JP2018096251A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compressor configured to compress carbon dioxide, which can realize higher durability.SOLUTION: A compressor includes a front housing 1 as a housing, and a compression mechanism 9 having a drive shaft 31 as a movable member and configured to compress carbon dioxide. The front housing 1 comprises aluminum alloy containing silicon of 9-12 wt.%. In the front housing 1, provided are a first bearing 11d as a slide portion, and a first peripheral portion 11e adjacent to the first bearing 11d. In the first bearing 11d and the first peripheral portion 11e, provided is a plating layer 20 mainly comprising nickel.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a compressor.

  The compressor includes a housing and a compression mechanism provided in the housing. The compression mechanism has a movable member and compresses the refrigerant. Examples of such a movable member include a vane in addition to a drive shaft and a piston. The housing is provided with a sliding portion for sliding the movable member. Some compressors employ carbon dioxide as a refrigerant. Such a compressor is disclosed in Patent Document 1, for example.

  In this type of compressor, when the refrigerant is compressed, the sliding portion is required to slide the movable member suitably. Therefore, in the compressor disclosed in Patent Document 2, a plating layer mainly composed of nickel is provided on the sliding portion. Thereby, in this compressor, the improvement of the slidability in a sliding part is achieved. Further, since the plating layer is mainly composed of nickel, the durability of the plating layer itself is increased.

JP 2006-170007 A JP-A 64-73186

  By the way, when carbon dioxide is adopted as a refrigerant as in the compressor described in Patent Document 1, since the carbon dioxide has a very high pressure during compression, the housing is required to have high durability. Therefore, it is conceivable to improve the durability of the housing by forming the housing with an aluminum alloy containing a predetermined amount of silicon.

  However, if the silicon content in the aluminum alloy is increased, the amount of silicon crystals crystallized from the housing increases, and the silicon crystals easily fall off from the housing. Here, as in the compressor described in Patent Document 2, if a sliding layer is provided with a plating layer, the sliding layer can prevent the silicon crystal from dropping from the housing by the plating layer. In the vicinity of the non-existent sliding portion, it is not possible to prevent the silicon crystals from falling off. As a result, the movable member is liable to be damaged by the dropped silicon crystal. For this reason, it is difficult to improve both the durability of the housing and prevent the movable member from being damaged, and it is difficult to improve the durability of the compressor.

  This invention is made | formed in view of the said conventional situation, Comprising: It is the problem which should be solved to provide the compressor which can implement | achieve higher durability in the compressor which compresses a carbon dioxide.

The compressor of the present invention is a compressor that includes a housing and a compression mechanism provided in the housing and having a movable member, and compresses the refrigerant by the compression mechanism,
The refrigerant is carbon dioxide;
The housing is made of an aluminum alloy containing 9 wt% or more and 12 wt% or less of silicon,
The housing is provided with a sliding part for sliding the movable member, and a peripheral part adjacent to the sliding part,
A plating layer containing nickel as a main component is formed on the sliding portion and the peripheral portion.

  In the compressor of the present invention, the housing is made of an aluminum alloy containing 9 wt% or more and 12 wt% or less of silicon, so that the durability of the housing can be sufficiently increased. In this compressor, since the plating layer is formed on the sliding portion and the peripheral portion, not only the silicon crystal can be prevented from falling off at the sliding portion but also at the peripheral portion. It can be prevented with a plating layer. For this reason, it can prevent suitably that a movable member is damaged with the crystal | crystallization of silicon which fell from the housing.

  Furthermore, in this compressor, since the plating layer is mainly composed of nickel, the plating layer itself exhibits excellent slidability. Thereby, even if the load which acts on a movable member in compressing a carbon dioxide is large, a movable member can be slid suitably in a sliding part. Moreover, since the hardness of a plating layer becomes high by having nickel as a main component, durability of plating layer itself can also be made high.

  Therefore, the compressor of the present invention can exhibit high durability in a compressor that compresses carbon dioxide.

  The sliding portion may be formed in a cylindrical shape having a first inner surface extending in the axial direction. In addition, the peripheral portion may be formed in a conical shape having a second inner surface that extends in the axial direction continuously with the first inner surface and has a diameter larger than that of the first inner surface as the distance from the first inner surface increases. And as for the 2nd inner surface, it is preferred that a generatrix is continuing in the shape of a curve to the 1st inner surface. In this case, the movable member can be suitably prevented from being damaged by the movable member coming into contact with the plating layer formed in the peripheral portion.

  The housing can accommodate the compression mechanism and can be provided with a receiving portion other than the sliding portion and the peripheral portion. And it is preferable that the plating layer is formed also in the accommodating part. In this case, it is possible to prevent the silicon crystal from dropping off even in the accommodating portion by the plating layer.

  The movable member may be a drive shaft that is rotationally driven. The sliding portion is preferably a bearing that rotatably supports the drive shaft. In this case, it is possible to prevent the drive shaft from being damaged by the silicon crystal dropped from the housing.

  The housing may have a cylinder block provided with a cylinder bore. The compression mechanism may include a drive shaft that is rotationally driven, a swash plate that can be rotated by rotation of the drive shaft, and a piston that engages with the swash plate and can reciprocate within the cylinder bore. The sliding portion can be a cylinder bore. The movable member is also preferably a piston. In this case, it is possible to prevent the piston from being damaged by the silicon crystal dropped from the housing.

