WO2021065905A1

WO2021065905A1 - Piston-type compressor

Info

Publication number: WO2021065905A1
Application number: PCT/JP2020/036897
Authority: WO
Inventors: 島田賢; 山本真也; 村西明広; 稲垣洋介
Original assignee: 株式会社豊田自動織機
Priority date: 2019-10-02
Filing date: 2020-09-29
Publication date: 2021-04-08
Also published as: JP7230762B2; BR112022005098A2; KR20220051001A; CN114585813B; JP2021059978A; CN114585813A

Abstract

A piston-type compressor according to the present invention has formed in cylinder blocks (21, 23) thereof first communication channels (37a, 41a) or the like connected to cylinder bores (35a, 39a) or the like. A drive shaft (3) has formed therein shaft channels (3a, 3b) which extend in the drive shaft axial (O) direction and path channels (3c, 3e) which extend in a radial direction of the drive shaft (3) in communication with the shaft channels (3a, 3b) and which are intermittently in communication with the first communication channels (37a, 41a) or the like in conjunction with rotation of the drive shaft (3). A movable body comprises: spools (55, 57) which are disposed within the shaft channels (3a, 3b) in such a manner as to be movable in the drive shaft axial direction (O); and lids (63, 65) which are disposed in the path channels (3c, 3e) in such a manner as to engage the spools (55, 57) and which are capable of changing communication areas with respect to the path channels (3c, 3e), the first communication channels (37a, 41a), and the like. The lids (63, 65) are configured to maximize the communication areas when the discharge flow rate is at a maximum level, and to minimize the communication areas when the discharge flow rate is at a minimum level.

Description

Piston compressor

The present invention relates to a piston type compressor.

Patent Document 1 discloses a conventional piston type compressor (hereinafter, simply referred to as a compressor). The compressor includes a housing, a drive shaft, a fixed swash plate, a plurality of pistons, a discharge valve, a moving body, and a control valve.

The housing has a cylinder block. In addition to forming a plurality of cylinder bores, the cylinder block is formed with a first connecting passage that communicates with the cylinder bores. Further, the housing is formed with a discharge chamber, a swash plate chamber, and a shaft hole. Refrigerant is sucked into the swash plate chamber from the outside of the compressor. In addition, the swash plate chamber communicates with the shaft hole.

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. The fixed swash plate has a constant inclination angle with respect to a plane perpendicular to the drive axis. The piston forms a compression chamber in the cylinder bore and is connected to a 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.

The moving body has a cylindrical shape and is provided on the outer peripheral surface of the drive shaft, and is arranged in the shaft hole. The moving body rotates integrally with the drive shaft in the shaft hole, and can move with respect to the drive shaft in the drive axis direction of the drive shaft based on the control pressure. A second passage is formed on the outer peripheral surface of the moving body. The control valve controls the pressure of the refrigerant to obtain the control pressure.

In this compressor, the drive shaft rotates and the fixed swash plate rotates, so that the piston reciprocates in the cylinder bore between top dead center and bottom dead center. Here, as the piston moves from the top dead center to the bottom dead center, the compression chamber becomes a suction stroke. Then, at this time, the refrigerant is sucked into the compression chamber by communicating the first passage and the second passage. On the other hand, the first passage and the second passage are not communicated with each other, and the piston moves from the bottom dead center to the top dead center, so that the compression chamber becomes a compression stroke for compressing the sucked refrigerant. It is a discharge process in which the compressed refrigerant is discharged to the discharge chamber. Then, in this compressor, the discharge flow rate, which is the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber, changes according to the position in the drive axis direction of the moving body.

Japanese Unexamined Patent Publication No. 5-306680

However, in the above-mentioned conventional compressor, a cylindrical moving body is provided on the outer peripheral surface of the drive shaft. Therefore, the load of the high-pressure refrigerant compressed in the compression chamber (hereinafter referred to as the compression load) acts on the moving body through the first communication passage communicating with the compression chamber during the compression stroke or the discharge stroke. As a result, in this compressor, the moving body is pressed in the shaft hole in the direction intersecting the drive axis direction, so that the moving body is pressed against the inner wall of the shaft hole. Therefore, the frictional force between the moving body and the shaft hole when moving in the direction of the drive axis becomes large. As a result, it becomes difficult for the moving body to move suitably in the direction of the drive axis, and the controllability is lowered.

Therefore, in order to move the moving body in the direction of the drive axis by a larger thrust, it is conceivable to increase the size of the moving body. However, in this case, it is necessary to increase the size of the shaft hole and the like in accordance with the increase in size of the moving body, and as a result, the size of the compressor increases.

The present invention has been made in view of the above-mentioned conventional circumstances, and it is an object to be solved to provide a piston type compressor capable of exhibiting high controllability and realizing miniaturization.

The piston type compressor of the present invention has a cylinder block in which a plurality of cylinder bores are formed, and has a discharge chamber, a swash plate chamber in which a refrigerant is sucked, and a housing in which a shaft hole is formed.
A drive shaft rotatably supported in the shaft hole,
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 discharge valve that discharges the refrigerant in the compression chamber to the discharge chamber,
A moving body provided on the drive shaft, which rotates integrally with the drive shaft and is movable with respect to the drive shaft in the drive axis direction of the drive shaft based on a control pressure.
A control valve for controlling the control pressure is provided.
A piston type compressor in which the discharge flow rate, which is the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber, changes according to the position of the moving body in the drive axis direction.
The cylinder block is formed with a first communication passage that communicates with the cylinder bore.
The drive shaft includes an axis extending in the direction of the drive axis, communicating with the axis and extending in the radial direction of the drive shaft, and intermittently communicating with the first passage as the drive shaft rotates. Axle is formed
The moving body is arranged in the axial path by engaging with a spool that is movably arranged in the drive axis direction and is arranged in the path, and has a communication area between the path and the first communication passage. Has a changeable lid and
The lid is characterized in that the communication area is maximized when the discharge flow rate is maximum, while the communication area is minimized when the discharge flow rate is minimum.

In the piston type compressor of the present invention, the spool of the moving body moves in the axial path of the drive shaft in the direction of the drive axis. Therefore, no compressive load acts on the spool of the moving body. Further, the lid of the moving body is engaged with the spool and arranged in the path, and the communication area between the path and the first communication passage is changed. The route only intermittently communicates with the first communication passage as the drive shaft rotates, and the lid maximizes the communication area when the discharge flow rate is maximum, while the communication area is maximum when the discharge flow rate is minimum. To minimize. During this time, the lid body communicates the path with the first passage when the compression chamber is in the suction stroke, and makes the route non-communication with the first passage when the compression chamber is in the compression stroke or the discharge stroke. As a result, the compressive load acts on the drive shaft through the first continuous passage, while the compressive load does not easily act on the moving body. Therefore, in this compressor, the moving body easily moves in the direction of the drive axis. Further, in this compressor, it is not necessary to make the moving body larger than necessary in order to obtain a large thrust.

Therefore, the piston type compressor of the present invention can exhibit high controllability and can realize miniaturization.

The drive shaft may have a guide surface that guides the lid in the direction of the drive axis. It is preferable that the communication start timing between the first communication passage and the route is defined by the guide surface thereof. In this case, a lid having a simple shape can be adopted, and processing to the drive shaft becomes easy. Further, since the minimum capacity can be realized by the lid, other controls can be omitted. Therefore, it is possible to reduce the manufacturing cost of the piston type compressor. Further, since the length of the lid in the direction of the drive axis can be shortened, it is possible to improve the mountability on a vehicle or the like by shortening the axis of the piston type compressor. Further, since the lid body has no weak portion, the durability is improved and high controllability can be exhibited.

Further, it is preferable that the timing of the end of communication between the first communication passage and the path is defined by the guide surface when the discharge flow rate is maximum, and by the lid when the discharge flow rate is minimum. In this case as well, a lid having a simple shape can be adopted.

