JP2019178631A - Piston-type compressor - Google Patents

Abstract

To provide a piston-type compressor which can change a flow rate of a refrigerant discharged to a discharge chamber from a compression chamber, and can reduce a power loss, vibration and a torque variation in a low flow-rate state while simplifying a structure.SOLUTION: In this piston-type compressor, a rotating body integrated with, or different from a drive shaft 3 can rotate integrally with the drive shaft 3, and a second communication path 45a or the like for intermittently communicating with first communication paths 41Fa to 41Fe accompanied by the rotation of the drive shaft 3 is formed. A suction valve 9F or the like sucks a refrigerant in a suction chamber 21a or the like into a compression chamber 51F or the like. A control valve 13 controls a flow rate for returning the refrigerant in a discharge chamber 23b to the compression chamber 51F or the like. The refrigerant controlled by the control valve 13 is introduced to the compression chamber 51F or the like via the first communication paths 41Fa to 41Fe or the like and the second communication path 45a or the like, and changes the flow rate of the refrigerant discharged to the discharge chamber 21b or the like from the compression chamber 51F or the like.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a piston type compressor.

  Patent Document 1 discloses a conventional piston type compressor. The compressor includes a housing, a drive shaft, a fixed swash plate, a plurality of pistons, and a discharge valve.

  The housing has a cylinder block in which a plurality of cylinder bores and a first communication passage communicating with the cylinder bore are formed. The housing is formed with a suction chamber, a discharge chamber, a swash plate chamber, and a shaft hole. An in-shaft passage communicating with the suction chamber is formed in the drive shaft.

  The drive shaft is rotatably supported in the shaft hole. The fixed swash plate can be rotated in the swash plate chamber by the rotation of the drive shaft, and the inclination angle with respect to the plane perpendicular to the drive shaft is constant. The piston forms a compression chamber in the cylinder bore and is connected to a fixed swash plate. A reed valve type discharge valve is provided between the compression chamber and the discharge chamber to discharge the refrigerant in the compression chamber to the discharge chamber.

  Further, in this compressor, a rotary valve separate from the drive shaft is provided. The rotary valve is provided in the shaft hole so as to be integrally rotatable with the drive shaft. The rotary valve is movable in the direction of the drive shaft center of the drive shaft by the differential pressure between the control pressure controlled by the control valve and the suction pressure. A valve opening communicating with the suction chamber is formed in the rotary valve. The valve opening is formed such that the communication angle around the drive axis with the first communication path varies depending on the position of the rotary valve in the drive axis direction.

  In the rotary valve, the first communication path and the valve opening communicate with each other depending on the position of the rotary valve in the drive axis direction. For this reason, the refrigerant in the suction chamber is sucked into the compression chamber through the valve opening and the first communication path. At this time, since the communication angle around the drive axis between the valve opening and the first communication path changes, the flow rate of the refrigerant sucked into the compression chamber changes, and the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber changes. To do. Thus, in this compressor, the structure is attempted to be simplified as compared with the compressor that changes the capacity by changing the inclination angle of the swash plate.

Japanese Patent Laid-Open No. 7-119631

  However, the conventional compressor has an inner valve in the rotary valve, and the flow rate of the refrigerant sucked into each compression chamber is reduced by the inner valve, so that the structure becomes complicated.

  Further, in the above conventional compressor, in a low flow rate state in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is reduced, the compression opening is communicated by the valve opening having a small communication angle in the rotary valve and the compression chamber. Refrigerant is supplied to the chamber. Further, since the communication between the valve opening and the compression chamber is not communicated, the supply of the refrigerant to the compression chamber is interrupted from the middle of the suction stroke. For this reason, the pressure in the compression chamber during the suction stroke may be lower than a predetermined suction pressure. For this reason, in the low flow rate state, the compression ratio becomes higher than in the other state, and there is a concern that power loss, vibration, and torque fluctuation due to friction become large.

  The present invention has been made in view of the above-described conventional situation, and is capable of changing the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber, while realizing simplification of the structure and power in a low flow rate state. An object to be solved is to provide a piston type compressor capable of reducing loss, vibration and torque fluctuation.

A piston type compressor of the present invention has a cylinder block in which a plurality of cylinder bores are formed, and a housing in which a suction chamber, a discharge chamber, a swash plate chamber, and a shaft hole are formed,
A drive shaft rotatably supported in the shaft hole;
A fixed swash plate that is rotatable in the swash plate chamber by rotation of the drive shaft and has a constant inclination angle with respect to a plane perpendicular to the drive shaft;
A piston that forms a compression chamber in the cylinder bore and is connected to the fixed swash plate;
A piston-type compressor including a discharge valve for discharging the refrigerant in the compression chamber to the discharge chamber,
A first communication path provided in the cylinder block and communicating with the cylinder bore;
A rotary body that is integral with or separate from the drive shaft, and that can rotate integrally with the drive shaft, and is formed with a second communication path that intermittently communicates with the first communication path as the drive shaft rotates. When,
A suction valve for sucking the refrigerant in the suction chamber into the compression chamber;
A control valve for controlling the flow rate of returning the refrigerant in the discharge chamber to the compression chamber,
The refrigerant controlled by the control valve is introduced into the compression chamber via the first communication path and the second communication path, and the flow rate of the refrigerant sucked into the compression chamber from the suction chamber is changed. And

  In the compressor of the present invention, the control valve controls the flow rate of returning the refrigerant in the discharge chamber to the compression chamber. Along with the rotation of the drive shaft, a part of the refrigerant after the discharge stroke is intermittently supplied to the first communication path through the second communication path of the rotating body. In this case, the refrigerant is recirculated from the discharge chamber to the compression chamber via the first communication path, and re-expands in the compression chamber. Therefore, if the pressure in the compression chamber does not become lower than the suction pressure in the suction chamber, the suction valve does not open, and at that time, the refrigerant is not sucked into the compression chamber from the suction chamber, so the flow rate of the refrigerant sucked into the compression chamber is Decrease. Therefore, the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is reduced.