  The housing may have a cylinder block provided with a cylinder bore. The compression mechanism may include a drive shaft that is rotationally driven, a swash plate that can be rotated by rotation of the drive shaft, and a piston that engages with the swash plate and can reciprocate within the cylinder bore. The sliding portion may be a bearing and a cylinder bore that rotatably support the drive shaft. The movable member is preferably a drive shaft and a piston. In this case, it is possible to prevent the drive shaft and the piston from being damaged by the silicon crystal dropped from the housing.

  The compressor of the present invention can exhibit high durability in a compressor that compresses carbon dioxide.

FIG. 1 is a cross-sectional view illustrating a compressor according to an embodiment. FIG. 2 is an enlarged cross-sectional view illustrating a bearing, a peripheral portion, a housing portion, a plating layer, and the like according to the compressor of the embodiment. FIG. 3 is an enlarged cross-sectional view of a main part showing a region A1 shown in FIG. 1 according to the compressor of the embodiment. FIG. 4 is an enlarged cross-sectional view of a main part illustrating a bearing, a peripheral portion, and a plating layer in the compressor of the embodiment. FIG. 5 is an enlarged cross-sectional view showing a bearing, a cylinder bore, a peripheral portion, a plating layer, and the like according to the compressor of the embodiment. 6 is an enlarged cross-sectional view of a main part showing a region A2 shown in FIG. 1 according to the compressor of the embodiment. FIG. 7 is an enlarged cross-sectional view of a main part showing a region A3 shown in FIG. 1 according to the compressor of the embodiment. FIG. 8 is an enlarged cross-sectional view of a main part similar to the region A1 shown in FIG. 1 in the compressor of the comparative example.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. The compressor of an Example is mounted in the vehicle and comprises the refrigerating circuit of the vehicle air conditioner.

  As shown in FIG. 1, the compressor of the embodiment includes a front housing 1, a rear housing 3, a cylinder block 5, a valve forming plate 7, and a compression mechanism 9. The front housing 1, the rear housing 3, the cylinder block 5 and the valve forming plate 7 constitute a “housing” of the present invention. The compressor of the present embodiment is a single-head piston type variable displacement swash plate compressor, and the compression mechanism 9 compresses carbon dioxide as a refrigerant.

  In the present embodiment, the front-rear direction of the compressor is defined with the side where the front housing 1 is located as the front side of the compressor and the side where the rear housing 3 is located as the rear side of the compressor. In FIG. 2 and subsequent figures, the front-rear direction is defined in correspondence with FIG. In addition, the attitude | position of a compressor is suitably changed according to the vehicle etc. in which it is mounted.

  The front housing 1 shown in FIG. 2 is made of an aluminum alloy containing 9 wt% or more and 12 wt% or less of silicon. The front housing 1 has a front wall 11a that extends in the vertical direction of the compressor in front and a peripheral wall 11b that is integrated with the front wall 11a and extends rearward from the front wall 11a. The front housing 1 has a substantially cylindrical shape due to the front wall 11a and the peripheral wall 11b. A crank chamber 13 is formed in the front housing 1 by the front wall 11a and the peripheral wall 11b. The crank chamber 13 is an example of the “accommodating portion” in the present invention.

  Further, the front housing 1 is provided with a boss 11c, a first bearing 11d, and a first peripheral portion 11e. The first bearing 11d is an example of the “bearing” in the present invention, and the first peripheral portion 11e is an example of the “peripheral portion” in the present invention. As shown in FIG. 1, the boss 11c protrudes forward from the front wall 11a. A first storage chamber 110 extending rearward from the front end of the boss 11c is formed in the boss 11c. A sealing member 15 is provided in the first storage chamber 110. The sealing member 15 seals between the outside of the compressor and the crank chamber 13 while rotatably holding a drive shaft 31 described later.

  2 and 3, the first bearing 11d is formed in a cylindrical shape having a first inner surface 111a extending linearly in the axial direction of the front housing 1, that is, in the front-rear direction of the compressor. The first peripheral portion 11e is formed coaxially with the first bearing 11d, and is adjacent to the first bearing 11d behind the first bearing 11d. The first peripheral portion 11e is formed in a conical shape having a second inner surface 111b having a diameter larger than that of the first inner surface 111a as the distance from the first inner surface 111a increases toward the rear side of the compressor. As for this 2nd inner surface 111b, the bus-line has continued with the curve shape with respect to the 1st inner surface 111a. Thereby, the 1st inner surface 111a and the 2nd inner surface 111b are continuing smoothly. Here, “smoothly continuous” means that the continuous first and second inner surfaces (in the above case, the first inner surface 111a and the second inner surface 111b correspond) have a common tangent. Means that.

  In this compressor, a plating layer 20 is formed on the front housing 1. More specifically, as shown in FIG. 2, the plated layer 20 is formed from the first bearing 11 d to the first peripheral portion 11 e in the front housing 1, as well as inside the front wall 11 a and the peripheral wall 11 b. It is formed on the peripheral surface, that is, the inner peripheral surface of the crank chamber 13. On the other hand, the plating layer 20 is not formed on the inner peripheral surface of the first housing portion 110 and the outer peripheral surface of the front housing 1, that is, on the front housing 1 where it touches the environment outside the compressor. For ease of explanation, the shape of the plating layer 20 is exaggerated in FIG. Further, in FIG. 1, illustration of the plating layer 20 is omitted.

