JP2010019091A - Swash plate compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swash plate compressor capable of satisfying both of seizure resistance and wear resistance between a swash plate and a shoe. <P>SOLUTION: This swash plate compressor is provided with the swash plate 8 provided in such a manner that the same can rotate synchronously with a drive shaft 5 in a crank chamber 6, and a pair of shoes 20a, 20b provided between the swash plate 8 and a piston 10 and converting oscillating motion of the swash plate 8 to reciprocating motion of the piston 10. Shoe sliding surfaces 82a, 83a on which the shoes 20a, 20b slides are formed on the swash plate 8. The shoe sliding surface 83a is divided in a circumference direction into a first coating C1 made of resin containing solid lubricant and second coating C2 having foreign substance embedding property. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a swash plate compressor.

  Patent Document 1 discloses a conventional swash plate compressor. This swash plate compressor includes a housing that forms a cylinder bore, a crank chamber, a suction chamber, and a discharge chamber therein, a piston that is reciprocally accommodated in the cylinder bore and defines a compression chamber in the cylinder bore, and an external drive source. A drive shaft that is driven and rotatably supported by the housing, a swash plate that is provided so as to be able to rotate synchronously with the drive shaft in the crank chamber, and a pair of swash plates and pistons, And a shoe for converting the swinging motion into the reciprocating motion of the piston. The swash plate is formed with a shoe sliding surface on which one shoe slides and a shoe sliding surface on which the other shoe slides.

  The shoe sliding surfaces are formed on both sides of the swash plate, and one shoe sliding surface is formed of a PAI coating layer mainly composed of PAI (polyamideimide) with excellent seizure resistance, and the shoe sliding surface on the other surface. The surface is formed of a PBI coating layer mainly composed of PBI (polybenzimidazole) having excellent wear resistance.

JP 2007-270994 A

  By the way, in the swash plate compressor, foreign matter such as wear powder is inevitably generated in the crank chamber, and the foreign matter may enter a gap formed between the swash plate and the shoe. In that case, in the conventional swash plate compressor, the PAI coating layer on one surface of the swash plate is easily worn by the foreign matter. For this reason, there is a possibility that the seizure resistance based on the PAI coating layer between the swash plate and the shoe may be lowered.

  However, at present, there is no material excellent in both seizure resistance and wear resistance, so even if one surface of the swash plate is replaced with a PAI coating layer and formed of a wear resistant material, In such a case, the seizure resistance itself between the swash plate and the shoe cannot be obtained.

  The present invention has been made in view of the above-described conventional situation, and provides a swash plate compressor that can satisfy both seizure resistance and wear resistance between a swash plate and a shoe. This is a problem to be solved.

The swash plate compressor of the present invention includes a housing that forms a cylinder bore, a crank chamber, a suction chamber, and a discharge chamber therein, a piston that is reciprocally accommodated in the cylinder bore and that defines a compression chamber in the cylinder bore, A drive shaft driven by an external drive source and rotatably supported by the housing; a swash plate provided in a synchronized manner with the drive shaft in the crank chamber; and a pair of the swash plate and the piston A swash plate compressor having a shoe sliding surface on which the shoe slides is formed on the swash plate. In
The shoe sliding surface is characterized in that it is divided in the circumferential direction by a first film made of a resin containing a solid lubricant and a second film having a foreign substance burying property.

  In the swash plate compressor of the present invention, the shoe sliding surface of the swash plate has a first coating, and the first coating is made of a resin containing a solid lubricant, so that the swash plate has excellent seizure resistance between the shoe and the shoe. Demonstrate sex. Further, in this swash plate type compressor, since the shoe sliding surface of the swash plate has the second coating, and the second coating has a foreign matter burying property, the foreign matter generated in the crank chamber is separated from the swash plate and the shoe. The foreign matter is captured by the second film even if it enters between the two. For this reason, the wear resistance of the first coating is also exhibited. The gap between the swash plate and the shoe does not become excessively large, the shoe suitably follows a change in the posture of the swash plate, and good seizure resistance between the swash plate and the shoe is maintained.

  Therefore, the swash plate compressor of the present invention can satisfy both seizure resistance and wear resistance between the swash plate and the shoe. For this reason, this swash plate type compressor can exhibit excellent durability.

  The swash plate type compressor of the present invention may be of a variable capacity type including a swash plate whose inclination angle can be varied with respect to the drive shaft, and further includes a swash plate whose inclination angle is fixed with respect to the drive shaft. It may be of a fixed capacity type. The piston may be a single-headed piston having one piston head or a double-headed piston having two piston heads.