  When a part of the refrigerant after the discharge stroke is not supplied to the first communication path via the second communication path of the rotating body, the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber does not decrease.

  On the other hand, in this compressor, when the pressure in the compression chamber becomes lower than the suction pressure in the suction chamber, the suction valve opens and the refrigerant in the suction chamber is sucked into the compression chamber. For this reason, the pressure in the compression chamber during the intake stroke does not become excessively low. For this reason, the compression ratio does not increase between a low flow rate state in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is reduced and a state in which it is not. For this reason, even in a low flow rate state, power loss, vibration, and torque fluctuation due to friction do not increase.

  Further, in this compressor, since the inclination angle of the fixed swash plate is constant and the inner valve is not employed, the structure can be simplified.

  Therefore, in the compressor of the present invention, the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber can be changed, and the power loss, vibration and torque fluctuation in the low flow rate state can be reduced while simplifying the structure. It is.

  The second communication path preferably communicates with the first communication path while the piston moves from the top dead center of the piston to the bottom dead center of the piston. In this case, the high-pressure refrigerant recirculated to the compression chamber is re-expanded in the compression chamber in the suction stroke and presses the piston, so that a power reduction effect can be obtained.

  When the second communication path communicates with the first communication path while the piston moves from the top dead center to the bottom dead center, the second communication path is the first communication path when the piston is located at the top dead center. It is preferable to communicate with the passage. In this case, the refrigerant can re-expand and press the piston at the moment when the compression chamber shifts to the suction stroke, and the power reduction effect can be further enhanced.

  If the compressor of the present invention is a double-headed piston type, a shoe, a swash plate, or a piston provided between the swash plate and the piston exhibits excellent durability.

  That is, in this compressor, the cylinder bore is composed of a one-side cylinder bore arranged on one side of the drive shaft in the drive axis direction and an other-side cylinder bore arranged on the other side in the drive axis direction. The first communication path includes a first communication path that communicates with one cylinder bore and a first communication path that communicates with the other cylinder bore. The piston has a one-side head that forms a one-side compression chamber in the one-side cylinder bore, and a second-side head that forms the other-side compression chamber in the other-side cylinder bore. The second communication path includes a first second communication path that communicates with the first first communication path, and a second second communication path that communicates with the other first communication path. The one side second communication path communicates with the one side first communication path while the one side piston moves from the top dead center to the bottom dead center. The other-side second communication path communicates with the other-side first communication path while the other-side piston moves from the top dead center to the bottom dead center. A pair of shoes is provided between the fixed swash plate and the piston.

  In this case, the high-pressure refrigerant recirculated to the one-side compression chamber is re-expanded in the one-side compression chamber in the suction stroke, and a biasing force acts in the direction from the top dead center to the bottom dead center. When the one side compression chamber is in the suction stroke, the other side compression chamber is in the compression stroke, and in the other side compression chamber, a compression reaction force acts on the piston. In other words, the urging force and the compression reaction force partially cancel each other in the drive axis direction. For this reason, the shoe, the swash plate or the piston exhibits excellent durability.

  The rotating body is preferably integrated with the drive shaft. In this case, the number of parts can be reduced, and the manufacturing cost can be further reduced.

  In the compressor of the present invention, the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber can be changed, and power loss, vibration, and torque fluctuation in a low flow rate state can be reduced while simplifying the structure. .

1 is a cross-sectional view of a piston-type compressor according to a first embodiment. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a schematic cross-sectional view illustrating the rotational phase between the drive shaft and the second communication path in the state of FIG. 2 in the piston compressor of the first embodiment. 4 is a cross-sectional view taken along the line III-III in FIG. FIG. 5 is a schematic cross-sectional view illustrating the rotation phase between the drive shaft and the second communication path in the state of FIG. 4 in the piston compressor of the first embodiment. FIG. 6 relates to the piston-type compressor of the first embodiment. The timing of the rotation angle of the drive shaft and the positions of the first head and the second head, the timing with the first horizontal hole and the second horizontal hole, It is a timing chart which shows the timing of a suction reed valve and a 2nd suction reed valve, and the timing of the pressure of the 1st compression chamber and the 2nd compression chamber. FIG. 7 is a graph showing the relationship between the volume and pressure of a certain compression chamber in the piston compressor of the first embodiment. FIG. 8 is a schematic cross-sectional view illustrating a rotational phase between a drive shaft and a second communication path similar to FIG. FIG. 9 is a schematic cross-sectional view illustrating a rotational phase between the drive shaft and the second communication path similar to that in FIG. 4 according to the piston compressor of the second embodiment. FIG. 10 relates to the piston type compressor of the second embodiment. The timing of the rotation angle of the drive shaft and the stroke of the first head and the second head, the timing of the first horizontal hole and the second horizontal hole, It is a timing chart which shows the timing of a suction reed valve and a 2nd suction reed valve, and the timing of the pressure of the 1st compression chamber and the 2nd compression chamber. FIG. 11 is a graph showing the relationship between the volume and pressure of a certain compression chamber in the piston compressor of the second embodiment.

