JP2011017269A - Swash plate-type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a swash plate-type compressor which can reduce a friction coefficient between a piston and a shoe when lubrication is insufficient because, for example, the compressor is left for a long period of time, and can prevent seizure during operation.SOLUTION: The swash plate-type compressor includes a cylinder block 11 having a plurality of cylinder bores 25, a drive shaft 17 rotatably supported by the cylinder block, a swash plate 30 which rotates in conjunction with rotation of the drive shaft, a piston 26 slidably contained in the cylinder bore, and the shoe 32 which is provided between the piston and the swash plate and is engaged in a shoe pocket 26b formed in the piston, and the piston reciprocates within the cylinder bore in accordance with rotation of the swash plate. The swash plate-type compressor is characterized in that a protection layer 71 formed of copper or a copper alloy is formed on a slide surface 26c which is in sliding-contact with the shoe in the shoe pocket.

Description

  The present invention relates to a swash plate compressor. More specifically, for example, the present invention relates to a swash plate type compressor constituting a refrigeration cycle of an air conditioner used in an automobile or the like.

  A swash plate compressor widely used in an air conditioner for automobiles is configured such that a swash plate (swash plate, SWP) fixed to be inclined with respect to a rotating shaft is inserted into a recess-shaped shoe pocket formed on a piston via a shoe. It is moored, and the swinging and rotating motion of the swash plate is converted into the reciprocating motion of the piston, and refrigerant gas is sucked, compressed, and discharged. Further, the swash plate type compressor having such a configuration is configured to change the discharge angle of the refrigerant gas by changing the inclination angle of the swash plate by changing the pressure in the crank chamber by the control valve and changing the stroke of the piston. Yes.

  In addition, a shoe constituting a swash plate compressor generally has a flat sliding surface portion and a spherical portion opposite to the sliding surface portion, and a shoe pocket formed on the sliding plane of the swash plate and the piston. The swash plate compressor is used as a refrigerant compressor for an air conditioner and is lubricated by lubricating oil circulating with the refrigerant, but the lubrication is insufficient. There is. In particular, when the operation is not performed for a long time, the lubricant on the swash plate surface is washed away by the refrigerant and may be exposed to severe sliding conditions such as lack of lubricant or no lubrication. In addition, an Al-Si alloy, which is a wear-resistant alloy, is used as the piston, but since Si is a hard particle, the coefficient of friction is high, for example, when operating in a state of insufficient lubrication, especially for a long period of time. When starting up after leaving it, the amount of lubricating oil will be extremely low, causing frictional heat generation between the piston and the shoe, resulting in a high temperature and seizure between the piston and the shoe. It was.

  In order to solve such a problem, it is considered effective to reduce the coefficient of friction between the shoe pocket constituting the piston and the sliding contact portion of the shoe. (See, for example, Patent Document 1 or Patent Document 2).

JP 2000-257555 A (Claim 5, FIG. 1) Japanese Patent No. 3039762 (Claims, FIG. 1)

  However, the protective film by tin plating is insufficient in hardness as a protective film on the sliding surface and easily wears, so that seizure may still occur between the piston and the shoe when the lubricating oil is insufficient. was there. The compressor is acclimated before shipping in the manufacturing process, and is also operated (acclimated) by an engine check, an air conditioner check, or the like when mounted on a vehicle (assembled in an engine) by an automobile manufacturer. It will then be passed to the user. It can happen that the compressor is left for a long time after it is operated. Especially when exported, it will be left for a long time. If left untreated for a long period of time, as described above, the lubricating oil is insufficient and the non-lubricated state is likely to occur, and the possibility of seizure increases. Moreover, although it is rare, it can occur for a long time even under the use conditions of general users. Therefore, since tin is soft, it is easy to wear, and there is a possibility that it will be worn even in a break-in operation as described above. Tin is also a material having an effect of seizure resistance, but if it is worn out and does not remain sufficiently, the effect cannot be expected.