The simplest shape when the communication start timing is defined by the guide surface and the communication end timing is defined by the guide surface when the discharge flow rate is maximum and by the lid when the discharge flow rate is minimum. Lid body can be adopted. Further, in this case, since the guide surface can form a path at a position shallow from the outer peripheral surface of the drive shaft, the strength against twisting of the drive shaft is improved, and high durability can be exhibited.

The cylinder bore may consist of a one-sided cylinder bore arranged on one side in the drive axis direction and a other-side cylinder bore arranged on the other side in the drive axis direction. Further, the piston may have 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-side cylinder bore. Further, the first continuous passage may include a one-sided first continuous passage communicating with the one-side cylinder bore and a other-side first continuous passage communicating with the other side cylinder bore. Further, the route may be composed of a one-sided route communicating with the one-sided first communication passage and the other-side route communicating with the other-side first communication passage. Further, the lid is arranged on the one-sided path and the one-sided lid whose communication area between the one-sided path and the one-sided first communication passage can be changed, and the other side path, and the other side and the other side. It may consist of a lid on the other side whose communication area with the first passage can be changed. In this case, the piston type compressor is a double-headed type.

In the case of a double-headed piston type compressor, the other side lid has a part of its outer peripheral edge forming the other side second communication passage forming the communication area between the other side path and the other side first communication passage. It is preferable that the shutter is used. In this case, the lid on the other side has a simple shape, and the position of a part of the outer peripheral edge of the shutter in the drive axis direction with respect to the position of the first passage on the other side changes, so that the second passage on the other side has a simple shape. The communication area can be changed, and the capacity of the compression chamber on the other side can be easily controlled.

In the case of a double-headed piston type compressor, the other side lid is a shutter, and the one side lid has its own second passage that constitutes the communication area between the one side path and the one side first passage. It is preferable that the frame is formed inside. In this case, the one-sided lid can precisely control the capacity of the one-sided compression chamber.

In the case of a double-headed piston type compressor, it is preferable that the other side lid is a shutter and the one side lid is also a shutter. In this case, the other side lid and the one side lid have a simple shape, and the capacities of the other side compression chamber and the one side compression chamber can be easily controlled.

The shutter preferably has an engaging piece that is engaged with the spool on the rear side in the rotation direction of the drive shaft. Since the shutter is pushed in the rotation direction on the rear side in the rotation direction of the drive shaft, if the engaging claw is engaged with the spool there, the engagement between the spool and the shutter becomes strong.

The spool may consist of a first spool with which one side lid is engaged and a second spool that is movable in the drive axis direction with respect to the first spool and with which the other side lid is engaged. In this case, the capacitance of the one-side compression chamber and the other-side compression chamber can be precisely controlled.

It is also preferable that the spool is a single spool in which one side lid and the other side lid are engaged. In this case, the capacity control of the one-side compression chamber and the other-side compression chamber can be easily performed.

The piston type compressor of the present invention can exhibit high controllability and can realize miniaturization.

FIG. 1 is a cross-sectional view of the piston type compressor of the first embodiment in the direction of the drive axis at the minimum flow rate. FIG. 2 is a cross-sectional view of the piston type compressor of the first embodiment in the drive axis direction at a predetermined flow rate. FIG. 3 is a cross-sectional view of the piston type compressor of the first embodiment in the drive axis direction at the maximum flow rate. FIG. 4 is a cross-sectional view of the drive shaft in the drive axis direction according to the piston type compressor of the first embodiment. FIG. 5 is an enlarged cross-sectional view of the moving body in the drive axis direction according to the piston type compressor of the first embodiment. FIG. 6 is an enlarged perspective view of the rear side frame body as viewed from a certain direction with respect to the piston type compressor of the first embodiment. FIG. 7 is an enlarged perspective view of the rear side frame body as viewed from another direction with respect to the piston type compressor of the first embodiment. FIG. 8 is a cross-sectional view of the piston type compressor of the first embodiment in a direction perpendicular to the drive shaft center of the drive shaft, the first spool, and the rear side frame. FIG. 9 is a cross-sectional view of a main part on the rear side in FIG. 1 relating to the piston type compressor of the first embodiment. FIG. 10 is a development view of the rear side frame, the drive shaft, and the like at the maximum flow rate, related to the piston type compressor of the first embodiment. FIG. 11 is a development view of the rear side frame, the drive shaft, and the like at a predetermined flow rate, related to the piston type compressor of the first embodiment. FIG. 12 is a development view of the rear side frame, the drive shaft, and the like at the minimum flow rate, related to the piston type compressor of the first embodiment. FIG. 13 is a perspective view of the front shutter viewed from a certain direction according to the piston type compressor of the first embodiment. FIG. 14 is a perspective view of the front shutter viewed from another direction according to the piston type compressor of the first embodiment. FIG. 15 is a cross-sectional view of the piston type compressor of the first embodiment in a direction perpendicular to the drive axis of the drive shaft, the second spool, and the front shutter. FIG. 16 is a cross-sectional view of a main part on the front side in FIG. 1 relating to the piston type compressor of the first embodiment. FIG. 17 is a development view of the front side shutter, the drive shaft, and the like at the maximum flow rate, relating to the piston type compressor of the first embodiment. FIG. 18 is a development view of the front side shutter, the drive shaft, and the like at a predetermined flow rate, relating to the piston type compressor of the first embodiment. FIG. 19 is a development view of the front shutter, the drive shaft, and the like at the minimum flow rate, relating to the piston type compressor of the first embodiment. FIG. 20 is a cross-sectional view of the moving body in the drive axis direction according to the piston type compressor of the second embodiment. FIG. 21 is a cross-sectional view of the moving body in the drive axis direction according to the piston type compressor of the third embodiment. FIG. 22 is a developed view of the rear shutter, the drive shaft, and the like at the minimum flow rate, relating to the piston type compressor of the modified example. FIG. 23 is a developed view of the front shutter, the drive shaft, and the like at the minimum flow rate, relating to the piston type compressor of the modified example.

Hereinafter, Examples 1 to 3 embodying the present invention will be described with reference to the drawings. The compressors of Examples 1 to 3 are double-headed piston type compressors. These compressors are mounted on the vehicle and constitute the refrigeration circuit of the air conditioner.

As shown in FIGS. 1 to 3, the compressor of the first embodiment includes a housing 1, a drive shaft 3, a fixed swash plate 5, a plurality of pistons 7, a rear side valve forming plate 9, and a front side valve forming. It includes a plate 11, a moving body 13, and a control valve 15. The housing 1 includes a rear housing 17, a front housing 19, a rear cylinder block 21, and a front cylinder block 23. The rear side corresponds to one side in the present invention, and the front side corresponds to the other side in the present invention.

In this embodiment, the side where the front housing 19 is located is the front side of the compressor, and the side where the rear housing 17 is located is the rear side of the compressor, and the front-rear direction of the compressor is defined. Further, the vertical direction of the compressor is defined with the upper side of the paper surface of FIGS. 1 to 3 as the upper side of the compressor and the lower side of the paper surface as the lower side of the compressor. Then, in FIGS. 4 and 4, the front-back direction and the up-down direction are displayed corresponding to FIGS. 1 to 3. The front-rear direction and the like in the embodiment are examples, and the posture of the compressor of the present invention is appropriately changed according to the vehicle on which the compressor is mounted.

The drive axis O of the drive shaft 3 extends in the front-rear direction of the compressor. In the front housing 19, an annular front side discharge chamber 19a is formed around the drive shaft center O. The front housing 19 is formed with a boss portion 19b and a front shaft hole 19c. The boss portion 19b projects forward in the drive axis O direction. The front shaft hole 19c penetrates the front housing 19 in the drive shaft center O direction. A shaft sealing device 25 is provided in the front shaft hole 19c.