  Embodiments 1 and 2 embodying the present invention will be described below with reference to the drawings.

Example 1
The piston type compressor of Example 1 is a so-called double-headed type as shown in FIG. This compressor includes a housing 1, a drive shaft 3, a fixed swash plate 5, five double-headed pistons 7 (see FIGS. 2 and 4), a first suction valve 9F, a second suction valve 9R, A first discharge valve 11F, a second discharge valve 11R, and a control valve 13 are provided.

  The housing 1 has a first cylinder block 15, a second cylinder block 17, a first housing 21 and a second housing 23. Hereinafter, the first housing 21 side of the compressor is referred to as the front, and the second housing 23 side is referred to as the rear. As shown in FIGS. 2 and 4, a suction passage 29 and a discharge passage 31, which will be described later, are located above.

  As shown in FIG. 1, a gasket 19 is disposed between the first cylinder block 15 and the second cylinder block 17. The gasket 19 seals the inside and the outside of the housing 1. The first cylinder block 15 and the second cylinder block 17 have a gasket 19 between them and are fastened together to form a swash plate chamber 25 between them. The first housing 21 is formed with an annular first suction chamber 21a and an annular first discharge chamber 21b. The first discharge chamber 21b is located on the outer peripheral side of the first suction chamber 21a. In the second housing 23, an annular second suction chamber 23a and an annular second discharge chamber 23b are formed. The second discharge chamber 23b is located on the outer peripheral side of the second suction chamber 23a.

  The first housing 21 and the first cylinder block 15 are fastened to each other with a first valve unit 33 therebetween. The second housing 23 and the second cylinder block 17 are fastened to each other with a second valve unit 35 therebetween. As shown in FIGS. 2 and 4, the first valve unit 33, the first cylinder block 15, the gasket 19, the second cylinder block 17 and the second valve unit 35 include five front and rear passages 27 extending in the front-rear direction, suction A passage 29 and a discharge passage 31 are formed. The suction chamber 21a and the suction chamber 23a are connected to each other by a suction passage 29 and are connected to the swash plate chamber 25 (see FIG. 1) by a front and rear passage 27. The first cylinder block 15 is formed with a suction port (not shown) that opens the suction passage 29 to the outside. As shown in FIG. 1, the first discharge chamber 21 b and the second discharge chamber 23 b are connected to each other by a discharge passage 31. The first cylinder block 15 is formed with a discharge port 31a that opens the discharge passage 31 to the outside.

  As shown in FIGS. 1 and 2, the first cylinder block 15 is formed with five first cylinder bores 37 Fa to 37 Fe communicating with the swash plate chamber 25. The first cylinder bores 37Fa to 37Fe are spaced equiangularly around the drive axis O of the drive shaft 3 as shown in FIG. As shown in FIGS. 1 and 4, the second cylinder block 17 is formed with five second cylinder bores 37 </ b> Ra to 37 </ b> Re communicating with the swash plate chamber 25. The second cylinder bores 37Ra to 37Re are spaced equiangularly around the drive axis O of the drive shaft 3 as shown in FIG. As shown in FIG. 1, the first cylinder bore 37Fa and the second cylinder bore 37Ra are coaxial and the same substantially cylindrical space. The same applies to the first cylinder bore 37Fb and the second cylinder bore 37Rb, the first cylinder bore 37Fc and the second cylinder bore 37Rc, the first cylinder bore 37Fd and the second cylinder bore 37Rd, and the first cylinder bore 37Fe and the second cylinder bore 37Re. The central axes of the first cylinder bores 37Fa to 37Fe and the second cylinder bores 37Ra to 37Re are separated from the drive axis O by an equal distance. The first cylinder bores 37Fa to 37Fe correspond to one side cylinder bores, and the second cylinder bores 37Ra to 37Re correspond to other side cylinder bores.

  The first housing 21, the first valve unit 33, the first cylinder block 15, the second cylinder block 17, the second valve unit 35, and the second housing 23 are located inside the first suction chamber 21a and the second suction chamber 23a. A shaft hole 39 extending in the direction of the drive axis O is formed.

  As shown in FIG. 2, the first cylinder block 15 is formed with front side first communication passages 41 Fa to 41 Fe extending from the first cylinder bores 37 Fa to 37 Fe toward the drive shaft O and communicating with the shaft hole 39. Yes. As shown in FIG. 4, the second cylinder block 17 is formed with rear side first communication passages 41Ra to 41Re extending from the second cylinder bores 37Ra to 37Re toward the drive shaft O and communicating with the shaft hole 39. Yes. As shown in FIG. 1, a control pressure chamber 23 c communicating with the shaft hole 39 is formed in the second housing 23.

  The drive shaft 3 extends rotatably in the shaft hole 39 and is supported by the housing 1. The drive shaft 3 has a sliding layer (not shown) on the outer peripheral surface, and is directly supported by the first cylinder block 15 and the second cylinder block 17. A shaft seal device 43 is disposed between the first housing 21 and the drive shaft 3. The shaft seal device 43 seals the inside and the outside of the housing 1.