  The present invention has been made in view of the above problems, and reduces the coefficient of friction between the piston and the shoe at the time of insufficient lubrication such as after being left for a long period of time. An object of the present invention is to provide a swash plate compressor capable of preventing seizure.

  In order to achieve the above object, a swash plate compressor according to the present invention rotates a cylinder block having a plurality of cylinder bores, a drive shaft rotatably supported by the cylinder block, and the rotation of the drive shaft. A swash plate; a piston slidably accommodated in the cylinder bore; and a shoe interposed between the piston and the swash plate and engaged with a shoe pocket formed in the piston. In the swash plate compressor in which the piston reciprocates in the cylinder bore in accordance with the rotation of the cylinder, a protective layer made of copper or a copper alloy is formed on a sliding surface in sliding contact with the shoe in the shoe pocket. Features.

  In the swash plate compressor according to the present invention, a second protective layer made of silver or a silver alloy may be further formed on the protective layer made of copper or a copper alloy.

  In the swash plate compressor according to the present invention, an underlayer made of nickel or a nickel alloy may be formed under the protective layer made of copper or a copper alloy.

  In the swash plate compressor according to the present invention, it is preferable that the thickness of the layer formed on the sliding surface in sliding contact with the shoe in the shoe pocket is 1.0 to 2.0 μm.

  According to the swash plate compressor according to the present invention, a protective layer made of copper or a copper alloy, which is superior in hardness to tin, is formed on the sliding surface in sliding contact with the shoe in the shoe pocket constituting the piston. Sufficient hardness as a protective film for the sliding surface, suppresses wear between the piston and the shoe, etc., even when the lubricating oil is insufficient, such as after being left for a long time, or in an unlubricated state, and seizure occurs between them Can be efficiently prevented.

It is the section schematic diagram showing one embodiment of the swash plate type compressor concerning the present invention. It is the elements on larger scale of FIG. 1, Comprising: It is the figure which showed the sliding contact state of a shoe and a shoe pocket. It is sectional drawing which showed the layer structure on the sliding surface. It is the figure which showed other embodiment of the swash plate type compressor which concerns on this invention, Comprising: It is the figure which showed the sliding contact state of a shoe and a shoe pocket. It is sectional drawing which showed the layer structure on the sliding surface containing a 2nd protective layer. In the swash plate type compressor which concerns on 1st Embodiment, it is sectional drawing which showed the other aspect of the layer structure on a sliding surface. In Experiment 1, it is the figure which showed time until an Example and a comparative example lock.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(1) First embodiment:
FIG. 1 is a schematic cross-sectional view showing an embodiment of a swash plate compressor according to the present invention. A swash plate compressor according to the present invention (hereinafter sometimes simply referred to as a “compressor”) is used in, for example, a vehicle air conditioner, and is hereinafter referred to as a reciprocating variable capacity type that is an embodiment of a swash plate compressor. The configuration of the swash plate compressor will be described as an example, but the present invention should not be construed as being limited to these descriptions.

  As shown in FIG. 1, the swash plate compressor 1 is a magnetic clutch type that receives power from the traveling engine 2 and rotates in synchronization with the traveling engine 2, and includes a condenser 3, a pressure reducing device 4, A refrigerating cycle 6 is constructed by pipe connection with the evaporator 5 and the like, and the discharge pressure is controlled to adjust the suction pressure. As shown in FIG. 1, the compressor 1 includes a cylinder block 11, a rear head 13 assembled via a valve plate 12 on the rear side (right side in the drawing) of the cylinder block 11, and the front side of the cylinder block 11. And a front head 14 assembled so as to close (left side in the figure). The front head 14, the cylinder block 11, the valve plate 12, and the rear head 13 are fastened in the axial direction by fastening bolts 15, and constitute a housing of the entire compressor.