  As shown in FIG. 2, the plating layer 20 includes a first plating layer 20a and a second plating layer 20b. The first plating layer 20a and the second plating layer 20b are both electroless nickel-phosphorus plating. Here, the second plating layer 20b has a lower phosphorus content than the first plating layer 20a.

  In forming the plating layer 20, that is, the first plating layer 20 a and the second plating layer 20 b, in the front housing 1, masking is performed on the inner peripheral surface of the first housing portion 110 and the outer peripheral surface of the front housing 1. In this state, the first plating layer 20a is first formed, and then the second plating layer 20b is laminated on the surface of the first plating layer 20a. As a result, in the plating layer 20, the first plating layer 20a is formed so as to be in contact with the front housing 1, and the second plating layer 20b is formed so as to be in contact with the first plating layer 20a.

  Thus, in the front housing 1, the plated layer 20 is formed on the first bearing 11 d, the first peripheral portion 11 e, and the inner peripheral surface of the crank chamber 13 along the respective shapes. That is, as shown in FIG. 4, the plating layer 20 is formed along the shape of the first inner surface 111a in the first bearing 11d, and the plating layer 20 is formed along the shape of the second inner surface 111b in the first peripheral portion 11d. Will be formed. Thus, when the drive shaft 31 is inserted through the first bearing 11d, the distance to the rotational axis O is constant at the length L1 in the plated layer 20 formed on the first inner surface 111a. On the other hand, in the plated layer 20 formed on the second inner surface 111b, the distance to the rotation axis O becomes L2 longer than the length L1 as it goes to the rear side of the compressor, and further to the rear side of the compressor. As it goes, the distance to the rotation axis O becomes L3 longer than the length L2. Thus, in the 1st peripheral part 11e, the distance from the rotating shaft center O to the plating layer 20 becomes long gradually as it goes to the back side of a compressor.

  The rear housing 3 shown in FIG. 1 is also made of an aluminum alloy containing 9 wt% or more and 12 wt% or less of silicon, similar to the front housing 1. Unlike the front housing 1, the plating layer 20 is not formed on the rear housing 3.

The rear housing 3 is provided with a suction chamber 17a, a discharge chamber 17b, an annular wall 17c, an outer peripheral wall 17d, a suction port 17e, and a discharge port 17f. The suction chamber 17 a is partitioned by an annular wall 17 c and is located on the center side of the rear housing 3. The discharge chamber 17b is partitioned by the annular wall 17c and the outer peripheral wall 17d, and is located on the outer peripheral side of the suction chamber 17a. The discharge chamber 17b is formed in an annular shape and surrounds the suction chamber 17a from the outer peripheral side.

  The suction port 17e communicates with the suction chamber 17a and extends in the front-rear direction of the rear housing 3. The rear end of the suction port 17 e is open to the rear end surface of the rear housing 3. Thus, the suction port 17e allows the suction chamber 17a to communicate with the outside of the compressor. The discharge port 17f communicates with the discharge chamber 17b and extends in the vertical direction of the rear housing 3. Thus, the discharge port 17f allows the discharge chamber 17b and the outside of the compressor to communicate with each other. A discharge check valve capable of switching between communication and non-communication between the outside of the compressor and the discharge chamber 17b may be provided between the discharge chamber 17b and the discharge port 17f.

  Furthermore, the rear housing 3 is provided with a first air supply passage 19a and a second air supply passage 19b, and a capacity control valve 20 is provided. The first air supply passage 19 a is connected to the discharge chamber 17 b and the capacity control valve 20. The rear end of the second air supply passage 19 b is connected to the capacity control valve 20, and the front end opens to the front end surface of the rear housing 3. The capacity control valve 20 adjusts the internal pressure of the crank chamber 13 by adjusting the opening degree by external power supply control. Details of the capacity control valve 20 will be described later.

  The cylinder block 5 is located between the front housing 1 and the rear housing 3. The cylinder block 5 is made of aluminum alloy containing 9 wt% or more and 12 wt% or less of silicon, like the front housing 1 and the rear housing 3.

  The cylinder block 5 is provided with a plurality of cylinder bores 21a and the same number of second peripheral portions 21b as the cylinder bores 21a. The cylinder block 5 is provided with a spring chamber 21c, a second storage chamber 21d, a second bearing 21e, a third peripheral portion 21f, and a fourth peripheral portion 21g. Further, the cylinder block 5 is provided with a third supply passage 19c and an extraction passage 19d. Although not shown, the cylinder block 5 is provided with a retainer groove for restricting the maximum opening degree of a suction reed valve 71a described later. The second bearing 21e is also an example of the “bearing” in the present invention. The second to fourth peripheral portions 21b, 21f, and 21g are also examples of the “peripheral portions” in the present invention.

