JP2014118922A - Variable displacement swash plate type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable displacement swash plate type compressor for enabling always smooth movement of a valve element of a check valve.SOLUTION: A check valve 50 includes a valve seat forming body 58 having a valve hole 64 and a valve seat 65, a valve housing 60 fixed to the valve seat forming body 58, a valve element 76 movably stored in the valve housing 60, and a coil spring 81 for giving energizing force to the valve element 76. Between the valve housing 60 and a housing, an annular elastic body is arranged for supporting the valve housing 60 on the housing. In the valve housing 60, a back pressure chamber 82 is formed which is defined by the back part of the valve element 76. The back pressure chamber 82 is communicated with a suction pressure region, and the annular elastic body seals a space between a discharge passage 48 and the back pressure chamber 82.

Description

  The present invention relates to a variable displacement swash plate compressor, and more particularly to a variable displacement swash plate compressor including a check valve installed in a discharge passage of a housing.

As a conventional technique related to the variable displacement swash plate compressor, for example, a check valve disclosed in Patent Document 1 can be cited.
Patent Document 1 describes a variable capacity swash plate compressor used in a vehicle air conditioning system.
In this variable displacement swash plate compressor, the check valve is housed by press fitting into a housing chamber adjacent to the discharge chamber in the rear housing.
The check valve includes a valve housing having a case and a valve member, a valve body, and a spring as an urging member.
The valve body of the check valve is biased in the direction to be closed by the spring, and is opened when the pressure of the discharged refrigerant gas exceeds the biasing force of the spring.

The variable capacity swash plate compressor is operated at the minimum capacity when cooling is not required while the engine is driven.
In the minimum capacity operation, the refrigerant gas is compressed with the minimum discharge capacity, but the check valve is closed to prevent the lubricating oil from flowing out to the external refrigerant circuit.
When the variable capacity swash plate compressor stops operating, the check valve is closed to prevent the backflow of the refrigerant gas from the external refrigerant circuit.
When the variable displacement swash plate compressor is operated with a discharge capacity exceeding the minimum capacity, the check valve is opened and the refrigerant gas is discharged to the external refrigerant circuit.

JP 2000-346241 A

However, in the check valve disclosed in Patent Document 1, since the case is supported in a cantilevered state with respect to the valve member, the case is controlled by the differential pressure between the upstream side and the downstream side of the check valve. There is a risk of tilting relative to the member.
When the case is inclined with respect to the valve member, the valve body is not smoothly moved, and there is a problem that the function as a check valve becomes insufficient.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a variable displacement swash plate compressor that can always smoothly move the valve body of the check valve.

  In order to solve the above problems, the present invention provides a discharge pressure region and a suction pressure region connected to an external refrigerant circuit, obtains a rotational driving force of a drive shaft from an external drive source via a power transmission mechanism, and The discharge capacity can be changed by controlling the pressure of the control pressure chamber that houses the swash plate that rotates integrally with the drive shaft, and a check valve is provided in the discharge passage between the discharge pressure area and the external refrigerant circuit in the housing. In the variable displacement swash plate compressor having the above structure, the check valve has a valve seat forming body having a valve hole and a valve seat, a valve housing fixed to the valve seat forming body, and movable into the valve housing. A valve body that is accommodated in and separated from the valve seat, and a biasing member that applies a biasing force to the valve body in a direction in which the valve body is brought into contact with the valve seat, The valve housing is disposed between the valve housing and the housing. An annular elastic body that supports the housing with respect to the housing, and a back pressure chamber is formed in the valve housing at a back portion of the valve body, and the back pressure chamber is formed in the suction pressure region or the control pressure. The annular elastic body communicates with a chamber and seals between the discharge passage and the back pressure chamber.

In the present invention, the space between the inner wall of the housing forming the discharge passage, the valve housing, and the outer periphery is divided by the annular elastic body. Therefore, when the check valve is opened, the space on the valve hole side and the back pressure chamber are opened. An urging force in the valve opening direction is generated due to the pressure difference between the two.
For this reason, the biasing force in the valve closing direction due to the biasing load of the biasing member at the time of valve opening is relatively reduced, and the biasing force in the valve closing direction due to the biasing load becomes the resistance of the refrigerant gas to be discharged. There is nothing.
Further, even if the valve housing disposed on the valve seat is in a cantilever state, the valve housing is not tilted because the valve housing is supported by the housing via the annular elastic body.
As a result, the valve body of the check valve can always move smoothly, and the function as the check valve can always be maintained.