  In the swash plate compressor of the present invention, the first coating is formed on a pressing portion that is a portion to which the shoe is pressed among the shoe sliding surfaces, and the second coating is the shoe separating on the shoe sliding surfaces. Preferably, it is formed in a separation portion that is a portion to be formed (claim 2).

  The swash plate of the swash plate compressor is formed with a shoe sliding surface on which one shoe slides and a shoe sliding surface on which the other shoe slides. Each shoe sliding surface has a pressing portion that is a portion where the shoe is pressed and a separation portion that is a portion where the shoe is separated.

  In other words, the swash plate of a swash plate type compressor that employs a single-headed piston has a pressing portion of the shoe sliding surface on the piston head side causing the piston to perform a compression stroke, and a pressing portion of the shoe sliding surface on the anti-piston head side is the piston. To perform the inhalation stroke. At this time, on the shoe sliding surfaces on the piston head side and the anti-piston head side, a separation portion is generated by being shifted 180 degrees in the circumferential direction from the pressing portion. In other words, in this swash plate compressor, the top dead center position of the shoe sliding surface on the piston head side and the bottom dead center position of the shoe sliding surface on the anti-piston head side are included in the pressing portion, and the shoe on the anti-piston head side The top dead center position of the sliding surface and the bottom dead center position of the shoe sliding surface on the piston head side are included in the separation portion.

  Further, in a swash plate of a swash plate type compressor that employs a double-headed piston, the pressing portions of one and the other shoe sliding surfaces cause the piston to perform a compression stroke. At this time, the one and other shoe sliding surfaces have separated portions that are 180 degrees apart from the pressing portion in the circumferential direction, and these separated portions cause the piston to perform a suction stroke. That is, in this swash plate compressor, the top dead center position of one shoe sliding surface is included in the bottom dead center position of the other shoe sliding surface, and the bottom dead center position of one shoe sliding surface is the other dead center position. It is included in the top dead center position of the shoe sliding surface. The top dead center position of the one and other shoe sliding surfaces is included in the pressing portion, and the bottom dead center position of the one and other shoe sliding surfaces is included in the separation portion.

  The foreign matter enters between the swash plate and the shoe at the separated portion of the shoe sliding surface. The foreign matter moves to the pressing portion of the shoe sliding surface, and wears the shoe sliding surface. For this reason, if the 1st coat is formed in the press part and the 2nd coat is formed in the separation part, a foreign substance can be caught with the 2nd coat, and the 1st coat is hard to be worn by a foreign substance.

  According to the test results of the inventors, it is preferable that the first coating is formed in 50 to 90% of the entire area of the pressed portion (Claim 3). When the first film is less than 50% of the total area of the pressed portion, the seizure resistance is not sufficient. If the first coating exceeds 90% of the total area of the pressed portion, the amount of wear resulting from the intrusion of foreign matter exceeds the allowable range.

  In the swash plate compressor according to the present invention, the first coating has two or more sections in the circumferential direction, the second coating has two or more sections in the circumferential direction, and the first coating and the second coating are alternately arranged in the circumferential direction. It is also preferable that it is formed (claim 4). Since the second coating film with foreign substance burying property is inferior in seizure resistance as compared with the first coating film, there is a concern about occurrence of seizure. However, according to the above configuration, as the drive shaft rotates, the solid lubricant and the resin constituting the first coating are transferred over a wide range to each second coating. Improvement is realized.

  The swash plate may be composed of a substrate and a sliding layer formed on the substrate and constituting a shoe sliding surface. And it is preferable that the sliding layer is divided into the circumferential direction by the 1st film and the 2nd film (Claim 5). In this case, since the sliding layer has a single-layer structure of each of the first film and the second film, the cost can be reduced as compared with the case of a multilayer structure.

  The piston can be a single-headed piston with a single piston head. In addition, the swash plate may have shoe sliding surfaces on the front and rear. In such a swash plate compressor, the shoe sliding surface on the piston head side is preferably divided in the circumferential direction by a first coating and a second coating (Claim 6). In this case, since the shoe is strongly pressed against the shoe sliding surface on the piston head side, the effect of the present invention can be sufficiently obtained by applying the present invention only to the shoe sliding surface on the piston head side. In addition, cost reduction can be realized. The shoe sliding surface on the side opposite to the piston head can be made of a resin containing a solid lubricant.

