from the shoe 7 of the piston 4. The thrust load acting on both surfaces of the swash plate 6 acts on one side when the piston 4 is pushed to compress the refrigerant gas, and on the other side, the piston 4 takes in the refrigerant gas. It works when pulling. For this reason, the thrust load acting on one surface of the swash plate 6 during compression is greater than the thrust load acting on the other surface of the swash plate 6 during suction.

  According to the inventor's research, among the two surfaces of the swash plate 6, the surface that receives a thrust load during compression has a sliding characteristic that requires more seizure than wear resistance. On the receiving surface, it was found that the wear resistance is more important than the non-seizure property even though the thrust load is smaller than the thrust load at the time of compression. Based on this research result, the surface layer 9 on one surface of the swash plate 6 is a PAI (polyamideimide resin) -based resin coating layer having excellent non-seizure properties, and the surface layer 10 on the other surface is excellent in wear resistance. PBI (polybenzimidazole resin) based resin coating layer.

  The surface layers 9 and 10 are not limited to the resin coating described above, and the surface layer 9 may be a PAI-based resin coating layer, and the surface layer 10 may be a surface layer of an Al alloy having excellent wear resistance. Further, as shown in FIG. 2, the surface layer 9 is a PAI-based resin coating layer, and the surface layer 10 is formed of PTFE (polytetrafluoroethylene) on a Cu alloy sintered layer 10a deposited on the surface of the substrate 8. The resin layer may be impregnated and coated.

  Thus, by applying the surface layer 9 excellent in non-seizure property to one surface of the swash plate 6 and the surface layer 10 excellent in wear resistance particularly to the other surface, The problem that only the surface layer of the swash plate 6 becomes unusable first can be solved, the service life of the surface layers on both sides of the swash plate 6 is balanced, and the durability (long life) of the swash plate 6 can be improved. .

In order to confirm the effect when the sliding characteristics of the surface layers 9 and 10 on both surfaces of the swash plate 6 are made different as described above, the present inventor manufactured a plurality of samples to perform a non-seizure test and wear resistance. A test was conducted.
The prepared samples are Examples 1 to 3 and Comparative Examples 1 to 4 of the present invention shown in Table 1 below. Each sample was a swash plate of a swash plate compressor in which the surface layers A, B, C, and D having the composition components shown in Table 2 below were coated on both surfaces.

That is, the surface layer A is obtained by adding 20% by volume of PTFE to PAI, and is applied to the swash plate by spray coating or the like. The surface layer B is obtained by adding 20% by volume of PTFE to PBI, and is applied to the swash plate by spray coating or the like. The surface layer C is made by adding 5% by mass of Sn and 10% by mass of Si to Al, and is applied to the swash plate by pressure welding or the like. The surface layer D is obtained by sintering Cu-based sintered alloy particles on a swash plate and impregnating the sintered layer with PTFE. The above surface layers A, B, C, and D are excellent in non-seizure property and wear resistance, but the surface layer A is particularly excellent in non-seizure property, and the surface layers B, C, and D are particularly excellent in wear resistance. Excellent.

  The comparative products 1 to 4 have the same surface layer on both sides, and the example products 1 to 3 have the surface layer A attached to one surface that presses the piston (the side that compresses the refrigerant gas). The surface layers B, C, and D are respectively attached to the other surface of the piston pulling side (the refrigerant gas sucking side). Therefore, while the comparative products 1 to 4 have the same sliding characteristics on both sides, the examples 1 to 3 have different sliding properties on both sides. In particular, a surface layer 9 having excellent non-seizure properties and a surface layer 10 having particularly excellent wear resistance are provided on the other surface.

  The above sample was actually installed in a swash plate compressor and operated, and evaluated for non-seizure property and wear resistance. The test conditions (operating conditions of the swash plate compressor) are shown in Table 3 below.

