JP7052964B2 - Variable capacity compressor - Google Patents

Description

The present invention relates to, for example, a variable displacement compressor used in an air conditioner for a vehicle or the like.

As a variable capacitance compressor provided with a capacitance control valve and whose discharge capacitance is controlled by adjusting the pressure in the crank chamber, for example, there is one having the configuration described in Patent Document 1.
In the variable displacement compressor described in Patent Document 1, in the second control valve that adjusts the opening degree of the discharge passage for discharging the refrigerant in the crank chamber to the suction chamber, the valve chamber that receives the pressure in the crank chamber and the pressure supply A partition member for partitioning the back pressure chamber that receives the pressure of the passage is provided. Further, the partition member has a side wall provided so as to surround the valve portion of the spool, and an end wall connected to one end side of the side wall and through which the shaft portion of the spool penetrates. Then, in the second control valve, the end surface on the side opposite to the end wall of the side wall of the partition member comes into contact with the wall surface on the side opposite to the back pressure chamber in the valve chamber, and the valve portion of the spool is on the side opposite to the back pressure chamber in the valve chamber. When it comes into contact with the wall surface of the spool, the pressure receiving portion of the spool comes into contact with the end wall of the partition member.

Japanese Unexamined Patent Publication No. 2016-108960

In the variable capacitance compressor described in Patent Document 1, the configuration of the second control valve is such that the back pressure chamber that receives the pressure of the pressure supply passage and the valve chamber that receives the pressure of the crank chamber are partitioned, and the back pressure A pressure receiving portion is provided in the chamber, and a valve portion is provided in the valve chamber. For this reason, the length of the second control valve along the axial direction of the drive shaft becomes longer, and it is necessary to provide a dedicated accommodation chamber inside the variable capacitance compressor for arranging the second control valve. There is a problem that the length of the variable capacitance compressor along the axial direction of the shaft becomes long.
The present invention has been made focusing on the above-mentioned problems, and an object of the present invention is to provide a variable capacitance compressor capable of suppressing an increase in size in a direction along an axial direction of a drive shaft. do.

In order to solve the above problems, one aspect of the present invention is to change the pressure in the crank chamber by adjusting the opening degree of the first control valve that changes the opening degree of the supply passage that supplies the refrigerant in the discharge chamber to the crank chamber. Then, change the tilt angle of the swash plate to adjust the stroke of the piston. Further, it is a variable displacement compressor that compresses the refrigerant sucked into the cylinder bore from the suction chamber by the piston whose stroke is adjusted and discharges it to the discharge chamber. Further, the variable displacement compressor is arranged in a second control valve that adjusts the opening degree of the discharge passage that communicates the crank chamber and the suction chamber, and a supply passage that is closer to the crank chamber than the first control valve. Moreover, it is provided with a check valve that prevents the movement of the refrigerant from the crank chamber to the first control valve. Further, the variable displacement compressor is provided with a throttle passage for communicating the supply passage between the first control valve and the check valve and the suction chamber. Further, the second control valve has a valve chamber arranged between one end of the drive shaft and the valve plate in the center bore, and a valve body movably housed in the valve chamber along the axial direction of the drive shaft. .. The valve chamber has a first wall surface arranged on one side in the movement direction of the valve body, a second wall surface arranged on the other side in the movement direction of the valve body, and a first wall surface opened in the first wall surface in the supply passage. It has a first port communicating with the area between the control valve and the check valve. In addition to this, the valve chamber has a second port that opens to the second wall surface and communicates with the crank chamber through a part of the discharge passage, and a suction chamber that opens to the second wall surface and communicates with a part of the discharge passage. Has a third port that communicates with. The valve body includes a first pressure receiving surface which is a surface facing the first wall surface and a second pressure receiving surface which is a surface facing the second wall surface, and is between the first control valve and the check valve in the supply passage. It moves between the first and second walls according to the difference between the pressure in the area and the pressure in the crank chamber. When the pressure in the region between the first control valve and the check valve in the supply passage is higher than the pressure in the crank chamber, the valve body abuts on the second wall surface and closes the second port and the third port. This minimizes the opening of the discharge passage. On the other hand, when the pressure in the region between the first control valve and the check valve in the supply passage is lower than the pressure in the crank chamber, the valve body separates from the second wall surface and opens the second port and the third port. This maximizes the opening of the discharge passage.

According to one aspect of the present invention, a valve chamber is formed between one end of the drive shaft and the valve plate in the center bore, and the pressure in the valve chamber is the pressure in the region between the first control valve and the check valve in the supply passage. A valve body that moves according to the difference between the pressure of the crank chamber and the pressure of the crank chamber is housed.
This eliminates the need to provide a dedicated accommodation chamber for arranging the second control valve inside the variable displacement compressor. Therefore, it is possible to provide a variable capacitance compressor capable of suppressing an increase in size in the direction along the axial direction of the drive shaft.

It is sectional drawing which shows the structure of the variable capacity compressor in 1st Embodiment of this invention. It is an enlarged view of the range surrounded by line II in FIG. It is a figure which shows the structure of a valve chamber. FIG. 3 is a sectional view taken along line IV-IV of FIG. It is a figure which shows the structure of a valve body. It is a figure which shows the operation performed by the variable capacity compressor of 1st Embodiment. It is a figure which shows the operation performed by the variable capacity compressor of 1st Embodiment. It is a figure which shows the operation performed by the variable capacity compressor of 1st Embodiment. It is a figure which shows the modification of 1st Embodiment.

The first embodiment of the present invention will be described below with reference to the drawings. In the description of the drawings referred to in the following description, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the plane dimensions, the ratio of the thickness of each layer, etc. are different from the actual ones. Therefore, the specific thickness and dimensions should be determined in consideration of the following explanation. In addition, it goes without saying that the drawings include parts having different dimensional relationships and ratios from each other.

Further, the first embodiment shown below exemplifies a configuration for embodying the technical idea of the present invention, and the technical idea of the present invention describes the materials of the components and their shapes. The structure, arrangement, etc. are not specified to the following. The technical idea of the present invention can be modified in various ways within the technical scope specified by the claims described in the claims. Further, the directions of "left and right" and "up and down" in the following description are merely definitions for convenience of explanation, and do not limit the technical idea of the present invention. Therefore, for example, if the paper surface is rotated 90 degrees, "left and right" and "up and down" are read interchangeably, and if the paper surface is rotated 180 degrees, "left" becomes "right" and "right" becomes "left". Of course it becomes.