  According to the test results of the inventors, as the second coating, copper-based metal (refers to copper or a copper alloy containing the largest amount of copper; hereinafter the same), tin-based metal (tin or tin containing the most tin). (Also, the same shall apply hereinafter) or an aluminum silicon-based metal (aluminum silicon (AlSi) or an aluminum silicon alloy containing the largest amount of aluminum silicon, hereinafter the same shall apply). The copper-based metal or tin-based metal can be formed by a method such as plating, thermal spraying, or sintering. When the swash plate substrate is made of an aluminum-based metal, the alumite applied to the surface of the substrate can also be the second coating.

  Embodiments 1 to 3 embodying the present invention will be described below with reference to the drawings.

  The swash plate type compressor of Example 1 is a variable capacity swash plate type compressor as shown in FIG. Note that the lower side in FIG. 1 is the front side, and the upper side is the rear side.

  In this compressor, a front housing 2 is joined to the front end of the cylinder block 1, and a rear housing 4 is joined to the rear end of the cylinder block 1 via a valve unit 3. Here, the cylinder block 1, the front housing 2, and the rear housing 4 constitute a housing. The cylinder block 1 and the front housing 2 are provided with shaft holes 1a and 2a extending in the axial direction, and a drive shaft 5 is rotatably supported in the shaft holes 1a and 2a via bearings or the like. .

  The inside of the front housing 2 is a crank chamber 6. In the crank chamber 6, a lug plate 7 is fixed to the drive shaft 5 through a bearing device between the crank chamber 6 and the front housing 2. Further, a swash plate 8 is provided in the crank chamber 6 behind the lug plate 7. The swash plate 8 is inserted through the drive shaft 5, and in this state, the link mechanism 9 provided between the slag plate 7 and the lug plate 7 is rotated in synchronization with the drive shaft 5 and the lug plate 7 so that the inclination angle changes. It has become.

  The cylinder block 1 is provided with a plurality of cylinder bores 1b extending concentrically extending in the axial direction. A single-headed piston 10 is housed in each cylinder bore 1b so as to be capable of reciprocating. The crank chamber 6 side of each piston 10 is a neck portion 10c. The neck portion 10c is provided with receiving seats 10a and 10b that are recessed with spherical surfaces, facing each other. The cylinder bore 1b side of each piston 10 is a piston head 10d. The piston head 10d is integrated with the neck portion 10c and can slide on the cylinder bore 1b.

  As shown in FIG. 2, a pair of front and rear shoes 20 a and 20 b are provided between the swash plate 8 and each piston 10. The swash plate 8 includes a substrate 81, a sliding layer 82 formed only on the peripheral portion of the front surface of the substrate 81, and a sliding layer 83 formed only on the peripheral portion of the rear surface of the base material 81. The front surface of the sliding layer 82 on the anti-piston head 10d side is a shoe sliding surface 82a on which the shoe 20a slides, and the surface of the sliding layer 83 on the rear piston head 10d side is slid on the shoe 20b. This is a shoe sliding surface 83a.

  The substrate 81 is made of an iron-based metal (referred to as iron or an iron alloy containing the most iron, hereinafter the same) or an aluminum-based metal (referred to as aluminum or an aluminum alloy containing the most aluminum as described below).

  As shown in FIG. 3A, the sliding layer 82 is made of a first coating C1 whose details will be described later. As shown in FIG. 3C, the sliding layer 83 is divided in the circumferential direction by a first film C1 and a second film C2 made of different materials, as will be described in detail later. Each of the first coating C1 and the second coating C2 has a single layer structure.

  The shoes 20a and 20b shown in FIGS. 1 and 2 are made of an iron-based metal or an aluminum-based metal. Nickel plating is applied to the surfaces of the shoes 20a and 20b made of an aluminum-based metal. Each shoe 20a, 20b is substantially hemispherical.

The first film C1 shown in FIGS. 3A and 3C is formed of a resin such as polyamide imide (PAI) in molybdenum disulfide (MoS ₂ ), graphite, tungsten disulfide (WS ₂ ), boron nitride ( BN), polytetrafluoroethylene (PTFE), and other solid lubricants are dispersed in the coating layer. With this configuration, the first coating C1 has excellent seizure resistance.

  The second coating C2 shown in FIG. 3C is a plating layer or thermal spraying of a copper-based metal, a tin-based metal, or an aluminum silicon-based metal (referred to as aluminum silicon (AlSi) or an aluminum silicon alloy containing the most aluminum silicon). Layer or sintered layer. With this configuration, the second coating C2 has a foreign substance burying property.

  The manufacturing method of the swash plate 8 is not particularly limited, but for example, the following two methods can be adopted.

