Patent Grant
8770088
This is a U.S. national stage of application No. PCT/JP2010/06758, filed on Jul. 29, 2010.
This application claims the priority of Japanese application no. 2009-177470 filed Jul. 30, 2009, the entire content of which is hereby incorporated by reference.
The present invention relates to a reciprocating compressor comprising an aperture control valve for an inlet passage.
Patent Document 1 teaches a reciprocating compressor comprising an aperture control valve for an inlet passage.
In the reciprocating compressor of Patent Document 1, the aperture control valve decreases the aperture of the inlet passage when flow rate of refrigerant gas circulating in an air conditioner provided with the compressor to effectively prevent inlet pressure pulsation caused by self-excited vibration of the inlet valves of the compressor from propagating to an evaporator and also self-excited vibration of a valve body of the aperture control valve.
Drawbacks of the aforementioned compressor are as follows.
(1) The aperture control valve 30 is inserted into and installed in the inlet chamber 21 from outside the compressor through an inlet port 24. Therefore, installation of the aperture control valve 30 is not easy.
(2) The aperture control valve 30 is connected to the circumferential sidewall of the inlet chamber. Therefore, some among a plurality of outlet holes 32a closely oppose the end wall of the inlet chamber to cause insufficiency of sectional area of the inlet passage near the outlet holes 32a and increase of pressure loss at the time of large flow rate of refrigerant gas, thereby decreasing compression capability and durability.
(3) The inlet chamber 21 forms an annular passage. Therefore, distances between the aperture control valve and cylinder bores 16a differ from each other, flaw rates of refrigerant gas sucked into the cylinder bores 16a during inlet stroke differ from each other, and operation of the compressor becomes unstable.
(4) In the inlet chamber 21 forming an annular passage, the space extending from the aperture control valve to the cylinder bores does not form a muffler. Therefore, the structure of the aperture control valve cannot be optimized from the viewpoint of decreasing inlet pressure pulsation.
An object of the present invention is to provide a reciprocating compressor comprising an aperture control valve for an inlet passage, wherein installation of the aperture control valve is easy, sufficient sectional area of the inlet passage is maintained near the outlet holes of the aperture control valve, distribution of flaw rates of refrigerant gas sucked into the cylinder bores during inlet stroke is even, and the inlet chamber operates as a muffler to make it possible to optimize the structure of the aperture control valve from the viewpoint of decreasing inlet pressure pulsation.
In accordance with the present invention, there is provided a reciprocating compressor comprising a cylinder block provided with a plurality of cylinder bores, a valve plate opposing one end of the cylinder block at one end face and provided with a plurality of inlet hole and outlet hole pairs each opposing one of the cylinder bores, and a cylinder head opposing the other end face of the valve plate and forming at the other end face side of the valve plate an annular outlet chamber and a cylindrical inlet chamber disposed radially inside the outlet chamber, wherein the cylinder head is provided with an inlet passage extending from the inlet chamber to connect with an external refrigerating circuit and an outlet passage extending from the outlet chamber to connect with the external refrigerating circuit, and further comprising an aperture control valve provided with an inlet hole connecting with the inlet passage and outlet holes communicating with the inlet chamber and controlling the aperture of the inlet passage in proportion to the pressure difference between the internal pressure of the inlet passage and the internal pressure of the inlet chamber, wherein the aperture control valve is disposed in the inlet chamber, and the aperture control valve engages the end wall of the inlet chamber opposing the valve plate at one end provided with the inlet hole and projects from the end wall of the inlet chamber toward the other end and the valve plate.
In the reciprocating compressor of the present invention, the inlet chamber can form a large space of great diameter because the inlet chamber is given a cylindrical form and disposed radially inside the annular outlet chamber. The aperture control valve can be engaged with the large-area end wall of the inlet chamber from the inlet chamber side before the cylinder head is assembled with the valve plate and the cylinder block so as to make the installation of the aperture control valve easy.
The aperture control valve is connected to the end wall of the inlet chamber of cylindrical form so as to reduce the variance of distances between the aperture control valve and the cylinder bores and the variance of flow rates of refrigerant gas sucked into the cylinder bores during inlet stroke, thereby stabilizing the operation of the reciprocating compressor.
