WO2014119721A1

WO2014119721A1 - Compressor

Info

Publication number: WO2014119721A1
Application number: PCT/JP2014/052242
Authority: WO
Inventors: 小林　俊之; 誠俊坂野; 近藤　淳; 均犬飼; 紀一出戸; 憲司西田; 真志中森
Original assignee: 株式会社豊田自動織機
Priority date: 2013-01-31
Filing date: 2014-01-31
Publication date: 2014-08-07
Also published as: JPWO2014119721A1; CN104968935A; KR20150103271A; JP5967227B2

Abstract

A cylinder bore (2) is formed from a cylindrical inner circumferential surface (41), and a circular bottom surface (42), which is formed from a portion of the front surface of a valve plate (6). The aperture surface (19a) of a discharge port (19) is formed in the bottom surface (42). A step part (43) and a curving part (41b) are formed along the circumferential direction of the bottom surface (42), between the inner circumferential surface (41) and the bottom surface (42). Whereas the inner circumferential surface (41) undergoes a cutting process, the bottom surface (42) does not, and thus the bottom surface (42) is the original casting surface formed by means of die cast molding.

Description

Compressor

The present invention relates to a compressor, and more particularly to a compressor having a piston.

A conventional compressor that pressurizes gas by a reciprocating piston includes a cylinder block in which a cylindrical cylinder bore in which the piston reciprocates is formed, and a rear housing in which a suction chamber and a discharge chamber are formed. A valve plate and a gasket are provided between the cylinder block and the rear housing, and the cylinder bore, the suction chamber, and the discharge chamber communicate with each other through the valve plate and the gasket. However, in this configuration, since the number of parts increases, it has been studied to integrate the valve plate and the cylinder block for the purpose of reducing the number of parts. Patent Document 1 describes a compressor in which a valve plate and a cylinder block are integrated.

JP-A-8-121330 (FIG. 1)

However, in the compressor described in Patent Document 1, the cylindrical inner peripheral surface of the cylinder bore and the bottom surface in which a hole communicating with the discharge chamber is formed are vertical. In such a shape, if the inner peripheral surface and the bottom surface are cut in the same process, the cutting resistance is different between the inner peripheral surface and the bottom surface, so that the cutting tool vibrates and the processing accuracy of the cylinder bore inner diameter deteriorates. End up. For this reason, it is necessary to cut the inner peripheral surface and the bottom surface in separate steps, but there is a problem that the manufacturing cost and time increase.

The present invention has been made to solve such problems, and an object thereof is to provide a compressor in which a valve plate and a cylinder block are integrated, which simplifies the processing work of the cylinder bore.

The compressor according to the present invention includes a cylindrical piston, an inner peripheral surface that is in sliding contact with the outer peripheral portion of the piston, and a bottom surface that extends with a gap between the front end portion of the piston and has a discharge port formed therein. A die-cast molded cylinder block having a cylinder bore, and a housing in which a discharge chamber is formed and coupled to the cylinder block. A compression chamber is formed in the cylinder bore from a piston, an inner peripheral surface, and a bottom surface. In the compressor in which the compression chamber and the discharge chamber communicate with each other via the discharge port, the cylinder bore has a machined surface that is cut and a cast surface that is not cut, and the bottom surface is the cast surface. In addition, the inner peripheral surface is a processed surface.
A connecting portion may be formed between the inner peripheral surface and the bottom surface along the circumferential direction of the bottom surface. The connecting portion may include a cast surface. The connecting portion may protrude from the bottom surface toward the piston side.
The connecting portion may be recessed toward the opposite side of the piston with respect to the bottom surface.
All of the connecting portions may be cast surfaces.

According to the present invention, since the bottom surface of the cylinder bore where the piston does not contact is left as the casting surface, only the inner peripheral surface with which the piston slides is cut when forming the cylinder bore. Since it can be omitted, the valve plate and the cylinder block can be integrated while simplifying the machining operation of the cylinder bore.