  In the cylinder block 5, the cylinder bores 21a are formed at equal angular intervals in the circumferential direction. And as shown in FIG. 6, the cylinder bore 21a is formed in the cylindrical shape which has the 1st inner surface 211a extended linearly in the axial direction of the cylinder block 5, ie, the front-back direction of a compressor. The second peripheral portion 21 b is formed coaxially with the cylinder bore 21 a and is adjacent to the cylinder bore 21 in front of the cylinder bore 21. The second peripheral portion 21b is formed in a conical shape having a second inner surface 211b having a diameter larger than that of the first inner surface 211a as it moves away from the first inner surface 211a toward the front side of the compressor. As for this 2nd inner surface 211b, the bus-line has continued with the curve shape with respect to the 1st inner surface 211a. Thereby, the first inner surface 211a and the second inner surface 211b are also smoothly continuous.

  As shown in FIG. 5, the spring chamber 21 c is recessed from the front end surface of the cylinder block 5 toward the rear. As shown in FIG. 1, the spring chamber 21 c communicates with the crank chamber 13. As shown in FIG. 5, the second storage chamber 21 d is recessed from the rear end surface of the cylinder block 5 toward the front.

  As shown in FIG. 7, the second bearing 21 e is formed in a cylindrical shape having a first inner surface 211 c extending in the axial direction of the cylinder block 5. The third and fourth peripheral portions 21f and 21g are formed coaxially and coaxially with the second bearing 21e. The third peripheral portion 21f is adjacent to the second bearing 21e in front of the second bearing 21e. The third peripheral portion 21f is formed in a conical shape having a second inner surface 211d having a diameter larger than that of the first inner surface 211c as it moves away from the first inner surface 211c toward the front side of the compressor. The second inner surface 211d has a continuous bus line in a curved line with respect to the first inner surface 211c. On the other hand, the fourth peripheral portion 21g is adjacent to the second bearing 21e behind the second bearing 21e. The fourth peripheral portion 21g is formed in a conical shape having a second inner surface 211e having a diameter larger than that of the first inner surface 211c as it moves away from the first inner surface 211c toward the rear side of the compressor. The second inner surface 211e also has a continuous bus line with respect to the first inner surface 211c. Thus, the first inner surface 211c and the second inner surfaces 211d and 211e are smoothly continuous.

  As shown in FIG. 5, the plated layer 20 is also formed on the cylinder block 5. Specifically, the plating layer 20 is formed from the cylinder bore 21a to the second peripheral portion 21b. At this time, the plated layer 20 is formed along the shape of the first inner surface 211a in the cylinder bore 21a, and the plated layer 20 is formed along the shape of the second inner surface 211b in the second peripheral portion 21b. Further, the plated layer 20 is formed from the inner peripheral surface of the spring chamber 21c to the third peripheral portion 21f, the second bearing 21e, the fourth peripheral portion 21g, and the inner peripheral surface of the second storage chamber 21d. . At this time, the plating layer 20 is formed along the shape of the first inner surface 211c in the second bearing 21e, and the plating layer 20 is formed along the shape of the second inner surfaces 211d and 211e in the third and fourth peripheral portions 21f and 21g. Is formed. On the other hand, the plated layer 20 is not formed on the outer peripheral surface of the cylinder block 5 other than the front end surface of the cylinder block 5 in contact with the front housing 1 and the rear end surface of the cylinder block 5 in contact with the valve forming plate 9.

  Both the third supply passage 19c and the extraction passage 19d extend in the front-rear direction of the cylinder block 5. As shown in FIG. 1, the front ends of the third supply passage 19 c and the extraction passage 19 d open to the crank chamber 13, and the rear ends open to the rear end surface of the cylinder block 5.

  As shown in FIG. 1, the valve forming plate 7 is disposed between the cylinder block 5 and the rear housing 3. The valve forming plate 7 includes a valve plate 70, a suction valve plate 71, a discharge valve plate 72, and a retainer plate 73. The valve plate 70, the discharge valve plate 72, and the retainer plate 73 are formed with the same number of suction holes 70a as the cylinder bore 21a. The valve plate 70 and the suction valve plate 71 are formed with the same number of discharge holes 70b as the cylinder bores 21a. Further, the valve plate 70, the suction valve plate 71, the discharge valve plate 72, and the retainer plate 73 are formed with a first communication hole 70c and a second communication hole 70d.

  Each cylinder bore 21a communicates with the suction chamber 17a through each suction hole 70a. Each cylinder bore 21a communicates with the discharge chamber 17b through each discharge hole 70b. The second air supply passage 19b and the third air supply passage 19c communicate with each other through the first communication hole 70c. Further, the extraction passage 19d and the suction chamber 15a communicate with each other through the second communication hole 70d.

  The intake valve plate 71 is provided on the front surface of the valve plate 70. The suction valve plate 71 is formed with a plurality of suction reed valves 71a capable of opening and closing the suction holes 70a by elastic deformation. The discharge valve plate 72 is provided on the rear surface of the valve plate 70. The discharge valve plate 72 is formed with a plurality of discharge reed valves 72a that can open and close the discharge holes 70b by elastic deformation. The retainer plate 73 is provided on the rear surface of the discharge valve plate 72. The retainer plate 73 regulates the maximum opening of each discharge reed valve 72a.

  In this compressor, the crank chamber 13 and the capacity control valve 20 are connected by the second and third air supply passages 19b and 19c and the first communication hole 70c. As a result, the crank chamber 13 and the discharge chamber 17b communicate with each other through the first to third air supply passages 19a to 19c, the first communication hole 70c, and the capacity control valve 20. Further, the crank chamber 13 and the suction chamber 17a communicate with each other through the extraction passage 19d and the second communication hole 70d.