In accordance with a preferred embodiment of the present invention, the outlet holes of the aperture control valve oppose the circumferential sidewall of the inlet chamber.
The aperture control valve is connected to the expansive end wall of the inlet chamber. Therefore, sufficient distance can be established between the outlet holes of the aperture control valve and the circumferential sidewall of the inlet chamber opposing the outlet holes so as to secure sufficient sectional area of the inlet passage near the outlet holes of the aperture control valve.
In accordance with another preferred embodiment of the present invention, the outlet holes of the aperture control valve are formed in the circumferential sidewall of a cylindrical body engaging the end wall of the inlet chamber at one end and projecting toward the other end and the valve plate, and wherein the outlet holes are located at a predetermined distance from the end wall of the inlet chamber at the portions of the peripheries close to the one end of the cylindrical body engaging the end wall of the inlet chamber.
As aforementioned, the inlet chamber can form a large space of great diameter so as to operate as a muffler. When an air passage is connected to a muffler, it is possible to control the length of the portion of the air passage projecting into the muffler so as to control the noise frequency to be decreased. In the aperture control valve of the compressor in accordance with the present preferred embodiment, the distance between the portions of the peripheries of the outlet holes close to the one end of the cylindrical body engaging the end wall of the inlet chamber and the end wall of the inlet chamber corresponds to the aforementioned length of the portion of the air passage projecting into the muffler. Therefore, it is possible to control the distance and make the noise frequency to be decreased resonant with the frequency of inlet pressure pulsation, thereby optimizing the structure of the aperture control valve from the viewpoint of decreasing inlet pressure pulsation.
In accordance with another preferred embodiment of the present invention, the aperture control valve fits in a concave formed in the end wall of the inlet chamber at one end provided with the inlet hole and abuts an anti-slip-off member at the other end to be prevented from axial movement.
When the aperture control valve fits in a concave formed in the end wall of the inlet chamber at one end, the installation of the aperture control valve in the compressor becomes easy. When the aperture control vale abuts an anti-slip-off member at the other end, the aperture control valve is prevented from slipping off the concave.
In accordance with another preferred embodiment of the present invention, the anti-slip-off member is selected from the group consisting of the valve plate, an outlet-valve-forming member provided with outlet valves, a head gasket disposed between the outlet-valve-forming member and the cylinder head, an inlet-valve-forming member provided with inlet valves, and a cylinder gasket disposed between the inlet-valve-forming member and the cylinder block.
When some existing element of the compressor is used as the anti-slip-off member, increase of the number of elements can be prevented.
In accordance with another preferred embodiment of the present invention, the anti-slip-off member and also a partition wall defining the inlet chamber is selected from the group consisting of an outlet-valve-forming member provided with outlet valves, a head gasket disposed between the outlet-valve-forming member and the cylinder head, an inlet-valve-forming member provided with inlet valves, and a cylinder gasket disposed between the inlet-valve-forming member and the cylinder block, and wherein a concave is formed in the one end of the cylinder block and the anti-slip-off member projects into the concave of the cylinder block.
When the aperture control valve projects into the concave of the cylinder block at the other end, the aperture control valve can be installed in the inlet chamber even if the height of the inlet chamber cannot be made large enough.
In accordance with another preferred embodiment of the present invention, the anti-slip-off member forms a biasing member for forcing the other end of the aperture control valve toward the one end.
When the biasing member operates as the anti-slip-off member, the aperture control valve can be reliably held by the compressor.
In accordance with another preferred embodiment of the present invention, the biasing member is a resilient member formed by one part of the outlet-valve-forming member cut out and raised up from the remaining part.
When one part of the outlet-valve-forming member is used as the biasing member, increase of the number of elements can be prevented.