  In the drive shaft 3, an in-shaft passage 45 a that opens at the rear end of the drive shaft 3 and communicates with the control pressure chamber 23 c and extends forward from the rear end is formed. The drive shaft 3 includes a first horizontal hole 45F that extends in the radial direction of the drive shaft 3 in front of the drive shaft 3 and opens to the outer peripheral surface of the drive shaft 3, and a radial direction of the drive shaft 3 behind the drive shaft 3. A second horizontal hole 45 </ b> R that extends to the outer peripheral surface of the drive shaft 3 is formed. The in-shaft passage 45a communicates with the first lateral hole 45F and the second lateral hole 45R. The first lateral hole 45F and the second lateral hole 45R are shifted by 180 ° around the drive axis O as shown in FIGS. As shown in FIG. 2, the first horizontal hole 45 </ b> F is formed at a position where it can communicate intermittently with the front-side first communication passages 41 </ b> Fa to 41 </ b> Fe as the drive shaft 3 rotates. As shown in FIG. 4, the second horizontal hole 45 </ b> R is formed at a position where it can intermittently communicate with the rear first communication paths 41 </ b> Ra to 41 </ b> Re. The drive shaft 3 is a rotating body of the present invention, and the in-shaft passage 45a, the first lateral hole 45F, and the second lateral hole 45R are second communication passages. The first horizontal hole 45F corresponds to one side second communication path, and the second horizontal hole 45R corresponds to the other side second communication path.

  As shown in FIG. 1, the fixed swash plate 5 is press-fitted and fixed to the drive shaft 3. A first thrust bearing 47 is provided between the first cylinder block 15 and the fixed swash plate 5, and a second thrust bearing 49 is provided between the second cylinder block 17 and the fixed swash plate 5. The front end surface of the fixed swash plate 5 is a flat surface 5 a orthogonal to the drive axis O, and the rear end surface of the first cylinder block 15 is also a flat surface 15 a orthogonal to the drive axis O. On the other hand, an annular protrusion 5 b is formed on the rear end face of the fixed swash plate 5, and an annular protrusion 17 a is formed on the front end face of the second cylinder block 17. The protrusion 17a has a smaller diameter than the protrusion 5b. The second thrust bearing 49 is supported by the protrusion 5b and the protrusion 17a so as to be elastically deformable in the front-rear direction. The fixed swash plate 5 can be rotated by the drive shaft 3 in the swash plate chamber 25 by the first thrust bearing 47 and the second thrust bearing 49. The fixed swash plate 5 has a constant inclination angle with respect to a plane perpendicular to the direction of the drive axis O.

  A double-headed piston 7 is provided in the first cylinder bores 37Fa to 37Fe and the second cylinder bores 37Ra to 37Re. The piston 7 includes a first head 7F that forms a first compression chamber 51F in the first cylinder bores 37Fa to 37Fe, and a second head 7R that forms a second compression chamber 51R in the second cylinder bores 37Ra to 37Re. ing. The first head 7F corresponds to one side head, and the second head 7R corresponds to the other side head. The piston 7 has a recess 7c between the first head 7F and the second head 7R, and a pair of hemispherical shoes that form a pair in the front and rear between the front and rear surfaces of the recess 7c of the piston 7 and the fixed swash plate 5. 53 is provided. The piston 7 is connected to the fixed swash plate 5 by a shoe 53.

  The first valve unit 33 is formed by stacking a first retainer 33a, a first discharge reed valve 33b, a first valve plate 33c, and a first suction reed valve 33d in this order. The first retainer 33a is located on the first housing 21 side. The first retainer 33a, the first discharge reed valve 33b, and the first valve plate 33c have a first suction port 33e that allows the first suction chamber 21a and the first compression chamber 51F to communicate with each other when the first suction reed valve 33d is opened. Is formed. The first valve plate 33c and the first suction reed valve 33d are formed with a first discharge port 33f that allows the first discharge chamber 21b and the first compression chamber 51F to communicate with each other when the first discharge reed valve 33b is opened. ing. The first valve unit 33 and the first suction port 33e constitute the first suction valve 9F, and the first valve unit 33 and the first discharge port 33f constitute the first discharge valve 11F.

  The second valve unit 35 includes a second retainer 35a, a second discharge reed valve 35b, a second valve plate 35c, and a second suction reed valve 35d that are stacked in this order. The second retainer 35a is located on the second housing 23 side. When the second suction reed valve 35d is opened in the second retainer 35a, the second discharge reed valve 35b, and the second valve plate 35c, the second suction port 35e that allows the second suction chamber 23a and the second compression chamber 51R to communicate with each other. Is formed. Further, the second discharge plate 35c and the second suction reed valve 35d are formed with a second discharge port 35f that allows the second discharge chamber 23b and the second compression chamber 51R to communicate with each other when the second discharge reed valve 35b is opened. ing. The second valve unit 35 and the second suction port 35e constitute the second suction valve 9R, and the second valve unit 35 and the second discharge port 35f constitute the second discharge valve 11R.

  A control valve 13 is provided in the second housing 23. The second housing 23 has a low pressure passage 13a, a high pressure passage 13b, and a control passage 13c. The low pressure passage 13 a connects the suction chamber 23 a and the control valve 13. The high-pressure passage 13 b connects the discharge chamber 23 b and the control valve 13. The control passage 13 c connects the control pressure chamber 23 c and the control valve 13. The control valve 13 senses the suction pressure Ps of the refrigerant in the suction chamber 23a by the low-pressure passage 13a, and reduces the flow rate of the refrigerant at the discharge pressure Pd in the discharge chamber 23b to make the refrigerant at the control pressure Pc. To introduce.