  In this compressor, the cylinder block 5 is sandwiched between the front housing 1 and the rear housing 3 while the valve forming plate 7 is interposed between the cylinder block 5 and the rear housing 3. In this state, the front housing 1, the cylinder block 5, the valve forming plate 7, and the rear housing 3 are fastened and integrated by a plurality of bolts (not shown).

  A drive shaft 31 is inserted through the front housing 1 and the cylinder block 5. Specifically, the drive shaft 31 is made of iron and has an outer peripheral surface 300. Although not shown in detail, the outer peripheral surface 300 is provided with a sliding coating layer made of PTFE (polytetrafluoroethylene) or the like in order to improve sliding properties. The drive shaft 31 is inserted through the shaft seal device 15 and the first bearing 11 d in the front housing 1. The drive shaft 31 is inserted into the spring chamber 21c, the second bearing 21e, and the second storage chamber 21d in the cylinder block 5. Thereby, the 1st bearing 11d and the 2nd bearing 21e support the drive shaft 31 so that sliding is possible. For this reason, the drive shaft 31 can rotate around the rotation axis O parallel to the front-rear direction of the compressor.

  Here, as shown in FIG. 3, when the drive shaft 31 is inserted into the first bearing 11d, the first inner surface 111a of the first bearing 11d in the plated layer 20, more specifically, the second plated layer 20b. In the portion formed at, the sliding contact with the outer peripheral surface 300 of the drive shaft 31 occurs. On the other hand, as described above, in the first peripheral portion 11e, the distance from the rotation axis O to the plating layer 20 is gradually increased toward the rear side of the compressor. For this reason, the plating layer 20 formed on the second inner surface 111b of the first peripheral portion 11e gradually moves away from the outer peripheral surface 300 in the radial direction of the first peripheral portion 11e as it goes to the rear side of the compressor. That is, the plating layer 20 formed on the first peripheral portion 11 e and the second inner surface 111 b does not participate in the sliding of the drive shaft 31.

  Similarly, when the drive shaft 31 is inserted into the second bearing 21e, as shown in FIG. 7, in the plated layer 20, a portion formed on the first inner surface 211c of the second bearing 21e is formed on the outer peripheral surface 300. Make sliding contact. In the plated layer 20, the portion formed on the second inner surface 211d of the third peripheral portion 21f gradually moves away from the outer peripheral surface 300 in the radial direction of the third peripheral portion 21f toward the front side of the compressor. Become. Further, in the plating layer 20, the portion formed on the second inner surface 211e of the fourth peripheral portion 21g gradually moves away from the outer peripheral surface 300 in the radial direction of the fourth peripheral portion 21g toward the rear side of the compressor. Become. That is, the plating layer 20 formed on the third and fourth peripheral portions 21 f and 21 g and the second inner surfaces 211 d and 211 e is not involved in the sliding of the drive shaft 31.

  As shown in FIG. 1, the rear end of the drive shaft 31 is inserted into and supported by the second thrust bearing 33b in the second storage chamber 21d. A coil spring 35 is provided behind the second thrust bearing 33b in the second storage chamber 21d. The coil spring 35 supports the second thrust bearing 33b while urging it forward.

  On the other hand, a screw portion 31 a is formed at the tip of the drive shaft 31. The drive shaft 31 is connected to a pulley or an electromagnetic clutch (not shown) through the screw portion 31a.

  A lug plate 37 is press-fitted into the drive shaft 31. The lug plate 37 is disposed forward in the crank chamber 13 and can rotate in the crank chamber 13 as the drive shaft 31 rotates. A first thrust bearing 33 a is provided between the lug plate 37 and the front wall 11 a of the front housing 1.

  A swash plate 39 is inserted through the drive shaft 31. The swash plate 39 is located behind the lug plate 37 in the crank chamber 13. Between the lug plate 37 and the swash plate 39, a tilt angle reducing spring 41 is provided around the drive shaft 31. The tilt angle reducing spring 41 biases the swash plate 39 toward the rear of the crank chamber 13 so that the tilt angle is decreased. Further, a circlip 43 is fixed to the drive shaft 31, and a return spring 45 is provided around the drive shaft 31 between the circlip 43 and the swash plate 39. The return spring 45 is disposed in the spring chamber 21c. The return spring 45 urges the swash plate 39 having the smallest inclination angle toward the front of the crank chamber 13.

  In the crank chamber 13, the lug plate 37 and the swash plate 39 are connected by a link member 47. The link member 47 supports the swash plate 39 so that the inclination angle of the swash plate 39 with respect to the direction orthogonal to the drive axis O can be changed.

  A piston 49 is accommodated in each cylinder bore 21a so as to be able to reciprocate. Specifically, the piston 49 is made of an aluminum alloy and has an outer peripheral surface 400. Although not shown in detail, the outer peripheral surface 400 of the piston 49 is provided with a sliding coating layer made of PTFE or the like in order to improve the slidability, similarly to the outer peripheral surface 300 of the drive shaft 31 described above.