In the variable displacement swash plate compressor, the valve housing or the valve seat forming body may be supported by the housing on the discharge passage side from the arrangement position of the annular elastic body.
In this case, since the valve housing or the valve seat forming body is supported by the housing on the discharge passage side from the arrangement position of the annular elastic body, it is suitable for a check valve cantilever support structure.

In the variable displacement swash plate compressor, the valve housing may have a peripheral wall portion on which the valve body slides, and the annular elastic body may be disposed on the peripheral wall portion.
In this case, the position corresponding to the movement range of the valve body in the peripheral wall portion is bent by receiving a load from the peripheral wall portion toward the radial center due to the elastic force of the annular elastic body. Airtightness with the surface can be increased.

In the variable displacement swash plate compressor, the valve housing or the housing may include a restricting portion that restricts movement of the annular elastic body.
In this case, a force for moving from the first space side to the second space side acts on the annular elastic body due to the differential pressure between the first space and the second space.
The restriction part provided in the valve housing or the housing can restrict the movement of the annular elastic body from the first space side to the second space side to position the annular elastic body with respect to the peripheral wall part.

  ADVANTAGE OF THE INVENTION According to this invention, the variable capacity | capacitance type swash plate type compressor which can always move the valve body of a non-return valve smoothly can be provided.

1 is a longitudinal sectional view of a variable capacity swash plate compressor according to a first embodiment of the present invention. 1 is a longitudinal sectional view showing a check valve in a closed state in a variable capacity swash plate compressor according to a first embodiment. It is a longitudinal cross-sectional view which shows the check valve of the valve opening state in the variable capacity | capacitance type swash plate type compressor which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows the non-return valve in the variable capacity | capacitance type swash plate type compressor which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the non-return valve in the variable capacity | capacitance type swash plate type compressor which concerns on the modification of 2nd Embodiment.

(First embodiment)
Hereinafter, a variable capacity swash plate compressor as a compressor according to a first embodiment will be described with reference to the drawings.
A variable capacity swash plate compressor (hereinafter referred to as “compressor”) shown in FIG. 1 is a vehicle air-conditioning compressor mounted on a vehicle.
In FIG. 1, the left side is the front and the right side is the rear.

In the compressor shown in FIG. 1, a front housing 12 is joined to the front end of the cylinder block 11, and a rear housing 13 is joined to the rear end of the cylinder block 11.
The cylinder block 11, the front housing 12 and the rear housing 13 are connected to each other by a plurality of through bolts (only one is shown in FIG. 1) 14.
The cylinder block 11 is formed with bolt through holes (not shown) through which the through bolts 14 are inserted, and the front housing 12 is formed with bolt through holes 15.
The rear housing 13 is formed with a bolt hole (not shown) having a female screw, and the male screw portion of the through bolt 14 is screwed into the bolt hole.
The cylinder block 11, the front housing 12, and the rear housing 13 are elements constituting the entire housing of the compressor.

A control pressure chamber 16 is formed in the front housing 12 by joining the front housing 12 and the cylinder block 11.
A shaft hole 17 is formed in the cylinder block 11.
A drive shaft 18 is inserted through the shaft hole 17, and the drive shaft 18 is rotatably supported by the cylinder block 11 via a radial bearing 19.
A shaft hole 20 is formed in the front housing 12, and a drive shaft 18 is inserted through the shaft hole 20.
The drive shaft 18 is rotatably supported by the front housing 12 via a radial bearing 21.

A shaft sealing device 22 is provided in the shaft hole 20, and a lip seal mainly made of a rubber material is used for the shaft sealing device 22.
The shaft seal device 22 has a function of preventing leakage of refrigerant gas and lubricating oil from the shaft hole 20.
The drive shaft 18 is operatively connected to an engine 23 as an external drive source mounted on the vehicle, and receives a power transmission from the engine 23 to obtain a rotational drive force.
The compressor of this embodiment employs a configuration in which the power of the engine 23 is always transmitted to the drive shaft 18 via a power transmission mechanism, and is a clutchless type compressor.
In this embodiment, a clutchless type compressor is used, but a compressor that receives power transmission from an external drive source via a clutch may be used.