(First Embodiment)
Hereinafter, the first embodiment of the present invention will be described with reference to the drawings.
(Constitution)
The configuration of the first embodiment will be described with reference to FIGS. 1 to 5.
(Variable capacity compressor)
As shown in FIG. 1, the variable displacement compressor 1 includes a cylinder block 2, a front housing 3, a valve plate 4, a cylinder head 5, a drive shaft 6, a supply passage 7, and a discharge passage 8. A first control valve 9 and a second control valve 10 are provided. The upper part in FIG. 1 is the upper part in the vertical direction. Similarly, the lower part in FIG. 1 is the lower part in the vertical direction.
In the first embodiment, as an example, a case where the variable capacity compressor 1 is configured as a clutchless variable capacity compressor applied to a vehicle (vehicle-mounted) air conditioner system (air conditioner system) will be described. do.
The cylinder block 2, the front housing 3, the valve plate 4, and the cylinder head 5 are fastened with a through bolt 11 via a gasket (not shown) to form a housing of the variable displacement compressor 1.

(Cylinder block)
A plurality of cylinder bores 21 and one center bore 22 are partitioned in the cylinder block 2.
The plurality of cylinder bores 21 are arranged in an annular shape.
A piston 23 is housed inside the cylinder bore 21.
The center bore 22 is centrally arranged inside the radial inside of the plurality of cylinder bores 21 arranged in an annular shape, and is a space penetrating the cylinder block 2.

(Front housing)
The front housing 3 closes one end side (front side; left side in FIG. 1) of the cylinder block 2. Further, the front housing 3 defines the crank chamber 30 together with the cylinder block 2.
The crank chamber 30 is a space formed by the front housing 3 and the cylinder block 2, and the swash plate 31 is arranged. Further, inside the crank chamber 30, a drive shaft 6 is arranged with the axial direction oriented horizontally.

The swash plate 31 is formed in an annular shape and surrounds the drive shaft 6 in the radial direction.
Further, the swash plate 31 is connected to a rotor 32 fixed to the drive shaft 6 via a link mechanism 33, and rotates together with the drive shaft 6. That is, the rotor 32 is fixed to the drive shaft 6 and rotates integrally with the drive shaft 6.
Further, the swash plate 31 can change the tilt angle (tilt angle) of the drive shaft 6 with respect to the axis.
The link mechanism 33 includes a first arm 33a, a second arm 33b, and a link arm 33c.
The first arm 33a protrudes from the surface of the rotor 32 facing the swash plate 31. The second arm 33b protrudes from the surface of the swash plate 31 facing the rotor 32. One end side of the link arm 33c is rotatably connected to the first arm 33a via the first connecting pin 33d. The other end side of the link arm 33c is rotatably connected to the second arm 33b via the second connecting pin 33e.

Further, the swash plate 31 is formed with a through hole 34 in a shape that allows the swash plate 31 to tilt within the range of the maximum tilt angle and the minimum tilt angle. The through hole 34 is formed with a minimum tilt angle restricting portion (not shown) that comes into contact with the drive shaft 6. When the tilt angle of the swash plate 31 when the swash plate 31 is orthogonal to the drive shaft 6 is set to 0 [°], the minimum tilt angle regulating unit can tilt the swash plate 31 to almost 0 [°]. It is formed as possible. Further, when the tilt angle of the swash plate 31 becomes maximum, the swash plate 31 comes into contact with the rotor 32 to regulate the increase in the tilt angle.

Between the rotor 32 and the swash plate 31, a tilt angle reducing spring 35 that urges the swash plate 31 in a direction to reduce the tilt angle is mounted until the swash plate 31 has the minimum tilt angle. Further, between the swash plate 31 and the spring support member 36, a tilt angle increasing spring 37 that urges the swash plate 31 in a direction of increasing the tilt angle is mounted.
The urging force of the tilt angle increasing spring 37 at the minimum tilt angle is set to be larger than the urging force of the tilt angle decreasing spring 35. Therefore, when the drive shaft 6 is not rotating, the tilt angle of the swash plate 31 is an angle at which the urging force of the tilt angle decreasing spring 35 and the urging force of the tilt angle increasing spring 37 are balanced.

The outer peripheral portion of the swash plate 31 is housed in an inner space formed at an end portion of the piston 23 that protrudes toward the crank chamber 30 side. As a result, the swash plate 31 is configured to interlock with the piston 23 via the pair of shoes 38. Therefore, each piston 23 reciprocates inside the housed cylinder bore 21 due to the rotation of the swash plate 31 accompanying the rotation of the drive shaft 6. That is, the swash plate 31 and the shoe 38 form a conversion mechanism that converts the rotation of the drive shaft 6 into the reciprocating motion of the piston 23. Further, the piston 23 is arranged in each of the plurality of cylinder bores 21 and reciprocates in the axial direction of the drive shaft 6. Further, the swash plate 31 is connected to the rotor 32 and is slidably attached to the drive shaft 6 so as to rotate synchronously with the rotor 32 and have a variable tilt angle with respect to the axis of the drive shaft 6.

(Valve plate)
The valve plate 4 is provided between the cylinder block 2 and the cylinder head 5, and one surface closes the other end side (right side in FIG. 1) of the cylinder block 2 to form each cylinder bore 21. It is blocked.
Further, the valve plate 4 is formed with a discharge hole 41 and a suction hole 42.
The discharge hole 41 and the suction hole 42 communicate with each cylinder bore 21, respectively.
That is, the valve plate 4 is formed with a discharge hole 41 and a suction hole 42 that close the other end side (rear side; right side in FIG. 1) of the cylinder block 2 and communicate with the cylinder bore 21.

(cylinder head)
The cylinder head 5 is provided so as to face the cylinder block 2 with the valve plate 4 interposed therebetween. That is, the cylinder head 5 is provided on the other end side of the cylinder block 2 via the valve plate 4.
Further, in the cylinder head 5, a suction chamber 51 and a discharge chamber 52 are formed so as to be partitioned inside the cylinder head 5. The suction chamber 51 and the discharge chamber 52 are closed by the other surface of the valve plate 4.
The suction chamber 51 is arranged at the center of the cylinder head 5 when viewed from the axial direction of the drive shaft 6.
Further, the suction chamber 51 is connected to the external refrigerant circuit on the suction side of the air conditioner system via the suction port 53 and the suction passage 54, and the low pressure side refrigerant (refrigerant gas) is connected from the external refrigerant circuit on the suction side. Inhale.

