JP6977651B2 - Piston compressor - Google Patents

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 bores are formed. Further, the housing is formed with a suction chamber, a discharge chamber, a swash plate chamber, and a shaft hole. The drive shaft is formed with an in-shaft passage that communicates with the suction chamber.

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 the fixed swash plate. A reed valve type discharge valve for discharging the refrigerant in the compression chamber to the discharge chamber is provided between the compression chamber and 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. Further, the rotary valve can move in the drive axis direction of the drive shaft by the differential pressure between the control pressure controlled by the control valve and the suction pressure. The rotary valve is formed with a valve opening that communicates with the suction chamber. The valve opening is formed so that the communication angle around the drive axis with the first communication passage changes depending on the position of the rotary valve in the drive axis direction.

In this rotary valve, the first communication passage and the valve opening communicate with each other depending on the position in the drive axis direction of the rotary valve. Therefore, the refrigerant in the suction chamber is sucked into the compression chamber via the valve opening and the first communication passage. At this time, since the communication angle around the drive axis between the valve opening and the first communication passage 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. do. In this way, this compressor is trying to realize the simplification of the structure as compared with the compressor in which the capacity is changed by changing the inclination angle of the swash plate.

Japanese Unexamined Patent Publication No. 7-119631

However, in the above-mentioned conventional compressor, since the inner valve is provided in the rotary valve and the flow rate of the refrigerant sucked into each compression chamber is reduced by the inner valve, the structure becomes complicated.

Further, in the above-mentioned 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 valve opening having a small communication angle in the rotary valve and the compression chamber communicate with each other to perform compression. Refrigerant is supplied to the room. Further, the communication between the valve opening and the compression chamber is not communicated, so that the supply of the refrigerant to the compression chamber is cut off from the middle of the suction stroke. Therefore, the pressure in the compression chamber during the suction stroke may be lower than the predetermined suction pressure. Therefore, in the low flow rate state, the compression ratio becomes higher than in the other state, and there is a concern that the power loss, vibration and torque fluctuation due to friction become large.

The present invention has been made in view of the above-mentioned conventional circumstances, and the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber can be changed, and the power in a low flow rate state can be realized while simplifying the structure. It is an issue to be solved to provide a piston type compressor capable of reducing loss, vibration and torque fluctuation.

The piston type compressor of the present invention has a cylinder block in which a plurality of cylinder bores are formed, and has a suction chamber, a discharge chamber, a swash plate chamber, and a housing in which a shaft hole is formed.
A drive shaft rotatably supported in the shaft hole and
A fixed swash plate that can be rotated 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 provided with a discharge valve for discharging the refrigerant in the compression chamber to the discharge chamber.
A first communication passage provided in the cylinder block and communicating with the cylinder bore,
A rotating body that is integrated with or separate from the drive shaft and can rotate integrally with the drive shaft, and a second communication passage that intermittently communicates with the first communication passage is formed as the drive shaft rotates. When,
A suction valve that sucks 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 is provided.
The refrigerant controlled by the control valve is introduced into the compression chamber via the first communication passage and the second communication passage, and is characterized in that the flow rate of the refrigerant sucked from the suction chamber into the compression 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. Then, as the drive shaft rotates, a part of the refrigerant after the discharge stroke is intermittently supplied to the first continuous passage through the second continuous passage of the rotating body. In this case, the refrigerant is returned from the discharge chamber to the compression chamber via the first communication passage, and re-expands in the compression chamber. Therefore, unless the pressure in the compression chamber becomes 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 that the flow rate of the refrigerant sucked into the compression chamber increases. 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 series passage through the second series passage 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. Therefore, the pressure in the compression chamber during the suction stroke does not become excessively low. Therefore, the compression ratio does not increase between the low flow rate state in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is reduced and the other state. Therefore, even in a low flow rate state, power loss, vibration, and torque fluctuation due to friction do not increase.

Further, in this compressor, the tilt angle of the fixed swash plate is constant and the inner valve is not adopted, so that 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 power loss, vibration and torque fluctuation in a low flow rate state can be reduced while simplifying the structure. Is.

The second communication passage preferably communicates with the first communication passage 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 refluxed into the compression chamber re-expands in the compression chamber in the suction stroke to press the piston, and the effect of reducing power can be obtained.

