1. Field of the Invention
The present invention relates to inclined plate-type compressors. Further, the invention relates to air conditioning systems, in particular, air conditioning systems for vehicles, which comprise such inclined plate-type compressors.
2, Description of Related Art
An inclined plate-type compressor is described in Japanese Patent Application Publication No. JP-A-2002-250279, wherein a discharge chamber having an annular shape is disposed along an outer circumferential portion of a cylinder head, a suction chamber is formed at a central portion of the cylinder head, and a discharge valve having reed valve-type valve bodies disposed on the discharge chamber for opening and closing discharge ports is formed in a valve plate. In this inclined plate-type compressor, each of the valve bodies of the discharge valve extends in the radial direction of the discharge chamber, and the root portions of the valve bodies are press-fitted to the valve plate by an end surface of a partition wall between the discharge chamber and the suction chamber.
In such an inclined plate-type compressor, because each of the valve bodies of the discharge valve extends in the radial direction of the discharge chamber which has a relatively small radial width, the length of each valve body is constrained by the width of the discharge chamber. In addition, a significant and potentially damaging stress may be generated at a root portion of the valve body when the valve body is opened or closed.
Accordingly, a need has arisen for an inclined plate-type compressor wherein a discharge chamber having an annular shape is disposed along an outer circumferential portion of a cylinder head, a suction chamber is formed at a central portion of the cylinder head, and a discharge valve having reed valve-type valve bodies is disposed on the discharge chamber for opening and closing discharge ports formed in a valve plate, in which stress, generated at a root portion of each valve body when the valve body is opened or closed, may be reduced as compared with that in the above-described, known inclined plate-type compressors.
To satisfy the foregoing need and other objects, an inclined plate-type compressor according to the present invention, comprises a cylinder head, a discharge chamber having an annular shape and disposed along an outer circumferential portion of the cylinder head, a suction chamber formed at a central portion of the cylinder head, a valve plate comprising a plurality of discharge ports in communication with the discharge chamber, and a discharge valve comprising a plurality of reed valve-type valve bodies disposed in the discharge chamber. Each of the valve bodies opens and closes a corresponding one of the discharge ports, and each of the valve bodies extends in a circumferential direction of the discharge chamber and oriented along the annular shape of the discharge chamber. Because each valve body of the discharge valve extends in the circumferential direction of the annular discharge chamber, the length of each valve body may be increased as compared with that in the above-described known inclined plate-type compressors wherein the valve body extends in the radial direction of the annular discharge chamber. Therefore, in the present invention, a stress, generated at a root portion of each valve body when the valve body is opened or closed, may be reduced.
An air conditioning system, according to the present invention, comprises an inclined plate-type compressor. The compressor comprises a cylinder head, a discharge chamber having an annular shape and disposed along an outer circumferential portion of the cylinder head, a suction chamber formed at a central portion of the cylinder head, a valve plate comprising a plurality of discharge ports in communication with the discharge chamber, and a discharge valve comprising a plurality of reed valve-type valve bodies disposed in the discharge chamber. Each of the valve bodies opens and closes a corresponding one of the discharge ports, and each of the valve bodies extends in a circumferential direction of the discharge chamber and oriented along the annular shape of the discharge chamber. Because each valve body of the discharge valve extends in the circumferential direction of the annular discharge chamber, the length of each valve body may be increased as compared with that in the above-described known inclined plate-type compressors wherein the valve body extends in the radial direction of the annular discharge chamber. Therefore, in the present invention, a stress, generated at a root portion of each valve body when the valve body is opened or closed, may be reduced.
In a preferred embodiment of the present invention, a head gasket is interposed between the valve plate and the cylinder head, and a retainer, which regulates an opening degree or extent of a corresponding valve body, is formed integrally with the head gasket to oppose the corresponding valve body. Further, portions of the retainer at either side of the retainer opposite a tip portion of the valve body and a retainer root portion of the retainer opposite a valve body root portion of the valve body remain attached to the head gasket, and head gasket portions adjacent to either side of the retainer portion are secured, e.g., press-fitted, to the valve plate by a first end surface of a partition wall between the discharge chamber and the suction chamber and a second end surface of an outer circumferential wall of the cylinder head. Moreover, the retainer root portion and the valve body root portion are secured, e.g., press-fitted to the valve plate by a seat surface of a fastening bolt threaded portion formed on the outer circumferential wall of the cylinder head. In such a structure, the valve body root portion and the retainer may be readily secured to the valve plate.