In accordance with another preferred embodiment of the present invention, the aperture control valve comprises a first housing of cylindrical form provided with the inlet hole and a valve seat, a valve body detachably abuts the valve seat to open and close the inlet hole, a biasing member for forcing the valve body toward the valve seat, and a second housing of cylindrical form closed at one end provided with a plurality of outlet holes in the circumferential sidewall and a small hole in the bottom wall and accommodating the valve body and the biasing member and fitting on and fixed to the first housing, wherein the space formed by the bottom wall of the second housing, the valve body, and the circumferential sidewall of the second housing communicates with the inlet chamber through the small hole formed in the bottom wall of the second housing when the other end of the aperture control valve abuts the anti-slip-off member.
In accordance with the aforementioned structure, the internal pressure of the inlet chamber reliably acts in the space formed by the bottom wall of the second housing, the valve body, and the circumferential sidewall of the second housing. Therefore, the valve body can move reliably in proportion to the pressure difference between the internal pressure of the inlet passage upstream of the valve body and the internal pressure of the inlet chamber downstream of the valve body.
In accordance with another preferred embodiment of the present invention, the compressor further comprises projections provided on the bottom wall of the second housing or the anti-slip-off member, wherein the projections form a space between the small hole formed in the bottom wall of the second housing and the anti-slip-off member when the other end of the aperture control valve abuts the anti-slip-off member.
When a space is established between the small hole formed in the bottom wall of the second housing and the anti-slip-off member, the internal pressure of the inlet chamber can reliably act in the space formed by the bottom wall of the second housing, the valve body, and the circumferential sidewall of the second housing.
In accordance with another preferred embodiment of the present invention, the compressor further comprises an O-ring fitting on the outer circumferential surface of the one end of the aperture control valve, wherein the O-ring is forced to abut the circumferential wall of the concave formed in the end wall of the inlet chamber to make the cylinder head hold the aperture control valve.
An O-ring can be used for making the cylinder head hold the aperture control valve.
In accordance with another preferred embodiment of the present invention, the aperture control valve comprises a first housing provided with the inlet hole and a valve seat, a valve body detachably abuts the valve seat to open and close the inlet hole, a biasing member for forcing the valve body toward the valve seat, and a second housing of cylindrical form closed at one end provided with a plurality of outlet holes in the circumferential sidewall and a small hole in the bottom wall and accommodating the valve body and the biasing member and fitting on and fixed to the first housing, wherein the end wall of the inlet chamber opposing the valve plate forms the first housing.
When one part of the cylinder head forms the first housing, the number of elements decreases and production cost decreases.
In accordance with another preferred embodiment of the present invention, the central axis of the aperture control valve extends parallel to the central axes of the cylinder bores and is located inside a circle inscribed in the cylinder bores.
In accordance with the aforementioned structure, the aperture control valve is disposed at the center of the inlet chamber and directed in parallel with the cylinder bores. Therefore, variance of the distances between the aperture control valve and the cylinder bores decreases and variance of the flow rates of the refrigerant gas sucked into the cylinder bores during inlet stroke decreases.
Preferred embodiments of the present invention will be described.
As shown in
The driving shaft 106 extends across a crank chamber 105 defined by the cylinder block 101 and the front housing 102. A swash plate 107 fits on the driving shaft 106. The swash plate 107 is connected to a rotor 108 fixed to the driving shaft 106 through a connection member 109 to be variable in inclination relative to the driving shaft 106. A coil spring 110 is disposed between the rotor 108 and the swash plate 107 to force the swash plate 107 in the direction of minimum inclination angle. A coil spring 111 is also provided. The coil springs 110 and 111 are disposed to face opposite surfaces of the swash plate 107. The coil spring 111 forces the swash plate 107 in the direction to increase the inclination angle of the swash plate 107.
One end of the driving shaft 106 passes through a boss 102a of the front housing 102 to extend out of the front housing 102, thereby being connected to a power transmission not shown in
Pistons 117 are inserted into the cylinder bores 101a. Each piston 117 is provided with a concave 117a at one end. The concave 117a accommodates a pair of shoes 118 for clamping the outer periphery of the swash plate 107 so as to be slidable relative to the outer periphery of the swash plate 107. Thus, the pistons 117 and the swash plate 107 are interlocked. Therefore, rotation of the driving shaft 106 is converted to reciprocal movement of the pistons 117 in the cylinder bores 101a.