Further, the suction chamber 51 communicates with each cylinder bore 21 via a suction hole 42 provided in the valve plate 4 and a suction valve (not shown).
The discharge chamber 52 is arranged at a position that surrounds the suction chamber 51 in an annular shape when viewed from the axial direction of the drive shaft 6. That is, the discharge chamber 52 is arranged in a ring shape on the outside of the suction chamber 51.
Further, the discharge chamber 52 communicates with each cylinder bore 21 via a discharge valve (not shown) and a discharge hole 41 provided in the valve plate 4.

Therefore, the low-pressure side refrigerant sucked into the inside of the suction chamber 51 from the external refrigerant circuit on the suction side is sucked into the cylinder bore 21 accommodating the piston 23 by the reciprocating motion of the piston 23. Then, due to the reciprocating motion of the piston 23, it is compressed to a high pressure and is discharged to the discharge chamber 52. That is, a compression portion for compressing the refrigerant sucked into the suction chamber 51 is formed by the cylinder bore 21 and the piston 23.
Further, the discharge chamber 52 is connected to the external refrigerant circuit on the discharge side of the air conditioner system via the discharge passage 55 and the discharge port 56. Therefore, the refrigerant compressed by the compression unit discharged to the discharge chamber 52 is discharged to the external refrigerant circuit on the discharge side via the discharge passage 55 and the discharge port 56 (refrigerant gas) on the high pressure side. ..

A discharge check valve 57 is arranged between the discharge chamber 52 and the discharge passage 55.
The discharge check valve 57 operates in response to a pressure difference between the discharge chamber 52 (upstream side) and the discharge passage 55 (downstream side). When the pressure difference is smaller than the preset threshold pressure, the discharge check valve 57 shuts off between the discharge chamber 52 and the discharge passage 55, and the refrigerant from the discharge passage 55 to the discharge chamber 52. Block the movement of. On the other hand, when the pressure difference is larger than the threshold pressure, the discharge check valve 57 communicates between the discharge chamber 52 and the discharge passage 55.
Therefore, the high-pressure side refrigerant discharged from the discharge chamber 52 to the discharge side external refrigerant circuit via the discharge passage 55 and the discharge port 56 is blocked from flowing back by the discharge check valve 57.

(Drive shaft)
The drive shaft 6 is arranged inside the front housing 3 and the cylinder block 2, and both ends thereof are rotatably supported by the front housing 3 and the cylinder block 2.
One end of the drive shaft 6 is inserted into the center bore 22. A first slide bearing 61 is arranged between the drive shaft 6 and the center bore 22.
Further, the end surface of the drive shaft 6 on the side facing the valve plate 4 is supported by an annular thrust plate 62.
The contact state (gap) between the drive shaft 6 and the thrust plate 62 is adjusted by the mounting state of the adjusting screw 63 with respect to the cylinder block 2.
The adjusting screw 63 is formed in an annular shape, and a male screw (not shown) is formed on the outer diameter surface. Further, on the surface of the center bore 22 facing the outer diameter surface of the adjusting screw 63, a female screw (not shown) that fits with the male screw formed on the adjusting screw 63 is formed.

Therefore, the adjusting screw 63 is arranged inside the center bore 22 at a position closer to the valve plate 4 than the drive shaft 6 by fitting the male screw to the female screw of the center bore 22.
Further, as shown in FIG. 4, the gap portion of the adjusting screw 63 is formed in a hexagonal shape.
Further, the adjusting screw 63 is formed with a screw side passage 63a for communicating the surface of the adjusting screw 63 facing the drive shaft 6 and the outer diameter surface of the adjusting screw 63.
The screw side passage 63a is formed in a shape in which a part of the surface of the adjusting screw 63 facing the drive shaft 6 is cut off when viewed from the axial direction of the drive shaft 6. Therefore, of the surfaces of the adjusting screw 63 facing the drive shaft 6, the portion of the surface facing the drive shaft 6 that does not form the screw side passage 63a is in contact with the thrust plate 62.

A part of the other end of the drive shaft 6 projects to the outside of the front housing 3 and is connected to a power transmission device (not shown). The power transmission device is connected to a driving force generation source (not shown) such as an engine via a belt. Therefore, when the driving force generated by the driving force generation source is transmitted to the power transmission device, the drive shaft 6 can rotate in synchronization with the rotation of the power transmission device.
A second slide bearing 64 and a shaft sealing device 65 are arranged between the drive shaft 6 and the front housing 3. The second slide bearing 64 rotatably supports the drive shaft 6 from the radial direction. Further, the load in the thrust direction toward the other end side of the drive shaft 6 is supported by the thrust bearing 66 via the rotor 32.

Therefore, the coupling formed by the drive shaft 6 and the rotor 32 is rotatably supported in the radial direction by the first slide bearing 61 and the second slide bearing 64, and is thrust by the thrust plate 62 and the thrust bearing 66. It is rotatably supported in the direction. One end (rear side) of the drive shaft 6 is inserted into the center bore 22 and supported by the cylinder block 2, and the other end (front side) of the drive shaft 6 is supported by the front housing 3.
The shaft sealing device 65 shields the inside of the crank chamber 30 from the external space.
Lubrication oil (not shown) is sealed inside the variable displacement compressor 1, and the oil is agitated when the drive shaft 6 rotates. Further, when the refrigerant moves inside the variable capacity compressor 1, the oil moves together with the refrigerant, and the inside of the variable capacity compressor 1 is lubricated.

(Supply passage)
The supply passage 7 communicates the discharge chamber 52 with the crank chamber 30, and is a passage for supplying the refrigerant of the discharge chamber 52 to the crank chamber 30.
Further, as shown in FIG. 2, the supply passage 7 has a head side supply passage forming portion 71, a plate side supply passage forming portion 72, and a block side supply passage forming portion 73.
The head-side supply passage forming portion 71 is a passage formed in the cylinder head 5 of the supply passage 7, and has a portion of the supply passage 7 for discharging the refrigerant supplied from the discharge chamber 52 and a plate-side supply passage forming portion 71. It communicates with the part 72.
The plate-side supply passage forming portion 72 is a portion of the supply passage 7 formed on the valve plate 4, and connects the head-side supply passage forming portion 71 and the valve chamber 100. The valve plate 4 is formed with a throttle passage 74 in which the plate-side supply passage forming portion 72 and the suction chamber 51 of the supply passage 7 are communicated with each other. A detailed description of the valve chamber 100 will be described later.

The block-side supply passage forming portion 73 is a passage formed in the cylinder block 2 of the supply passages 7, and communicates the plate-side supply passage forming portion 72 with the crank chamber 30. Further, a part of the block side supply passage forming portion 73 communicates with the center bore 22.
Further, a check valve 75 is arranged at the end of the block side supply passage forming portion 73 on the crank chamber 30 side. That is, the throttle passage 74 communicates the supply passage between the first control valve 9 and the check valve 75 with the suction chamber 51.