A rotation support 24 is fixed to the drive shaft 18, and the rotation support 24 can rotate integrally with the drive shaft 18.
A thrust bearing 25 that receives a load in the axial direction of the drive shaft 18 is interposed between the rotary support 24 and the inner wall surface of the front housing 12.
A swash plate 26 is supported on the rotary support 24.
The swash plate 26 is fitted to the drive shaft 18 at a set inclination angle, is tiltable in the axial direction of the drive shaft 18, and is supported so as to be slidable in the axial direction with respect to the drive shaft 18. Yes.
A hinge mechanism 27 is interposed between the rotary support 24 and the swash plate 26.
The hinge mechanism 27 allows the swash plate 26 to tilt with respect to the rotary support 24 and connects the drive shaft 18 to the swash plate 26 so that torque can be transmitted.

The cylinder block 11 is formed with a plurality of cylinder bores 28 (only one is shown in FIG. 1).
A single-headed piston 29 is accommodated in each cylinder bore 28 so as to be capable of reciprocating.
Each piston 29 is anchored to the outer periphery of the swash plate 26 via a shoe 30.
Between the cylinder block 11 and the rear housing 13, a suction valve forming plate 31, a valve plate 32, a discharge valve forming plate 33 and a retainer forming plate 34 are interposed.

A suction valve forming plate 31, a valve plate 32, a discharge valve forming plate 33 and a retainer forming plate 34 are interposed between the cylinder block 11 and the rear housing 13, so that a suction chamber 35 is provided inside the rear housing 13. The discharge chamber 36 is partitioned.
The suction chamber 35 is formed on the center side of the rear housing 13, and the discharge chamber 36 is formed around the suction chamber 35 in the rear housing 13.
As shown in FIG. 1, a partition wall 37 formed in the rear housing 13 separates the suction chamber 35 and the discharge chamber 36.

The valve plate 32 is formed with a suction port 38 that communicates the suction chamber 35 and the cylinder bore 28, and a discharge port 39 that communicates the discharge chamber 36 and the cylinder bore 28.
The suction port 38 and the discharge port 39 are respectively formed corresponding to the number of cylinder bores 28.
The suction valve forming plate 31 is formed with suction valves 40 that open and close the suction ports 38, and the suction valves 40 are formed corresponding to the number of suction ports 38.
The discharge valve forming plate 33 is formed with discharge valves 41 for opening and closing the discharge ports 39, and the discharge valves 41 are formed corresponding to the number of discharge ports 39.
The suction valve 40 and the discharge valve 41 are lead type on-off valves that can be bent by elastic deformation.
The retainer forming plate 34 includes a plurality of retainers 43 corresponding to the number of discharge valves 41.
The retainer 43 regulates the curvature of the discharge valve 41 and regulates the maximum opening degree of the discharge valve 41.

As shown in FIG. 1, the rear housing 13 is formed with a suction port 45 connected to the external refrigerant circuit 44, and the suction port 45 and the suction chamber 35 are communicated by a suction passage 46.
A discharge port 47 connected to the external refrigerant circuit 44 is formed in the rear housing 13, and the discharge port 47 and the discharge chamber 36 are communicated by a discharge passage 48.
In the discharge passage 48 between the discharge chamber 36 and the discharge port 47, a check valve 50 for preventing the backflow of the refrigerant gas from the discharge port 47 is provided.
The suction chamber 35 and the suction passage 46 correspond to a suction pressure region, and the discharge chamber 36 and the discharge passage 48 correspond to a discharge pressure region.

The refrigerant circuit (refrigeration cycle) of the vehicle air conditioner includes a compressor as a part of the refrigerant circuit, and an external refrigerant circuit 44 connected to the discharge chamber 36 and the suction chamber 35 of the compressor.
For example, carbon dioxide or chlorofluorocarbon is used as the refrigerant.
The external refrigerant circuit 44 includes a heat exchanger 51, an expansion valve 52, and a heat exchanger 53 in order from the discharge chamber 36 side.

By the way, the cylinder block 11 is formed with an extraction passage 54 that allows the control pressure chamber 16 and the suction chamber 35 to communicate with each other.
The extraction passage 54 is a passage for releasing the refrigerant gas in the control pressure chamber 16 to the suction chamber 35.
In the present embodiment, an air supply passage 55 that connects the discharge chamber 36 and the control pressure chamber 16 is formed across the cylinder block 11 and the rear housing 13.
The air supply passage 55 is a passage for supplying refrigerant gas having a discharge pressure to the control pressure chamber 16.
In the rear housing 13, a capacity control valve 56 is disposed in the middle of the air supply passage 55.