The cylinder head 104 cooperates with the valve plate 103 to define as inlet chamber 119 and an outlet chamber 120. The inlet chamber 119 communicates with the cylinder bores 101a through communication holes 103a formed in the valve plate 103 and inlet valves not shown in
The outlet chamber 120 has an annular form and the inlet chamber 119 is disposed radially inside the outlet chamber 120. The inlet chamber 119 forms a cylindrical space coaxial with the driving shaft 106 defined by a circumferential sidewall 104e formed by the boundary wall between the inlet chamber 119 and the outlet chamber 120, one end wall formed by the valve plate 103, and the other end wall 104f formed by the bottom wall of the cylinder head 104 opposing the valve plate 103.
A center gasket not shown in
The cylinder block 101 is provided with a muffler 121. The muffler 121 is formed by an annular wall 101b formed on the outer surface of the cylinder block 101 and a cover 122 connected to the annular wall 101b with a seal member inserted between them. A check valve 200 is installed in a muffler space 123. The check valve 200 is located at the connection between the muffler space 123 and an outlet passage 124 formed in the cylinder head 104 and the cylinder block 101. The check valve 200 operates in proportion to the pressure difference between the internal pressure of the outlet passage 124 upstream of the check valve 200 and the internal pressure of the muffler space 123 downstream of the check valve 200. The check valve 200 closes the outlet passage 124 when the pressure difference is smaller than a predetermined level and opens the outlet passage 124 when the pressure difference is larger than the predetermined level. The outlet chamber 120 is connected to a high-pressure side external refrigerant circuit of an air conditioner through the outlet passage 124, the check valve 200, the muffler space 123 and an outlet port 122a.
The cylinder head 104 is provided with an inlet port 104a connecting with a low pressure side refrigerant circuit of the air conditioner and an inlet passage 104b extending from the inlet chamber 119, passing through the center portion of the end wall 104f of the cylinder head 104 to extend out of the inlet chamber 119, extending radially outward along the outside surface of the end wall 104f, and reaching the inlet port 104a.
An aperture control valve 300 is installed. The aperture control valve 300 is located at the connection between the inlet passage 104b and the inlet chamber 119. The aperture control valve 300 operates in proportion to the pressure difference between the internal pressure of the inlet passage 104b upstream of the aperture control valve 300 and the internal pressure of the inlet chamber 119 downstream of the aperture control valve 300. The aperture control valve 300 decreases the aperture of the inlet passage 104b to the minimum level when the pressure difference is smaller than a predetermined level, i.e., when the flow rate of refrigerant gas is very low, and increases the aperture of the inlet passage 104b when the flow rate of refrigerant gas increases and the pressure difference becomes larger than the predetermined level. The aperture control valve 300 decreases the aperture of the inlet passage 104b when the flow rate of refrigerant gas is very low to prevent pulsation of the internal pressure of the inlet chamber 119 from propagating to the air conditioner.
The cylinder head 104 is further provided with a displacement control valve 400. The displacement control valve 400 controls the aperture of a first communication passage 125 extending between the outlet chamber 120 and the crank chamber 105 to control the flow rate of the discharging refrigerant gas led into the crank chamber 105. The refrigerant gas in the crank chamber 105 is led into the inlet chamber 119 through a second communication passage formed by spaces between the bearings 115, 116 and the driving shaft 106, a space 101c between the end of the driving shaft 106 and the valve plate 103, and a fixed orifice 103c formed in the valve plate 103. The displacement control valve 400 can control the flow rate of the discharging refrigerant gas led into the crank chamber 105 to control the internal pressure of the crank chamber 105, thereby controlling the inclination angle of the swash plate 7, the stroke of the pistons 117, and the displacement of the variable displacement swash plate compressor 100. The displacement control valve 400 is an externally controlled displacement control valve operating in proportion to external control signals. The displacement control valve 400 detects the internal pressure of the inlet chamber 119 through a communication passage 126 to control the supply of electric current to a solenoid of the displacement control valve 400, thereby controlling the displacement of the compressor 100 to control the internal pressure of the inlet chamber 119 to a predetermined level. When the supply of electric current to the solenoid is stopped, the displacement control valve 400 forces a valve body thereof to open, thereby minimizing the displacement of the compressor 100.