The check valve 75 operates in response to a pressure difference between the supply passage between the first control valve 9 (upstream side) and the check valve 75 and the crank chamber 30 (downstream side). Then, when the pressure in the supply passage between the first control valve 9 and the check valve 75 becomes lower than the pressure in the crank chamber 30, the check valve 75 moves between the crank chamber 30 and the first control valve 9. It shuts off to prevent the movement of the refrigerant from the crank chamber 30 to the first control valve 9. On the other hand, the check valve 75 moves between the first control valve 9 and the crank chamber 30 when the pressure in the crank chamber 30 becomes lower than the pressure in the supply passage between the first control valve 9 and the check valve 75. Communicate.
That is, the check valve 75 is arranged on the side of the supply passage 7 closer to the crank chamber 30 than the first control valve 9, and prevents the refrigerant from moving from the crank chamber 30 to the first control valve 9.

(Discharge passage)
The discharge passage 8 communicates the crank chamber 30 and the suction chamber 51, and is a passage for discharging the refrigerant of the crank chamber 30 to the suction chamber 51.
Further, the discharge passage 8 has an in-axis passage 81, a block-side discharge passage forming portion 82, and a plate-side discharge passage forming portion 83.
The in-shaft passage 81 is a passage formed inside the drive shaft 6 of the discharge passage 8. That is, a part of the discharge passage 8 is formed inside the drive shaft 6.
One end of the in-shaft passage 81 is open to the side surface of the drive shaft 6 and communicates with the crank chamber 30. The other end of the in-shaft passage 81 is open to the end surface of the drive shaft 6 on the side facing the valve plate 4, communicates with a part of the center bore 22 via the screw side passage 63a, and has the adjusting screw 63. It communicates with a part of the valve chamber 100 through the gap portion. Therefore, the discharge passage 8 also includes a part of the valve chamber 100.

Therefore, the in-shaft passage 81 communicates the crank chamber 30 with the region of the center bore 22 on the valve plate 4 side.
The block-side discharge passage forming portion 82 is a passage formed in the cylinder block 2 of the discharge passage 8, and includes a throttle 82a, an expansion portion 82b, and a discharge portion 82c.
The throttle 82a is formed in a shape in which a part of the surface of the cylinder block 2 facing the valve plate 4 is cut off, and the in-axis passage 81 and the expansion portion 82b are always in communication with each other.

The expansion portion 82b is a passage formed between the cylinder bore 21 and the center bore 22 in the cylinder block 2, and allows the throttle 82a and the discharge portion 82c to communicate with each other.
That is, the expansion portion 82b of the discharge passage 8 is provided at a position closer to the crank chamber 30 than the valve chamber 100, communicates with the third port P3, and has a larger flow path cross-sectional area than the third port P3. .. The third port P3 will be described later.
The discharge portion 82c is a passage formed in the cylinder block 2 at a position farther from the crank chamber 30 than the expansion portion 82b, and communicates the expansion portion 82b with the plate-side discharge passage forming portion 83.

That is, the discharge portion 82c included in the discharge passage 8 is arranged outside the valve chamber 100 in the radial direction (diametrical direction of the drive shaft 6) when viewed from the axial direction of the drive shaft 6, and includes the expansion portion 82b and the suction chamber 51. The flow path cross-sectional area is smaller than that of the expansion portion 82b.
The block-side discharge passage forming portion 82 is formed, for example, by closing the opening of the expansion portion 82b on the crank chamber 30 side of the center bore 22 with a closing member 84.
The plate-side discharge passage forming portion 83 is an opening formed in the valve plate 4 of the discharge passage 8, and allows the discharge portion 82c and the suction chamber 51 to communicate with each other.

(First control valve)
The first control valve 9 communicates the discharge chamber 52 and the crank chamber 30 inside the cylinder head 5, and is arranged in the supply passage 7.
Further, the first control valve 9 can adjust the opening degree (cross-sectional area) of the supply passage 7.
By adjusting the opening degree of the supply passage 7 by the first control valve 9, it is possible to control the amount of the refrigerant introduced from the discharge chamber 52 into the crank chamber 30. Therefore, it is possible to change the stroke of the piston 23 by changing the pressure of the crank chamber 30 and changing the inclination angle of the swash plate 31 by adjusting the opening degree of the supply passage 7 by the first control valve 9. Will be. Then, by changing the stroke of the piston 23, it becomes possible to variably control the discharge capacity (flow rate of the discharged refrigerant) of the variable capacity compressor 1.

That is, the variable capacitance compressor 1 changes the tilt angle of the swash plate 31 by changing the pressure of the crank chamber 30 by adjusting the opening degree of the first control valve 9, and adjusts the stroke of the piston 23. Further, the variable displacement compressor 1 compresses the refrigerant sucked from the suction chamber 51 into the cylinder bore 21 by the piston 23 whose stroke is adjusted, and discharges the refrigerant into the discharge chamber 52.
For example, when the air conditioner is operating, that is, when the variable displacement compressor 1 is operating, the amount of energization of the solenoid built in the first control valve 9 is adjusted based on a signal received from the outside. To. As a result, the discharge capacity of the variable capacitance compressor 1 is variably controlled so that the pressure in the suction chamber 51 becomes a predetermined value. At this time, the first control valve 9 can control the suction pressure to an optimum value according to the external environment.
Further, for example, when the air conditioner is not operating, that is, when the variable displacement compressor 1 is not operating, the supply passage 7 is forcibly opened by not energizing the solenoid built in the first control valve 9. Then, the discharge capacity of the variable displacement compressor 1 is controlled to the minimum.

(Second control valve)
The second control valve 10 is accommodated in a valve chamber 100 arranged between one end of the drive shaft 6 and the valve plate 4 of the center bore 22 and in the valve chamber 100 so as to be movable along the axial direction of the drive shaft 6. It has a valve body 110.
(Valve room)
The valve chamber 100 is formed by a part of the center bore 22 on the side closer to the valve plate 4.
Further, as shown in FIG. 3, the valve chamber 100 is a space of the center bore 22 arranged between one end of the drive shaft 6 and the valve plate 4. One end of the drive shaft 6 is an end on the side facing the valve plate 4.
Further, the valve chamber 100 has a first wall surface 101, a second wall surface 102, a peripheral wall surface 103, a first port P1, a second port P2, and a third port P3, and has an in-axis passage 81. It communicates with the other end of the wall.