The rear housing 17 is formed with a control pressure chamber 17a and a rear discharge chamber 17b. The control pressure chamber 17a is located on the center side of the rear housing 17. The rear discharge chamber 17b is formed in an annular shape around the drive shaft center O, and is located on the outer peripheral side of the control pressure chamber 17a.

The front side cylinder block 23 and the rear side cylinder block 21 are provided between the front housing 19 and the rear housing 17. A front valve forming plate 11 is provided between the front housing 19 and the front cylinder block 23, a gasket 27 is provided between the front cylinder block 23 and the rear cylinder block 21, and a rear cylinder block is provided. A rear side valve forming plate 9 is provided between the 21 and the rear housing 17, and these are fastened by bolts (not shown) extending in the drive axis O direction.

The front side cylinder block 23 and the rear side cylinder block 21 form a swash plate chamber 29. The swash plate chamber 29 is connected to an external evaporator (not shown) by a suction port 29a formed in the front cylinder block 23, and sucks a low-pressure refrigerant. Further, the front side cylinder block 23 and the rear side cylinder block 21 form a discharge passage 31 extending in the drive axis O direction. The discharge passage 31 penetrates the front side valve forming plate 11 and communicates with the front side discharge chamber 19a. Further, the discharge passage 31 penetrates the rear side valve forming plate 9 and communicates with the rear side discharge chamber 17b. The discharge passage 31 is connected to an external condenser (not shown) by a discharge port 31a formed in the front cylinder block 23, and discharges a high-pressure refrigerant. The refrigerant contains oil.

The rear cylinder block 21 has a boss portion 21a that projects rearward in the drive axis O direction. The boss portion 21a penetrates the front side valve forming plate 11 and extends into the control pressure chamber 17a. In the rear side cylinder block 21, a rear side shaft hole 33a, which is a columnar space, is formed in the drive shaft center O direction. The rear shaft hole 33a is open to the control pressure chamber 17a.

In the front side cylinder block 23, a front side shaft hole 33b, which is a columnar space, is formed in the drive axis O direction. The front shaft hole 33b is coaxial with the rear shaft hole 33a and has a slightly larger diameter than the rear shaft hole 33a. The front side shaft hole 33b communicates with the front side shaft hole 19c by an insertion hole 11g formed in the front side valve forming plate 11.

Further, as shown in FIG. 9, the rear side cylinder block 21 is formed with rear side cylinder bores 35a to 35e. The rear cylinder bores 35a to 35e are columnar spaces extending in the drive axis O direction, and are equally spaced from each other around the drive axis O.

The rear side cylinder block 21 is formed with rear side first continuous passages 37a to 37e connecting the rear side cylinder bores 35a to 35e and the rear side shaft hole 33a. The rear-side first communication passages 37a to 37e extend in the radial direction from the drive shaft center O. As shown in FIGS. 1 to 3, the first continuous passages 37a to 37e on the rear side are inclined rearward while being separated from the drive shaft center O.

As shown in FIG. 16, the front side cylinder block 23 is formed with front side cylinder bores 39a to 39e. The front side cylinder bores 39a to 39e are columnar spaces extending in the drive axis O direction, and are equally spaced from each other around the drive axis O. The rear cylinder bores 35a to 35e and the front cylinder bores 39a to 39e are coaxial and have the same diameter, respectively.

The front side cylinder block 23 is formed with front side first continuous passages 41a to 41e for connecting the front side cylinder bores 39a to 39e and the front side shaft hole 33b. The front-side first communication passages 41a to 41e extend in the radial direction from the drive shaft center O. As shown in FIGS. 1 to 3, the first continuous passages 41a to 41e on the front side are inclined forward while being separated from the drive shaft center O.

A fixed swash plate 5 is fixed to the outer peripheral surface of the drive shaft 3 by press fitting in the swash plate chamber 29. The fixed swash plate 5 is formed with

inclined surfaces

5a and 5b having a constant inclination angle with respect to a plane perpendicular to the drive axis O of the drive shaft 3 in the front-rear direction. The fixed swash plate 5 is sandwiched between the front cylinder block 23 and the rear cylinder block 21 via

thrust bearings

43 and 45, respectively.

Hemispherical shoes

49a and 49b are provided on the

inclined surfaces

5a and 5b of the fixed swash plate 5, respectively. The

shoes

49a and 49b are provided with double-headed pistons 7. Each piston 7 has a rear side head 7a and a front side head 7b. The rear side head 7a forms a rear side compression chamber 51 in the rear side cylinder bores 35a to 35e. The front side head 7b forms a front side compression chamber 53 in the front side cylinder bore 39a.

The rear side valve forming plate 9 includes a valve plate 9a arranged on the rear side cylinder block 21 side, a discharge valve plate 9b arranged behind the valve plate 9a, and a retainer arranged further behind the discharge valve plate 9b. It consists of a plate 9c. The valve plate 9a is formed with discharge ports 9d for communicating the rear cylinder bores 35a to 35e with the rear discharge chambers 17b, respectively. The discharge valve plate 9b is formed with a discharge reed valve 9e that closes each discharge port 9d by an elastic restoring force. The retainer plate 9c is formed with a retainer 9f that regulates the opening degree of each discharge reed valve 9e.

The front side valve forming plate 11 includes a valve plate 11a arranged on the front side cylinder block 23 side, a discharge valve plate 11b arranged in front of the valve plate 11a, and a retainer arranged further in front of the discharge valve plate 11b. It consists of a plate 11c. The valve plate 11a is formed with discharge ports 11d for communicating the front cylinder bores 39a to 39e with the front discharge chamber 19a, respectively. The discharge valve plate 11b is formed with a discharge reed valve 11e that closes each discharge port 11d by an elastic restoring force. The retainer plate 11c is formed with a retainer 11f that regulates the opening degree of each discharge reed valve 11e. The

discharge reed valves

9e and 11e correspond to the discharge valves of the present invention.

The control valve 15 is provided in the rear housing 17. The control pressure chamber 17a and the rear discharge chamber 17b are connected by an air supply passage 47a. The control pressure chamber 17a and the swash plate chamber 29 are connected by an bleed air passage 47b, and a control valve 15 is arranged in the middle of the bleed air passage 47b. The control valve 15 adjusts the opening degree of the bleed air passage 47b by a signal of a controller (not shown) to control the control pressure in the control pressure chamber 17a.

The outer peripheral surface of the drive shaft 3 is preferably inside the rear shaft hole 33a and the front shaft hole 33b, except for the portion where the fixed swash plate 5 is press-fitted and the portion where the

thrust bearings

43 and 45 are arranged. The coating is applied so that it can rotate and slide. In the drive shaft 3, as shown in FIG. 4, the first axis 3a extending in the drive axis O direction on the rear side and the first axis 3a in front of the first axis 3a are communicated with each other to drive. A second axis path 3b extending in the axis O direction is formed. The first axis path 3a is a columnar space, which is opened at the rear end of the drive shaft 3 so as to communicate with the control pressure chamber 17a. The second axis 3b is a columnar space having a diameter smaller than that of the first axis 3a. A step 3j is formed between the first axis 3a and the second axis 3b.

Further, the drive shaft 3 has a rear side radial path 3c that communicates with the first axis path 3a on the rear side and extends in the radial direction of the drive shaft 3, and a drive shaft 3 that communicates with the second axis path 3b at substantially the center. An internal suction port 3d extending in the radial direction and a front side radial path 3e extending in the radial direction of the drive shaft 3 in front of the second axis 3b are formed.