In the first method, an alumite-treated substrate 81 is first prepared. Next, a liquid paint composed of components of the first film C1 containing MoS ₂ as a solid lubricant is coated on the peripheral edge of the substrate 81. At this time, the coating range is the predetermined range which is the formation range of the first film C1 in the circumferential direction. As a coating technique, it is desirable to use a transfer process such as roll coating. According to the transfer process, unlike the spray process, it is easy to avoid the paint from entering the formation range of the second film C2, and it is not necessary to mask the formation range of the second film C2 when coating is performed. . The first film C1 thus formed is then cured by baking, and then its surface is polished. Thereby, the 1st film C1 adjusted to the predetermined range, the predetermined dimension, and the predetermined surface roughness is formed.

  After the formation of the first coating C1, a second coating C2 of tin plating is formed by electroless plating in the formation range of the second coating C2 at the peripheral edge of the rear surface of the substrate 81. However, the second coating C2 of tin plating may be formed by electrolytic plating. In addition, the present inventors have confirmed that the coating material which comprises the 1st film C1 does not deteriorate by the plating process of the 2nd film C2.

In the second method, first, a ferrous metal substrate 81 is prepared. Next, the copper-based metal is sprayed on the formation range of the second coating C2 in the peripheral edge portion of the rear surface of the substrate 81 while masking the spraying unnecessary portion including the formation range of the first coating C1. The surface of the formed second film C2 is cut and polished. Subsequently, a liquid paint composed of components of the first film C1 containing MoS ₂ as a solid lubricant is coated on the formation range of the first film C1 on the peripheral edge of the substrate 81. The coating method may be either a transfer process or a spray process, but in the case of the spray technique, it is necessary to mask the formation range of the second film C2. The first film thus formed is then cut and polished.

  As shown in FIG. 1, the rear housing 4 is formed with a suction chamber 4a and a discharge chamber 4b. The cylinder bore 1 b can communicate with the suction chamber 4 a via the suction valve mechanism of the valve unit 3 and can communicate with the discharge chamber 4 b via the discharge valve mechanism of the valve unit 3.

  A capacity control valve 11 is accommodated in the rear housing 4. The capacity control valve 11 communicates with the suction chamber 4a through the detection passage 4c, and connects the discharge chamber 4b with the crank chamber 6 through the air supply passage 4d. The capacity control valve 11 detects the pressure in the suction chamber 4a, thereby changing the opening degree of the air supply passage 4d and changing the discharge capacity of the compressor. The crank chamber 6 and the suction chamber 4a communicate with each other through an extraction passage 4e. A condenser 13, an expansion valve 14 and an evaporator 15 are connected to the discharge chamber 4 b by a pipe 12, and the evaporator 15 is connected to the suction chamber 4 a by a pipe 12.

  A pulley 16 is rotatably provided at the front end of the front housing 2 via a bearing device, and the pulley 16 is fixed to the drive shaft 5. A belt 18 that is rotationally driven by an engine 17 is wound around the pulley 16.

  In the compressor configured as described above, the swash plate 8 rotates synchronously as the drive shaft 5 rotates, and each piston 10 reciprocates within the cylinder bore 1b via each pair of shoes 20a and 20b. Thereby, each compression chamber formed on the piston head 10d side of the piston 10 changes in volume while repeating the suction stroke and the compression stroke. In the suction stroke in which the piston 10 moves in the direction of increasing the volume of the compression chamber, the refrigerant gas in the suction chamber 4a is sucked into the compression chamber. In the compression stroke in which the piston 10 moves in the direction of decreasing the volume of the compression chamber, the refrigerant gas is compressed and discharged from the compression chamber into the discharge chamber 4b. In this way, the refrigeration operation is performed by the refrigeration circuit including the compressor, the condenser 13, the expansion valve 14, and the evaporator 15. During this time, the shoes 20 a and 20 b are in sliding contact with the shoe sliding surfaces 82 a and 83 a of the swash plate 8 and the hemispherical surfaces are in sliding contact with the receiving seats 10 a and 10 b of the piston 10.

  As shown in FIG. 3A, the shoe sliding surface 82a on the anti-piston head 10d side includes a pressing portion P that is a portion where the shoe 20a is pressed and a separation portion D that is a portion where the shoe 20a is separated. have. Further, as shown in FIG. 3C, the shoe sliding surface 83a on the piston head 10d side includes a pressing portion P that is a portion where the shoe 20b is pressed and a separation portion D that is a portion where the shoe 20b is separated. And have. The first coating C1 occupies a region of 50% of the total area of the pressing portion P, and the second coating C2 occupies the remaining 50% of the region.