It is sectional drawing of the compressor which concerns on Embodiment 1 of this invention. It is sectional drawing of the cylinder bore formed in the cylinder block of the compressor which concerns on this Embodiment 1. FIG. It is a figure for demonstrating the procedure which forms the cylinder bore formed in the cylinder block of the compressor which concerns on this Embodiment 1. FIG. It is sectional drawing of the cylinder bore formed in the cylinder block of the compressor which concerns on this Embodiment 2. FIG. It is a figure for demonstrating the procedure which forms the cylinder bore formed in the cylinder block of the compressor which concerns on this Embodiment 2. FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 shows a cross-sectional view of the compressor according to Embodiment 1 of the present invention. The swash plate compressor 1 is provided so as to be connected to a cylinder block 3 in which a plurality of cylinder bores 2 are formed, a front housing 4 provided to be joined to the front end of the cylinder block 3, and a rear end of the cylinder block 3. The rear housing 5 is provided. A valve plate 6 is provided between the cylinder block 3 and the rear housing 5, and the valve plate 6 is formed integrally with the cylinder block 3. The cylinder block 3 and the front housing 4 are die-cast. The cylinder bore 2 has an inner peripheral surface 41 and a bottom surface 42 and has a bottomed cylindrical shape.

In the crank chamber 7 in the front housing 4, a drive shaft 8 is rotatably inserted by being inserted into the front housing 4 and the shaft hole 3 b of the cylinder block 3. The drive shaft 8 is provided with a rotor 9, and a long hole 10 a is formed at the tip of a support arm 10 provided so as to extend from the rear surface side of the rotor 9. A pin 10b is slidably inserted into the long hole 10a, and a swash plate 13 is tiltably connected to the pin 10b.

A sleeve 11 is provided on the drive shaft 8 so as to be adjacent to the rear end of the rotor 9, and the sleeve 11 is always pressed against the rotor 9 by a coil spring 12. A pivot 11a (only one is shown) provided so as to protrude from the left and right sides of the sleeve 11 is inserted into an engagement hole (not shown) of the swash plate 13, so that the swash plate 13 swings around the pivot 11a. It has become. On the rear surface side of the swash plate 13, a swing plate 14 is supported via a thrust bearing or the like, and the swing plate 14 is restricted from rotating by a not-shown notch. A plurality of connecting rods 15 are connected to the swing plate 14, and each connecting rod 15 is connected to a cylindrical piston 16 inserted in each cylinder bore 2. As will be described later, the inner peripheral surface of the cylinder bore 2 is cut so as to be slidably contacted with the piston 16 over the entire circumference.

With such a configuration, the rotational movement of the drive shaft 8 is converted into the rocking motion of the rocking plate 14 through the rotor 9 and the swash plate 13, and each piston 16 reciprocates in each cylinder bore 2. The stroke of the piston 16 and the angle of the swing plate 14 with respect to the drive shaft 8 are changed according to the pressure difference between the pressure in the crank chamber 7 and the suction pressure. The compression chamber 24 is defined by the inner peripheral surface 41 and the bottom surface 42 of the cylinder bore 2 and the piston 16.

The rear housing 5 is provided with a suction chamber 17 that opens to the rear end surface and communicates with the shaft hole 3 b of the cylinder block 3. A discharge chamber 18 is formed around the suction chamber 17. A discharge port 19 communicating with each compression chamber 24 is formed in the valve plate 6 formed integrally with the cylinder block 3, and a discharge valve 20 and a retainer 21 are provided on the discharge chamber 18 side of each discharge port 19. Yes. The discharge chamber 18 and the discharge port 19 can communicate with each other by opening the discharge valve 20.

The cylinder block 3 is formed with a communication passage 22 that communicates each compression chamber 24 with the shaft hole 3 b, and a cylindrical rotary valve 30 inserted into the shaft hole 3 b is driven via the base 23. The shaft 8 is coupled to the inner end 8a. The rotary valve 30 includes a suction passage 32 that sequentially connects the communication passages 22 and the suction chamber 17.