  In this compressor, as shown in FIGS. 2 and 3, the position of the first horizontal hole 45F around the drive axis O is set as follows in relation to the top dead center position of the fixed swash plate 5. .

  That is, when the first head 7F is positioned at the top dead center due to the rotation of the drive shaft 3 and, for example, the first compression chamber 51F of the first cylinder bore 37Fa finishes the discharge stroke, the first horizontal hole 45F is formed in the first cylinder bore 37Fa. The front side first communication passage 41Fa communicated with the first cylinder passage 37Fb and the front side first communication passage 41Fb communicated with the second cylinder bore 37Fb. Then, as shown in FIG. 6, while the drive shaft 3 rotates by θ1 angle and the first head 7F of the piston 7 moves from the top dead center to the bottom dead center by a certain position, as shown in FIG. The one horizontal hole 45F communicates with the front-side first communication path 41Fa or the front-side first communication path 41Fb. When the drive shaft 3 rotates past the θ1 angle and the first head 7F moves beyond a certain position, the first horizontal hole 45F is disconnected from the front-side first communication path 41Fb. For this reason, as shown in FIG. 6, the first suction reed valve 33d is opened.

  As shown in FIGS. 4 and 5, the position of the second horizontal hole 45 </ b> R around the drive axis O is set as follows in relation to the top dead center position of the fixed swash plate 5.

  That is, when the second head 7R is positioned at the top dead center due to the rotation of the drive shaft 3, and the second compression chamber 51R of the second cylinder bore 37Rd finishes the discharge stroke, for example, the second horizontal hole 45R is formed in the second cylinder bore 37Rd. The rear side first communication passage 41Rd communicates with the first communication passage 41Rd. Then, as shown in FIG. 6, while the drive shaft 3 rotates by θ1 angle and the second head 7R of the piston 7 moves from the top dead center to the bottom dead center by a certain position, the second horizontal hole 45R is on the rear side. It communicates with the first communication path 41Rd. When the drive shaft 3 rotates past the θ1 angle and the second head 7R moves beyond a certain position, the second horizontal hole 45R is not in communication with the rear first communication path 41Rd. For this reason, as shown in FIG. 6, the second suction reed valve 35d is opened.

  This compressor is used in a vehicle air conditioner. When the drive shaft 3 is driven by an engine or a motor, the fixed swash plate 5 is rotated by the drive shaft 3 in the swash plate chamber 25. Therefore, the first head 7F and the second head 7R of the piston 7 move from the bottom dead center to the top dead center, and also move from the top dead center to the bottom dead center.

  For this reason, as shown in FIG. 1, when the volume of the first compression chamber 51F increases and the pressure in the first compression chamber 51F becomes lower than that of the first suction chamber 21a, the first suction reed valve 33d opens and the first suction reed valve 33d opens. The first suction chamber 21a communicates with the first compression chamber 51F, and the refrigerant having the suction pressure Ps is sucked into the first compression chamber 51F from the first suction chamber 21a. When the volume of the first compression chamber 51F is reduced and the pressure in the first compression chamber 51F is higher than that of the first discharge chamber 21b, the first discharge reed valve 33b is opened and the first discharge chamber 21b and the first compression chamber 21F are compressed. The refrigerant | coolant of the discharge pressure Pd is discharged from the 1st compression chamber 51F to the 1st discharge chamber 21b.

  Further, when the volume of the second compression chamber 51R is increased and the pressure in the second compression chamber 51R becomes lower than that of the second suction chamber 23a, the second suction reed valve 35d is opened, and the second suction chamber 23a and the second compression chamber 23R are opened. The chamber 51R communicates, and the refrigerant having the suction pressure Ps is sucked into the second compression chamber 51R from the second suction chamber 23a. When the volume of the second compression chamber 51R is reduced and the pressure in the second compression chamber 51R is higher than that of the second discharge chamber 23b, the second discharge reed valve 35b is opened and the second discharge chamber 23b and the second compression chamber are opened. The chamber 51R communicates, and the refrigerant having the discharge pressure Pd is discharged from the second compression chamber 51R to the second discharge chamber 23b.

  The first suction chamber 21a and the second suction chamber 23a are supplied with refrigerant from the suction port of the suction passage 29 via the evaporator. The refrigerant in the first discharge chamber 21b and the second discharge chamber 23b is discharged toward the condenser through the discharge port 31a of the discharge passage 31.

  Meanwhile, in this compressor, the control valve 13 controls the control pressure Pc in the control pressure chamber 23c using the discharge pressure Pd in the second discharge chamber 23b. As shown in FIG. 6, the first horizontal hole 45 </ b> F intermittently communicates with the front first communication paths 41 </ b> Fa to 41 </ b> Fe as the drive shaft 3 rotates. For this reason, a part of the refrigerant after the discharge stroke is intermittently supplied to the front first communication passages 41Fa to 41Fe through the in-shaft passage 45a and the first lateral hole 45F of the drive shaft 3. The refrigerant supplied to the front side first communication passages 41Fa to 41Fe is recirculated to the first compression chamber 51F in the initial suction stroke without being discharged from the first discharge chamber 21b to the outside. In this case, as shown in FIG. 6, the pressure in the first compression chamber 51 </ b> F is higher near the top dead center than the pressure indicated by a broken line indicated by a compressor using only a general suction valve.