By adjusting the opening of the capacity control valve 56, the amount of high-pressure refrigerant gas introduced into the control pressure chamber 16 via the air supply passage 55 and the refrigerant derived from the control pressure chamber 16 via the extraction passage The balance with the derived amount of gas is controlled, and the pressure in the control pressure chamber 16 is determined.
In accordance with the pressure in the control pressure chamber 16, the difference from the pressure in the cylinder bore 28 via the piston 29 is changed, and the inclination angle of the swash plate 26 with respect to the drive shaft 18 is changed.
As a result, the compressor can change the stroke of the piston 29, that is, the discharge capacity of the refrigerant gas.

For example, when the pressure in the control pressure chamber 16 decreases, the inclination angle of the swash plate 26 increases and the discharge capacity of the compressor increases.
A swash plate 26 shown by a two-dot chain line in FIG.
Conversely, when the pressure in the control pressure chamber 16 increases, the inclination angle of the swash plate 26 decreases, and the discharge capacity of the compressor decreases.
A swash plate 26 shown by a solid line in FIG. 1 shows a state of a minimum inclination angle.

By the way, in the compressor of this embodiment, a check valve 50 is provided in the discharge passage 48 between the discharge chamber 36 and the discharge port 47.
Hereinafter, the check valve 50 will be described in detail.
As shown in FIG. 2, in the discharge passage 48, a first storage chamber 57 is formed at a position communicating with the discharge chamber 36 by enlarging a part of the inner diameter of the discharge passage 48.
A cylindrical valve seat forming body 58 is press-fitted into the first storage chamber 57.
In the discharge passage 48, a second storage chamber 59 in which the inner diameter of the passage is set smaller than that of the first storage chamber 57 is formed downstream of the first storage chamber 57 in the refrigerant gas flow direction.
The second housing chamber 59 houses a valve housing 60 having a bottomed cylindrical shape.
The retaining ring 61 fitted to the inner peripheral surface of the first storage chamber 57 restricts the valve seat forming body 58 from coming out of the first storage chamber 57.

The valve seat forming body 58 includes a large-diameter portion 62 that comes into contact with the rear housing 13 in the first housing chamber 57 and a small-diameter portion 63 that is formed concentrically with the large-diameter portion 62 on the second housing chamber 59 side. .
The outer diameter of the small diameter portion 63 is set smaller than the outer diameter of the large diameter portion 62.
The valve seat forming body 58 has a valve hole 64 formed through the center of the large diameter portion 62 and the small diameter portion 63.
An annular end surface formed on the second accommodating chamber 59 side of the small diameter portion 63 is a valve seat 65.
A locking groove 66 is recessed in the outer peripheral surface of the small diameter portion 63.
Incidentally, the valve seat forming body 58 is supported by the rear housing 13 on the discharge passage 48 side from the position where an O-ring 72 described later is disposed.

The valve housing 60 includes a cylindrical peripheral wall portion 67 and a bottom wall portion 68 that covers an end portion of the peripheral wall portion 67.
The outer peripheral diameter of the peripheral wall portion 67 is set smaller than the inner peripheral diameter of the rear housing 13 forming the second storage chamber 59 so that a gap is formed between the valve housing 60 and the rear housing 13 in the second storage chamber 59. ing.
Further, the dimension of the peripheral wall portion 67 is set so that a gap is also formed between the bottom wall portion 68 and the rear housing 13.
Accordingly, a space S is formed in the second storage chamber 59 between the inner wall of the rear housing 13 and the outer periphery of the valve housing 60.

On the inner peripheral surface of the peripheral wall 67 on the opening side (the valve seat forming body 58 side), a locking projection 69 is formed over the entire circumference.
The locking projection 69 is locked in the locking groove 66 of the valve seat forming body 58.
The valve housing 60 is integrally assembled to the valve seat forming body 58 by locking the locking projection 69 to the locking groove 66.
On the opening side (valve seat forming body 58 side) of the peripheral wall portion 67, four communication holes 70 are formed at positions opposed to each other in the radial direction of the peripheral wall portion 67.
One communication hole 70 is positioned to face the discharge passage 48 that connects the second storage chamber 59 and the discharge port 47.