The rear side path 3c is formed at a predetermined angle around the drive shaft center O as shown in FIG. 8, and has a predetermined length parallel to the drive shaft center O as shown in FIGS. 10 and 11. Is formed of. The rear end of the rear side path 3c is a rear end regulation surface 3f, and the front end of the rear side path 3c is a front end regulation surface 3g. The rear end regulation surface 3f and the front end regulation surface 3g extend in a direction perpendicular to the drive axis O.

As shown in FIGS. 8 and 9, the drive shaft 3 forms guide

surfaces

32a and 32b extending in the drive shaft center O direction by its own thickness portion which is the difference between the inner diameter and the outer diameter of the drive shaft 3. .. The guide surface 32a and the guide surface 32b are flush with each other and extend parallel to the drive axis O. The guide surface 32a is located on the leading side of the drive shaft 3 in the rotational direction, and the guide surface 32b is located on the trailing side of the drive shaft 3 in the rotational direction.

As shown in FIG. 15, the front side path 3e is also formed at a predetermined angle around the drive axis O, and as shown in FIGS. 17 to 19, it has a predetermined length parallel to the drive axis O. It is formed. The rear end of the front side path 3e is the rear end regulation surface 3h, and the front end of the front side path 3e is the front end regulation surface 3i. The rear end regulation surface 3h and the front end regulation surface 3i extend in a direction perpendicular to the drive axis O. The front side path 3e has a smaller angle around the drive axis O and a shorter length in the drive axis O direction than the rear side path 3c.

As shown in FIGS. 15 and 16, the drive shaft 3 also forms

guide surfaces

34a and 34b extending in the drive axis O direction due to its own thickness portion which is the difference between the inner diameter and the outer diameter of the drive shaft 3. .. The guide surface 34a and the guide surface 34b are flush with each other and extend parallel to the drive axis O. The guide surface 34a is located on the leading side of the drive shaft 3 in the rotational direction, and the guide surface 34b is located on the trailing side of the drive shaft 3 in the rotational direction.

As shown in FIGS. 1 to 3, a first spool 55 and a second spool 57 are provided in the drive shaft 3. The first spool 55 is arranged so as to be movable in the drive axis O direction in the first axial path 3a via the first spring 2 between the first spool 55 and the step 3j. As shown in FIG. 5, the first spool 55 has a thick cylinder portion 55a having an outer diameter slightly smaller than the inner diameter of the first axis 3a and formed into a thick cylindrical shape, and a thick cylinder portion 55a. A thin-walled cylinder 55b located in the front and having an outer diameter equal to that of the thick-walled cylinder 55a and formed in a cylindrical shape thinner than the thick-walled cylinder 55a, and an end 55c that closes the rear end of the thick cylinder 55a. It consists of. The first spool 55 is made of resin. On the outer peripheral surface of the end portion 55c, a seal 55d made of a material is provided so that the first spool 55 can easily move in the first axis 3a in the drive axis O direction and the control pressure of the control pressure chamber 17a cannot be easily released. There is.

A first internal flow path 59 is formed in the thick-walled cylinder portion 55a and the thin-walled cylinder portion 55b, and the drive axis O is formed between the inner peripheral surface of the thick-walled cylinder portion 55a and the inner peripheral surface of the thin-walled cylinder portion 55b. A contact surface 55 g orthogonal to the above is formed. The thick-walled cylinder portion 55a is formed with a first communication window 55e that opens the first internal flow path 59 to the outside.

As shown in FIGS. 1 to 3, the second spool 57 is connected to the front end of the second axis 3b via the second spring 4 in the second axis 3b and the thin-walled cylinder portion 55b in the drive axis O direction. It is arranged so that it can be moved to. The urging force of the second spring 4 is set stronger than the urging force of the first spring 2.

As shown in FIG. 5, the second spool 57 has a cylindrical tubular portion 57a whose outer diameter is slightly smaller than the inner diameter of the second axial path 3b and the thin-walled tubular portion 55b, and a cylindrical portion 57a at the front end of the tubular portion 57a. It is composed of a formed spring seat portion 57b. The second spool 57 is also made of resin. On the outer peripheral surface on the rear side of the cylinder portion 57a, a seal 57c made of a material that allows the second spool 57 to easily move in the thin-walled cylinder portion 55b in the drive axis O direction and the control pressure of the control pressure chamber 17a is difficult to escape is provided. Has been done.

A second internal flow path 61 communicating with the first internal flow path 59 of the first spool 55 is formed in the tubular portion 57a. Further, an internal intake 57d communicating with the second internal flow path 61 is formed substantially in the center of the tubular portion 57a in the drive axis O direction, and the second internal flow path 61 is outward in front of the tubular portion 57a. A second communication window 57e to be opened is formed.

As shown in FIGS. 1 to 3, the fixed swash plate 5 is formed with an internal suction port 5c formed so as to extend radially from the swash plate chamber 29. The internal suction port 5c coincides with the internal suction port 3d of the drive shaft 3. The internal intake 57d of the tubular portion 57a of the second spool 57 has an internal suction throttle mechanism SV whose communication area with the internal suction port 3d and the internal suction port 5c changes depending on the position of the second spool 57 in the drive axis O direction. It is configured.

The swash plate chamber 29 passes through the internal suction port 5c of the fixed swash plate 5, the internal suction port 3d of the drive shaft 3, and the internal suction throttle mechanism SV, and as shown in FIG. 5, the second internal flow path 61 of the second spool 57. And communicate with the first internal flow path 59 of the first spool 55. The first internal flow path 59 communicates with the first communication window 55e, and the second internal flow path 61 communicates with the second communication window 57e.

The first communication window 55e and the second communication window 57e are 180 ° out of phase around the drive axis O. The first communication window 55e communicates with the rear side first communication passages 37a to 37e that communicate with the rear side compression chamber 51 that performs the suction stroke. Further, the second communication window 57e communicates with the front side first communication passages 41a to 41e communicating with the front side compression chamber 53 that performs the suction stroke.

An engaging hole 55f is formed in the thick cylinder portion 55a of the first spool 55. The engagement hole 55f is located behind the first communication window 55e in the drive axis O direction. The engaging piece 63a of the rear side frame body 63 is engaged with the engaging hole 55f, whereby the frame body 63 is arranged in the thick cylinder portion 55a of the first spool 55. The frame body 63 corresponds to the rear side lid body. The frame body 63 is guided to the guide surfaces 32a and 32b of the drive shaft 3 according to the position of the first spool 55 in the drive shaft center O direction.

Further, an engaging hole 57f is also formed in the tubular portion 57a of the second spool 57. The engagement hole 57f is located in front of the second communication window 57e in the drive axis O direction. An engaging piece 65a of the front shutter 65 is engaged with the engaging hole 57f, whereby the shutter 65 is arranged in the tubular portion 57a of the second spool 57. The shutter 65 corresponds to the front side lid. The shutter 65 is guided to the guide surfaces 34a and 34b of the drive shaft 3 according to the position of the second spool 57 in the drive shaft center O direction. The first and

second spools

55 and 57, the frame body 63 and the shutter 65 correspond to the moving body of the present invention.

As shown in FIGS. 6 and 7, the frame 63 includes a semi-cylindrical shielding portion 63b, a first rim portion 63c extending from one end of the shielding portion 63b in the drive axis O direction, and a shielding portion 63b. It has a second rim portion 63d extending from the end in the drive axis O direction, and a third rim portion 63e connecting the first rim portion 63c and the second rim portion 63d in a semi-cylindrical shape. The engaging piece 63a is formed by bending from the third rim portion 63e in the drive axis O direction. The front end surface of the shielding portion 63b is a contact surface 63h formed at right angles to the drive axis O, and the rear end surface of the third rim portion 63e is a contact surface formed at right angles to the drive axis O. It is said to be 63i. The first rim portion 63c is formed with a recess 63f bent so as to approach the drive shaft center O.