As shown in FIG. 2, the cylinder bore 2 includes a cylindrical inner peripheral surface 41 and a circular bottom surface 42 configured from a part of the front surface of the valve plate 6. An opening surface 19 a of the discharge port 19 is formed on the bottom surface 42. The inner peripheral surface 41 is cut, whereas the bottom surface 42 is not cut. Between the inner peripheral surface 41 and the bottom surface 42, there are a stepped portion 43 that protrudes from the bottom surface 42 toward the piston 16, and a curved portion 41 b that connects the stepped portion 43 and the bottom surface 42. Here, the stepped portion 43 and the curved portion 41b constitute a connecting portion that connects the inner peripheral surface 41 and the bottom surface 42, both of which are casting surfaces. In FIG. 2, the stepped portion 43 and the curved portion 41 b are exaggerated and the actual height of the stepped portion 43 with respect to the bottom surface 42 is approximately less than several tens of μmm.

The piston 16 includes a cylindrical outer peripheral portion 51 that is in sliding contact with the inner peripheral surface 41 of the cylinder bore 2, a top portion 52 that faces the bottom surface 42 of the cylinder bore 2, and a chamfered portion 53 that connects the outer peripheral portion 51 and the top portion 52. Yes. The top portion 52 and the chamfered portion 53 are tip portions of the piston 16. When the top portion 52 is closest to the bottom surface 42, that is, at the top dead center position, the tip portion of the piston 16 that faces the bottom surface 42 faces the connection portion without sliding against the inner peripheral surface 41. At this time, the chamfered portion 53 faces the connecting portion. Even when the top portion 52 is closest to the bottom surface 42, a very small gap is formed between them.

Next, a method for forming the cylinder bore 2 in the cylinder block 3 of the compressor according to Embodiment 1 of the present invention will be described with reference to FIG.
As shown in FIG. 3A, when the cylinder block 3 is die-cast, a cylindrical hole 2 ′ that is a prototype of the cylinder bore 2 is formed. Each of the inner peripheral surface 41 ′ and the bottom surface 42 ′ of the cylindrical hole 2 ′ is a cast surface as it is formed by die casting.

Subsequently, the inner peripheral surface 41 ′ is cut so that the tip of a cutting tool (not shown) is slightly separated from the bottom surface 42 ′. At this time, since the tip of the cutting tool does not contact the bottom surface 42 ′ and only the inner peripheral surface 41 ′ is cut, the cutting tool performs cutting without contacting and vibrating the bottom surface 42 ′. As a result, as shown in FIG. 3B, the cylinder bore 2 is formed, and a step protruding from the bottom surface 42 along the circumferential direction of the bottom surface 42 between the inner peripheral surface 41 and the bottom surface 42. A portion 43 is formed. The inner peripheral surface 41 is a machined surface that has been cut, whereas the bottom surface 42 is a cast surface that is still formed by die casting. As described above, the top portion 52 (see FIG. 2) of the piston 16 does not contact the bottom surface 42. Therefore, even if the bottom surface 42 is a cast surface, the compression performance of the swash plate compressor 1 (see FIG. 1). There is no problem.

In this way, since the bottom surface 42 where the piston 16 does not contact is left as the casting surface, only the inner peripheral surface 41 with which the outer peripheral portion 51 of the piston 16 is in sliding contact may be cut when the cylinder bore 2 is formed. Since the labor of processing can be saved, the valve plate 6 and the cylinder block 3 can be integrated while simplifying the processing work of the cylinder bore 2. In addition, since the inner peripheral surface 41 and the bottom surface 42 are not cut in the same process, the vibration of the cutting tool does not affect the cutting of the inner peripheral surface 41, so that the inner peripheral surface 41 is accurately cut. Can do.