  The refrigerant recirculated to the first compression chamber 51F is re-expanded in the first compression chamber 51F. For this reason, if the pressure in the first compression chamber 51F does not become lower than the suction pressure Ps in the first suction chamber 21a, the first suction reed valve 33d of the first suction valve 9F is not opened and the first suction chamber 21a is not opened. The refrigerant is not sucked into the first compression chamber 51F. For this reason, the flow rate of the refrigerant sucked into the first compression chamber 51F decreases. Therefore, the flow rate of the refrigerant discharged from the first compression chamber 51F to the first discharge chamber 21b decreases.

  Further, in this compressor, the second horizontal hole 45R intermittently communicates with the rear first communication paths 41Ra to 41Re. Therefore, a part of the refrigerant after the discharge stroke is intermittently supplied to the rear first communication passages 41Ra to 41Re via the in-shaft passage 45a and the second lateral hole 45R of the drive shaft 3. The refrigerant supplied to the rear first communication passages 41Ra to 41Re is recirculated to the second compression chamber 51R at the initial stage of the suction stroke without being discharged from the second discharge chamber 23b to the outside. Also in this case, as shown in FIG. 6, the pressure in the second compression chamber 51 </ b> R becomes higher near the top dead center than the pressure indicated by the broken line indicated by the compressor using only a general suction valve.

  The refrigerant returned to the second compression chamber 51R is re-expanded in the second compression chamber 51R. Therefore, if the pressure in the second compression chamber 51R does not become lower than the suction pressure Ps in the second suction chamber 23a, the second suction reed valve 35d of the second suction valve 9R is not opened, and the second suction chamber 23a The refrigerant is not sucked into the second compression chamber 51R. For this reason, the flow rate of the refrigerant sucked into the second compression chamber 51R also decreases. Therefore, the flow rate of the refrigerant discharged from the second compression chamber 51R to the second discharge chamber 23b also decreases.

  A part of the refrigerant after the discharge stroke passes through the in-shaft passage 45a, the first lateral hole 45F and the second lateral hole 45R of the drive shaft 3, and the front first communication passages 41Fa to 41Fe and the rear first communication passages 41Ra to 41Re. In the case where the refrigerant is not supplied, the flow rate of the refrigerant discharged from the first compression chamber 51F to the first discharge chamber 21b and the flow rate of the refrigerant discharged from the second compression chamber 51R to the second discharge chamber 23b do not decrease.

  On the other hand, if the first horizontal hole 45F is not in communication with the front side first communication passages 41Fa to 41Fe and the pressure in the first compression chamber 51F is lower than the suction pressure Ps in the first suction chamber 21a, the first suction is performed. The first suction reed valve 33d of the valve 9F is opened, and the refrigerant in the first suction chamber 21a is sucked into the first compression chamber 51F. For this reason, the pressure in the first compression chamber 51F during the intake stroke does not become excessively low.

  Further, if the second horizontal hole 45R is not in communication with the rear first communication passages 41Ra to 41Re and the pressure in the second compression chamber 51R becomes lower than the suction pressure Ps in the second suction chamber 23a, the second suction is performed. The second suction reed valve 35d of the valve 9R is opened, and the refrigerant in the second suction chamber 23a is sucked into the second compression chamber 51R. For this reason, the pressure in the second compression chamber 51R during the suction stroke does not become excessively low.

  For this reason, in this compressor, the compression ratio between a low flow rate state in which the flow rate of the refrigerant discharged from the first and second compression chambers 51F and 51R to the first and second discharge chambers 21b and 23b is reduced, and a state in which it is not. Will not be high. For this reason, even in a low flow rate state, power loss, vibration, and torque fluctuation due to friction do not increase.

  In particular, in this compressor, the first horizontal hole 45F extends from the first side 7F until the first head 7F moves to the bottom dead center until the first head 7F moves to the bottom dead center. It connects with passage 41Fa-41Fe. The second horizontal hole 45R is connected to the rear first communication paths 41Ra to 41Re between the time when the second head 7R is located at the top dead center and the time when the second head 7F moves to the bottom dead center. Communicate. For this reason, the high-pressure refrigerant recirculated to the first and second compression chambers 51F and 51R is re-expanded in the first and second compression chambers 51F and 51R in the suction stroke to press the piston 7. More specifically, the refrigerant re-expands and pushes the piston 7 at the moment when the first compression chamber 51F and the second compression chamber 51R shift to the suction stroke. For this reason, in this compressor, the reduction effect of motive power is acquired.

  Thus, in this compressor, as shown in FIG. 7, the relationship between the volume and pressure of the first compression chamber 51F and the second compression chamber 51R is A → B1 → B2 → C → D. In this case, since the flow rate of the refrigerant discharged from the first and second compression chambers 51F and 51R to the first and second discharge chambers 21b and 23b is reduced, a compressor using only a general suction valve is shown. Compared with the relation A → B → C → D, the work amount is reduced by the hatched portion.

  Moreover, in this compressor, since the inclination angle of the fixed swash plate 5 is constant and the inner valve is not employed, the structure can be simplified.