If the second communication passage communicates with the first communication passage while the piston moves from top dead center to bottom dead center, the second communication passage is the first communication when the piston is located at top dead center. It is preferable to communicate with the passage. In this case, the refrigerant re-expands and presses 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, the shoe, swash plate or 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-sided cylinder bore arranged on one side in the drive axis direction of the drive shaft and a other-side cylinder bore arranged on the other side in the drive axis direction. The first communication passage consists of a one-side first communication passage that communicates with the one-side cylinder bore and a other-side first communication passage that communicates with the other-side cylinder bore. The piston has a one-sided head that forms a one-sided compression chamber in the one-sided cylinder bore and a other-side head that forms the other-side compression chamber in the other-side cylinder bore. The second communication passage has a one-sided second communication passage communicating with the one-side first communication passage and a other-side second communication passage communicating with the other side first communication passage. The one-sided second communication passage communicates with the one-sided first communication passage while the one-side head moves from the top dead center to the bottom dead center. The other side second communication passage communicates with the other side first communication passage while the other side head 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 refluxed to the one-side compression chamber re-expands in the one-side compression chamber in the suction stroke, and an urging force acts on the piston in the direction from the top dead center to the bottom dead center. Further, 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. That is, the urging force and the compression reaction force cancel each other out in the direction of the drive axis. Therefore, the shoe, swash plate or piston exhibits excellent durability.

It is preferable that the rotating body is 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. ..

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

Hereinafter, Examples 1 and 2 embodying the present invention will be described with reference to the drawings.

(Example 1)
As shown in FIG. 1, the piston type compressor of the first embodiment is a so-called double-headed compressor. 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, and a second suction valve 9R. It includes a first discharge valve 11F, a second discharge valve 11R, and a control valve 13.

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 the front side, and the second housing 23 side is the rear side. Further, as shown in FIGS. 2 and 4, the suction passage 29 and the discharge passage 31, which will be described later, are located above.

As shown in FIG. 1, a gasket 19 is arranged 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 to each other 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. The second housing 23 is formed with an annular second suction chamber 23a and an annular second discharge chamber 23b. 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 have a first valve unit 33 between them and are fastened to each other. The second housing 23 and the second cylinder block 17 have a second valve unit 35 between them and are fastened to each other. 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 have five front-rear passages 27 extending in the front-rear direction and suction. A passage 29 and a discharge passage 31 are formed. The suction chamber 21a and the suction chamber 23a are communicated with each other by the suction passage 29 and also communicated with the swash plate chamber 25 (see FIG. 1) by the front and rear passages 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 21b and the second discharge chamber 23b 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 37Fa to 37Fe that communicate with the swash plate chamber 25. As shown in FIG. 2, the first cylinder bores 37Fa to 37Fe are spaced at equal angles around the drive shaft center O of the drive shaft 3. As shown in FIGS. 1 and 4, the second cylinder block 17 is formed with five second cylinder bores 37Ra to 37Re communicating with the swash plate chamber 25. As shown in FIG. 4, the second cylinder bores 37Ra to 37Re are spaced at equal angles around the drive shaft center O of the drive shaft 3. As shown in FIG. 1, the first cylinder bore 37Fa and the second cylinder bore 37Ra are coaxial and identical substantially cylindrical spaces. 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 equidistant from the drive axis O. The first cylinder bores 37Fa to 37Fe correspond to the one-side cylinder bore, and the second cylinder bores 37Ra to 37Re correspond to the other-side cylinder bore.

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 inside the first suction chamber 21a and the second suction chamber 23a. A shaft hole 39 extending in the drive shaft center O direction is formed.

As shown in FIG. 2, the first cylinder block 15 is formed with front-side first communication passages 41Fa to 41Fe extending from the first cylinder bores 37Fa to 37Fe toward the drive shaft center O and communicating with the shaft hole 39. There is. 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 center O and communicating with the shaft hole 39. There is. Further, as shown in FIG. 1, a control pressure chamber 23c 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 sealing device 43 is arranged between the first housing 21 and the drive shaft 3. The shaft sealing device 43 seals the inside and the outside of the housing 1.