As shown in
The valve body 320 is provided with a flat surface 320a for abutting the valve seat, and an external circumferential side surface 320b for slidably abutting the internal circumferential side surface 340c of the second housing 340. The open area of the outlet holes 340a increases and decreases as the valve body 320 moves.
As shown in
As shown in
The inlet chamber 119 can form a large space of great diameter because the inlet chamber 119 is given a cylindrical form and disposed radially inside the annular outlet chamber 120. The aperture control valve 300 can be engaged with the wide end wall 104f of the inlet chamber 119 before the cylinder head 104 is assembled with the valve plate 103 and the cylinder block 101. Thus, installation of the aperture control valve 300 becomes easy.
The aperture control valve 300 is connected to the large-area end wall 104f of the inlet chamber 119. Therefore, sufficient distance can be established between the outlet holes 340a of the aperture control valve 300 and the circumferential sidewall 104e of the inlet chamber 119 opposing the outlet holes 340a so as to secure sufficient sectional area of the inlet passage near the outlet holes 340a of the aperture control valve 300.
As shown in
The aperture control valve 300 fits in a circular concave 104c formed in the end wall 104f of the inlet chamber 119 at the one end provided with the inlet hole 310a. Thus, the installation of the aperture control valve 300 in the compressor 100 becomes easy. The other end of the aperture control valve 300 is directed to the outlet-valve-forming member 130. Therefore, even if the aperture control valve 300 is forced in the direction of slipping off from the circular concave 104c, the aperture control valve 300 abuts the outlet-valve-forming member 130 at the other end and the O-ring 350 does not escape from the circular concave 104c. Thus, the outlet-valve-forming member 130 prevents the slipping off of the aperture control valve 300.
The central axis of the circular concave 104c and eventually the central axis of the aperture control valve 300 extend parallel to the central axes of the cylinder bores 101a and are located inside a circle inscribed in the cylinder bores 101a so as to be substantially aligned with the central axis of the driving shaft 106. Therefore, the aperture control valve 300 is located substantially at the center of the inlet chamber 119 of cylindrical form and substantially at equal distance from the cylinder bores 101a. Therefore, variance among the flow rates of the refrigerant gas sucked into the cylinder bores 101a during inlet stroke decreases, compressing operations in the cylinder bores 101a are made appropriate, and good performance of the compressor 100 is achieved.
As shown in
The bottom wall of the second housing 340 is provided with downward projections 340e. Therefore, even if the aperture control valve 300 abuts the outlet-valve-forming member 130, a space is formed between the bottom wall of the second housing 340 and the outlet-valve-forming member 130 by the projections 340e, communication between the inlet chamber 119 and the small hole 340d and eventually the space 360 is maintained, and internal pressure of the inlet chamber 119 is reliably applied on the rear surface of the valve body 320. Therefore, the valve body 320 operates reliably in proportion to the pressure difference between the internal pressure of the inlet passage 104b upstream of the valve body 320 and the internal pressure of the inlet chamber 119 downstream of the valve body 320. The operation characteristics of the valve body 320 are determined by the pressure receiving area of the valve body 320 and the biasing force of the compression coil spring 330.
In the first preferred embodiment, the central axis of the aperture control valve 300 is substantially aligned with the central axis of the driving shaft 106. As shown in
The circular concave 104c is inclined. The aperture control valve 300 is fitted in the inclined circular concave 104c at the one end provided with the inlet hole 310a and slantedly opposes the outlet-valve-forming member 130 disposed adjacent to the valve plate 103 at the other end. Some of the outlet holes 340a slantedly oppose the end wall 104f of the inlet chamber 119 or the outlet-valve-forming member 130, and some of the remaining outlet holes 340a oppose the circumferential sidewall 104e of the inlet chamber 119. Every one of the outlet holes 340a is sufficiently distanced from the opposite wall. Therefore, sufficient sectional area of the inlet passage is secured near the outlet holes 340a of the aperture control valve 300.