  As shown in FIG. 6, when the piston 49 is accommodated in the cylinder bore 21a, a portion of the plated layer 20 formed on the first inner surface 211a of the cylinder bore 21a comes into sliding contact with the outer peripheral surface 400 of the piston 49. On the other hand, in the plated layer 20, the portion formed on the second inner surface 211b of the second peripheral portion 21b gradually moves away from the outer peripheral surface 400 in the radial direction of the second peripheral portion 21b toward the front side of the compressor. Become. That is, the plated layer 20 formed on the second peripheral portion 21b and the second inner surface 211b is not involved in the sliding of the piston 49.

  Further, as shown in FIG. 1, the piston 49 is housed in the cylinder bore 21a, so that the rear end surface of the piston 49 faces the valve forming plate 7 in the cylinder bore 21a. Thereby, the piston 49 partitions the compression chamber 51 on the rear side of the cylinder bore 21a.

  Each piston 49 is provided with an engaging portion 49a. In the engaging portion 49a, hemispherical shoes 53a and 53b are respectively provided. Each of the shoes 53 a and 53 b functions as a conversion mechanism, and converts the rotation of the swash plate 39 into the reciprocating motion of each piston 49. Thus, each piston 49 can reciprocate within the cylinder bore 21a with a stroke corresponding to the inclination angle of the swash plate 39. In addition to the shoes 53a and 53b, a wobble type conversion mechanism that supports the swing plate on the rear side of the swash plate 39 via a thrust bearing and connects the swing plate and each piston 49 by a connecting rod is adopted. You can also

  The compression mechanism 9 is configured by the drive shaft 31, the lug plate 37, the swash plate 39, the link member 47, each piston 49, each pair of shoes 53a, 53b, and the like.

  In this compressor, a pipe connected to the evaporator is connected to the suction port 17e. A pipe connected to the condenser is connected to the discharge port 17f. The condenser is connected to the evaporator via a pipe and an expansion valve. Thus, the compressor, the evaporator, the expansion valve, the condenser, and the like constitute a refrigeration circuit for the vehicle air conditioner. In addition, illustration of an evaporator, an expansion valve, a condenser, and each piping is abbreviate | omitted.

  In the compressor configured as described above, when the drive shaft 31 rotates, the swash plate 39 rotates, and each piston 49 reciprocates while sliding in the cylinder bore 21a. For this reason, the compression chamber 51 changes its volume according to the stroke of the piston 49. For this reason, in this compressor, the suction stroke for sucking carbon dioxide as a refrigerant into the compression chamber 51, the compression stroke for compressing carbon dioxide in the compression chamber 51, and the compressed carbon dioxide are discharged to the discharge chamber 17b. The discharge stroke and the like are repeatedly performed.

  In the meantime, in this compressor, the discharge capacity can be appropriately changed by adjusting the internal pressure of the crank chamber 13 by the capacity control valve 20.

  Specifically, the high-pressure carbon dioxide introduced into the crank chamber 13 from the discharge chamber 17b through the first to third supply passages 19a to 19c and the first communication hole 70c by adjusting the opening of the capacity control valve 20. And the amount of carbon dioxide led out from the crank chamber 13 to the suction chamber 17a through the extraction passage 19d and the second communication hole 70d are controlled, and the internal pressure of the crank chamber 13 is determined. Then, the differential pressure between the crank chamber 13 and the compression chamber 51 is changed according to the change in the internal pressure of the crank chamber 13, and the inclination angle of the swash plate 39 is changed. As a result, the stroke of each piston 49 is changed, and the compressor The discharge capacity is adjusted.

  For this reason, in this compressor, if the opening degree of the capacity control valve 20 is increased, the internal pressure of the crank chamber 13 increases. For this reason, the inclination angle of the swash plate 39 decreases, the stroke of each piston 49 decreases, and the discharge capacity per rotation of the drive shaft 31 decreases. On the contrary, if the opening degree of the capacity control valve 20 is decreased, the internal pressure of the crank chamber 13 is decreased. For this reason, the inclination angle of the swash plate 39 is increased, the stroke of the piston 49 is increased, and the discharge capacity per one rotation of the drive shaft 31 is increased.

  In this compressor, the front housing 1, the rear housing 3, and the cylinder block 5 are formed of an aluminum alloy containing 9 wt% or more and 12 wt% or less of silicon. For this reason, it is possible to sufficiently increase the durability of the front housing 1, the rear housing 3, and the cylinder block 5. Further, the thermal expansion coefficient of the front housing 1 and the cylinder block 5 can be made closer to the thermal expansion coefficient of the iron drive shaft 31 and the aluminum alloy piston 49. For this reason, in this compressor, the drive shaft 31 supported by the first and second bearings 11d and 21e is difficult to rotate or the pistons 49 are difficult to reciprocate in the cylinder bores 21a due to temperature changes. This can be suitably prevented.

  In the front housing 1, a plated layer 20 is formed on the first bearing 11d and the first peripheral portion 11e. In the cylinder block 5, the plated layer 20 is formed on the cylinder bore 21a, the first peripheral portion 21b, the second bearing 21e, the third peripheral portion 21f, and the fourth peripheral portion 21g. For this reason, in this compressor, even if the front housing 1 and the cylinder block 5 are formed of an aluminum alloy containing silicon as described above, the silicon crystals fall off at the first and second bearings 11d and 21d and the cylinder bore 21a. Can be prevented by the plating layer 20. Further, in this compressor, it is possible to prevent the silicon crystal from falling off in the first to fourth peripheral portions 11b, 21b, 21e, and 21f that are not involved in the sliding of the drive shaft 31 and the piston 49. For this reason, in this compressor, the drive shaft 31 and the piston 49 are damaged by the silicon crystals dropped from the front housing 1 and the cylinder block 5, and more specifically, the drive shaft 31 and the piston 49 are damaged by the silicon crystals. It can prevent suitably that the provided sliding coating layer peels or the outer peripheral surfaces 300 and 400 of the drive shaft 31 and piston 49 are damaged.