In another preferred embodiment of the present invention, a head stepped portion and a gasket stepped portion for receiving each valve body are disposed on the second end surface of the outer circumferential wall of the cylinder head and an outer circumferential portion of the head gasket, respectively. A first portion of the outer circumferential portion of the head gasket, which is positioned inside of the gasket stepped portion, and an outer circumferential portion of the discharge valve are secured, e.g., press-fitted, to the valve plate by a portion of the second end surface of the outer circumferential wall of the cylinder head, which is positioned inside of the head stepped portion. A second portion of the outer circumferential portion of the head gasket, which is positioned outside of the gasket stepped portion is secured, e.g., press-fitted, to the valve plate by a portion of the second end surface of the outer circumferential wall of the cylinder head, which is positioned outside of the head stepped portion.
In this structure, the outer circumferential portion of the discharge valve and the outer circumferential portion of the head gasket may be readily secured to the valve plate. Because a double annular seal is formed by the portions of the outer circumferential portion of the head gasket positioned inside and outside of the gasket stepped portion, the head gasket has increased sealing performance.
In yet another preferred embodiment of the present invention, a bead is formed on the portion of the outer circumferential portion of the head gasket, which is positioned outside of the gasket stepped portion, and a compression ratio of the bead, when the portion of the outer circumferential portion of the head gasket, which is positioned outside of the gasket stepped portion, is secured, e.g., press-fitted, to the valve plate by the portion of the second end surface of the outer circumferential wall of the cylinder head, which is positioned outside of the head stepped portion, is less than 100%.
In this structure, by maintaining the compression ratio of the bead at a value less than 100%, the seal achieved by the portion of the outer circumferential portion of the head gasket, which is positioned outside of the gasket stepped portion, becomes a combination of a plane seal and a line seal. Although a plane seal has an increased degree of sealability, if there are scratches or other imperfections on the sealing surface, the sealability tends to deteriorate markedly, and the seal lacks stability. On the other hand, although a line seal has a lower degree of sealability than the plane seal, even if there are scratches or other imperfections on the sealing surface, the sealability does not decrease as much, and the seal is stable. Therefore, by combining such a plane seal and line seal, an increased sealing performance and a stable sealing may be achieved.
In still another preferred embodiment of the present invention, the inclined plate-type compressor has a communication passage for placing a fine annular space, formed between the head stepped portion, an outer surface of the discharge valve, and the valve plate, in communication with a lower-pressure region of the compressor. In this structure, because the pressure in the fine annular space is reduced, the sealability due to the portion of the outer circumferential portion of the head gasket, which is positioned outside of the gasket stepped portion, is increased.
Thus, in the inclined plate-type compressor according to the present invention, by extending each valve body of the discharge valve in the circumferential direction of the discharge chamber, the length of each valve body may be increased as compared with that in the above-described known inclined plate-type compressors, wherein the valve body extends in the radial direction over the width of the annular discharge chamber, and a stress, which is generated at the root portion of each valve body when the valve body is opened or closed, may be reduced remarkably. Further, in the preferred embodiments of the present invention, an increased degree of sealability may be readily achieved at a portion including the head gasket.
Further objects, features, and advantages of the present invention will be understood from the following detailed description of preferred embodiments of the present invention with reference to the accompanying figures.
Embodiments of the invention now are described with reference to the accompanying figures, which are given by way of example only, and are not intended to limit the present invention.
Piston 15 engages inclined plate 12 via a pair of shoes 14 which slide on the outer circumferential portion of inclined plate 12. Piston head 150 of piston 15 is inserted into cylinder bore 160 formed in cylindrical cylinder block 16. A plurality of cylinder bores 160 are disposed around central axis X at a predetermined interval, and each piston head 150 of pistons 15 is inserted into one of cylinder bores 160.