In the drive shaft 3, an in-shaft passage 45a that opens to the rear end of the drive shaft 3 and communicates with the control pressure chamber 23c and extends forward from the rear end is formed. Further, the drive shaft 3 has a first lateral hole 45F extending in the radial direction of the drive shaft 3 in front of the drive shaft 3 and opening on 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 lateral hole 45R that extends to and opens on the outer peripheral surface of the drive shaft 3 is formed. The in-axis passage 45a communicates with the first horizontal hole 45F and the second horizontal hole 45R. As shown in FIGS. 3 and 5, the first lateral hole 45F and the second lateral hole 45R are displaced by 180 ° around the drive axis O. As shown in FIG. 2, the first lateral hole 45F is formed at a position where it can intermittently communicate with the front side first communication passages 41Fa to 41Fe as the drive shaft 3 rotates. As shown in FIG. 4, the second lateral hole 45R is formed at a position where it can intermittently communicate with the rear side first communication passages 41Ra to 41Re. The drive shaft 3 is a rotating body of the present invention, and the in-shaft passage 45a, the first horizontal hole 45F, and the second horizontal hole 45R are the second continuous passages. The first lateral hole 45F corresponds to the second passage on one side, and the second lateral hole 45R corresponds to the second passage on the other side.

As shown in FIG. 1, the fixed swash plate 5 is press-fitted into the drive shaft 3 and fixed. 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 5a orthogonal to the drive axis O, and the rear end surface of the first cylinder block 15 is also a flat surface 15a orthogonal to the drive axis O. On the other hand, an annular ridge 5b is formed on the rear end surface of the fixed swash plate 5, and an annular ridge 17a is formed on the front end surface of the second cylinder block 17. The ridge 17a has a smaller diameter than the ridge 5b. The second thrust bearing 49 is supported by the ridges 5b and 17a so as to be elastically deformable in the front-rear direction. The fixed swash plate 5 is rotatable 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 orthogonal to the drive axis O direction.

Double-headed pistons 7 are provided in the first cylinder bores 37Fa to 37Fe and the second cylinder bores 37Ra to 37Re. The piston 7 has 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 hemispherical shoe paired in the front-rear direction between the front-rear surface 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 a stack of 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 side of the first housing 21. When the first suction reed valve 33d is opened in the first retainer 33a, the first discharge reed valve 33b, and the first valve plate 33c, the first suction port 33e communicates the first suction chamber 21a and the first compression chamber 51F. Is formed. Further, 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 form the first discharge valve 11F.

The second valve unit 35 is a stack of a second retainer 35a, a second discharge reed valve 35b, a second valve plate 35c, and a second suction reed valve 35d in this order. The second retainer 35a is located on the second housing 23 side. If 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 communicates the second suction chamber 23a and the second compression chamber 51R. Is formed. Further, in the second valve plate 35c and the second suction reed valve 35d, a second discharge port 35f for communicating the second discharge chamber 23b and the second compression chamber 51R is formed 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 form the second discharge valve 11R.

The second housing 23 is provided with a control valve 13. Further, the second housing 23 is formed with a low pressure passage 13a, a high pressure passage 13b, and a control passage 13c. The low pressure passage 13a connects the suction chamber 23a and the control valve 13. The high-pressure passage 13b connects the discharge chamber 23b and the control valve 13. The control passage 13c connects the control pressure chamber 23c 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 throttles the flow rate of the refrigerant of the discharge pressure Pd in the discharge chamber 23b to make the refrigerant of the control pressure Pc into the control pressure chamber 23c. Introduce to.

In this compressor, as shown in FIGS. 2 and 3, the position of the first lateral 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 located at the top dead center due to the rotation of the drive shaft 3, for example, when the first compression chamber 51F of the first cylinder bore 37F finishes the ejection stroke, the first lateral hole 45F is the first cylinder bore 37F. It communicates with the front side first communication passage 41Fa communicating with the second cylinder bore 37Fb and the front side first communication passage 41Fb communicating 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. 1 The side hole 45F communicates with the front side first communication passage 41F or the front side first communication passage 41Fb. Then, when the drive shaft 3 rotates past the θ1 angle and the first head 7F moves beyond a certain position, the first lateral hole 45F becomes non-communication with the front side first communication passage 41Fb. Therefore, as shown in FIG. 6, the first suction reed valve 33d opens.

Further, as shown in FIGS. 4 and 5, the position of the second lateral hole 45R around the drive shaft center 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 located at the top dead center due to the rotation of the drive shaft 3, for example, when the second compression chamber 51R of the second cylinder bore 37Rd finishes the ejection stroke, the second lateral hole 45R is the second cylinder bore 37Rd. It communicates with the rear side first communication passage 41Rd which communicates with. 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 lateral hole 45R is on the rear side. It communicates with the first communication passage 41Rd. Then, when the drive shaft 3 rotates past the θ1 angle and the second head 7R moves beyond a certain position, the second lateral hole 45R becomes non-communication with the rear side first communication passage 41Rd. Therefore, as shown in FIG. 6, the second suction reed valve 35d opens.