Further, a passage is formed between the valve chamber 100 and the in-axis passage 81 by the gap portion of the thrust plate 62 and the gap portion of the adjusting screw 63. The inner diameter of the gap portion of the thrust plate 62 is larger than the inner diameter of the in-axis passage 81. The inner diameter of the gap portion of the adjusting screw 63 is larger than the inner diameter of the gap portion of the thrust plate 62.
The first wall surface 101 is a wall surface of the valve chamber 100 on the side close to the valve plate 4, and constitutes a wall surface arranged on one side (rear side) of the valve body 110 in the moving direction.

In the first embodiment, as an example, a case where the first wall surface 101 is formed by a suction valve forming plate 104 on which a suction valve (not shown) is formed will be described. The suction valve forming plate 104 is a plate-shaped member arranged between the cylinder block 2 and the valve plate 4.
The second wall surface 102 is a wall surface facing the first wall surface 101 in the axial direction of the drive shaft 6, and constitutes a wall surface arranged on the other side (front side) of the valve body 110 in the moving direction.
The first port P1 is an opening that opens to the first wall surface 101 and allows the region between the first control valve 9 and the check valve 75 in the supply passage 7 to communicate with the valve chamber 100. That is, the first port P1 opens to the first wall surface 101 and communicates with the region between the first control valve 9 and the check valve 75 in the supply passage 7.

The second port P2 is an opening that opens in the second wall surface 102 and allows the gap portion of the adjusting screw 63 to communicate with the valve chamber 100. That is, the second port P2 is an opening that communicates with the crank chamber 30 through a part of the discharge passage 8. Further, the second port P2 communicates with the crank chamber 30 via the in-axis passage 81.
Further, as shown in FIG. 4, the second port P2 includes a region of the center bore 22 in which the drive shaft 6 is arranged when viewed from the axial direction of the drive shaft 6.

The third port P3 is an opening that opens to the second wall surface 102 and allows the expansion portion 82b and the valve chamber 100 to communicate with each other. That is, the third port P3 is an opening that communicates with the suction chamber 51 through a part of the discharge passage 8.
Further, as shown in FIG. 4, the third port P3 is arranged outside the region of the center bore 22 where the drive shaft 6 is arranged when viewed from the axial direction of the drive shaft 6.
The peripheral wall surface 103 is a wall surface that connects the first wall surface 101 and the second wall surface 102, and is formed in an annular shape when viewed from the axial direction of the drive shaft 6.

Further, a part of the peripheral wall surface 103 communicates with the block side supply passage forming portion 73.
As described above, the supply passage 7 is formed in the cylinder block 2 by a path different from the valve chamber 100 and the center bore 22, and has a block-side supply passage connecting the crank chamber 30 and the valve chamber 100. In addition to this, the supply passage 7 is formed on the first wall surface 101 and is connected to the plate side supply passage, the plate side supply passage and the first control valve 9 which are connected to the valve chamber 100 via the first port P1. It has a supply passage on the head side.

(Valve body)
The valve body 110 is formed in a disk shape.
The valve chamber 100 can be formed using, for example, a space required for arranging the drive shaft 6 and the thrust plate 62 on the center bore 22 and further attaching the adjusting screw 63 to the cylinder block 2. .. Therefore, the valve chamber 100 is not a space formed as a dedicated accommodation chamber for arranging the second control valve 10 (valve body 110) inside the variable capacity compressor 1, but is in the variable capacity compressor 1. It is a configuration that can be formed using an existing configuration.
As the material for forming the valve body 110, for example, a metal material or a resin material can be used, but in order to reduce the weight of the valve body 110, a resin material is used as the material for forming the valve body 110. Is preferable. When the valve body 110 is made of a resin material, for example, a polyphenylene sulfide resin, a nylon (polyamide) resin, or the like can be used as the resin material.

The thickness direction of the valve body 110 is parallel to the axial direction of the drive shaft 6.
The thickness of the valve body 110 (the length in the left-right direction in FIGS. 1 and 5) is the length along the axial direction of the drive shaft 6 of the valve chamber 100 (in FIGS. 1 and 5, the length in the left-right direction). Less than (length).
Further, as shown in FIG. 5, the valve body 110 includes a large diameter portion 110a and a small diameter portion 110b.
The large diameter portion 110a is arranged closer to the drive shaft 6 than the small diameter portion 110b.
The outer diameter of the large diameter portion 110a is smaller than the inner diameter of the peripheral wall surface 103.
A second recess 112a is formed on the second pressure receiving surface 112, which is a surface of the large diameter portion 110a facing the drive shaft 6.
The bottom surface of the second recess 112a faces the in-axis passage 81 when viewed from the axial direction of the drive shaft 6.
A part of the second pressure receiving surface 112 where the second recess 112a is not formed faces the third port P3 and the diaphragm 82a when viewed from the axial direction of the drive shaft 6.
Therefore, the second pressure receiving surface 112 is a surface facing the second wall surface 102.

The small diameter portion 110b is continuous with the large diameter portion 110a and is arranged closer to the valve plate 4 than the large diameter portion 110a.
The outer diameter of the small diameter portion 110b is smaller than the outer diameter of the large diameter portion 110a. Further, the center of the circle formed by the small diameter portion 110b and the center of the circle formed by the large diameter portion 110a overlap each other when viewed from the axial direction of the drive shaft 6.
A first recess 111a is formed on the first pressure receiving surface 111, which is a surface of the small diameter portion 110b facing the valve plate 4.
The bottom surface of the first recess 111a faces the first port P1 when viewed from the axial direction of the drive shaft 6.
Therefore, the first pressure receiving surface 111 is a surface facing the first wall surface 101.
As described above, the valve body 110 includes a first pressure receiving surface 111 which is a surface facing the first wall surface 101 and a second pressure receiving surface 112 which is a surface facing the second wall surface 102.

(Operation / action)
An example of the operation performed by the variable capacitance compressor 1 of the first embodiment and the operation will be described with reference to FIGS. 1 to 5 and FIGS. 6 to 8.
When the variable capacitance compressor 1 is used, when the rotor 32 and the swash plate 31 rotate due to the rotation of the drive shaft 6, the rotation of the drive shaft 6 is converted into the reciprocating motion of the piston 23 by the swash plate 31 and the shoe 38, and the cylinder bore 21 Compresses the refrigerant supplied to the inside of the.
The stroke of the piston 23 inside the cylinder bore 21 is changed by adjusting the opening degree of the supply passage 7 by the first control valve 9.
Here, in the configuration of the first embodiment, the valve body in which the first pressure receiving surface 111 faces the first wall surface 101 and the second pressure receiving surface 112 faces the second wall surface 102 in the valve chamber 100 provided in the cylinder block 2. It houses 110.