A cup-like, cylindrical front housing 18 defines a crank chamber 17, in which drive shaft 10, rotor 11, and inclined plate 12 are disposed. Front housing 18 faces one surface of cylinder block 16. A cylinder head 19 faces the other surface of cylinder block 16. Cylinder head 19 has an outer circumferential wall 190, an inner circumferential wall 195, an annular discharge chamber 196, which is formed between outer circumferential wall 190 and inner circumferential wall 195, and a circular suction chamber 197, which is formed inside of inner circumferential wall 195 at a central portion of cylinder head 19. Suction chamber 197 and discharge chamber 196 are distinguished, in part, by their cross-sectional shapes. Discharge chamber 196 communicates with cylinder bore 160 via a discharge port, and suction chamber 197 communicates with cylinder bore 160 via a suction port. Each of the discharge ports and the suction ports is in communication with other known components of an air conditioning system, such as a condenser and an evaporator (not shown).
A disc-like, valve plate 22 is interposed between cylinder block 16 and cylinder head 19. Valve plate 22 has discharge ports 220 and suction ports 221 aligned and in communication with corresponding cylinder bores 160. Each pair of discharge ports 220 and suction ports 221 is arranged along a line extending radially from the center of valve plate 22.
As depicted in
A retainer 240 for regulating the degree of opening of each valve body 230 is formed on head gasket 24 integrally with head gasket 24 so as to oppose each valve body 230. Retainer 240 is formed by cutting head gasket 24 and raising the cut portion. Both side portions 241 of retainer 240 opposite a tip portion of the corresponding valve body 230 and a retainer root portion 242 of retainer 240 opposite the valve body root portion of the corresponding valve body 230 remain attached to head gasket 24. In head gasket 24, a central recessed portion 243 formed with retainers 240, a flange-like, outer circumferential portion 244, and a gasket stepped portion for receiving each valve body 230, forming a boundary between central recessed portion 243 and outer circumferential portion 244, are formed. A first bead 245 extending around the circumference is disposed on outer circumferential portion 244.
On the end surface of outer circumferential wall 190 of cylinder head 19, an inner recessed portion 191 opposite the outer circumferential portion of central recessed portion 243 of head gasket 24 and the outer circumferential portion of discharge valve 23, seat surfaces 192 of the threaded portions of this fastening bolt extend radially inward from inner recessed portion 191, an outer circumferential portion 193 of wall 190 opposite outer circumferential portion 244 of head gasket 24, and a head stepped portion 194 for receiving the valve bodies and forming a boundary between outer circumferential portion 193 and inner recessed portion 191, are formed. The end surface of inner circumferential wall 195 of cylinder head 19 is formed flush relative to inner recessed portion 191 and seat surfaces 192 of fastening bolt, threaded portions at the end surface of the outer circumferential wall 190 of cylinder head 19.
As depicted in
On the end surface of the cylinder head-side of cylinder block 16, a central recessed portion 161 is formed opposite to central recessed portion 261 of cylinder gasket 26, and an outer circumferential portion 162 is formed opposite outer circumferential portion 262 of cylinder gasket 26. A stepped portion 163 for receiving the suction valve bodies defines the boundary between central recessed portion 161 and outer circumferential portion 162.
Cylinder block 16, cylinder gasket 26, suction valve 25, valve plate 22, discharge valve 23, head gasket 24, and cylinder head 19 are fastened together by through bolts 27.
When the above-described parts are fastened together by through bolts 27, as depicted in
Further, when the above-described components are fastened together by through bolts 27, as depicted in
When the above-described components are fastened together by through bolts 27, as depicted in
Moreover, when the above-described components are fastened together by through bolts 27, as depicted in
Further, when the above-described components are fastened together by through bolts 27, as depicted in
When the above-described components are fastened together by through bolts 27, as depicted in
Moreover, when the above-described components are fastened together by through bolts 27, as depicted in
In addition, when the above-described components are fastened together by through bolts 27, as depicted in
When the above-described components are fastened together by through bolts 27, as depicted in
In such variable displacement, inclined plate-type compressor A, the rotation of drive shaft 10 is transmitted to inclined plate 12 via rotor 11 and link mechanism 13. The reciprocating movement of the outer circumferential portion of inclined plate 12 in the axial direction parallel to drive shaft 10, which is ascribed to the rotation of inclined plate 12, is transmitted to pistons 15 via shoes 14. Piston head 150 of each piston 15 moves reciprocally in cylinder bore 160. Refrigerant gas, which is circulated from an external refrigeration circuit and flows into cylinder bore 160 through the external suction inlet, suction chamber 197, suction port 221, and valve body 250 of suction valve 25, is compressed by piston 15. The compressed refrigerant gas is discharged to discharge chamber 196 through discharge port 220 and valve body 230 of discharge valve 23. The refrigerant gas discharged into discharge chamber 196 is circulated to the external refrigeration circuit through the external discharge outlet.