This compressor is used in vehicle air conditioners. If 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, respectively, and also move from the top dead center to the bottom dead center.

Therefore, as shown in FIG. 1, when the volume of the first compression chamber 51F is expanded and the pressure in the first compression chamber 51F is lower than that of the first suction chamber 21a, the first suction lead valve 33d is opened and the first suction lead valve 33d is opened. 1 The suction chamber 21a and the first compression chamber 51F communicate with each other, and the refrigerant having the suction pressure Ps is sucked into the first compression chamber 51F from the first suction chamber 21a. Then, when the volume of the first compression chamber 51F is reduced and the pressure in the first compression chamber 51F becomes higher than that of the first discharge chamber 21b, the first discharge lead valve 33b opens and the first discharge chamber 21b and the first compression are performed. It communicates with the chamber 51F, and the refrigerant having a discharge pressure Pd is discharged from the first compression chamber 51F to the first discharge chamber 21b.

Further, when the volume of the second compression chamber 51R is expanded 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 to open the second suction chamber 23a and the second compression chamber. It communicates with the chamber 51R, and the refrigerant having the suction pressure Ps is sucked into the second compression chamber 51R from the second suction chamber 23a. Then, when the volume of the second compression chamber 51R is reduced and the pressure in the second compression chamber 51R becomes higher than that of the second discharge chamber 23b, the second discharge lead valve 35b is opened to open the second discharge chamber 23b and the second compression chamber. It communicates with the chamber 51R, and the refrigerant having the discharge pressure Pd is discharged from the second compression chamber 51R to the second discharge chamber 23b.

The refrigerant passing through the evaporator is supplied to the first suction chamber 21a and the second suction chamber 23a from the suction port of the suction passage 29. Further, 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.

During this period, in this compressor, the control valve 13 controls the control pressure Pc in the control pressure chamber 23c by using the discharge pressure Pd in the second discharge chamber 23b. Then, as shown in FIG. 6, as the drive shaft 3 rotates, the first lateral hole 45F intermittently communicates with the front side first communication passages 41Fa to 41Fe. Therefore, a part of the refrigerant after the discharge stroke is intermittently supplied to the front side first continuous passages 41Fa to 41Fe via the in-axis passage 45a of the drive shaft 3 and the first lateral hole 45F. The refrigerant supplied to the front-side first communication passages 41Fa to 41Fe is returned to the first compression chamber 51F at the initial stage of the suction stroke without being discharged to the outside from the first discharge chamber 21b. In this case, as shown in FIG. 6, the pressure in the first compression chamber 51F is higher near the top dead center than the pressure shown by the broken line shown by the compressor using only a general suction valve.

The refrigerant refluxed into the first compression chamber 51F re-expands in the first compression chamber 51F. Therefore, unless the pressure in the first compression chamber 51F becomes lower than the suction pressure Ps in the first suction chamber 21a, the first suction reed valve 33d of the first suction valve 9F does not open and from the first suction chamber 21a. The refrigerant is not sucked into the first compression chamber 51F. Therefore, the flow rate of the refrigerant sucked into the first compression chamber 51F is reduced. Therefore, the flow rate of the refrigerant discharged from the first compression chamber 51F to the first discharge chamber 21b is reduced.

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

The refrigerant refluxed into the second compression chamber 51R re-expands in the second compression chamber 51R. Therefore, unless the pressure in the second compression chamber 51R becomes lower than the suction pressure Ps in the second suction chamber 23a, the second suction reed valve 35d of the second suction valve 9R does not open, and the second suction chamber 23a does not open. The refrigerant is not sucked into the second compression chamber 51R. Therefore, 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 is passed through the in-axis passage 45a, the first horizontal hole 45F and the second horizontal hole 45R of the drive shaft 3, and the front side first communication passages 41F to 41Fe and the rear side first communication passage 41Ra to 41Re. 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 lateral 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 lead valve 33d of the valve 9F opens, and the refrigerant in the first suction chamber 21a is sucked into the first compression chamber 51F. Therefore, the pressure in the first compression chamber 51F during the suction stroke does not become excessively low.