When the first control valve 9 opens the supply passage 7 when controlling the opening degree of the supply passage 7, the valve chamber 100 passes through the first port P1 which is applied to the first pressure receiving surface 111 including the first recess 111a. The pressure of the refrigerant moving to increases.
Therefore, the valve body 110 is pushed by the pressure of the refrigerant that passes through the first port P1 and moves to the valve chamber 100, and the valve body 110 moves in the direction away from the valve plate 4.
As a result, as shown in FIG. 6, the first pressure receiving surface 111 is separated from the first wall surface 101, and the second pressure receiving surface 112 comes into contact with the second wall surface 102. In FIG. 6, the flow of the refrigerant is indicated by a broken line arrow.

When the second pressure receiving surface 112 comes into contact with the second wall surface 102, the valve body 110 closes the third port P3, so that the crank chamber 30 and the suction chamber 51 communicate with each other via the throttle 82a of the discharge passage 8. As a result, the opening degree of the discharge passage 8 is minimized.
That is, in the valve body 110, when the first control valve 9 opens the supply passage 7, the pressure of the refrigerant that passes through the first port P1 and moves to the valve chamber 100 is higher than the pressure of the refrigerant of the second port P2. When it becomes high, it comes into contact with the second wall surface 102. As a result, the in-axis passage 81 and the expansion portion 82b are communicated with each other only by the throttle 82a, and the opening degree of the discharge passage 8 is set to the minimum opening degree larger than zero.

Therefore, when the pressure in the region between the first control valve 9 and the check valve 75 in the supply passage 7 is higher than the pressure in the crank chamber 30, the valve body 110 abuts on the second wall surface 102 and the second port By closing P2 and the third port P3, the opening degree of the discharge passage 8 is minimized.
The throttle 82a included in the discharge passage 8 always communicates the second port P2 and the third port P3.
Further, when the first pressure receiving surface 111 is separated from the first wall surface 101, the refrigerant flows from the valve chamber 100 toward the check valve 75 through the supply passage 7, and the pressure on the inlet side of the check valve 75 rises. Therefore, the check valve 75 opens the supply passage 7, and the refrigerant is supplied to the crank chamber 30.

When the first control valve 9 closes the supply passage 7, immediately after the first control valve 9 closes the supply passage 7, it exists between the first control valve 9 and the check valve 75 in the supply passage 7. The refrigerant is discharged to the suction chamber 51 via the throttle passage 74. In addition to this, the refrigerant present in the crank chamber 30 flows back and presses the check valve 75, and as shown in FIG. 7, the check valve 75 closes the supply passage 7. In FIG. 7, as in FIG. 6, the flow of the refrigerant is indicated by a broken line arrow.
When the check valve 75 closes the supply passage 7, the pressure of the valve chamber 100 becomes equal to the pressure Ps of the suction chamber 51, the pressure of the suction chamber 51 acts on the first pressure receiving surface 111, and the pressure of the suction chamber 51 acts on the second pressure receiving surface 112. The pressure Pc of the crank chamber 30 acts. As a result, the differential pressure (Pc-Ps) between the pressure Pc of the crank chamber 30 and the pressure Ps of the suction chamber 51 acts on the valve body 110.

After the first control valve 9 closes the supply passage 7, when the differential pressure (Pc-Ps) acting on the valve body 110 exceeds a preset threshold pressure, the valve body 110 is moved by the pressure Pc of the crank chamber 30. It is pushed and moved, and as shown in FIG. 8, the second pressure receiving surface 112 is separated from the second wall surface 102. In FIG. 8, as in FIG. 6, the flow of the refrigerant is indicated by a broken line arrow.
Then, when the first pressure receiving surface 111 abuts on the first wall surface 101, the second port P2 and the third port P3 communicate with each other through between the valve body 110 and the second wall surface 102 in the valve chamber 100. , The first port P1 is cut off from the second port P2 and the third port P3. As a result, the opening degree of the discharge passage 8 is maximized.

That is, the valve body 110 has a second wall surface when the pressure of the refrigerant of the first port P1 becomes lower than the pressure of the refrigerant of the second port P2 by closing the supply passage 7 by the first control valve 9. Separate from 102. As a result, the opening degree of the discharge passage 8 is maximized by setting the distance between the valve body 110 and the second wall surface 102 as the maximum value.
Therefore, when the pressure in the region between the first control valve 9 and the check valve 75 in the supply passage 7 is lower than the pressure in the crank chamber 30, the valve body 110 is separated from the second wall surface 102 and the second port. By opening P2 and the third port P3, the opening degree of the discharge passage 8 is maximized.

When pressure is applied to the second pressure receiving surface 112 including the second recess 112a, the valve body 110 moves in a direction away from the drive shaft 6. Further, when pressure is applied to the first pressure receiving surface 111 including the first recess 111a, the valve body 110 moves in a direction away from the valve plate 4.
As described above, the valve body 110 has the first wall surface 101 and the second wall surface according to the difference between the pressure in the region between the first control valve 9 and the check valve 75 in the supply passage 7 and the pressure in the crank chamber 30. It moves between the drive shaft 6 and the drive shaft 6 along the axial direction. Further, the outer peripheral surface of the large diameter portion 110a forms a guide surface when the valve body 110 moves inside the valve chamber 100.
That is, the second control valve 10 is arranged in the discharge passage 8, and adjusts the opening degree of the discharge passage 8 according to the pressure change of the supply passage 7.
The above-mentioned first embodiment is an example of the present invention, and the present invention is not limited to the above-mentioned first embodiment, and even if it is an embodiment other than this embodiment, it relates to the present invention. Various changes can be made according to the design, etc., as long as they do not deviate from the technical idea.

(Effect of the first embodiment)
The variable capacitance compressor 1 of the first embodiment can achieve the effects described below.
(1) The second control valve 10 for adjusting the opening degree of the discharge passage 8 is arranged in the valve chamber 100 between one end of the drive shaft 6 and the valve plate 4 in the center bore, and the drive shaft 6 to the valve chamber 100. Has a valve body 110 movably housed along the axial direction of the. In addition to this, when the pressure in the region between the first control valve 9 and the check valve 75 in the supply passage 7 is higher than the pressure in the crank chamber 30, the valve body 110 abuts on the second wall surface 102. By closing the second port P2 and the third port P3, the opening degree of the discharge passage 8 is minimized. On the other hand, when the pressure in the region between the first control valve 9 and the check valve 75 in the supply passage 7 is lower than the pressure in the crank chamber 30, the valve body 110 is separated from the second wall surface 102 and is second. By opening the port P2 and the third port P3, the opening degree of the discharge passage 8 is maximized.
Therefore, a valve chamber 100 is formed between one end of the drive shaft 6 and the valve plate 4 in the center bore, and the valve body 110 is housed in the valve chamber 100 to control the second control inside the variable displacement compressor 1. It is not necessary to provide a dedicated storage chamber for arranging the valve 10.
As a result, it becomes possible to provide the variable capacitance compressor 1 capable of suppressing the increase in size of the drive shaft 6 in the axial direction.