In variable displacement inclined plate-type compressor A, as depicted in
Further, in this inclined plate-type compressor A, because the portions of head gasket 24 adjacent to either side 241 of retainer 24 facing the tip portion of valve body 230 is press-fitted to valve plate 22 together with discharge valve 23 by inner recessed portion 191 on the end surface of outer circumferential wall 190 of cylinder head 19 and the end surface of inner circumferential wall 195, and as depicted in
Moreover, in this inclined plate-type compressor A, because the portion adjacent to gasket stepped portion 246 on the outer circumferential portion of central recessed portion 243 of head gasket 24 and the outer circumferential portion of discharge valve 23 are press-fitted to valve plate 22 by inner recessed portion 191 on the end surface of outer circumferential wall 190 of cylinder head 19, and outer circumferential portion 244 of head gasket 24 is press-fitted to valve plate 22 by outer circumferential portion 193 on the end surface of outer circumferential wall 190 of cylinder head 19, the securing of the outer circumferential portion of discharge valve 23 and outer circumferential portion 244 of head gasket 24 to valve plate 22 may be facilitated. Because a double annular seal is formed by the portion adjacent to gasket stepped portion 246 on the outer circumferential portion of central recessed portion 243 of head gasket 24 and head gasket outer circumferential portion 244, the sealability of head gasket 24 may be increased. In the securing portion of the outer circumferential portion of cylinder gasket 26 and the outer circumferential portion of suction valve 25 to valve plate 22, because a similar structure is employed, an advantage similar to the above-described advantage may be obtained.
In addition, in this inclined plate-type compressor A, because the compression ratio of bead 245 formed on outer circumferential portion 244 of head gasket 24 is less than 100%, a combination of a plane seal and a line seal may be achieved for the seal due to head gasket outer circumferential portion 244. As described above, although a plane seal has an increased degree of sealability, if there are scratches or other imperfections on the sealing surface, the sealability tends to decrease significantly, and the seal lacks stability. On the other hand, although a line seal has a lower degree of sealability than the plane seal, even if there are scratches or other imperfections on the sealing surface, the sealability does not decrease so much, and the seal is stable. Therefore, by the above-described combination of the plane seal and the line seal, an increased sealing performance and a stable sealing may be achieved. In the securing portion of outer circumferential portion 262 of cylinder gasket 26 to valve plate 22, because a similar structure is employed, an advantage similar to the above-described advantage may be obtained.
In this inclined plate-type compressor A, because fine annular space 300, formed between gasket stepped portion 246 on outer circumferential portion 244 of head gasket 24, the outer surface of discharge valve 23, and valve plate 22, communicates with the lower pressure region of inclined plate-type compressor A such as the external suction inlet, suction chamber 197, crank chamber 17, via a communication passage, the pressure in fine annular space 300 may be reduced. The sealability due to outer circumferential portion 244 of head gasket 24 also may be increased. In the securing portion of outer circumferential portion 262 of cylinder gasket 26 and the outer circumferential portion of suction valve 25, because a similar structure is employed, an advantage similar to the above-described advantage may be obtained.
The present invention may be applied broadly to an inclined plate-type compressor including a wobble plate-type compressor.
Although embodiments of the present invention have been described in detail herein, the scope of the invention is not limited thereto. It will be appreciated by those skilled in the art that various modifications may be made without departing from the scope of the invention. Accordingly, the embodiments disclosed herein are only exemplary. It is to be understood that the scope of the invention is not to be limited thereby, but is to be determined by the claims which follow.
Number | Date | Country | Kind |
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2004/139280 | May 2004 | JP | national |