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

Therefore, in this compressor, the compression ratio is in 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 in a non-low flow rate state. Will not be high. Therefore, 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 lateral hole 45F is the first communication on the front side between the time when the first head 7F is located at the top dead center and the time when the first head 7F moves to the bottom dead center. It communicates with the passages 41Fa to 41Fe. Further, from the time when the second head 7R is located at the top dead center to the time when the second head 7F moves to the bottom dead center, the second side hole 45R becomes the rear side first communication passage 41Ra to 41Re. Communicate. Therefore, the high-pressure refrigerant refluxed into the first and second compression chambers 51F and 51R re-expands in the first and second compression chambers 51F and 51R in the suction stroke to press the piston 7. More specifically, at the moment when the first compression chamber 51F and the second compression chamber 51R shift to the suction stroke, the refrigerant re-expands and presses the piston 7. Therefore, in this compressor, the effect of reducing power can be obtained.

Thus, in this compressor, as shown in FIG. 7, the relationship between the volume and the 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, the compressor using only a general suction valve shows. The amount of work is reduced only in the shaded area compared to the relationship A → B → C → D.

Further, in this compressor, since the inclination angle of the fixed swash plate 5 is constant and the inner valve is not adopted, 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 flow rate is low while realizing the simplification of the structure. 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 refluxed to the first compression chamber 51F re-expands in the first compression chamber 51F in the suction stroke, and the piston 7 is killed at the first head 7F. The urging force acts in the 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 in the second compression chamber 51R, a compression reaction force acts on the piston 7. That is, the urging force and the compression reaction force cancel each other out in the O direction of the drive axis. Therefore, the shoe 53, the fixed swash plate 5, or the piston 7 exhibits excellent durability.

Further, 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)
In the compressor of the second embodiment, the positions of the first lateral hole 55F and the second lateral hole 55R around the drive shaft center O are different from those of the first embodiment.

That is, as shown in FIGS. 8 and 10, when the drive shaft 3 rotates, the drive shaft 3 rotates by a θ2 angle while the first head 7F moves past the top dead center to a fixed position to the bottom dead center. The first lateral hole 55F communicates with the front side first communication passages 41F to 41Fe. Then, the first lateral hole 55F communicates with the front side first communication passages 41F to 41Fe 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. Then, when the drive shaft 3 rotates past the θ3 angle and the first head 7F moves beyond the fixed position, the first lateral hole 55F becomes non-communication with the front side first communication passages 41Fa to 41Fe. Therefore, the first suction reed valve 33d opens.

The first horizontal hole 55F and the second horizontal hole 55R are displaced by 180 ° around the drive axis O. Therefore, 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 passes the top dead center and moves to a fixed position to the bottom dead center. At the stage, the second side hole 55R communicates with the rear side first communication passages 41Ra to 41Re. Then, the second lateral hole 55R communicates with the rear side first communication passages 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 communicated with the rear side first communication passages 41Ra to 41Re. Therefore, the second suction reed valve 35d opens. Other configurations are the same as in the first embodiment.

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

The refrigerant refluxed into the first compression chamber 51F re-expands in the first compression chamber 51F. Therefore, the first suction reed valve 33d is opened once, then closed, and then reopened. Therefore, the flow rate of the refrigerant sucked into the first compression chamber 51F is reduced.

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

The refrigerant refluxed into the second compression chamber 51R re-expands in the second compression chamber 51R. Therefore, the second suction reed valve 35d is opened once, then closed, and then reopened. Therefore, the flow rate of the refrigerant sucked into the second compression chamber 51R is reduced.

Thus, in this compressor, as shown in FIG. 11, the relationship between the volume and the 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, the compressor using only a general suction valve shows. The amount of work is reduced only in the shaded area compared to the relationship A → B → C → D. Other effects are the same as in Example 1.

Although the present invention has been described above with reference to Examples 1 and 2, the present invention is not limited to the above-mentioned Examples 1 and 2, and can be appropriately modified and applied without departing from the spirit thereof. Needless to say.

For example, in Examples 1 and 2 above, the present invention is embodied in a double-headed compressor, but the present invention can also be embodied in a single-headed compressor. If the present invention is a single-headed compressor, the structure can be further simplified and the manufacturing cost can be further reduced. The present invention can also be applied to a wobble compressor.