Because of the inclined installation of the aperture control valve 300, a space is established between the bottom wall of the second housing 340 and the outlet-valve-forming member 130 even if the bottom wall of the second housing 340 is not provided with such projections as the projections 340e formed on the bottom wall of the second housing 340 in the first embodiment. Thus, the inlet chamber 119 reliably communicates with the small hole 340d and eventually the space 360.
In the first preferred embodiment, the aperture control valve 300 is held by the circular concave 104c and eventually the cylinder head 104 by means of the O-ring 350 fitted on the outer circumferential surface of the one end of the aperture control valve 300. As shown in
In the third preferred embodiment, the aperture control valve 300 is held by the cylinder head 104 by means of press fitting. As shown in
Aforementioned structure enables omission of the press fitting operation and makes the installation of the aperture control valve 300 in the circular concave 104c easy. Each of the resilient members 130a is made from a part of the existing member 130. Therefore, the number of elements does not increase.
As shown in
A circumferential groove formed in the flange 340b of the second housing 340 is resiliently fitted on a circumferential projection formed on one end of the first housing 310′ so as to fix the second housing 340 to the first housing 310′ and eventually the cylinder head 104. The number of elements decreases by forming the first housing 310′ integrally with the cylinder head 104.
In the preferred embodiments 1 to 5, the outlet-valve-forming member 130 operates as the anti-slip-off member. The valve plate 103 or the head gasket disposed between the outlet-valve-forming member 130 and the cylinder head 104 can operate as the anti-slip-off member.
It is possible to make holes large enough for accommodating the aperture control valve 300 in the head gasket, the outlet-valve-forming member 130 and the valve plate 103, thereby making the inlet-valve-forming member provided with the inlet valves or the cylinder gasket disposed between the inlet-valve-forming member and the cylinder block 101 operate as the anti-slip-off member. In accordance with the aforementioned structure, an extra space equal to the sum of the thicknesses of the head gasket, the outlet-valve-forming member 130 and the valve plate 103 is formed in the axial direction. Thus, the installation space of the aperture control valve 300 increases.
As shown in
When the other end of the aperture control valve 300 enters into the concave 101c of the cylinder block 101, the aperture control valve 300 can be installed in the inlet chamber 119 without difficulty even if the cylinder head 104 cannot be made sufficiently high. When the inlet port 104a is disposed in the circumferential side portion of the cylinder head 104, the aperture control valve 300 can be installed without difficulty even if the inlet port 104a is located near the valve plate 103. In
In
In the preferred embodiments 1, 3 and 6, the bottom wall of the second housing 340 is provided with projections 340e for reliably communicating the space 360 with the inlet chamber 119. The anti-slip-off members such as the outlet-valve-forming member 130, etc. can be provided with projections.
In the aforementioned preferred embodiments, the minimum opening of the aperture control valve is established by the outlet holes 340a. It is possible to completely close the outlet holes 340a when the valve body 320 sits on the valve seat and make a communication hole formed in another member, for example the valve body 320, operate as the minimum opening of the aperture control valve.
In the aforementioned preferred embodiments, the aperture control valve is provided with the minimum opening for preventing the inlet passage from shutting off when the valve body sits on the valve seat. The aperture control valve can be such that the inlet passage is completely closed when the valve body sits on the valve seat.
The present invention can be applied to variable displacement swash plate compressors, fixed displacement swash plate compressors, wobble plate compressors, and any other type of reciprocating compressors.
The present invention can be widely applied to reciprocating compressors provided with aperture control valves for inlet passages.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-177470 | Jul 2009 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2010/062758 | 7/29/2010 | WO | 00 | 1/30/2012 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2011/013734 | 2/3/2011 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5873704 | Ota et al. | Feb 1999 | A |
| 6352416 | Ota et al. | Mar 2002 | B1 |
| Number | Date | Country |
|---|---|---|
| 10-205446 | Aug 1998 | JP |
| 11-280646 | Oct 1999 | JP |
| 2000-265948 | Sep 2000 | JP |
| 2006-214396 | Aug 2006 | JP |
| 2008-128091 | Jun 2008 | JP |
| WO 2007049430 | May 2007 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20120128509 A1 | May 2012 | US |