  Further, by forming the plated layer 20 in this way, the first inner surface 111a is not exposed in the first bearing 11d, and the first inner surface 211c is not exposed in the second bearing 21e. For this reason, it is possible to prevent the first inner surfaces 111a and 211c from being worn by the rotating drive shaft 31. Similarly, since the plated layer 20 does not expose the first inner surface 211a of the cylinder bore 21a, it is possible to prevent the first inner surface 211a from being worn by the reciprocating piston 49.

  Further, in this compressor, the plating layer 20 includes a first plating layer 20a and a second plating layer 20b, and both the first and second plating layers 20a and 20b are mainly composed of nickel. For this reason, in this compressor, the plating layer 20 itself exhibits excellent slidability. Thereby, in this compressor, even if the load which acts on the drive shaft 31 and each piston 49 in compressing carbon dioxide is large, the first and second bearings 11d and 21d and each cylinder bore 21 have the drive shaft 31 and each piston. 49 can be suitably slid. Moreover, since the hardness of the plating layer 20 is increased by using nickel as a main component, the durability of the plating layer 20 itself is also increased. In particular, the second plating layer 20b that is in direct sliding contact with the drive shaft 31 and each piston 49 has a lower phosphorus content than the first plating layer 20a. For this reason, the second plating layer 20b is less likely to be worn and can exhibit excellent durability.

  Here, in the compressor, the first bearing 11d is formed in a cylindrical shape having a first inner surface 111a extending linearly in the front-rear direction of the compressor. On the other hand, the 1st peripheral part 11e is formed in the cone shape which has the 2nd inner surface 111b which diameter-expands rather than the 1st inner surface 111a as it leaves | separates from the 1st inner surface 111a to the back side of a compressor. And as for the 2nd inner surface 111b, the bus line has continued with the curve shape with respect to the 1st inner surface 111a. Thereby, in this compressor, it can prevent suitably that the drive shaft 31 is damaged by the part formed in the 2nd inner surface 111b of the 1st peripheral part 11e contacting the drive shaft 31 in the plating layer 20. .

  This effect will be described in detail by comparison with a compressor of a comparative example. The compressor of the comparative example shown in FIG. 8 has substantially the same configuration as the compressor of the embodiment, but the first peripheral portion 11f is provided in the housing 1 in the compressor of the comparative example. The first peripheral portion 11f is formed in a conical shape having a second inner surface 111c having a diameter larger than that of the first inner surface 111a as the distance from the first inner surface 111a increases toward the rear side of the compressor. Here, as for the 2nd inner surface 111c, the bus-line is continuing linearly with respect to the 1st inner surface 111a. That is, in the compressor of the comparative example, the first inner surface 111a and the second inner surface 111c are not smoothly continuous, and a corner portion is generated at a location where the second inner surface 111c is connected to the first inner surface 111a. . Then, by forming the plating layer 20 along the second inner surface 111c having such a shape, a corner portion is also generated in the plating layer 20 at a place where the second inner surface 111c is connected to the first inner surface 111a. . As a result, in the compressor of the comparative example, the sliding coating layer is peeled off when the plating layer 20 formed on the second inner surface 111c contacts the outer peripheral surface 300 of the drive shaft 31 in the region P2 in FIG. The drive shaft 31 is easily damaged.

  On the other hand, in the compressor of the embodiment, as described above, the bus line of the second inner surface 111b of the first peripheral portion 11e is continuous with the first inner surface 111a of the first bearing 11d in a curved shape. For this reason, as shown in FIG. 3, the 1st inner surface 111a and the 2nd inner surface 111b are continuing smoothly, and a corner | angular part does not exist in the location where the 2nd inner surface 111b connects with the 1st inner surface 111a. Then, since the plating layer 20 is formed along the second inner surface 111b having such a shape, no corner portion is generated in the plating layer 20 at a place where the second inner surface 111b is connected to the first inner surface 111a. . As a result, in the compressor of the embodiment, in the region P1 in the figure, the contact between the plating layer 20 formed on the second inner surface 111b and the outer peripheral surface 300 of the drive shaft 31 is relaxed, and the sliding coating layer is peeled off. It is difficult for the drive shaft 31 to be damaged. The same applies to the plated layer 20 formed on the second inner surfaces 211d and 211e shown in FIG. 7, and the contact with the outer peripheral surface 300 of the drive shaft 31 is relaxed. Similarly, with respect to the plated layer 20 formed on the second inner surface 211b shown in FIG. 6, contact with the outer peripheral surface 400 of the piston 49 is alleviated when each piston 49 reciprocates. As a result, in this compressor, the plated layer 20 formed on the second inner surface 211b can be suitably prevented from being damaged by contacting the outer peripheral surface 400 of the piston 49.