(2) The supply passage 7 is formed in the cylinder block 2 by a path different from the valve chamber 100 and the center bore 22, and has a block-side supply passage connecting the crank chamber 30 and the valve chamber 100. In addition to this, the supply passage 7 is formed on the first wall surface 101 and is connected to the plate side supply passage, the plate side supply passage and the first control valve 9 which are connected to the valve chamber 100 via the first port P1. It has a supply passage on the head side.
As a result, by processing the cylinder block 2, the valve plate 4, and the cylinder head 5, which are the existing configurations of the variable capacitance compressor 1, the variable displacement compressor 1 can be supplied without adding a new configuration. It becomes possible to form the passage 7.

(3) A part of the discharge passage 8 is formed inside the drive shaft 6.
As a result, it becomes possible to form the discharge passage 8 by using the drive shaft 6 which is an existing configuration in the variable capacitance compressor 1.
(4) The second port P2 includes a region of the center bore 22 in which the drive shaft 6 is arranged when viewed from the axial direction of the drive shaft 6. In addition to this, the third port P3 is arranged outside the region of the center bore 22 where the drive shaft 6 is arranged when viewed from the axial direction of the drive shaft 6.
As a result, the second port P2 and the third port P3 can be easily provided on the second wall surface 102.

(5) The discharge passage 8 is provided at a position closer to the crank chamber 30 than the valve chamber 100, and has an expansion portion 82b that communicates with the third port P3 and has a larger flow path cross section than the third port P3. In addition to this, the discharge passage 8 is arranged outside the valve chamber 100 in the radial direction when viewed from the axial direction of the drive shaft 6 to communicate the expansion portion 82b and the suction chamber 51, and to flow more than the expansion portion 82b. It has a discharge portion 82c having a small road cross section. Further, the discharge portion 82c is provided at a position farther from the crank chamber 30 than the expansion portion 82b.
As a result, even when the third port P3 is provided at a position close to the cylinder bore 21 in the center bore 22, the third port P3 and the suction chamber 51 can be easily connected by providing the expansion portion 82b. It will be possible.
In addition to this, in the expansion portion 82b, the flow velocity of the refrigerant moving from the crank chamber 30 to the suction chamber 51 decreases, and the direction of movement of the refrigerant is reversed, so that the oil contained in the refrigerant flows out to the suction chamber 51. Can be suppressed.

(6) The discharge passage 8 includes a throttle 82a that always communicates the second port P2 and the third port P3.
As a result, regardless of whether the supply passage 7 is open or closed, the oil contained in the refrigerant can be supplied between the center bore 22 and the drive shaft 6, so that the drive shaft can be supplied. It is possible to smoothly perform the lubrication of 6.
Further, when the second pressure receiving surface 112 of the valve body 110 is in contact with the second wall surface 102, the flow of the refrigerant discharged from the crank chamber 30 to the suction chamber 51 acts on the second pressure receiving surface 112. The two ports P2 are wider than the region of the center bore 22 through which the drive shaft 6 is inserted. Therefore, the flow velocity of the refrigerant discharged from the crank chamber 30 to the suction chamber 51 becomes extremely low, and the force with which the flow of the refrigerant presses the second pressure receiving surface 112 becomes small, so that the second pressure receiving surface 112 of the valve body 110 becomes. It is possible to prevent careless separation from the second wall surface 102.

(7) The second port P2 communicates with the crank chamber 30 via an in-shaft passage 81 that opens on the surface of the drive shaft 6 facing the valve body 110.
As a result, the second port P2 and the crank chamber 30 can be easily communicated with each other.
(8) The valve body 110 includes a second recess 112a which is a recess formed in the second pressure receiving surface 112, and the bottom surface of the second recess 112a faces the in-axis passage 81.
As a result, the pressure of the refrigerant that passes through the second port P2 and moves to the valve chamber 100 can be efficiently received by the second recess 112a, and the valve body 110 is efficiently moved away from the drive shaft 6. It becomes possible to move to.

(9) The valve body 110 includes a first recess 111a which is a recess formed on the first pressure receiving surface 111, and the bottom surface of the first recess 111a faces the first port P1.
As a result, the pressure of the refrigerant that passes through the first port P1 and moves to the valve chamber 100 can be efficiently received by the first recess 111a, and the valve body 110 is efficiently moved away from the valve plate 4. It becomes possible to move to.

(Modified example of the first embodiment)
(1) In the first embodiment, a part of the discharge passage 8 is formed by the in-axis passage 81 formed inside the drive shaft 6, but the present invention is not limited to this, and is not limited to this, for example, as shown in FIG. In addition, the drive shaft 6 may be configured not to form the in-axis passage 81.
In this case, a part of the discharge passage 8 is, for example, a gap formed between the drive shaft 6 and the first slide bearing 61 (a gap reserved for rotating the drive shaft 6) and a cylinder block. It may be formed by the block side discharge passage 85 formed in 2.
The block-side discharge passage 85 is a passage that communicates the center bore 22 and the expansion portion 82b.
In FIG. 9, as in FIG. 6, the flow of the refrigerant is indicated by a broken line arrow.