Embodiment 2. FIG.
Next, the structure of the compressor which concerns on Embodiment 2 of this invention is shown. In the second embodiment, the same reference numerals as those in FIGS. 1 to 3 are the same or similar components, and the detailed description thereof is omitted.
The compressor according to the second embodiment of the present invention is obtained by changing the form of the connecting portion formed between the inner peripheral surface 41 and the bottom surface 42 with respect to the first embodiment.

As shown in FIG. 4, an annular groove 63 that is recessed with respect to the bottom surface 42 is formed between the inner peripheral surface 41 and the bottom surface 42 along the circumferential direction of the bottom surface 42. Here, the groove 63 constitutes a connecting portion that connects the inner peripheral surface 41 and the bottom surface 42. The groove 63 has a deepest portion 63a, a cylindrical outer peripheral surface 63b that extends continuously from the inner peripheral surface 41 and reaches the deepest portion 63a, and a depth from the deepest portion 63a toward the inside in the radial direction of the cylinder bore 2. A frustoconical inner peripheral side surface 63c. The inner peripheral surface 41, the outer peripheral side surface 63b, and the inner peripheral side surface 63c are cut, whereas the bottom surface 42 is not cut. In FIG. 4, the groove 63 is exaggerated, and the actual depth of the groove 63 is approximately less than several tens of μmm. Other configurations are the same as those of the first embodiment.

Next, a method for forming the cylinder bore 2 in the cylinder block 3 of the compressor according to Embodiment 2 of the present invention will be described with reference to FIG.
As shown in FIG. 5 (a), the process is the same as in the first embodiment until the cylinder block 3 having the cylindrical hole 2 'serving as a prototype of the cylinder bore 2 is die-cast. Therefore, each of the inner peripheral surface 41 ′ and the bottom surface 42 ′ of the cylindrical hole 2 ′ is a cast surface as it is formed by die casting.

Subsequently, the inner peripheral surface 41 ′ is cut with a cutting tool (not shown). At this time, it is preferable that the contact area between the tip of the cutting tool and the bottom surface 42 ′ is made as small as possible by using a cutting tool whose tip contacting the bottom surface 42 ′ has a triangular cross-sectional shape, for example. Using such a cutting tool, at the same time as cutting the inner peripheral surface 41 ′, between the inner peripheral surface 41 and the bottom surface 42 ′, along the circumferential direction of the bottom surface 42 ′, with respect to the bottom surface 42 ′. An annular recess is formed. As a result, as shown in FIG. 5B, the cylinder bore 2 is formed, and a circle that is recessed with respect to the bottom surface 42 along the circumferential direction of the bottom surface 42 between the inner peripheral surface 41 and the bottom surface 42. An annular groove 63 is formed. By using a cutting tool having a tip having a triangular cross-sectional shape, the groove 63 has a configuration including the deepest portion 63a, an outer peripheral side surface 63b, and an inner peripheral side surface 63c. Since the contact area between the tip of the cutting tool and the bottom surface 42 ′ is small, even if the inner peripheral surface 41 ′ is cut and the groove 63 is formed at the same time, the vibration of the cutting tool is suppressed and the machining accuracy of the cylinder bore inner diameter is improved. Deterioration can also be suppressed.

Also in the second embodiment, the inner peripheral surface 41 with which the outer peripheral portion 51 of the piston 16 is slidably contacted is a processed surface that has been cut, whereas the bottom surface 42 that is not in contact with the piston 16 is formed by die casting. It is an as-cast surface. For this reason, when the cylinder bore 2 is formed, only the inner peripheral surface 41 with which the piston 16 is slidably contacted needs to be cut, and the processing work can be saved, so that the same effect as in the first embodiment can be obtained. .