Further, in the first and second embodiments, the drive shaft 3 is a rotating body, but the rotating body may be a separate body from the drive shaft 3.

The control pressure chamber may be provided between the rear end of the drive shaft and the second valve unit instead of the second housing. Further, the control pressure chamber may be provided so as to be located between the rear end of the drive shaft and the second valve unit while being located in the second housing. Further, the control pressure chamber need not be formed in the housing. The control passage and the in-axis passage in the drive shaft may be directly communicated with each other.

The control valve may be any as long as it controls the flow rate of returning the refrigerant in the discharge chamber to the compression chamber, and is not limited to the control valve 13 as in Examples 1 and 2, but also the discharge chamber and the control pressure chamber. A spool that adjusts the opening degree between and may be used. Further, it is also possible to combine the control valve 13 as in Examples 1 and 2 with the spool for adjusting the opening degree between the discharge chamber and the control pressure chamber to form a control valve.

The present invention can be used for vehicle air conditioners.

37Fa to 37Fe, 37Ra to 37Re ... Cylinder bores (37Fa to 37Fe ... one side cylinder bore (first cylinder bore), 37Ra to 37Re ... other side cylinder bore (second cylinder bore))
21a, 23a ... Inhalation chamber (21a ... 1st inhalation chamber, 23a ... 2nd inhalation chamber)
21b, 23b ... Discharge chamber (21b ... 1st discharge chamber, 23b ... 2nd discharge chamber)
25 ... Slope chamber 39 ... Shaft hole 1 ... Housing (21 ... 1st housing, 23 ... 2nd housing, 15 ... 1st cylinder block, 17 ... 2nd cylinder block)
3 ... Drive shaft, rotating body 5 ... Fixed swash plate 51F, 51R ... Compression chamber (51F ... First compression chamber, 51R ... Second compression chamber)
7 ... Piston (7F ... One side head (first head), 7R ... One side head (second head))
11F, 11R ... Discharge valve (11F ... 1st discharge valve, 11R ... 2nd discharge valve)
41Fa to 41Fe, 41Ra to 41Re ... 1st passage (41Fa to 41Fe ... 1st passage on one side (1st passage on the front side), 41Ra to 41Re ... 1st passage on the other side (1st passage on the rear side)) )
45a, 45F, 45R, 55F, 55R ... 2nd passage (45a ... in-axis passage, 45F, 55F ... 1st side 2nd passage (first horizontal hole), 45R, 55R ... other side 2nd passage (1st) 2 side hole))
9F, 9R ... Suction valve (9F ... 1st suction valve, 9R ... 2nd suction valve)
13 ... Control valve O ... Drive shaft center 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 and
A fixed swash plate that can be rotated 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 provided with a discharge valve for discharging the refrigerant in the compression chamber to the discharge chamber.
A first communication passage provided in the cylinder block and communicating with the cylinder bore,
A rotating body that is integrated with or separate from the drive shaft and can rotate integrally with the drive shaft, and a second communication passage that intermittently communicates with the first communication passage is formed as the drive shaft rotates. When,
A suction valve that sucks 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 is provided.
The refrigerant controlled by the control valve is introduced into the compression chamber via the first communication passage and the second communication passage, and is characterized in that the flow rate of the refrigerant sucked from the suction chamber into the compression chamber is changed. Piston type compressor. The piston type compressor according to claim 1, wherein the second communication passage communicates with the first communication passage while the piston moves from the top dead center of the piston to the bottom dead center of the piston. The piston type compressor according to claim 2, wherein the second communication passage communicates with the first communication passage when the piston is located at the top dead center. The cylinder bore is composed of a one-sided cylinder bore arranged on one side in the drive axis direction of the drive shaft and a other-side cylinder bore arranged on the other side in the drive axis direction.
The first communication passage includes a one-sided first communication passage communicating with the one-side cylinder bore and a other-side first communication passage communicating with the other-side cylinder bore.
The piston has a one-sided head that forms a one-sided compression chamber in the one-sided cylinder bore and a other-sided head that forms the other-side compression chamber in the other-sided cylinder bore.
The second communication passage has a one-sided second communication passage communicating with the one-side first communication passage and a other-side second communication passage communicating with the other side first communication passage.
The one-sided second communication passage communicates with the one-sided first communication passage while the one-side head moves from top dead center to bottom dead center.
The other side second communication passage communicates with the other side first communication passage while the other side head moves from top dead center to 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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