An annular groove 71 is formed on the outer periphery of the peripheral wall portion 67 in the circumferential direction, and an O-ring 72 as an annular elastic body is attached to the annular groove 71.
The O-ring 72 is made of a rubber material and has a circular cross section.
In the present embodiment, the O-ring 72 is mounted between the communication hole 70 and the bottom wall portion 68 that covers the end portion of the peripheral wall portion 67 on the outer peripheral surface of the peripheral wall portion 67.
The position of the peripheral wall portion 67 to which the O-ring 72 is attached is a position corresponding to the movement range of the valve body 76.
In addition to the function of supporting the valve housing 60 on the rear housing 13, the O-ring 72 divides the space S around the valve housing 60 into two.
The space portion S is divided into a first space S1 communicating with the discharge passage 48 and the communication hole 70 by an O-ring 72, and a second space S2 on the bottom wall portion 68 side, and the first space S1 and the second space S2 The airtightness is maintained by the O-ring 72 during the interval.
The first space S1 corresponds to a discharge pressure region.

A cylindrical wall 73 that protrudes toward the valve seat forming body 58 protrudes from the bottom wall portion 68 of the valve housing 60.
A back pressure introduction hole 74 is provided through the bottom wall portion 68, and the back pressure introduction hole 74 communicates with the second space S2.
The second space S <b> 2 communicates with the suction chamber 35 through a suction communication path 75 formed in the rear housing 13.
Therefore, the suction pressure is introduced into the valve housing 60 through the suction communication passage 75, the second space S 2, and the back pressure introduction hole 74.
Therefore, the second space S2 corresponds to a suction pressure region.

A valve body 76 having a covered cylindrical shape is accommodated in the valve housing 60.
The valve body 76 includes a disk-shaped lid portion 77 and a cylindrical portion 78 extending from the peripheral edge of the lid portion 77 toward the bottom wall portion 68 of the valve housing 60.
The valve body 76 is accommodated in the valve housing 60 so that the outer peripheral surface of the cylindrical portion 78 can be slidably contacted with the inner peripheral surface of the peripheral wall portion 67 of the valve housing 60.
The valve body 76 is guided by the peripheral wall portion 67 of the valve housing 60 so as to be movable in a direction in which it is in contact with and away from the valve seat 65.
In the lid portion 77, the surface facing the valve hole 64 and the valve seat 65 constitutes a seal portion 79.
The opposite surface of the seal portion 79 constitutes a pressure receiving portion 80.
When the valve body 76 moves most toward the bottom wall portion 68, the pressure receiving portion 80 comes into contact with the tip of the cylindrical wall 73.
Therefore, the cylindrical wall 73 has a function as a stopper that defines the movement range of the valve body 76.

One end of a coil spring 81 as an urging member is supported around the cylindrical wall 73 in the bottom wall portion 68 of the valve housing 60.
The other end of the coil spring 81 is in contact with the lid portion 77 (pressure receiving portion 80) of the valve body 76.
The valve body 76 is urged in the direction in which the seal portion 79 is seated on the valve seat 65 (valve closing direction) by the urging force generated by the spring load (the urging load) of the coil spring 81.
The urging force due to the spring load of the coil spring 81 is set to be larger than the urging force in the valve opening direction that acts on the valve element 76 when compression with the minimum discharge capacity is performed.

In the state where the seal portion 79 of the valve body 76 is in contact with the valve seat 65, the space defined by the peripheral wall portion 67, the bottom wall portion 68, the cylindrical wall 73 and the valve body 76 of the valve housing 60 is a back pressure. A chamber 82 is formed.
Refrigerant gas at the suction pressure of the suction chamber 35 is introduced into the back pressure chamber 82 via the back pressure introduction hole 74, the second space S 2, and the suction communication passage 75. By introducing the refrigerant gas having the suction pressure, the suction pressure acts on the pressure receiving portion 80 of the valve body 76.
That is, the back pressure chamber 82 is defined in the valve housing 60 at the back portion of the valve body 76 and communicates with the suction pressure region.
A space between the back pressure chamber 82 and the discharge passage 48 is sealed with an O-ring 72.
In the present embodiment, when the pressure receiving portion 80 of the valve body 76 and the cylindrical wall 73 abut, the back pressure introduction hole 74 and the back pressure chamber 82 are blocked.

The check valve 50 according to this embodiment includes a valve seat forming body 58, a valve housing 60, a valve body 76, and a coil spring 81.
The check valve 50 is attached to the valve seat 65 (in the valve closing direction) by the biasing force of the coil spring 81 when the engine 23 is stopped and the compressor is stopped and the air conditioner switch is OFF. It is energized.
Therefore, when the compressor is stopped, the valve body 76 is seated on the valve seat 65 by the urging force in the valve closing direction due to the spring load of the coil spring 81 to close the valve hole 64 (valve closed state).