As shown in FIGS. 8 and 9, the frame body 63 is movably provided in the rear side radial path 3c of the drive shaft 3 by being engaged with the first spool 55, and is provided together with the drive shaft 3 on the rear side shaft hole 33a. Rotate inside. Here, in the frame body 63, the rear end surface of the shielding portion 63b has a profile 63g having a predetermined shape. The profile 63g forms the rear side second continuous passage 64 together with the first to

third rim portions

63c, 63d, 63e. As shown in FIGS. 10 and 11, the rear side second communication passage 64 constitutes a communication area between the rear side path 3c and the rear side first communication passages 37a to 37e. The inside of the frame body 63 forms the rear side second communication passage 64 which constitutes the communication area between the rear side path 3c and the rear side first communication passages 37a to 37e. The rear side path 3c intermittently communicates with the rear side first communication passages 37a to 37e as the drive shaft 3 rotates.

The profile 63g includes a first straight line portion 631 extending from the second rim portion 63d to the front side in the rotation direction of the drive shaft 3, a first inclined portion 632 inclined with respect to the drive axis O direction, and a second inclined portion 633. , A second straight line portion 634 extending rearward from the first rim portion 63c in the rotational direction of the drive shaft 3. The profile 63g includes a first straight portion 631, a first inclined portion 632, a second inclined portion 633, and a second straight portion 634 from the second rim portion 63d to the first rim portion 63c on the rear side in the rotation direction of the drive shaft 3. It is formed continuously in the order of. The first inclined portion 632 is located on the rear side of the profile 63 g in the rotational direction of the drive shaft 3. The second inclined portion 633 is located on the front side of the profile 63g in the rotational direction of the drive shaft 3. The inclination angle β1 of the second inclined portion 633 with respect to the drive axis O direction is set to be smaller than the inclination angle α1 of the first inclined portion 632 with respect to the drive axis O direction. In the first embodiment, the profile 63g is composed of the first straight portion 631, the first inclined portion 632, the second inclined portion 633, and the second straight portion 634, but the number of the inclined portions and the straight portions is appropriately designed. May be good.

As shown in FIGS. 13 and 14, the shutter 65 includes a semi-cylindrical shielding portion 65b and an engaging piece 65a. That is, the shutter 65 does not have the first to third rim portions 63c to 63e like the frame body 63. Of the outer peripheral edge of the shielding portion 65b, the front end surface is a contact surface 65d formed at a right angle to the drive axis O, and the rear end surface is a contact surface 65e formed at a right angle to the drive axis O. It is said that. The contact surface 65e is located on the rear side of the drive shaft 3 in the rotational direction. The contact surface 65e is an end surface on the rear side of the engaging piece 65a. Further, in the outer peripheral edge of the shielding portion 65b, the other portion of the rear end surface is a profile 65c having a predetermined shape.

The profile 65c includes a first straight portion 651 formed by the rear end surface of the engaging piece 65a, a first inclined portion 652 and a second inclined portion 653 inclined with respect to the drive axis O direction, and a second inclined portion. It is composed of a second straight line portion 654 extending from the portion 653 to the front side in the rotation direction of the drive shaft 3. The profile 65c is continuously formed in the order of the first straight line portion 651, the first inclined portion 652, the second inclined portion 653, and the second straight line portion 654. The first inclined portion 652 is located on the rear side of the profile 65c in the rotational direction of the drive shaft 3. The second inclined portion 653 is located on the front side of the profile 65c in the rotational direction of the drive shaft 3. The inclination angle β2 of the second inclined portion 653 with respect to the drive axis O direction is set to be smaller than the inclination angle α2 of the first inclined portion 652 with respect to the drive axis O direction. In the first embodiment, the profile 65c is composed of the first straight portion 651, the first inclined portion 652, the second inclined portion 653, and the second straight portion 654, but the number of the inclined portions and the straight portions is appropriately designed. Good. For example, the second straight line portion 654 may be deleted so that the second inclined portion 653 is connected to the guide surface 34a on the front side in the rotation direction.

The engaging piece 65a is formed by bending in the drive axis O direction from the contact surface 65e of the shielding portion 65b. The engaging piece 65a is provided on the rear side of the drive shaft 3 in the rotational direction. It can be said that the engaging piece 65a is provided on the rear side of the shielding portion 65b in the rotation direction. Further, it can be said that the engaging piece 65a is provided on the rear side in the rotational direction with respect to the central position of the inner peripheral surface of the shutter 65.

The left and right end faces of the shielding portion 65b extend parallel to the drive axis O. The shutter 65 includes a rear end surface 65f mounted on the guide surface 34b and a front end surface 65g mounted on the guide surface 34a. The rear end surface 65f extends in the drive axis O direction at the rear end portion in the rotation direction of the shutter 65. The front end surface 65g extends in the drive axis O direction at the front end portion in the rotation direction of the shutter 65. The rear end surface 65f is formed to have a longer length in the drive axis O direction than the front end surface 65g. Therefore, the area where the guide surface 34b, which is the rear side of the drive shaft 3 in the rotation direction, and the rear end surface 65f come into contact with each other is such that the guide surface 34a, which is the front side of the drive shaft 3 in the rotation direction, and the front end surface 65g come into contact with each other. It is wider than the area.

As shown in FIGS. 15 and 16, the shutter 65 is movably provided in the front side path 3e of the drive shaft 3 by being engaged with the second spool 57, and is provided in the front side shaft hole 33b together with the drive shaft 3. To rotate. The profile 65c, which is a part of the outer peripheral edge of the shutter 65, forms the front side second passage 66. As shown in FIGS. 17 to 19, the front side second communication passage 66 constitutes a communication area between the front side path 3e and the front side first communication passages 41a to 41e. The front side path 3e intermittently communicates with the front side first communication passages 41a to 41e as the drive shaft 3 rotates.

In the compressor configured as described above, as shown in FIGS. 1 to 3, when the drive shaft 3 is rotationally driven by the engine or motor via the electromagnetic clutch or pulley, the fixed swash plate 5 rotates and the piston 7 reciprocates. Therefore, the rear-side head 7a reciprocates between the top dead center and the bottom dead center in the rear cylinder bores 35a to 35e with a stroke corresponding to the inclination angle of the

inclined surfaces

5a and 5b. Further, the front side head 7b reciprocates between the top dead center and the bottom dead center in the front cylinder bores 39a to 39e with a stroke corresponding to the inclination angle of the

inclined surfaces

5a and 5b. The rear side head 7a and the front side head 7b are 180 ° out of phase with each other by the rotation angle of the drive shaft 3.

Here, as the rear side head 7a moves from the top dead center to the bottom dead center, the rear side compression chamber 51 becomes a suction stroke. A low-pressure refrigerant that has passed through an evaporator through a suction port 29a exists in the swash plate chamber 29. The refrigerant in the swash plate chamber 29 passes through the internal suction port 5c of the fixed swash plate 5, the internal suction port 3d of the drive shaft 3, and the internal suction throttle mechanism SV, and as shown in FIG. 5, the second inside of the second spool 57. It exists in the flow path 61, the first internal flow path 59 of the first spool 55, and the first communication window 55e. Then, as shown in FIGS. 1 to 3, at this time, the rear side first communication passages 37a to 37e and the rear side second communication passage 64 communicate with each other, so that the refrigerant is sucked into the rear side compression chamber 51. On the other hand, the rear side first communication passages 37a to 37e and the rear side second communication passage 64 are not communicated with each other, and the rear side head 7a moves from the bottom dead center to the top dead center, so that the rear side compression chamber 51 Is a compression stroke for compressing the sucked refrigerant, and further is a discharge stroke for discharging the compressed refrigerant to the rear side discharge chamber 17b.