  In Table 3, “Constant maximum load” in the item “Load” means that the thrust load acting on the swash plate fluctuates in a sine curve, but the degree of opening of the regulator of the car air conditioner system is constant. This shows that the test was conducted such that the maximum value of the thrust load that fluctuates in a sine curve is constant. The test rotation number was divided into two levels of 5000 rpm and 10,000 rpm, and each was performed for 15 minutes. The meaning of “refrigerant” in the item of “lubrication” is that in a car air conditioner, the lubricating gas is contained in the refrigerant gas passing through the swash plate compressor, and the lubricant is supplied to the swash plate in a mist form. So it shows that. The “partner material” is a shoe that is in sliding contact with the swash plate, and “SUJ2” represents the material of the shoe.

  The test results are good when the swash plate compressor is operated at 5000 rpm and 10000 rpm for 15 minutes, and the wear and seizure states of the surface layers on both sides of the swash plate are visually observed and there is no wear or seizure (indicated by ◯). ), When it was in a state where wear and seizure were conspicuous and could cause problems in performance, it was evaluated as bad (indicated by x). And the durability of the swash plate was evaluated based on them. In this case, the surface layers on both sides were comprehensively viewed as good, and those that were not good were indicated as x.

As a result of the test, in Comparative Examples 1 to 4 in which the surface layers on both sides of the swash plate were the same, one of the surface layers on both sides was judged to be “bad”. In Comparative Example 1 evaluated as having poor wear resistance, damage due to wear was severe on the surface on which the thrust load was applied when refrigerant gas was sucked.
In Comparative Examples 2 to 4, which were evaluated as having poor seizure properties, adhesion to the mating material (shoe) occurred early in terms of thrust load acting when the refrigerant gas was compressed, and this adhesion progressed. The result was seizure.

  In contrast, in Examples 1 to 3, one surface (the surface on which the thrust load acts upon compression) is a surface layer A having excellent non-seizure properties, and the other surface (the surface on which the thrust load acts upon inhalation) is wear-resistant. Since the surface layers B, C, and D have excellent properties, both sides have no problem in wear resistance and non-seizure properties, and as a result, the durability of the swash plate is increased and it can be used for a long time.

The present invention is not limited to the embodiments described above and shown in the drawings, and can be expanded or changed as follows.
The materials constituting the surface layers 9 and 10 on both sides of the swash plate are not limited to those described above.
The sliding member that varies the sliding characteristics of one surface and the other surface is not limited to the swash plate of the swash plate compressor, but is widely used for sliding members that require different sliding characteristics on one surface and the other surface. Can be applied. For example, in a damping material for absorbing vibration of the ground to reduce the shaking of a building, the sliding characteristics of both surfaces may be varied in order to vary the friction coefficient of both surfaces.
Sliding properties include non-seizure, wear resistance, fatigue resistance, conformability, foreign material embedment, corrosion resistance, and erosion resistance. As a surface layer that adheres to both sides of the sliding member, As long as their sliding characteristics are different from each other.

1 is a sectional view of a swash plate of a swash plate compressor according to an embodiment of the present invention. Partial enlarged sectional view of swash plate Cross section of swash plate compressor

Explanation of symbols

  In the drawings, 1 is a swash plate compressor, 2 cylinder block, 4 is a piston, 6 is a swash plate, 7 is a shoe, 8 is a base material, and 9 and 10 are surface layers.

Claims (4)

  A sliding member characterized in that a surface layer having different sliding characteristics is provided on one surface and the other surface.   2. The surface layer provided on each of the one surface and the other surface, wherein one surface layer is excellent in non-seizure property and the other surface layer is excellent in wear resistance. The sliding member as described.   The one surface layer of the one surface and the other surface is formed of a resin material, and the other surface layer is formed of a metal material. Sliding member. The sliding member according to any one of claims 1 to 3,
A sliding member characterized in that it has a plate shape in which the surface layer is formed on both front and back surfaces, and is used as a swash plate of a swash plate compressor.

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