Next, the operation of the compressor according to this embodiment will be described.
When the engine 23 is driven and the compressor is driven and the air conditioner switch is in the OFF state, the compressor performs compression with the minimum discharge capacity.
At this time, the refrigerant gas is slightly discharged from the discharge chamber 36, but the discharge pressure is small and the pressure difference from the suction chamber 35 is small.
The valve body 76 of the check valve 50 is seated on the valve seat 65 by the urging force of the coil spring 81 in the valve closing direction and closes the valve hole 64.
When compression is performed with the minimum discharge capacity, the refrigerant gas and the lubricating oil circulate through a circulation path formed inside the compressor.
When compression is performed with the minimum discharge capacity, the check valve 50 is closed to prevent the lubricating oil from flowing out to the external refrigerant circuit 44.

Next, when the air conditioner switch is turned on, the solenoid of the capacity control valve 56 is excited, and the opening degree of the air supply passage 55 is adjusted according to the required temperature of the air conditioner.
By adjusting the opening of the supply passage 55, the pressure in the control pressure chamber 16 decreases, the swash plate 26 leaves the minimum inclination angle, and the compressor performs compression with a discharge capacity exceeding the minimum discharge capacity.
The refrigerant gas in the suction chamber 35 is sucked into the cylinder bore 28 by the movement from the top dead center to the bottom dead center of the piston 29, and the refrigerant gas in the cylinder bore 28 is compressed to a predetermined pressure and then discharged into the discharge chamber 36. The

When the refrigerant gas is discharged from the discharge chamber 36 to the discharge passage 48, the discharge pressure of the discharge chamber 36 increases from the minimum discharge capacity.
When the urging force in the valve opening direction acting on the valve body 76 exceeds the urging force of the coil spring 81, the valve body 76 moves away from the valve seat 65.
As shown in FIG. 3, the valve body 76 moves until the tip of the cylindrical portion 78 comes into contact with the bottom wall portion 68.
As a result, the check valve 50 is opened, the valve hole 64 is opened, and the valve hole 64 communicates with the discharge passage 48 on the downstream side of the check valve 50 via the communication hole 70 and the first space S1. The refrigerant gas in the discharge chamber 36 is discharged to the external refrigerant circuit 44 through the check valve 50.

Refrigerant gas from the suction chamber 35 is introduced into the back pressure chamber 82 of the check valve 50 through the back pressure introduction hole 74, the second space S 2, and the suction communication passage 75, and the refrigerant from the suction chamber 35 is introduced. The pressure of the gas acts on the pressure receiving part 80 of the valve body 76.
Therefore, after compression of the check valve 50, when compression is performed with a discharge capacity exceeding the minimum discharge capacity, the pressure of the refrigerant gas in the discharge chamber 36 acts on the seal portion 79 of the valve body 76, and the valve body The pressure of the refrigerant gas from the suction chamber 35 acts on the pressure receiving portion 80 of 76.
Thereafter, when the discharge capacity increases, the pressure of the refrigerant gas in the discharge chamber 36 increases and the suction pressure of the suction chamber 35 decreases. As the discharge capacity increases, the pressure difference between the suction chamber 35 and the discharge chamber 36 increases. Become.

As the pressure difference between the suction chamber 35 and the discharge chamber 36 increases, the biasing force in the direction of opening the valve body 76 increases, and the biasing force of the coil spring 81 causes the pressure difference between the suction chamber 35 and the discharge chamber 36. It becomes relatively small with respect to the urging force in the direction in which the valve body 76 is opened.
As a result, the biasing force of the coil spring 81 of the check valve 50 is relatively increased by the biasing force in the valve opening direction due to the pressure difference between the suction chamber 35 and the discharge chamber 36 as the check valve 50 opens. The flow path resistance due to the urging force of the check valve 50 in the valve closing direction is reduced.

When the air conditioner switch is turned off, the solenoid of the capacity control valve 56 is demagnetized, and the air supply passage 55 is fully opened by the capacity control valve 56.
When the air supply passage 55 is fully opened, the swash plate 26 tilts toward the minimum inclination angle, and the discharge capacity becomes small. Finally, the swash plate 26 becomes the minimum inclination angle and becomes the minimum discharge capacity. The discharge pressure decreases.
When the minimum discharge capacity is reached, the amount of refrigerant gas discharged into the discharge chamber 36 decreases, and the pressure in the suction chamber 35 increases.
The discharge pressure of the refrigerant gas having the minimum discharge capacity acts on the seal portion 79, and the refrigerant gas in the suction chamber 35 is introduced into the back pressure chamber 82. However, the pressure difference between the suction chamber 35 and the discharge chamber 36 is small. Thus, the biasing force in the direction of opening the valve body 76 due to the pressure difference between the suction chamber 35 and the discharge chamber 36 hardly occurs.
For this reason, the valve body 76 is urged and moved so that the seal portion 79 is seated on the valve seat 65 by the urging force of the coil spring 81 and closes the valve hole 64.