Further, as the front head 7b moves from the top dead center to the bottom dead center, the front compression chamber 53 becomes a suction stroke. The refrigerant in the swash plate chamber 29 is also present in the second internal flow path 61 of the second spool 57 and the second communication window 57e. At this time, the front side first communication passages 41a to 41e and the front side second communication passage 66 communicate with each other, so that the refrigerant is sucked into the front side compression chamber 53. On the other hand, the front side first communication passages 41a to 41e and the front side second communication passage 66 are not communicated with each other, and the front side head 7b moves from the bottom dead center to the top dead center, so that the front side compression chamber 53 Is a compression stroke for compressing the sucked refrigerant, and further is a discharge stroke for discharging the compressed refrigerant to the front side discharge chamber 19a. The refrigerant discharged to the rear side discharge chamber 17b and the refrigerant discharged to the front side discharge chamber 19a are discharged from the discharge port 31a to the condenser via the discharge passage 31.

At this time, if the control valve 15 increases the pressure of the control pressure chamber 17a, the first spool 55 moves forward against the urging force of the first spring 2 and the second spool 55, as shown in FIG. 57 also moves forward against the urging force of the second spring 2. At this time, the first spool 55 moves forward independently until the contact surface 55g of the first spool 55 comes into contact with the second spool 57. After the contact surface 55g of the first spool 55 comes into contact with the second spool 57, the first spool 55 and the second spool 57 move forward as one. Therefore, as shown in FIG. 10, the frame body 63 has the contact surface 63h in contact with the front end regulation surface 3g and is located at the front end of the rear side path 3c. Therefore, since the rear side first communication passages 37a to 37e communicate with the rear side second communication passage 64 under a large communication area, a large amount of refrigerant is sucked into the rear side compression chamber 51.

Further, as shown in FIG. 17, the shutter 65 is located at the front end of the front side path 3e with the contact surface 65d in contact with the front end regulation surface 3i. Therefore, since the front side first communication passages 41a to 41e communicate with the front side second communication passage 66 under a large communication area, a large amount of refrigerant is sucked into the front side compression chamber 53.

Therefore, in this compressor, the discharge flow rate discharged from the rear side compression chamber 51 to the rear side discharge chamber 17b is maximized, and the discharge flow rate discharged from the front side compression chamber 53 to the front side discharge chamber 19a is also maximum. It has become. Therefore, the refrigerant having the maximum discharge flow rate is discharged to the condenser. That is, when the discharge flow rate is maximum, the frame body 63 maximizes the communication area between the rear side first communication passages 37a to 37e and the rear side second communication passage 64. Further, the shutter 65 maximizes the communication area between the front side first communication passages 41a to 41e and the front side second communication passage 66 when the discharge flow rate is maximum.

If the control valve 15 slightly lowers the pressure in the control pressure chamber 17a from the state of FIG. 3 in which the control valve 15 increases the pressure in the control pressure chamber 17a, the first spool 55 and the second spool 57 become as shown in FIG. Move backwards. As the pressure in the control pressure chamber 17a decreases, the second spool 57 moves rearward until the contact surface 65e abuts on the rear end regulation surface 3h. On the other hand, the first spool 55 moves rearward together with the second spool 57 as the pressure in the control pressure chamber 17a decreases, and after the contact surface 65e abuts on the rear end regulation surface 3h, the first spool 55 moves. Move backwards alone. Therefore, as shown in FIG. 11, the frame body 63 moves rearward from the state shown in FIG. 10 with the contact surface 63h separated from the front end regulation surface 3g. Therefore, as the rear side first communication passages 37a to 37e overlap the profile 63g, the communication area between the rear side first communication passages 37a to 37e and the rear side second communication passage 64 decreases. Therefore, the amount of the refrigerant sucked into the rear compression chamber 51 is reduced.

On the other hand, the shutter 65 is as shown in FIG. 18 from the state shown in FIG. 17 when the control valve 15 slightly lowers the pressure in the control pressure chamber 17a from the state shown in FIG. 3 in which the control valve 15 increases the pressure in the control pressure chamber 17a. In addition, the contact surface 65d is separated from the front end regulation surface 3i, and the shutter 65 moves rearward. Therefore, as the front side first communication passages 41a to 41e overlap the profile 65c, the communication area between the front side first communication passages 41a to 41e and the front side second communication passage 66 decreases. Therefore, the amount of the refrigerant sucked into the front compression chamber 53 is reduced.

When the pressure in the control pressure chamber 17a further decreases, the shutter 65 moves rearward until the contact surface 65e abuts on the rear end regulation surface 3h, and is located at the rear end of the front side path 3e, as shown in FIG. To do. Therefore, the end timing of communication between the front side first communication passages 41a to 41e and the front side second communication passage 66 is defined by the second inclined portion 653. In this case, a small amount of refrigerant is sucked into the front compression chamber 53.

Therefore, the discharge flow rate discharged from the front side compression chamber 53 to the front side discharge chamber 19a is almost zero. The discharge flow rate discharged from the rear side compression chamber 51 to the rear side discharge chamber 17b depends on the position of the profile 63g with respect to the rear side first communication passages 37a to 37e, and is discharged from the rear side compression chamber 51 to the rear side discharge chamber 17b. It is the flow rate between the maximum and minimum of the discharged flow rate. Therefore, the refrigerant having a predetermined discharge flow rate is discharged to the condenser.

When the control valve 15 further reduces the pressure in the control pressure chamber 17a, the first spool 55 succumbs to the urging force of the first spring 2 and moves further rearward, as shown in FIG. The second spool 57 does not move further rearward because the contact surface 65e is in contact with the rear end regulation surface 3h due to the urging force of the second spring 2. Therefore, as shown in FIG. 12 from the state of FIG. 11, the frame body 63 has the contact surface 63i in contact with the rear end regulation surface 3f and is located at the rear end of the rear side path 3c. Therefore, the end timing of communication between the rear side first communication passages 37a to 37e and the rear side second communication passage 64 is defined by the second inclined portion 633. In this case, a small amount of refrigerant is sucked into the rear compression chamber 51.

Further, as shown in FIG. 19, the shutter 65 is located at the rear end of the front side path 3e with the contact surface 65e in contact with the rear end regulation surface 3h. Therefore, the end timing of communication between the front side first communication passages 41a to 41e and the front side second communication passage 66 is defined by the second inclined portion 653. In this case, a small amount of refrigerant is sucked into the front compression chamber 53.

Therefore, in this compressor, the discharge flow rate discharged from the rear side compression chamber 51 to the rear side discharge chamber 17b and the discharge flow rate discharged from the front side compression chamber 53 to the front side discharge chamber 19a are small, and the condenser has a small discharge flow rate. Discharges only the refrigerant with the minimum discharge flow rate. That is, the frame body 63 minimizes the communication area between the rear side first communication passages 37a to 37e and the rear side second communication passage 64 when the discharge flow rate is the minimum. Further, the shutter 65 minimizes the communication area between the front side first communication passages 41a to 41e and the front side second communication passage 66 when the discharge flow rate is the minimum.

In this way, by setting the minimum discharge flow rate to a small amount instead of zero, the refrigerant is internally circulated inside the compressor, and the lubricity inside the compressor is improved. Further, when the discharge flow rate is increased from the state of the minimum discharge flow rate, the control valve 15 can easily increase the pressure in the control pressure chamber 17a, and the controllability is improved. Further, at the minimum discharge flow rate, the refrigerant flows into the rear side compression chamber 51 and the front side compression chamber 53, so that the refrigerant does not flow into the

respective compression chambers

51 and 53. The amount of pressure drop in the inhalation stroke can be reduced. As a result, the load applied to the piston 7 and the

shoes

49a and 49b in the suction stroke can be reduced. Therefore, the power of the compressor can be reduced. Further, the differential pressure between the

compression chambers

51 and 53 and the swash plate chamber 29 at the minimum discharge flow rate can reduce the inflow of oil contained in the refrigerant from the swash plate chamber 29 into the

compression chambers

51 and 53. Therefore, the oil can be easily retained in the swash plate chamber 29, and the lubricity in the swash plate chamber 29 can be improved.