  A crank chamber 16 defined by the front head 14 and the cylinder block 11 accommodates a drive shaft 17 having one end protruding from the front head 14. A relay member 19 attached in the axial direction by a bolt 18 is fixed to a portion of the drive shaft 17 protruding from the front head 14. The relay member 19 is rotatably fitted to the side portion of the front head 14. The drive pulley 20 connected to the traveling engine 2 via a belt is fixed by means such as screwing. Further, one end side of the drive shaft 17 is hermetically sealed with the front head 14 via a seal member 21 provided between the front shaft 14 and is rotatably supported by a radial bearing 22. The other end of the drive shaft 17 is rotatably supported by a radial bearing 23 accommodated in the cylinder block 11.

  The cylinder block 11 has a through hole 24 in which the radial bearing 23 is accommodated, a gap 46 that communicates with the through hole 24 and is adjacent to the other end of the drive shaft 17, and the through hole 24 and the gap 46 are the center. A plurality of cylinder bores 25 arranged at equal intervals are formed on the circumference. A piston 26 is inserted into each cylinder bore 25 so as to be able to reciprocate. The piston 26 is formed hollow by joining a head portion 26 a inserted into the cylinder bore 25 and a shoe pocket 26 b protruding into the crank chamber 16 in the axial direction.

  A thrust flange 27 that rotates integrally with the drive shaft 17 in the crank chamber 16 is fixed to the drive shaft 17. The thrust flange 27 is rotatably supported with respect to the front head 14 via a thrust bearing 28. A swash plate 30 is connected to the thrust flange 27 via a link member 29. The swash plate 30 is attached so as to be tiltable around a hinge ball 31 provided on the drive shaft 17, and rotates integrally with the rotation of the thrust flange 27. The swash plate 30 is moored in the shoe pocket 26b of the piston 26 via a pair of shoes 32 provided on the front and back of the peripheral portion. Inside the shoe pocket, the shoe pocket 26 b and the sliding surface 26 c are in sliding contact with the shoe 32.

  Therefore, when the drive shaft 17 rotates, the swash plate 30 rotates along with this, and the rotational motion of the swash plate 30 is converted into the reciprocating linear motion of the piston 26 via the shoe 32 moored in the shoe pocket 26b. The volume of the compression chamber formed between the piston 26 and the valve plate 12 in the cylinder bore 25 is changed.

  A suction hole 34 and a discharge hole 35 are formed in the valve plate 12 corresponding to each cylinder bore 25. Further, the rear head 13 is provided with a suction chamber 36 for storing the refrigerant to be supplied to the compression chamber, and a discharge chamber 37 for storing the refrigerant discharged from the compression chamber. The suction chamber 36 is formed in the central portion of the rear head 13, communicates with a suction port (not shown) that communicates with the outlet side of the evaporator 5, and can communicate with the compression chamber via the suction hole 34 of the valve plate 12. ing. The discharge chamber 37 is continuously formed around the suction chamber 36, communicates with a discharge port (not shown) leading to the inlet side of the condenser 3, and is compressed through the discharge hole 35 of the valve plate 12. Communication with the room is possible. Here, the suction hole 34 is opened and closed by a suction valve 39 provided on the front side end face of the valve plate 12, and the discharge hole 35 is opened and closed by a discharge valve 40 provided on the rear side end face of the valve plate 12. It has become. The suction chamber 36 communicates with the gap 46 via a through hole 42 and a control valve 43 provided in the valve plate 12.

  The discharge capacity of the compressor 1 is determined by the stroke of the piston 26, which is the pressure applied to the front surface of the piston 26, that is, the pressure in the compression chamber (pressure in the cylinder bore 25) and the pressure applied to the back surface of the piston, That is, it is determined by the differential pressure with respect to the pressure in the crank chamber 16 (crank chamber pressure Pc). Specifically, if the pressure in the crank chamber 16 is increased, the differential pressure between the compression chamber and the crank chamber 16 is reduced, so that the inclination angle (swinging angle) of the swash plate 30 is reduced. 26, the discharge capacity is reduced, and conversely, if the pressure in the crank chamber 16 is reduced, the differential pressure between the compression chamber and the crank chamber 16 is increased. The angle) increases, and the stroke of the piston 26 increases and the discharge capacity increases.