  Therefore, in this compressor, the flow rate of the refrigerant discharged from the first and second compression chambers 51F and 51R to the first and second discharge chambers 21b and 23b can be changed, and the structure can be simplified and the flow rate can be reduced. It is possible to reduce power loss, vibration and torque fluctuation in the state.

  Further, since this compressor is a double-headed type, the high-pressure refrigerant recirculated to the first compression chamber 51F is re-expanded in the first compression chamber 51F in the intake stroke, and the piston 7 is dead from the top of the first head 7F. A biasing force acts in a direction from the point toward the bottom dead center of the first head 7F. Further, when the first compression chamber 51F is in the suction stroke, the second compression chamber 51R is in the compression stroke, and the compression reaction force acts on the piston 7 in the second compression chamber 51R. That is, the urging force and the compression reaction force partially cancel each other in the direction of the drive axis O. For this reason, the shoe 53, the fixed swash plate 5 or the piston 7 exhibits excellent durability.

  Furthermore, in this compressor, since the rotating body is integrated with the drive shaft 3, the number of parts can be reduced and the manufacturing cost can be further reduced.

(Example 2)
The compressor of the second embodiment is different from the first embodiment in the positions of the first horizontal hole 55F and the second horizontal hole 55R around the drive axis O.

  That is, as shown in FIGS. 8 and 10, when the drive shaft 3 rotates, the drive shaft 3 is rotated by a θ2 angle while the first head 7 </ b> F moves to the fixed position past the top dead center to the bottom dead center. Thus, the first lateral hole 55F communicates with the front-side first communication passages 41Fa to 41Fe. Then, until the first head 7F of each piston 7 further moves to a certain position and the drive shaft 3 further rotates by θ3 angle, the first lateral hole 55F communicates with the front side first communication paths 41Fa to 41Fe. Then, when the drive shaft 3 rotates past the θ3 angle and the first head 7F moves beyond the predetermined position, the first lateral hole 55F is disconnected from the front side first communication paths 41Fa to 41Fe. For this reason, the first suction reed valve 33d is opened.

  The first lateral hole 55F and the second lateral hole 55R are shifted by 180 ° around the drive axis O. For this reason, as shown in FIGS. 9 and 10, when the drive shaft 3 rotates, the drive shaft 3 rotates by θ2 angle while the second head 7R moves to a certain position from the top dead center to the bottom dead center. In the stage, the second lateral hole 55R communicates with the rear first communication passages 41Ra to 41Re. The second lateral hole 55R communicates with the rear first communication paths 41Ra to 41Re until the second head 7R of each piston 7 further moves to a certain position and the drive shaft 3 further rotates by θ3 angle. Then, when the drive shaft 3 rotates past the θ3 angle and the second head 7R moves beyond the fixed position, the second lateral hole 55R is not in communication with the rear first communication paths 41Ra to 41Re. For this reason, the second suction reed valve 35d is opened. Other configurations are the same as those of the first embodiment.

  In this compressor, as the drive shaft 3 rotates, the first horizontal hole 55F intermittently communicates with the front first communication paths 41Fa to 41Fe. For this reason, it is intermittently supplied to the front side first communication passages 41Fa to 41Fe via the in-shaft passage 45a and the first lateral hole 55F of the drive shaft 3. The refrigerant supplied to the front side first communication passages 41Fa to 41Fe is recirculated to the first compression chamber 51F in the initial suction stroke without being discharged from the first discharge chamber 21b to the outside. In this case, as shown in FIG. 10, the pressure in the first compression chamber 51 </ b> F becomes higher near the top dead center than the pressure indicated by the broken line indicated by the compressor using only a general suction valve.

  The refrigerant recirculated to the first compression chamber 51F is re-expanded in the first compression chamber 51F. For this reason, the first suction reed valve 33d is once opened, then closed and then opened again. For this reason, the flow rate of the refrigerant sucked into the first compression chamber 51F decreases.

  As the drive shaft 3 rotates, the second lateral hole 55R intermittently communicates with the rear first communication passages 41Ra to 41Re. For this reason, it is intermittently supplied to the rear side first communication passages 41Ra to 41Re via the in-shaft passage 45a and the second lateral hole 55R of the drive shaft 3. The refrigerant supplied to the rear first communication passages 41Ra to 41Re is recirculated to the second compression chamber 51R at the initial stage of the suction stroke without being discharged from the second discharge chamber 23b to the outside. Also in this case, as shown in FIG. 10, the pressure in the second compression chamber 51 </ b> R becomes higher near the top dead center than the pressure indicated by the broken line indicated by the compressor using only a general suction valve.

  The refrigerant returned to the second compression chamber 51R is re-expanded in the second compression chamber 51R. For this reason, the second suction reed valve 35d is once opened and then closed and then opened again. For this reason, the flow rate of the refrigerant sucked into the second compression chamber 51R decreases.

  Thus, in this compressor, as shown in FIG. 11, the relationship between the volume and pressure of the first compression chamber 51F and the second compression chamber 51R is A → B → B1 → B2 → B3 → C → D. In this case, since the flow rate of the refrigerant discharged from the first and second compression chambers 51F and 51R to the first and second discharge chambers 21b and 23b is reduced, a compressor using only a general suction valve is shown. Compared with the relation A → B → C → D, the work amount is reduced by the hatched portion. Other functions and effects are the same as those of the first embodiment.