The operation of the compressor from the maximum discharge flow rate to the minimum discharge flow rate has been explained above. Hereinafter, the operation of the compressor from the state where the discharge flow rate changes from the minimum state to the maximum state will be briefly described.

When the control valve 15 raises the pressure in the control pressure chamber 17a from the state where the discharge flow rate in FIG. 1 is the minimum, the first spool 55 moves to the front side against the urging force of the first spring 2, and the rear side second. The communication area between the single passages 37a to 37e and the rear side second passage 64 begins to increase. During this time, the second spool 57 does not move, and the communication area between the front side first communication passages 41a to 41e and the front side second communication passage 66 is maintained in the minimum state. When the pressure in the control pressure chamber 17a further increases, the contact surface 55g of the first spool 55 comes into contact with the second spool 57 to be in the state shown in FIG. 2, and the first spool 55 and the second spool 57 are integrated. Start moving forward. Therefore, the communication area between the rear side first communication passages 37a to 37e and the rear side second communication passage 64 becomes the communication area according to the profile 63g, and the front side first communication passages 41a to 41e and the front side second communication passage 66. The area of communication with is beginning to increase. Then, when the pressure in the control pressure chamber 17a is further increased, both the first spool 55 and the second spool 57 are in a state of being moved to the frontmost position. Therefore, the communication area between the rear side first communication passages 37a to 37e and the rear side second communication passage 64 and the communication area between the front side first communication passages 41a to 41e and the front side second communication passage 66 are maximized. The discharge flow rate of 3 is in the maximum state.

In this way, in this compressor, the first spool 55 moves in the first axis 3a of the drive shaft 3 in the drive axis O direction, and the second spool 57 drives in the second axis 3b of the drive shaft 3. It moves in the O direction of the axis. Therefore, the compressive load does not directly act on the first and

second spools

55 and 57.

Further, in the frame body 63, when the rear side compression chamber 51 communicates with the rear side first communication passages 37a to 37e during the suction stroke, and when the rear side compression chamber 51 communicates with the rear side first communication passages 37a to 37e Makes the rear side route 3c non-communication with the rear side first communication passages 37a to 37e. As a result, the compressive load acts on the drive shaft 3 through the rear-side first continuous passages 37a to 37e, while the compressive load does not easily act on the first spool 55 and the frame body 63.

The shutter 65 communicates the front side path 3e with the front side first communication passages 41a to 41e when the front side compression chamber 53 is in the suction stroke, and the front side when the front side compression chamber 53 is in the compression stroke or the discharge stroke. The route 3e is not communicated with the front side first communication passages 41a to 41e. As a result, a compressive load acts on the drive shaft 3 through the front-side first passages 41a to 41e, while the compressive load does not easily act on the second spool 57 and the shutter 65.

Therefore, in this compressor, the first spool 55, the second spool 57, the frame body 63, and the shutter 65 can easily move in the drive axis O direction. Further, in this compressor, it is not necessary to make the moving body larger than necessary in order to obtain a large thrust.

Therefore, this compressor can exhibit high controllability and can be miniaturized.

Further, in this compressor, as shown in FIG. 10, since the frame body 63 has the first rim portion 63c, the communication start timing between the rear side first communication passages 37a to 37e and the rear side path 3c is the first. It is defined by the rim portion 63c. Therefore, it is difficult for the high-pressure refrigerant remaining in the rear side compression chamber 51 to return to the rear side path 3c. If the discharge flow rate is reduced and the frame body 63 moves slightly rearward so that the recess 63f communicates with the rear side first communication passages 37a to 37e, the recess 63f realizes an early communication start timing. Can be done.

On the other hand, as shown in FIG. 17, since the shutter 65 does not have the first rim portion 63c like the frame body 63, the communication start timing between the front side first communication passages 41a to 41e and the front side path 3e is set. It is defined by the guide surface 34a. Therefore, the shutter 65 having a simple shape can be adopted, and the processing to the drive shaft 3 is also easy. Further, since the minimum capacity can be realized by the shutter 65, other control can be omitted. Therefore, it is possible to reduce the manufacturing cost of the compressor. Further, since the length of the shutter 65 in the drive axis O direction can be shortened, the mountability on a vehicle or the like can be improved by shortening the axis of the compressor. Further, since the shutter 65 does not have a weak portion such as the first rim portion 63c of the frame body 63, the durability is improved and high controllability can be exhibited. Further, the first rim portion 63c is near the communication start timing and is easily affected by the load due to the high-pressure refrigerant remaining in the compression chamber. In this respect, the shutter 65 is less likely to be affected by the load of the high-pressure refrigerant remaining in the compression chamber like the first rim portion 63c, and the durability is further improved.

Further, in this compressor, as shown in FIG. 17, the communication end timing between the front side first communication passages 41a to 41e and the front side path 3e is defined by the guide surface 34b when the discharge flow rate is maximum. As shown in 19, when the discharge flow rate is the minimum, it is defined by the shutter 65. Therefore, the shape of the shutter 65 is the simplest. Further, since the guide surfaces 34a and 34b can form the front side axle 3e at a position shallow from the outer peripheral surface of the drive shaft 3, the strength against twisting of the drive shaft 3 is improved and high durability can be exhibited. ..

Further, in this compressor, since the front side lid is the shutter 65 and the rear side lid is the frame 63, the frame 63 has a slightly more complicated shape than the shutter 65, but the rear side. The capacity of the compression chamber 51 can be precisely controlled. Further, since this compressor employs the first spool 55 and the second spool 57, the capacity of the rear side compression chamber 51 and the front side compression chamber 53 can be precisely controlled.

Further, in this compressor, since the engaging piece 65a of the shutter 65 is provided on the rear side of the drive shaft 3 in the rotational direction, the drive shaft 3 pushes the engaging piece 65a in the rotational direction to the second spool 57. The engagement with the shutter 65 is strong.

The area where the guide surface 34b on the rear side in the rotation direction of the drive shaft 3 and the rear end surface 65f abut is wider than the area where the guide surface 34a on the front side in the rotation direction of the drive shaft 3 and the front end surface 65g abut. Therefore, it is possible to secure a wide contact area when the drive shaft 3 pushes the shutter 65 in the rotational direction, and the posture of the shutter 65 is stable.

As shown in FIG. 20, the compressor of the second embodiment employs a single spool 58, and the shutter 65 and the frame body 63 are engaged with the spool 58. The spool 58 includes a tubular portion 58a, an end portion 58b that closes the rear end of the tubular portion 58a, and a spring seat portion 58c formed in a cylindrical shape at the front end of the tubular portion 58a. An internal flow path 60, an internal intake 58d that opens the internal flow path 60 to the outside, a first communication window 58e, and a second communication window 58f are formed in the tubular portion 58a. A seal 58g is provided on the outer peripheral surface of the end portion 58b. Other configurations are the same as those of the compressor of the first embodiment.

In the compressor of the second embodiment, the capacity control of the front side compression chamber 53 and the rear side compression chamber 51 can be easily performed. Other effects are the same as those of the compressor of Example 1.

As shown in FIG. 21, the compressor of the third embodiment employs a single spool 58, and the front side shutter 65 and the rear side shutter 65 are engaged with the spool 58. The front side shutter 65 and the rear side shutter 65 have the same structure as the shutter 65 of the first embodiment. Other configurations are the same as those of the compressors of Examples 1 and 2. The profile, which is a part of the outer peripheral edge of the rear shutter 65, forms the rear second passage as well as the front shutter 65. The rear side second communication passage constitutes a communication area between the rear side path 3c and the rear side first communication passages 37a to 37e, similarly to the front side second communication passage 66.