  In the compressor 1, an air supply passage 41 that is formed across the cylinder block 11, the valve plate 12, and the rear head 13 and that connects the discharge chamber 37 and the crank chamber 16 is formed. A control valve 43 is arranged in the air supply passage 41.

  Further, the compressor 1 is provided with an in-axis passage 50 that constitutes a part of the refrigerant path along the axis of the drive shaft 17. An opening 53 is provided on one end side (right side in FIG. 1) of the in-shaft passage 50 so as to communicate with the gap 46. Further, the drive shaft 17 communicates with the in-shaft passage 50 from the side wall of the drive shaft 17 in the vicinity of the contact portion between the thrust bearing 52 and the drive shaft 17 in the vicinity of the contact portion between the thrust bearing 52 and the drive shaft 17. An in-shaft through hole 51b is provided. Then, the refrigerant in the crank chamber 16 flows through the gap between the thrust bearing 28 that supports the thrust flange 27 and the inner wall of the crank chamber 16, and further flows into the gap of the radial bearing 22. Further, the refrigerant flows into the in-shaft passage 50 through the in-shaft through hole 51a. Further, the refrigerant flows from the crank chamber 16 to the in-shaft passage 50 through the in-shaft through hole 51b. Thus, the refrigerant flowing into the in-shaft passage 50 is blown out from the opening 53 into the gap 46. Then, the refrigerant passes through a through hole 42 provided in the valve plate 12 and is sent to the suction chamber 36 via the control valve 43. In this way, an extraction passage that communicates the crank chamber 16 and the suction chamber 36 is formed. The refrigerant path formed by the in-shaft passage 50, the gap 46, and the through hole 42 constitutes a part of the refrigerant path that connects the crank chamber 16 and the suction chamber 37 via the control valve 43 that controls the flow rate of the refrigerant. Will be. In addition, the arrow in FIG. 1 shows the flow direction of a refrigerant | coolant (oil) (it is the same also in another figure).

  In the compressor 1, the control valve 43 is provided on both the air supply passage 41 and the extraction passage as described above. The control valve 43 is mounted in a control valve mounting hole 45 formed in the rear head 13 and adjusts the opening of the supply passage 41 and the opening of the extraction passage, thereby adjusting the pressure of the crank chamber 16 (crank chamber pressure Pc). ), And has an actuator such as an electromagnetic solenoid, and the opening of the air supply passage is controlled by adjusting the amount of current supplied to the solenoid.

  In the compressor 1 of FIG. 1, a filter 60 is disposed so that the refrigerant is filtered into the gap 46. In the three-way control valve, the spool valve has a small hole diameter, so it is difficult to mix foreign particles such as wear powder and dust. This is because it also dislikes the mixing of foreign substances. Here, the gap 46 is preferably a cylindrical space, and the filter 60 is preferably a bowl-shaped filter that can be accommodated in the cylindrical space.

  FIG. 2 is a partially enlarged view of FIG. 1 and shows a sliding contact state of the shoe 32 and the shoe pocket 26b. FIG. 3 is a cross-sectional view showing the layer structure on the sliding surface 26c (in FIG. 2, an underlayer 72 made of nickel or a nickel alloy and a zinc treatment layer 73 made of zinc are shown later. Not.)

The piston 26 including the shoe pocket 26b is made of aluminum or aluminum alloy as a base material. As the aluminum alloy, for example, an Al—Si alloy, an Al—Si—Cu alloy, or the like can be used. Further, the shoe 32 can be made of, for example, a SUJ2 material (a high carbon chromium bearing steel material), which is a representative bearing steel, and a SUJ2 material including alumina ceramics (Al ₂ O ₃ ) as a base material.