1 ... Variable capacity compressor, 2 ... Cylinder block, 3 ... Front housing, 4 ... Valve plate, 5 ... Cylinder head, 6 ... Drive shaft, 7 ... Supply passage, 8 ... Discharge passage, 9 ... First control valve, 10 ... Second control valve, 11 ... Through bolt, 21 ... Cylinder bore, 22 ... Center bore, 23 ... Piston, 30 ... Crank chamber, 31 ... Thrust plate, 32 ... Rotor, 33 ... Link mechanism, 33a ... First arm, 33b ... Second arm, 33c ... Link arm, 33d ... First connecting pin, 33e ... Second connecting pin, 34 ... Through hole, 35 ... Tilt angle decreasing spring, 36 ... Spring support member, 37 ... Tilt angle increasing spring, 38 ... Shoe, 41 ... Discharge hole, 42 ... Suction hole, 51 ... Suction chamber, 52 ... Discharge chamber, 53 ... Suction port, 54 ... Suction passage, 55 ... Discharge passage, 56 ... Discharge port, 57 ... Discharge check valve, 61 ... One sliding bearing, 62 ... thrust plate, 63 ... adjusting screw, 63a ..., 64 ... second sliding bearing, 65 ... shaft sealing device, 66 ... thrust bearing, 71 ... head side supply passage forming portion, 72 ... plate side supply passage Forming part, 73 ... Block side supply passage forming part, 74 ... Squeezing passage, 75 ... Check valve, 81 ... In-shaft passage, 82 ... Block side discharge passage forming part, 82a ... Squeezing, 82b ... Expansion part, 82c ... Discharge Part, 83 ... Plate side discharge passage forming portion, 84 ... Closing member, 85 ... Block side discharge passage, 100 ... Valve chamber, 101 ... First wall surface, 102 ... Second wall surface, 103 ... Circumferential wall surface, 104 ... Suction valve forming Plate, 110 ... valve body, 110a ... large diameter portion, 110b ... small diameter portion, 111 ... first pressure receiving surface, 111a ... first recess, 112 ... second pressure receiving surface, 112a ... second recess, P1 ... first port, P2 ... 2nd port, P3 ... 3rd port

Claims (8)

A cylinder block in which a plurality of cylinder bores arranged in an annular shape and a center bore arranged inside the plurality of cylinder bores are partitioned.
A valve plate that closes one end of the cylinder block and has a discharge hole and a suction hole that communicate with the cylinder bore.
A front housing that closes the other end of the cylinder block and defines a crank chamber together with the cylinder block.
A cylinder head in which a suction chamber is provided so as to face the cylinder block with the valve plate in between and is arranged in the center, and a discharge chamber is annularly arranged outside the suction chamber. ,
A drive shaft having one end inserted through the center bore and supported by the cylinder block and the other end supported by the front housing.
A piston that is arranged in each of the plurality of cylinder bores and reciprocates in the axial direction of the drive shaft, and
A rotor fixed to the drive shaft and rotating integrally with the drive shaft,
A swash plate that is connected to the rotor and is slidably attached to the drive shaft so that the tilt angle is variable with respect to the axis of the drive shaft by rotating synchronously with the rotor.
A conversion mechanism that converts the rotation of the swash plate into the reciprocating motion of the piston,
A supply passage that communicates the discharge chamber and the crank chamber,
A first control valve arranged in the supply passage and adjusting the opening degree of the supply passage,
A discharge passage that communicates the crank chamber and the suction chamber,
A second control valve arranged in the discharge passage and adjusting the opening degree of the discharge passage,
A check valve located closer to the crank chamber than the first control valve in the supply passage and blocking the movement of the refrigerant from the crank chamber to the first control valve.
A supply passage between the first control valve and the check valve and a throttle passage for communicating the suction chamber are provided, and the pressure in the crank chamber is changed by adjusting the opening degree of the first control valve. The tilt angle of the swash plate is changed to adjust the stroke of the piston, and the piston whose stroke is adjusted further compresses the refrigerant sucked from the suction chamber into the cylinder bore and discharges the refrigerant into the discharge chamber. It ’s a capacity compressor,
The second control valve is housed in a valve chamber of the center bore arranged between one end of the drive shaft and the valve plate, and in the valve chamber so as to be movable along the axial direction of the drive shaft. With a valve body,
The valve chamber is opened to the first wall surface arranged on one side in the moving direction of the valve body, the second wall surface arranged on the other side in the moving direction of the valve body, and the first wall surface. A first port communicating with the area between the first control valve and the check valve in the supply passage, and a first port opening to the second wall surface and communicating with the crank chamber through a part of the discharge passage. It has two ports and a third port that opens into the second wall surface and communicates with the suction chamber through a part of the discharge passage.
The valve body includes a first pressure receiving surface which is a surface facing the first wall surface and a second pressure receiving surface which is a surface facing the second wall surface, and the first control valve in the supply passage. It moves between the first wall surface and the second wall surface according to the difference between the pressure in the region between the check valve and the pressure in the crank chamber.
When the pressure in the region between the first control valve and the check valve in the supply passage is higher than the pressure in the crank chamber, the valve body abuts on the second wall surface and the second port and By closing the third port, the opening of the discharge passage is minimized.
When the pressure in the region between the first control valve and the check valve in the supply passage is lower than the pressure in the crank chamber, the valve body is separated from the second wall surface and the second port and A variable displacement compressor characterized in that the opening degree of the discharge passage is maximized by opening the third port. The supply passage is formed in the cylinder block by a route different from the valve chamber and the center bore, and is formed in the block side supply passage connecting the crank chamber and the valve chamber and the first wall surface. Further, it is characterized by having a plate-side supply passage connected to the valve chamber via the first port, and a head-side supply passage connected to the plate-side supply passage and the first control valve. The variable capacity compressor according to claim 1. The second port includes a region of the center bore in which the drive shaft is arranged when viewed from the axial direction of the drive shaft.
The third port is according to claim 1 or 2, wherein the third port is arranged outside the region where the drive shaft is arranged in the center bore when viewed from the axial direction of the drive shaft. The variable capacitance compressor described. The discharge passage is provided at a position closer to the crank chamber than the valve chamber, communicates with the third port, and has a flow path cross section larger than that of the third port. It has a discharge portion which is arranged outside the valve chamber in the radial direction when viewed from the direction, communicates the expansion portion and the suction chamber, and has a flow path cross section smaller than that of the expansion portion.
The variable capacitance compressor according to any one of claims 1 to 3, wherein the discharge unit is provided at a position farther from the crank chamber than the expansion unit. The variable capacitance compressor according to any one of claims 1 to 4, wherein the discharge passage includes a throttle that connects the second port and the third port. One of claims 1 to 5, wherein the second port communicates with the crank chamber via an in-shaft passage that opens on a surface of the drive shaft facing the valve body. The variable capacitance compressor described in item 1. The second pressure receiving surface faces the drive shaft and is opposed to the drive shaft.
The valve body includes a second recess which is a recess formed on the second pressure receiving surface.
The variable capacitance compressor according to claim 6, wherein the bottom surface of the second recess faces the in-axis passage. The first pressure receiving surface faces the valve plate and
The valve body includes a first recess, which is a recess formed on the first pressure receiving surface.
The variable capacitance compressor according to any one of claims 1 to 7, wherein the bottom surface of the first recess faces the first port.

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