According to the compressor of this embodiment, there exist the following effects.
(1) The space between the inner wall of the rear housing 13 that forms the discharge passage 48 and the outer periphery of the valve housing 60 is divided by the O-ring 72. Therefore, when the check valve 50 is opened, An urging force in the valve opening direction due to the differential pressure with the back pressure chamber 82 is generated. For this reason, the biasing force in the valve closing direction due to the spring load of the coil spring 81 at the time of valve opening is relatively reduced, and the biasing force in the valve closing direction due to the spring load becomes the resistance of the refrigerant gas to be discharged. Absent. Even if the valve housing 60 is fixed to the valve seat 65 in a cantilever state, the valve housing 60 is supported by the rear housing 13 via the O-ring 72, and the valve seat forming body 58 is attached to the O-ring 72. The valve housing 60 is not inclined with respect to the valve seat forming body 58 because it is supported by the rear housing 13 on the discharge passage 48 side from the arrangement position. As a result, the valve body 76 of the check valve 50 can always move smoothly, and the function as the check valve 50 can always be maintained.
(2) Since the valve housing 60 bends by receiving a load from the peripheral wall portion 67 toward the radial center due to the elastic force of the O-ring 72, the valve housing 60 has an airtightness between the peripheral wall portion 67 and the sliding surface of the valve body 76. Can be increased. Therefore, the discharged refrigerant gas is not excessively discharged from the clearance at the sliding surface between the peripheral wall portion 67 and the valve body 76 to the back pressure chamber 82, and the reduction of the compression efficiency due to the excessive outflow of the refrigerant gas is prevented. can do.

(3) The O-ring 72 is subjected to a force that moves toward the second space S2 due to the differential pressure between the first space S1 and the second space S2, but the annular groove 71 provided in the peripheral wall portion 67 The movement of 72 from the first space S1 side to the second space S2 side can be restricted. The annular groove 71 can position the O-ring 72 with respect to the peripheral wall portion 67.
(4) The O-ring 72 that divides the space S into the first space S1 and the second space S2 is heated by the high-pressure and high-temperature discharge pressure refrigerant in the first space S1, but is introduced into the second space S2. It is cooled by refrigerant gas with low and low suction pressure. For this reason, the deterioration of the O-ring 72 can be prevented, and the valve housing 60 can be prevented from being inclined with respect to the valve seat forming body 58 due to the deterioration of the O-ring 72.

(5) When the check valve 50 is opened, the lubricating oil is separated from the refrigerant gas having a discharge pressure that collides with the valve body 76 and the valve housing 60. Since the back pressure chamber 82 into which the refrigerant gas of the suction pressure is introduced is formed, the separated lubricating oil is slid between the valve body 76 and the peripheral wall portion 67 due to the differential pressure between the valve hole 64 side and the back pressure chamber 82. Introduced into the clearance of the moving surface. As a result, the sliding surfaces of the valve body 76 and the peripheral wall portion 67 can be lubricated. Further, since the separated excess lubricating oil is introduced into the back pressure chamber 82 through the clearance of the sliding surface between the valve body 76 and the peripheral wall portion 67, the suction chamber is provided via the second space S2 and the suction communication passage 75. 35 can also be introduced.

(Second Embodiment)
Next, a compressor according to the second embodiment will be described.
In the present embodiment, the mounting position of the O-ring with respect to the valve housing and the means for preventing the positional deviation of the O-ring are different from those in the first embodiment.
In this embodiment, the same code | symbol is used for the same structure as 1st Embodiment using the description of 1st Embodiment.