  In the above, the present invention has been described with reference to the first and second embodiments. However, the present invention is not limited to the first and second embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

  For example, in the first and second embodiments, the present invention is embodied in the double-headed compressor, but the present invention can also be embodied in a single-headed compressor. If the present invention is a single-head compressor, the structure is further simplified, and the manufacturing cost can be further reduced. The present invention can also be applied to a wobble compressor.

  In the first and second embodiments, the driving shaft 3 is a rotating body. However, the rotating body may be a separate body from the driving shaft 3.

  The control pressure chamber may be provided not between the second housing but between the rear end of the drive shaft and the second valve unit. The control pressure chamber may be provided between the rear end of the drive shaft and the second valve unit while being positioned in the second housing. Furthermore, the control pressure chamber need not be formed in the housing. The control passage and the in-shaft passage in the drive shaft may be in direct communication.

  The control valve may be anything as long as it controls the flow rate of returning the refrigerant in the discharge chamber to the compression chamber, and not only the control valve 13 as in the first and second embodiments, but also the discharge chamber and the control pressure chamber. It may be a spool that adjusts the opening between the two. It is also possible to combine the control valve 13 as in the first and second embodiments and a spool that adjusts the opening between the discharge chamber and the control pressure chamber to form a control valve.

  The present invention is applicable to a vehicle air conditioner.

37Fa-37Fe, 37Ra-37Re ... cylinder bore (37Fa-37Fe ... one side cylinder bore (first cylinder bore), 37Ra-37Re ... other side cylinder bore (second cylinder bore))
21a, 23a ... suction chamber (21a ... first suction chamber, 23a ... second suction chamber)
21b, 23b ... discharge chamber (21b ... first discharge chamber, 23b ... second discharge chamber)
25 ... Swash plate chamber 39 ... Shaft hole 1 ... Housing (21 ... First housing, 23 ... Second housing, 15 ... First cylinder block, 17 ... Second cylinder block)
DESCRIPTION OF SYMBOLS 3 ... Drive shaft, rotary body 5 ... Fixed swash plate 51F, 51R ... Compression chamber (51F ... 1st compression chamber, 51R ... 2nd compression chamber)
7 ... piston (7F ... one side head (first head), 7R ... other side head (second head))
11F, 11R ... discharge valve (11F ... first discharge valve, 11R ... second discharge valve)
41Fa-41Fe, 41Ra-41Re ... first communication path (41Fa-41Fe ... one side first communication path (front side first communication path), 41Ra-41Re ... other side first communication path (rear side first communication path) )
45a, 45F, 45R, 55F, 55R ... second communication passage (45a ... shaft passage, 45F, 55F ... one side second communication passage (first lateral hole), 45R, 55R ... other side second communication passage (first 2 horizontal holes))
9F, 9R ... suction valve (9F ... first suction valve, 9R ... second suction valve)
13 ... Control valve O ... Drive shaft 53 ... Shoe

Claims (5)

A housing having a cylinder block in which a plurality of cylinder bores are formed, a suction chamber, a discharge chamber, a swash plate chamber, and a shaft hole;
A drive shaft rotatably supported in the shaft hole;
A fixed swash plate that is rotatable in the swash plate chamber by rotation of the drive shaft and has a constant inclination angle with respect to a plane perpendicular to the drive shaft;
A piston that forms a compression chamber in the cylinder bore and is connected to the fixed swash plate;
A piston-type compressor including a discharge valve for discharging the refrigerant in the compression chamber to the discharge chamber,
A first communication path provided in the cylinder block and communicating with the cylinder bore;
A rotating body that is integral with or separate from the drive shaft, and that can rotate integrally with the drive shaft, and is formed with a second communication path that intermittently communicates with the first communication path as the drive shaft rotates. When,
A suction valve for sucking the refrigerant in the suction chamber into the compression chamber;
A control valve for controlling the flow rate of returning the refrigerant in the discharge chamber to the compression chamber,
The refrigerant controlled by the control valve is introduced into the compression chamber via the first communication path and the second communication path, and the flow rate of the refrigerant sucked into the compression chamber from the suction chamber is changed. Piston type compressor.   2. The piston compressor according to claim 1, wherein the second communication passage communicates with the first communication passage while the piston moves from a top dead center of the piston to a bottom dead center of the piston.   The piston-type compressor according to claim 2, wherein the second communication path communicates with the first communication path when the piston is located at the top dead center. The cylinder bore is composed of a one-side cylinder bore disposed on one side of the drive shaft in the direction of the drive axis, and an other-side cylinder bore disposed on the other side of the drive axis.
The first communication path includes a first communication path that communicates with the one-side cylinder bore and a first communication path that communicates with the other-side cylinder bore.
The piston has a one-side head that forms a one-side compression chamber in the one-side cylinder bore, and a second-side head that forms the other-side compression chamber in the other-side cylinder bore,
The second communication path includes a second communication path on one side communicating with the first communication path on the one side, and a second communication path on the other side communicating with the first communication path on the other side.
The one side second communication path communicates with the one side first communication path while the one side piston moves from the top dead center to the bottom dead center,
The other side second communication path communicates with the other side first communication path while the other side piston moves from the top dead center to the bottom dead center.
The piston type compressor according to claim 1, wherein a pair of shoes is provided between the fixed swash plate and the piston.   The piston type compressor according to any one of claims 1 to 4, wherein the rotating body is integrated with the drive shaft.

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