  The pressing portion P of the shoe sliding surface 83a causes each piston 10 to perform a compression stroke, and the pressing portion P of the shoe sliding surface 82a on the anti-piston head 10d side causes each piston 10 to perform an intake stroke. At this time, the shoe sliding surfaces 83a and 82a on the piston head 10d side and the anti-piston head 10d side are separated from the pressing portion P by 180 degrees in the circumferential direction, and a separation portion D is generated.

  That is, in this compressor, the top dead center position TDC of the shoe sliding surface 83a on the piston head 10d side and the bottom dead center position BDC of the shoe sliding surface 82a on the anti-piston head 10d side are included in the pressing portion P. The top dead center position TDC of the shoe sliding surface 82a on the piston head 10d side and the bottom dead center position BDC of the shoe sliding surface 83a on the piston head 10d side are included in the separation portion D.

  In this compressor, the shoe sliding surfaces 82a and 83a of the swash plate 8 have the first coating C1, and the first coating C1 is a resin coating made of a resin containing a solid lubricant, for example, PAI. The plate 8 exhibits excellent seizure resistance between the shoes 20a and 20b.

  Further, in this compressor, the shoe sliding surface 83a of the swash plate 8 has the second coating C2, and the second coating C2 has a foreign substance burying property. The foreign matter generated in the crank chamber 6 enters between the swash plate 8 and the shoe 20b at the separation portion D of the shoe sliding surface 83a. However, the foreign matter is captured by the second coating C2. For this reason, the foreign matter does not move to the pressing portion P of the shoe sliding surface 83a, and the foreign matter does not easily wear the first coating C1 on the pressing portion P. Therefore, the wear resistance of the first coating C1 is also exhibited. . The gap between the swash plate 8 and the shoe 20b does not become excessively large, the shoe 20b preferably follows the change in the posture of the swash plate 8, and good seizure resistance between the swash plate 8 and the shoe 20b. Sex is maintained.

  In addition, the shoe 20a is only pressed against the pressing portion P of the shoe sliding surface 82a of the swash plate 8 in the suction stroke, and the force is not so much. Therefore, the shoe sliding surface 82a of the swash plate 8 does not have the second coating C2, and even if foreign matter enters between the swash plate 8 and the shoe 20a at the separation portion D, the first coating C1 Wear is not a problem.

  Therefore, this compressor can satisfy both seizure resistance and wear resistance between the swash plate 8 and the shoes 20a, 20b. For this reason, this compressor can exhibit the outstanding durability.

  Further, in this compressor, the shoe sliding surface 82a on the anti-piston head 10d side is composed only of the first coating C1, and only the shoe sliding surface 83a on the piston head 10d side is the first coating C1 and the second coating C2. Is divided in the circumferential direction. For this reason, cost reduction can be realized. Note that the shoe sliding surface 82a on the anti-piston head 10d side can be divided in the circumferential direction by the first coating C1 and the second coating C2.

  Further, in this compressor, the sliding layer 82 has a single-layer structure of the first coating C1, and the sliding layer 83 has a single-layer structure of the first coating C1 or the second coating C2, respectively. The cost can be kept lower than in some cases.

(Evaluation)
In order to evaluate the seizure resistance of the compressor of Example 1, the following tests were performed. First, as shown in FIG. 4, a swash plate specimen 88 and a shoe 92 simulating the swash plate 8 are prepared. The swash plate specimen 88 is formed by forming a sliding layer 88b on the upper surface of the same type of substrate 88a as the swash plate 8. The shoe 92 is placed so that a substantially flat surface is brought into contact with the sliding layer 88 b of the swash plate specimen 88. Then, the shoe 92 is pressed against the swash plate specimen 88 with a predetermined load by a pressing jig 99 having a recess 38a corresponding to the hemispherical surface of the shoe 92. Thus, the swash plate specimen 88 is rotated under the conditions of a sliding speed of 10.4 m / s, a load of 1.96 kN, no lubrication, and an atmosphere of R134a with the swash plate specimen 88 and the shoe 92 in contact with each other. It was measured whether seizure occurred in seconds.

Here, the sliding layer 88b is composed of a first coating C1 made of PAI containing MoS ₂ and a second coating C2 made of tin plating or alumite. The shoe 92 is made of SUJ2. The ratio of the first coating C1 to the entire sliding layer 88b (hereinafter referred to as the first coating occupation ratio) was gradually changed from 0% to 100%. The results are shown in FIG.