  Therefore, the compressor of an Example can exhibit high durability in the compressor which compresses a carbon dioxide.

  In particular, in this compressor, the plating layer 20 is also formed on the inner peripheral surface of the crank chamber 13. Thereby, it is possible for the plated layer 20 to prevent silicon crystals from dropping into the crank chamber 13. In the compressor, since the plating layer 20 is also formed on the inner peripheral surfaces of the spring chamber 21c and the second housing portion 21d, silicon crystals may fall out in the spring chamber 21c and the second housing portion 21d. It can be prevented by the plated layer 20.

  Furthermore, in this compressor, among the first plating layer 20a and the second plating layer 20b constituting the plating layer 20, the first plating layer 20a has a higher phosphorus content than the second plating layer 20b. Yes. For this reason, when forming the plating layer 20, the first plating layer 20 a can be suitably formed on the front housing 1 and the cylinder block 5.

  Further, in this compressor, the plating layer 20 is not formed on the outer peripheral surface of the cylinder block 5 in addition to the inner peripheral surface of the first housing part 110 and the outer peripheral surface of the front housing 1. Thereby, since it can prevent that the plating layer 20 deteriorates by touching the environment outside the compressor, also in this point, this compressor can exhibit high durability.

  Further, in this compressor, the drive shaft 31 supported by the first and second bearings 11d and 21e slides with the portions formed on the first inner surfaces 111a and 211c in the plated layer 20. As a result, in this compressor, it is possible to reduce the number of parts and reduce the manufacturing cost as compared with the case where the drive shaft 31 is supported by a rolling bearing or a sliding bearing. Yes.

  Furthermore, in this compressor, the first inner surface 111a of the first bearing 11d and the first inner surface 211c of the second bearing 21e extend linearly in the front-rear direction of the compressor. For this reason, the plating layer 20 formed along the shape of the first inner surfaces 111a and 211c can slide on the drive shaft 31 suitably. Similarly, since the first inner surface 211a of the cylinder bore 21a also extends linearly in the front-rear direction of the compressor, the plated layer 20 formed along the shape of the first inner surface 211a slides favorably with the piston 49. It is possible to do.

  While the present invention has been described with reference to the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments and can be appropriately modified and applied without departing from the spirit thereof.

  For example, the compression mechanism 9 may employ a vane type compression mechanism or a scroll type compression mechanism.

  Further, in the compressor of the embodiment, the plating layer 20 is constituted by two layers of the first plating layer 20a and the second plating layer 20b, but not limited thereto, the plating layer 20 is constituted by one layer. It may be composed of three or more layers.

  The present invention can be used for an air conditioner or the like.

1. Front housing (housing)
5 ... Cylinder block (housing)
9 ... Compression mechanism 11d ... 1st bearing (sliding part, bearing)
11e ... 1st peripheral part (peripheral part)
13 ... Crank chamber (accommodating part)
20 ... Plating layer 21a ... Cylinder bore (sliding part)
21b ... 2nd peripheral part (peripheral part)
21e ... second bearing (sliding part, bearing)
21f ... Third peripheral portion (peripheral portion)
21g ... Fourth peripheral part (peripheral part)
31 ... Drive shaft (movable member)
49. Piston (movable member)
111a, 211a, 211c ... first inner surface 111b, 211b, 211d, 211e ... second inner surface

Claims (6)

A compressor including a housing and a compression mechanism provided in the housing and having a movable member, and compressing the refrigerant by the compression mechanism;
The refrigerant is carbon dioxide;
The housing is made of an aluminum alloy containing 9 wt% or more and 12 wt% or less of silicon,
The housing is provided with a sliding part for sliding the movable member, and a peripheral part adjacent to the sliding part,
A compressor characterized in that a plating layer mainly composed of nickel is formed on the sliding portion and the peripheral portion. The sliding portion is formed in a cylindrical shape having a first inner surface extending in the axial direction,
The peripheral portion extends in the axial direction continuously with the first inner surface, and is formed in a conical shape having a second inner surface that is larger in diameter than the first inner surface as the distance from the first inner surface increases.
2. The compressor according to claim 1, wherein the second inner surface has a generatrix continuous in a curved line with respect to the first inner surface. The housing contains the compression mechanism, and is provided with a housing portion other than the sliding portion and the peripheral portion,
The compressor according to claim 1, wherein the plating layer is also formed in the housing portion. The movable member is a drive shaft that is rotationally driven,
The compressor according to any one of claims 1 to 3, wherein the sliding portion is a bearing that rotatably supports the drive shaft. The housing has a cylinder block provided with a cylinder bore,
The compression mechanism includes a drive shaft that is rotationally driven, a swash plate that can be rotated by the rotation of the drive shaft, and a piston that engages with the swash plate and can reciprocate within the cylinder bore,
The sliding portion is the cylinder bore;
The compressor according to any one of claims 1 to 3, wherein the movable member is the piston. The housing has a cylinder block provided with a cylinder bore,
The compression mechanism includes a drive shaft that is rotationally driven, a swash plate that can be rotated by the rotation of the drive shaft, and a piston that engages with the swash plate and can reciprocate within the cylinder bore,
The sliding portion is a bearing that rotatably supports the drive shaft and the cylinder bore,
The compressor according to any one of claims 1 to 3, wherein the movable member is the drive shaft and the piston.

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