  As shown in FIGS. 2 and 3, in the swash plate compressor 1 according to the present invention, a protective layer 71 including a layer made of copper or a copper alloy is formed on a sliding surface 26c in sliding contact with a shoe 32 in a shoe pocket 26b. Has been. Copper used as the protective layer 71 has a viscous hardness of 100 to 160 HV, is very hard compared to tin (viscus hardness = 5 to 7 HV), has sufficient hardness as a protective film for the sliding surface 26c, and wears. Therefore, seizure between the shoe 32 and the shoe pocket 26b of the piston 26 can be prevented. In addition, if the protective layer is made of a metal harder than copper or a copper alloy, the protective layer is easily peeled off, and if it is actually peeled off, the inside of the swash plate compressor may be damaged. By using a copper alloy, the possibility of damaging the inside of the swash plate compressor is extremely low. Moreover, since copper is harder than tin, it is estimated that a friction coefficient is small.

  As shown in FIG. 3, in the present embodiment, in addition to the protective layer 71 made of copper or a copper alloy serving as the outermost layer, a base layer 72 made of nickel or a nickel alloy, and a zinc treatment layer 73 made of zinc. Are formed in this order between the protective layer 71 and the sliding surface 26c as viewed from the protective layer 71. By forming a base layer 72 made of nickel or a nickel alloy under the protective layer 71 made of copper or a copper alloy (on the piston 26 side), the adhesion of copper is improved, and in particular, made of copper or a copper alloy. This is optimal when the protective layer 71 is formed by plating (described later). Moreover, an effect can be maintained for a long time by the adhesiveness of copper improving.

  As shown in FIG. 3, it is preferable to form a zinc treatment layer 73 made of zinc between the sliding surface 26 c of the shoe pocket 26 b and the base layer 72. By forming the zinc treatment layer 73, the base layer 73 and the like are efficiently formed, and the adhesion of the layer is also improved. The thickness of the zinc treatment layer 73 made of zinc is preferably 50 nm or less. When it becomes thicker than 50 nm, aluminum is melted greatly, and Si comes to protrude. Si has a property that is difficult to be plated. The zinc treatment layer 73 can be easily formed by a zinc substitution method, that is, a method in which at least the shoe pocket 26b of the aluminum alloy piston 26 is immersed in a solution containing zinc ions and zinc is chemically deposited on the surface thereof. Can do. At this time, the alumina layer (deposited by oxidation of aluminum) deposited on the surface of the shoe pocket 26b is removed.

  The thickness of the layer formed on the sliding surface 26c of the shoe pocket 26b (the total of the protective layer 71, the base layer 72, and the zinc treatment layer 73 in the present embodiment) is as shown in FIG. Although there is no restriction | limiting in particular, It is preferable to set it as 1.0-2.0 micrometers, More preferably, it is 1.0-1.5 micrometers. If the thickness of the layer is less than 1.0 μm, it may be lost due to wear and the effects of the present invention may not be achieved. On the other hand, when the thickness of such a layer exceeds 2.0 μm, there arises a problem in strength such that the protective layer 71 and the like are easily peeled off, and a gap generated by peeling or wearing of the protective layer 71 is a shoe pocket. 26b and the shoe 32 may be easily rattled.

  Moreover, when forming the base layer 72 which consists of nickel or a nickel alloy as shown in FIG. 3, the protective layer 71 which consists of copper or a copper alloy should just be 0.5-1.5 micrometers. The underlayer 72 made of nickel or a nickel alloy may be 0.5 μm or less.

  The protective layer 71 made of copper or a copper alloy may be made of a copper alloy containing copper as a main component in addition to copper alone. Similarly, the underlayer 72 made of nickel or a nickel alloy is also made of nickel alone. In addition to this, it may be formed of a nickel alloy containing nickel as a main component. As a metal to be alloyed with copper or nickel, for example, copper (as a nickel alloy), nickel (as a copper alloy), zinc, lead, indium, or phosphorus (as a nickel alloy) can be used.

  The means for forming the protective layer 71 made of copper or a copper alloy or the base layer 72 made of nickel or a nickel alloy is not particularly limited, but is preferably formed by plating. In addition, wet plating methods such as electroless plating and chemical plating, CVD (Chemical Vapor Deposition), PVD (Physical Vapor Deposition), vacuum deposition Further, a dry plating method such as sputtering can be used, and a composite plating method can also be used.