  As is clear from FIG. 5, when the occupation ratio of the first coating C1 was 0 to 30%, there was no significant change in the seizure time, but the occupation ratio of the first coating C1 increased from around 30%. As a result, the seizure time gradually increased. Here, since the seizure time when the occupation ratio of the first coating is 0% is 25 seconds, it is determined that the seizure time of 50 seconds or more, which is twice or more, is acceptable, and falls under this condition. It was considered that the seizure resistance characteristic of the first coating C1 works effectively when the occupation ratio of the first coating C1 is 50% or more. In an actual compressor, the compressive load is applied to the swash plate 8 on the pressing portion P side of the sliding layers 82 and 83. It is preferable that one film C1 is contained at a ratio of 50% or more.

  In addition, the following tests were conducted to evaluate the wear resistance of the compressor. As shown in FIG. 6, the test apparatus includes a swash plate specimen 88, a shoe 92, and a pressing jig 99 as described above. Then, a foreign substance F made of 150 μl of lubricating oil L and 10 mg of alumina powder was placed on the upper surface of the sliding layer 88b of the swash plate specimen 88, and then the shoe 92 was pressed against the swash plate specimen 88 with a load of 50 kg, In this state, the swash plate specimen 88 is rotated five times. Due to the rotation of the swash plate specimen 88, the foreign matter F enters between the swash plate specimen 88 and the shoe 92, and the upper surface of the sliding layer 88b is worn by the foreign matter F. The amount of film thickness reduction of the sliding layer 88b at this time was measured as the amount of wear.

  The composition of the shoe 92 and the sliding layer 88b in which the occupation ratio of the first film is gradually changed from 0% to 100% and the seizure resistance test described above are the same. The film thickness of the first coating C1 is initially set to 20 μm. The results are shown in FIG.

  As is clear from FIG. 7, when the occupation ratio of the first coating C1 was 0 to 90%, the wear amount was not particularly increased but was within an allowable range. However, the amount of wear suddenly increased when the occupation ratio of the first coating C1 exceeded 90%. This is because the occupation ratio of the second coating C2 is decreased by the increase in the first coating C1, and the foreign matter embedment property of the second coating C2 is not exhibited. Thus, it was considered that if the occupation ratio of the first coating C1 is 90% or less, the foreign matter embedding property of the second coating C2 works effectively. In an actual compressor, the compressive load is applied to the swash plate 8 on the pressing portion P side of the sliding layers 82 and 83. It is preferable that one film C1 is included at a ratio of 90% or less. In summary, the first coating C1 is preferably formed in 50 to 90% of the total area of the pressing portion P. In addition, the 1st film C1 may be formed in the separation part D separately from the 2nd film C2 in the circumferential direction.

  In the compressor of Example 2, as shown in FIGS. 8A to 8C, the formation ranges of the first coating C1 and the second coating C2 on the shoe sliding surfaces 82a and 83a of the swash plate 8 are implemented. Different from Example 1. Others are the same as those in the first embodiment, and a duplicate description is omitted.

  In the shoe sliding surfaces 82a and 83a on the piston head 10d side and the anti-piston head 10d side, the first coating C1 is divided into three sections in the circumferential direction, and the second coating C2 is divided into three sections in the circumferential direction. The first coating C1 and the second coating C2 are alternately arranged in the circumferential direction. More specifically, the first coating C1 is divided and arranged in an area of 30 ° in the circumferential direction and with an angular difference of 30 °, and the second coating C2 is divided and arranged between the first coatings C1. For this reason, the first coating C1 is formed with 50% of the total area of the pressing part P, and the second coating C2 is formed with 50% of the total area of the pressing part P.

  When the drive shaft 5 rotates, a part of the coating material of the first coating C1 is transferred to the second coating C2 side by friction between the sliding layers 82 and 83 and the shoes 20a and 20b. At this time, since the first coating C1 and the second coating C2 are alternately divided and arranged in three sections, the paint spreads over the second coating C2 over a wide area, and the entire shoe sliding surfaces 82a and 83a. Improved seizure resistance is achieved.

  The compressor of Example 3 is a fixed capacity type swash plate type compressor using a double-headed piston 26 as shown in FIGS. 9 and 10. Note that the lower side in FIG. 9 is the front side, and the upper side is the rear side.

  In this compressor, a front housing 22 is joined to the front ends of a pair of cylinder blocks 21a and 21b via a valve unit 23a, and a discharge chamber 22b is formed in the front housing 22. A rear housing 24 is joined to the rear ends of the cylinder blocks 21a and 21b via a valve unit 23b, and a suction chamber 24a and a discharge chamber 24b are formed in the rear housing 24. Here, the cylinder blocks 21a and 21b, the front housing 22 and the rear housing 24 constitute a housing. The discharge chambers 22b and 24b communicate with a single discharge chamber (not shown).