In the compressor of the third embodiment, the capacity control of the front side compression chamber 53 and the rear side compression chamber 51 can be performed more easily. Other effects are the same as those of the compressor of Example 1.

In the above, the present invention has been described in accordance with Examples 1 to 3, but the present invention is not limited to the above Examples 1 to 3, and can be appropriately modified and applied without departing from the spirit thereof. Needless to say.

For example, the piston type compressor of the present invention may be a single-headed piston type compressor using a single-headed piston having a head on only one side.

Further, in the compressors of Examples 1 to 3, when the discharge flow rate is set to the minimum flow rate state, by changing the shape of the profile 63 g, as shown in FIG. 22, the rear side first passages 37a to 37e As shown in FIG. 23, the communication area between the front side first communication passage 64 and the rear side second communication passage 64 is set to substantially zero, and the shape of the profile 65c is changed so that the front side first communication passage 41a to 41e and the front side second communication passage 41a to 41e are changed. The communication area with 66 may be set to substantially zero. That is, when the discharge flow rate is set to the minimum flow rate, the rear side first passages 37a to 37e do not overlap with the rear side second passage 64 but overlap only with the shielding portion 63b due to the rotation of the drive shaft 3. As such, the front-side first passages 41a to 41e may not overlap with the front-side second passage 66, but may overlap only with the shielding portion 65b.

Further, in the compressors of Examples 1 to 3, external control may be performed to control the control pressure by switching ON and OFF of the current from the outside to the control valve 15, and the control may be performed regardless of the current from the outside. Internal control to control the pressure may be performed. Here, in the case of performing external control, if the control valve 15 is configured to increase the valve opening degree by turning off the current to the control valve 15, the valve opening degree is increased when the compressor is stopped. Can be increased, and the control pressure in the control pressure chamber 17a can be lowered. Therefore, since the compressor can be started with the discharge flow rate being the minimum flow rate, the start-up shock can be reduced.

Further, in the compressors of the first to third embodiments, even if the inlet control is performed by changing the flow rate of the refrigerant gas introduced from the rear side discharge chamber 17b to the control pressure chamber 17a through the air supply passage 47a by the control valve 15. good. In this case, the control pressure chamber 17a can be quickly increased in pressure, and the discharge flow rate can be rapidly increased. Here, in the case of performing external control, if the control valve 15 is configured to reduce the valve opening degree by turning off the current to the control valve 15, the valve opening degree is increased when the compressor is stopped. Can be reduced, and the control pressure in the control pressure chamber 17a can be lowered. Therefore, since the compressor can be started with the discharge flow rate being the minimum flow rate, the start-up shock can be reduced.

Further, in the compressors of Examples 1 to 3, instead of the control valve 15, a three-way valve whose opening degree can be adjusted in both the air supply passage 47a and the bleed air passage 47b may be adopted.

The present invention can be used for vehicle air conditioners and the like.

35a-35e, 39a-39e ... Cylinder bores (35a-35e ... Rear cylinder bores, 39a-39e ... Front cylinder bores)
21, 23 ... Cylinder block (21 ... Rear side cylinder block, 23 ... Front side cylinder block)
17b, 19a ... Discharge chamber (17b ... Rear side discharge chamber, 19a ... Front side discharge chamber)
29 ...

Slanted plate chambers

33a, 33b, 19c ... Shaft holes (33a ... Rear side shaft holes, 33b ... Front side shaft holes)
1 ... Housing (17 ... Rear housing, 19 ... Front housing)
3 ... Drive

shafts

51, 53 ... Compression chamber (51 ... Rear side compression chamber, 53 ... Front side compression chamber)
7 ... Piston (7a ... Rear head, 7b ... Front head)
9e, 11e ... Discharge valve (discharge reed valve)
O ... Drive

shaft center

55, 57, 63, 65 ... Moving body (55 ... 1st spool, 57 ... 2nd spool, 63 ... Frame body, 65 ... Shutter)
15 ... Control valves 37a to 37e, 41a to 41e ... 1st passage (37a to 37e ... 1st passage on the rear side, 41a to 41e ... 1st passage on the front side)
3a, 3b ... Axle (3a ... 1st axis, 3b ... 2nd axis)
3c, 3e ... Route (3c ... Rear side route, 3e ... Front side route)
32a, 32b, 34a, 34b ... Guide surface

Claims

A housing having a cylinder block in which a plurality of cylinder bores are formed, a discharge chamber, a swash plate chamber in which a refrigerant is sucked, and a shaft hole are formed.
A drive shaft rotatably supported in the shaft hole,
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 discharge valve that discharges the refrigerant in the compression chamber to the discharge chamber,
A moving body provided on the drive shaft, which rotates integrally with the drive shaft and is movable with respect to the drive shaft in the drive axis direction of the drive shaft based on a control pressure.
A control valve for controlling the control pressure is provided.
A piston type compressor in which the discharge flow rate, which is the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber, changes according to the position of the moving body in the drive axis direction.
The cylinder block is formed with a first communication passage that communicates with the cylinder bore.
The drive shaft includes an axis extending in the direction of the drive axis, communicating with the axis and extending in the radial direction of the drive shaft, and intermittently communicating with the first passage as the drive shaft rotates. Axle is formed
The moving body is arranged in the axial path by engaging with a spool that is movably arranged in the drive axis direction and is arranged in the path, and has a communication area between the path and the first communication passage. Has a changeable lid and
The lid is a piston type compressor, characterized in that the communication area is maximized when the discharge flow rate is maximum, while the communication area is minimized when the discharge flow rate is minimum.
The drive shaft has a guide surface that guides the lid body in the direction of the drive shaft center.
The piston type compressor according to claim 1, wherein the communication start timing between the first communication passage and the path is defined by the guide surface.
The drive shaft has a guide surface that guides the lid body in the direction of the drive shaft center.
The timing of the end of communication between the first communication passage and the path is defined by the guide surface when the discharge flow rate is maximum, and is defined by the lid when the discharge flow rate is minimum. 2. The piston type compressor according to 2.
The cylinder bore is composed of a one-sided cylinder bore arranged on one side in the drive axis direction and a other-side cylinder bore arranged on the other side in the drive axis direction.
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 first communication passage includes a one-sided first passage that communicates with the one-side cylinder bore and a other-side first passage that communicates with the other cylinder bore.
The route includes a one-sided route that communicates with the one-sided first communication passage and the other-side route that communicates with the other-side first communication passage.
The lid is arranged on the one-sided path and has a one-sided lid whose communication area between the one-sided path and the one-sided first communication passage can be changed, and the other side is arranged on the other side. It consists of a lid on the other side whose communication area between the route and the first passage on the other side can be changed.
The other side lid is a shutter in which a part of its own outer peripheral edge forms a second side passage that constitutes a communication area between the other side path and the other side first communication passage. The piston type compressor according to any one of 1 to 3.
The fourth aspect of claim 4, wherein the one-sided lid is a frame body in which the inside of the one-sided second connecting passage forms a communication area between the one-sided path and the one-sided first connecting passage. Piston compressor.
The one-sided lid is a shutter in which a part of its own outer peripheral edge forms a one-sided second connecting passage forming a communication area between the one-sided path and the one-sided first connecting passage. 4. The piston type compressor according to 4.
The piston type compressor according to claim 4 or 6, wherein the shutter has an engaging piece that is engaged with the spool on the rear side in the rotation direction of the drive shaft.
The spool is movable in the drive axis direction with respect to the first spool with which the one-side lid is engaged and the second spool with which the other lid is engaged. The piston type compressor according to any one of claims 4 to 7.
The piston type compressor according to any one of claims 4 to 7, wherein the spool is a single one in which the one-side lid and the other-side lid are engaged.