  As described above, the swash plate compressor 1 according to the present embodiment is made of copper or a copper alloy, which is superior in hardness to tin, on the sliding surface 26c in sliding contact with the shoe 32 in the shoe pocket 26b constituting the piston 26. Since the protective layer 71 is formed, it has sufficient hardness as a protective film for the sliding surface 26c, and even between the piston 26 and the shoe 32, etc., even in the operation when lubrication is insufficient such as after being left for a long period of time. Since wear can be suppressed, seizure between them can be efficiently prevented.

  The swash plate compressor 1 of the present invention having such a configuration is used for a fixed capacity compressor constituting a refrigeration cycle of an air conditioner used in an automobile or the like, a variable capacity compressor using carbon dioxide or the like as a refrigerant, or the like. be able to.

(2) Second embodiment:
In the first embodiment described above, a protective layer 71 made of copper or a copper alloy is formed on the sliding surface 26c and appears on the surface as the outermost layer. However, the present invention is not limited to this, and FIG. As shown in FIG. 5, a layer (second protective layer 74) made of silver or a silver alloy may be further formed on the protective layer 71 made of copper or a copper alloy.

  In the following description, only the main part of the swash plate compressor 1 according to the present invention is shown and described, and the other parts are not shown and described. Further, the same structure and the same members as those of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

  FIG. 4 is a view showing another embodiment of the swash plate compressor 1 according to the present invention, and is a view showing a sliding contact state of the shoe 32 and the shoe pocket 26b, and FIG. 7 is a cross-sectional view showing a layer configuration on a sliding surface 26c including a protective layer 74. FIG. (Note that FIG. 4 does not show the base layer 72 made of nickel or a nickel alloy and the zinc treatment layer 73 made of zinc, as in FIG. 2).

  In the present embodiment, a second protective layer 74 made of silver or a silver alloy is further formed on the protective layer 71 made of copper or a copper alloy in the configuration shown in FIG. 3 of the first embodiment. ing. Silver has a hardness of 55 to 130 HV, which is harder than that of tin (viscus hardness = 5 to 7 HV), and even when peeled off due to wear, a protective layer 71 made of copper or a copper alloy is formed below. Therefore, wear of the sliding surface can be suppressed, and seizure between the shoe pocket shoe 26 and the shoe 32 of the piston 26 can be prevented.

  The thickness of the layer formed on the sliding surface 26c of the shoe pocket 26b (in this embodiment, the total of the protective layer 71, the underlayer 72, the zinc treatment layer 73, and the second protective layer 74) is as shown in FIG. Similarly to the configuration of 3, it is preferably 1.0 to 2.0 μm, and more preferably 1.0 to 1.5 μm. Moreover, in the structure of FIG. 5, the 2nd protective layer 74 which consists of silver or a silver alloy is 0.3-0.4 micrometer, and the protective layer 71 which consists of copper or a copper alloy is 0.1-0. What is necessary is just to be 2 micrometers. The underlayer 72 made of nickel or a nickel alloy may have the same thickness as that shown in FIG.

  The second protective layer 74 made of silver or a silver alloy may be formed of a silver alloy containing silver as a main component in addition to the simple silver, like the protective layer 72 made of copper or a copper alloy. Good. As a metal to be alloyed with silver, for example, copper, nickel, zinc, lead, and indium can be used. Further, as a means for forming the second protective layer 74 made of silver or a silver alloy, it is preferable to form by plating similarly to the protective layer 71 made of copper or a copper alloy as described above. The publicly known techniques mentioned for the protective layer 71 and the like can be applied.

  In the swash plate compressor 1 according to the present embodiment, a protective layer 71 made of copper or a copper alloy having a hardness higher than that of tin is formed on the sliding surface 26c that is in sliding contact with the shoe 32 in the shoe pocket 26b constituting the piston 26. Further, since the second protective layer 74 made of silver or a silver alloy, which is also superior in hardness to tin, is formed thereon, it has sufficient hardness as a protective film for the sliding surface 26c and is left for a long period of time. Even during operation when lubrication is insufficient, for example, the wear between the piston 26 and the shoe 32 can be suppressed, and seizure between them can be efficiently prevented.