  A drive shaft 25 is rotatably supported on the cylinder blocks 21 a and 21 b, and a seal member 22 a is provided between the drive shaft 25 and the front housing 22. A plurality of cylinder bores 21d and 21e are provided in the cylinder blocks 21a and 21b in the front-rear direction, and a double-headed piston 26 is accommodated in the cylinder bores 21d and 21e that are paired in the front-rear direction. The cylinder bores 21 d and 21 e and the piston 26 divide the compression chamber on the piston heads 26 c and 26 d side of the piston 26.

  The drive shaft 25 is formed with an introduction hole 25a communicating with the suction chamber 24a, and suction guide grooves 25b are provided in the radial direction before and after the introduction hole 25a. The cylinder blocks 21a and 21b are respectively provided with suction passages 21f that communicate the cylinder bores 21d and 21e with the introduction holes 25a through suction guide grooves 25b.

  A crank chamber 21c is defined between the cylinder blocks 21a and 21b. A swash plate 28 is fixed to the drive shaft 25 in the crank chamber 21c. The swash plate 28 is provided with a pair of hemispherical shoes 29a and 29b which are paired in the front and rear, and each piston 26 has a neck portion 26e between the piston heads 26c and 26d moored by the pair of shoes 29a and 29b. . A pair of thrust bearings 27 are provided between both end surfaces of the swash plate 28 and inner end surfaces of the cylinder blocks 21a and 21b. The swash plate 28 is interposed between the cylinder blocks 21a and 21b via the thrust bearing 27. Is sandwiched between.

  As shown in FIG. 10, the swash plate 28 is formed on the substrate 61, the peripheral portion of the front surface of the substrate 61, the sliding layer 62 slidable with the shoe 29 a, and the peripheral portion of the rear surface of the substrate 61. The shoe 29b and the sliding layer 63 are slidable. The surface of the sliding layer 62 on the front piston head 26c side is a shoe sliding surface 62a on which the shoe 29a slides, and the surface of the sliding layer 63 on the rear piston head 26d side is on shoe sliding on which the shoe 29b slides. It is a moving surface 63a. Similar to the first or second embodiment, the sliding layers 62 and 63 are divided in the circumferential direction by a first coating C1 having excellent seizure resistance and a second coating C2 having a foreign matter burying property.

An aluminum-based metal is used for the substrate 61 and the shoes 29a and 29b. The first coating C1 is a coating layer in which a solid lubricant such as MoS ₂ is dispersed in a resin, for example, PAI. The second coating C2 is a tin-based or copper-based metal plating layer or anodized. It is considered as a layer. It is also possible to form the second coating C2 by thermal spraying or sintering.

  The compressor configured as described above is mounted on a vehicle with a pulley or an electromagnetic clutch coupled to the drive shaft 25 shown in FIG. The pulley or electromagnetic clutch is driven by the engine via a belt. If the drive shaft 25 is rotationally driven while the engine is being driven, the swash plate 28 rotates synchronously with the drive shaft 25, and the piston 26 moves in the cylinder bores 21d and 21e with a stroke corresponding to the inclination angle of the swash plate 28. Reciprocates. Further, when the drive shaft 25 is rotationally driven, the introduction hole 25a and the compression chamber are communicated or blocked via the suction guide groove 25b and the suction passage 21f in conjunction with the piston 26. Therefore, when the piston 26 moves from right to left, the introduction hole 25a communicates with the right compression chamber, and is sucked into the right compression chamber through the suction chamber 24a and the introduction hole 25a. At that time, the left compression chamber and the introduction chamber 25a are shut off, and the refrigerant gas is compressed in the left compression chamber and then discharged into the discharge chamber 24b. When the piston 26 moves from left to right, the operations of the left and right compression chambers are reversed.

  In the swash plate 28, the pressing portions P of the front and rear shoe sliding surfaces 62a and 63a cause the piston 26 to perform a compression stroke. At this time, the front and rear shoe sliding surfaces 62a and 63a are separated from the pressing portion P by 180 degrees in the circumferential direction, and these separating portions D cause the piston 26 to perform a suction stroke. That is, in this compressor, the top dead center position TDC of the front shoe sliding surface 62a is the bottom dead center position BDC of the rear shoe sliding surface 63a, and the bottom dead center position BDC of the front shoe sliding surface 62a. Is the top dead center position TDC of the rear shoe sliding surface 63a. The top dead center position TDC of the front and rear shoe sliding surfaces 62a, 63a is included in the pressing portion P, and the bottom dead center position BDC of the front and rear shoe sliding surfaces 62a, 63a is included in the separation portion D.