Further, in the second embodiment, since the groove portion 63 that is a connection portion does not protrude from the bottom surface 42 toward the piston 16 side, the chamfered portion 53 of the piston 16 can be made smaller than in the first embodiment. . When the chamfered portion 53 is provided on the piston 16, the dead volume of the compression chamber 24 when the piston 16 reaches the top dead center is increased correspondingly, and the volume efficiency is lowered. However, by reducing the chamfered portion 53 of the piston 16 to reduce the dead volume of the compression chamber 24, it is possible to suppress a decrease in volume efficiency. Furthermore, in the first embodiment, the location where the communication path 22 (see FIG. 1) is connected to the cylinder bore 2 is limited to the position opposite to the bottom surface 42 with respect to the stepped portion 43 (see FIG. 2). However, in the second embodiment, since the communication path 22 can be connected so as to communicate with the groove portion 63, the degree of freedom in designing the communication path 22 can be increased.

In the second embodiment, the connecting portion has a cylindrical outer peripheral side surface 63b that reaches the deepest portion 63a along the inner peripheral surface, and the depth decreases from the deepest portion 63a toward the inside in the radial direction of the cylinder bore 2. Although the groove portion 63 has the frustoconical inner peripheral side surface 63c, it is not limited to this form. A groove portion having a frustoconical outer peripheral side surface whose depth increases from the inner peripheral surface 41 toward the inner side in the radial direction of the cylinder bore 2, and a cylindrical inner peripheral side surface extending in parallel to the inner peripheral surface 41 from the deepest portion 63a. It may be. Further, when the groove portion is formed at the same time as cutting the inner peripheral surface 41, the groove portion may have any shape as long as vibration of the cutting tool can be suppressed. Further, when the inner peripheral surface 41 ′ and the bottom surface 42 ′ of the cylindrical hole 2 ′ are formed by die casting, the groove portion 63 may also be die cast. In this case, since only the inner peripheral surface 41 needs to be cut, all the groove portions 63 are cast surfaces.

In Embodiments 1 and 2, the swash plate compressor 1 has been described. However, the present invention is not limited to the swash plate compressor. Any type of compressor may be used as long as the gas is compressed by reciprocating the piston.
Further, in the swash plate compressor 1, the piston 16 and the swash plate 13 are connected by the connecting rod 15 and the swing plate 14, but the piston 16 and the swash plate 13 may be connected by a shoe.

In Embodiments 1 and 2, the entire bottom surface 42 remains a cast surface, but a part of the surface may be cut. For example, since the precision of die casting was not stable for some reason, a part of the bottom surface 42 ′ may be cut as an additional step for the case where the shape of the bottom surface 42 ′ is not a uniform plane. Good.

1 swash plate compressor (compressor), 2 cylinder bore, 3 cylinder block, 5 rear housing (housing), 16 piston, 18 discharge chamber, 19 discharge port, 24 compression chamber, 41 inner peripheral surface, 41b curved portion (connection portion) ), 42 bottom surface, 43 stepped portion (connecting portion), 51 outer peripheral portion, 52 top portion (piston tip portion), 53 chamfered portion (piston tip portion), 63, 73 groove portion (connecting portion).

Claims

A cylindrical piston;
A die-cast cylinder having a cylinder bore having an inner peripheral surface slidably in contact with the outer peripheral portion of the piston and a bottom surface extending with a gap between the piston and a bottom surface on which a discharge port is formed. Block,
A housing having a discharge chamber formed therein and coupled to the cylinder block, and a compression chamber defined within the cylinder bore from the piston, the inner peripheral surface, and the bottom surface. In the compressor communicating with the chamber via the discharge port,
The cylinder bore has a machined surface that has been machined and a cast surface that is not machined.
The compressor having the bottom surface as the casting surface and the inner peripheral surface as the processing surface.
The compressor according to claim 1, wherein a connecting portion is formed between the inner peripheral surface and the bottom surface along a circumferential direction of the bottom surface.
The compressor according to claim 2, wherein the connecting portion includes the casting surface.
4. The compressor according to claim 2, wherein the connecting portion protrudes from the bottom surface toward the piston side.
The compressor according to claim 2 or 3, wherein the connection portion is recessed toward the opposite side of the piston with respect to the bottom surface.
The compressor according to claim 5, wherein all of the connection portions are the casting surface.