(3) Modification of the embodiment:
The aspect described above shows one aspect of the present invention, and the present invention is not limited to the above-described embodiment, and has the configuration of the present invention and can achieve the objects and effects. It goes without saying that modifications and improvements within the scope are included in the content of the present invention. Further, the specific structure, shape, and the like in carrying out the present invention are not problematic as other structures, shapes, and the like as long as the objects and effects of the present invention can be achieved. The present invention is not limited to the above-described embodiments, and modifications and improvements within the scope that can achieve the object of the present invention are included in the present invention.

  For example, in the first embodiment and the second embodiment described above, the base layer 72 made of nickel or nickel alloy is formed under the protective layer 71 made of copper or copper alloy (on the piston 26 side). Although shown, it is not limited to this, and as shown in FIGS. 6 and 7, a configuration in which the underlayer 72 made of nickel or a nickel alloy is not formed may be adopted.

  6 is a cross-sectional view showing another aspect of the layer configuration on the sliding surface 26c in the swash plate compressor 1 according to the first embodiment, and FIG. 7 is a swash plate compressor 1 according to the second embodiment. FIG. 3 is a cross-sectional view showing another aspect of the layer configuration on the sliding surface 26c. The layer configuration shown in FIGS. 6 and 7 does not form the base layer 72 made of nickel or a nickel alloy. By not forming the underlayer 72 made of nickel or a nickel alloy, the adhesion of the protective layer 71 made of copper or a copper alloy is slightly reduced as compared with the case where the underlayer 72 is formed. The effect can be maintained, and the underlayer 72 made of nickel or nickel alloy has a high hardness, so the underlayer 72 made of peeled nickel or nickel alloy may damage the inside of the swash plate compressor 1. It is effective when you dislike such scratches.

  Even when the underlayer 72 made of nickel or a nickel alloy is not formed as shown in FIG. 6, the layers formed on the sliding surfaces of the shoe pockets (in FIG. 6, the protective layer 71 and the zinc-treated layer 73 are not formed). The total thickness is preferably 1.0 to 2.0 μm, and more preferably 1.0 to 1.5 μm. Further, the protective layer 71 made of copper or copper alloy may be 1.0 to 2.0 μm in the configuration of FIG.

In addition, the specific structure, shape, and the like when implementing the present invention may be other structures as long as the object of the present invention can be achieved.

EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to this Example at all.

[Example 1]
The swash plate type compressor having the configuration shown in FIG. 1 has the layer configuration shown in FIG. 3 on the sliding surface in sliding contact with the shoe of the shoe pocket in the swash plate type compressor, and the thickness of each layer is as follows. A swash plate compressor was obtained. The copper layer and the nickel layer were formed by an electrolytic plating method, and the zinc treatment layer was formed by a zinc substitution method. The piston including the shoe pocket is made of an aluminum alloy, and the shoe is made of bearing steel.
(Thickness of each layer)
Copper layer (protective layer) 0.5 μm
Nickel layer (underlayer) 0.45 μm
Zinc treatment layer 50nm

[Example 2]
In Example 1, the swash plate type of the present invention is the same as Example 1 except that the sliding surface of the shoe pocket in sliding contact with the shoe has the layer configuration of FIG. 6 and the thickness of each layer is as follows. A compressor was obtained.
(Layer structure and thickness)
Copper layer (protective layer) 0.95 μm
Zinc treatment layer 50nm

[Example 3]
In Example 1, the swash plate type of the present invention is the same as Example 1 except that the sliding surface of the shoe pocket in sliding contact with the shoe has the layer configuration of FIG. 5 and the thickness of each layer is as follows. A compressor was obtained.
(Layer structure and thickness)
Silver layer (second protective layer) 0.3 μm
Copper layer (protective layer) 0.2 μm
Nickel layer (underlayer) 0.45 μm
Zinc treatment layer 50nm

[Comparative Example 1]
In Example 2, a swash plate compressor was obtained as the same configuration as in Example 1 except that a layer (tin layer) made of tin plating was formed instead of the copper layer, and the thickness of each layer was as follows. It was.
(Layer structure and thickness)
Tin layer (protective layer) 0.95μm
Zinc treatment layer 50nm

[Comparative Example 2]
In the first embodiment, the swash plate compressor has the same configuration as that of the first embodiment except that no protective layer or the like is formed on the sliding surface and the sliding surface of the shoe pocket appears on the surface. Got.