  As described above, in the fixed capacity swash plate type compressor using the double-headed piston 26, both the front and rear shoe sliding surfaces 62a and 63a have the sliding layers 62 and 63 formed of the first coating C1 and the second coating C2. Thus, a compressor that satisfies both seizure resistance and wear resistance is provided.

  In addition, this invention is not restrict | limited to the said Examples 1-3. For example, the solid lubricant constituting the first coating C1 is not limited to that illustrated, but may be other. The first coating C1 may be a laminate of a resin containing a solid lubricant, for example, a coating made of PAI and a coating made of another material (including the second coating C2). Similarly, the second coating C2 may be a laminate of a coating made of a plating layer, a sprayed layer, a sintered layer or an alumite layer and a coating made of another material (including the first coating C1). . In addition, the first coating C1 and the second coating C2 may be divided and arranged in two sections or in four sections or more.

  The present invention is applicable to a vehicle air conditioner.

1 is a longitudinal sectional view of a swash plate compressor according to Embodiment 1. FIG. 1 is an enlarged longitudinal sectional view of a main part of a swash plate compressor of Example 1. FIG. FIG. 4A is a schematic view of the swash plate viewed from the front, FIG. 5B is a schematic cross-sectional view of the swash plate, and FIG. It is a schematic diagram. It is a schematic cross section of an apparatus for measuring the seizing time between a swash plate specimen and a shoe. It is a graph which shows the relationship between image sticking time and the occupation rate of a 1st film. It is a schematic perspective view of the apparatus which measures the abrasion loss of a sliding layer. It is a graph which shows the relationship between an abrasion loss and the occupation rate of a 1st film. In connection with the swash plate compressor of Example 2, FIG. (A) is a schematic view of the swash plate viewed from the front, FIG. (B) is a schematic sectional view of the swash plate, and FIG. It is a schematic diagram. 6 is a longitudinal sectional view of a swash plate compressor according to Embodiment 3. FIG. FIG. 4 is an enlarged vertical sectional view of a main part of a swash plate compressor according to a third embodiment.

Explanation of symbols

1b, 21d, 21e ... Cylinder bores 4a, 24a ... Suction chamber 4b, 22b, 24b ... Discharge chamber 5, 25 ... Drive shaft 6, 21c ... Crank chamber 8, 28 ... Swash plate 82a, 83a, 62a, 63a ... Shoe sliding Surface 10, 26 ... Piston 10d, 26c, 26d ... Piston head 20a, 20b, 29a, 29b ... Shoe 62, 63, 82, 83 ... Sliding layer C1 ... First coating C2 ... Second coating P ... Pressing portion D ... Remote part

Claims (7)

A housing that forms a cylinder bore, a crank chamber, a suction chamber, and a discharge chamber therein, a piston that is reciprocally accommodated in the cylinder bore and defines a compression chamber in the cylinder bore, and is driven by an external drive source, and the housing A swash plate, which is provided between the swash plate and the piston in a pair with a drive shaft that is rotatably supported on the swash plate, and a swash plate that is rotatably provided in synchronization with the drive shaft in the crank chamber. A swash plate compressor in which a swash plate is formed with a shoe sliding surface on which the shoe slides.
The swash plate compressor, wherein the shoe sliding surface is divided in a circumferential direction by a first film made of a resin containing a solid lubricant and a second film having a foreign substance burying property.   The first coating is formed on a pressing portion of the shoe sliding surface which is a portion where the shoe is pressed, and the second coating is a portion of the shoe sliding surface where the shoe is separated. The swash plate type compressor according to claim 1, wherein the swash plate compressor is formed at a separation portion.   3. The swash plate compressor according to claim 2, wherein the first coating is formed by 50 to 90% of the total area of the pressing portion.   2. The first coating has two or more sections in the circumferential direction, the second coating has two or more sections in the circumferential direction, and the first coating and the second coating are alternately formed in the circumferential direction. The described swash plate compressor. The swash plate comprises a substrate and a sliding layer formed on the substrate and constituting the shoe sliding surface,
The swash plate type compressor according to any one of claims 1 to 4, wherein the sliding layer is divided in a circumferential direction by the first coating and the second coating.   The piston is a single-headed piston having a single piston head, the swash plate has the shoe sliding surfaces on the front and rear sides, and the shoe sliding surfaces on the piston head side are the first coating and the second coating. The swash plate compressor according to any one of claims 1 to 5, wherein the compressor is divided in a circumferential direction.   The swash plate compressor according to any one of claims 1 to 6, wherein the second coating is made of a copper-based metal, a tin-based metal, or an aluminum silicon-based metal.

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