[Test Example 1]
The swash plate compressors obtained in Examples 1 to 3, Comparative Example 1 and Comparative Example 2 were subjected to a non-lubrication test. Such a non-lubricating test was conducted after 24 hours of running-in in advance, and the time until the vehicle was operated in a non-lubricated state according to the following conditions and locked (operation stopped) was compared and evaluated. FIG. 7 shows the time until the example and the comparative example are locked (relative value with respect to the time of the criterion). In addition, the time of the criterion determined beforehand was set to 100, and it passed as the time when it was longer than it until it locked.
(Test conditions)
Compressor rotation speed = 1000 rpm
Pressure: Equilibrium pressure (Gauge pressure is about 0.5Mpa)

  As shown in FIG. 8, Examples 1 to 3 exceeded the criterion time, and all were good results. In particular, Example 1 in which the copper layer (protective layer) and the nickel layer (underlayer) were formed was able to maintain the operation in the unlubricated state at least twice as long as the criterion time. On the other hand, in Comparative Example 1 in which the tin layer was formed on the sliding surface, the lock was applied in less than the criterion time, and in Comparative Example 2 in which no layer such as a protective layer was formed on the sliding surface, the time was shorter. The results were inferior to those of the examples.

  The swash plate compressor of the present invention can be used as, for example, a vehicle air conditioner in the automobile industry.

DESCRIPTION OF SYMBOLS 1 Swash plate type compressor 2 Engine for driving | running | working 3 Condenser 4 Pressure reducing device 5 Evaporator 6 Refrigeration cycle 11 Cylinder block 12 Valve plate 13 Rear head 14 Front head 15 Fastening bolt 16 Crank chamber 17 Drive shaft 18 Bolt 19 Relay member 20 Drive pulley 21 Seal member 22, 23 Radial bearing 24 Through hole 25 Cylinder bore 26 Piston 26a Head 26b Shoe pocket 26c Sliding surface 27 Thrust flange 28 Thrust bearing 29 Link member 30 Swash plate 31 Hinge ball 32 Shoe 34 Suction hole 35 Discharge hole 36 Suction chamber 37 Discharge chamber 39 Suction valve 40 Discharge valve 41 Air supply passage 42 Through hole 43 Control valve 45 Control valve mounting hole 46 Void portion 50 In-shaft passage 53 Openings 51a, 51b In-shaft passage hole 52 Thrust bearing 60 Filter 60a Filter bottom 71 Protective layer 72 Underlayer 73 Zinc-treated layer 74 Second protective layer

Claims (4)

A cylinder block having a plurality of cylinder bores, a drive shaft rotatably supported by the cylinder block, a swash plate rotating as the drive shaft rotates, a piston slidably received in the cylinder bore, and the piston And a swash plate compressor that includes a shoe that engages with a shoe pocket formed in the piston, and the piston reciprocates in the cylinder bore as the swash plate rotates. In
A swash plate type compressor, wherein a protective layer made of copper or a copper alloy is formed on a sliding surface in sliding contact with the shoe in the shoe pocket.   The swash plate compressor according to claim 1, wherein a second protective layer made of silver or a silver alloy is further formed on the protective layer made of copper or a copper alloy.   The swash plate compressor according to claim 1 or 2, wherein a base layer made of nickel or a nickel alloy is formed under the protective layer made of copper or a copper alloy. 4. The swash plate compressor according to claim 1, wherein a thickness of a layer formed on a sliding surface in sliding contact with the shoe in the shoe pocket is 1.0 to 2.0 μm. .

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