As shown in FIG. 4, the check valve 90 included in the compressor of this embodiment includes a valve seat forming body 58, a valve housing 91, a valve body 76, and a coil spring 81.
The valve housing 91 includes a cylindrical peripheral wall portion 92 and a bottom wall portion 93 that covers an end portion of the peripheral wall portion 92.
The outer peripheral diameter of the peripheral wall portion 92 is set smaller than the inner peripheral diameter of the rear housing 13 forming the second storage chamber 59 so that a gap is formed between the valve housing 60 and the rear housing 13 in the second storage chamber 59. ing.
Further, the dimension of the peripheral wall portion 92 is set so that a gap is also formed between the bottom wall portion 93 and the rear housing 13.
Accordingly, a space S is formed in the second storage chamber 59 between the inner wall of the rear housing 13 and the outer periphery of the valve housing 60.

On the inner peripheral surface of the peripheral wall portion 92 on the opening side (the valve seat forming body 58 side), a locking projection 94 is formed over the entire circumference.
The locking projection 94 is locked in the locking groove 66 of the valve seat forming body 58.
The valve housing 91 is integrally assembled to the valve seat forming body 58 by locking the locking projection 94 to the locking groove 66.
Four communication holes 95 are formed on the opening side (valve seat forming body 58 side) of the peripheral wall portion 92 at positions opposed to each other in the radial direction of the peripheral wall portion 92.
One communication hole 95 is located opposite to the discharge passage 48 connecting the second storage chamber 59 and the discharge port 47.

An O-ring 72 is mounted on the outer periphery of the peripheral wall portion 92 at a position closer to the bottom wall portion 93 than the moving range of the valve body 76.
In this embodiment, the O-ring 72 divides the space S around the valve housing 91 into two parts in addition to the function of supporting the bottom wall 93 side of the valve housing 91 on the rear housing 13.
The space portion S is divided into a first space S1 communicating with the discharge passage and the communication hole 95 by the O-ring 72, and a second space S2 on the bottom wall portion 93 side, and the first space S1 and the second space S2 are separated from each other. Airtightness is maintained by an O-ring 72 during the interval.

A stepped portion 98 is formed on the inner wall of the rear housing 13 that forms the second storage chamber 59.
The stepped portion 98 is formed by setting the inner diameter of the second storage chamber 59 on the suction communication passage 75 side to be small, and an annular stepped surface 99 is formed on the stepped portion 98.
The O-ring 72 is in contact with the stepped surface 99 so that the movement of the valve housing 91 toward the bottom wall portion 93 is restricted and positioned.

According to this embodiment, there exists an effect equivalent to the effect (1) of 1st Embodiment, and (3)-(5).
Furthermore, the O-ring 72 can be positioned with respect to the valve housing 91 by forming the stepped portion 98 on the inner wall of the rear housing 13 without providing an annular groove in the valve housing 91.
Further, since the O-ring 72 is mounted on the outer periphery of the peripheral wall portion 92 at a position closer to the bottom wall portion 93 than the moving range of the valve body 76, the valve housing 91 is deformed in the radial direction by the pressure contact of the O-ring 72. Thus, the smooth movement of the valve body 76 in the valve housing 91 can be achieved.
Furthermore, according to the present embodiment, the effect of preventing the inclination of the valve housing 91 with respect to the valve seat forming body 58 is greater than that of the first embodiment.

(Modification)
Next, a compressor according to a modification of the second embodiment will be described.
In this modification, the mounting position of the O-ring with respect to the valve housing and the means for preventing the positional deviation of the O-ring are different from those of the second embodiment.
In the present embodiment, the same reference numerals are used for the same configurations as those in the first and second embodiments, with the description of the first and second embodiments being used.

In this modification, as shown in FIG. 5, the first step portion 100 and the second step portion 101 are formed on the inner wall of the rear housing 13 that forms the second storage chamber 59.
The largest inner peripheral diameter in the second storage chamber 59 is set larger than the outer peripheral diameter of the O-ring 72 attached to the valve housing 91.
Therefore, in the space where the largest inner peripheral diameter is set in the second storage chamber 59, the valve housing 91 can be inserted without interfering with the rear housing 13 in a state where the O-ring 72 is mounted on the valve housing 91. it can.

The inner peripheral diameter set by forming the first step portion 100 is set slightly smaller than the outer peripheral diameter of the O-ring 72 attached to the valve housing 91.
Therefore, in the space in which the inner peripheral diameter set by forming the first step portion 100 is set, the valve housing 91 is elastically deformed while the O-ring 72 is elastically deformed while the O-ring 72 is mounted on the valve housing 91. Can be inserted.
In the rear housing 13, the entire circumference is between the inner wall where the largest inner peripheral diameter is set in the second storage chamber 59 and the inner wall where the inner peripheral diameter set by the formation of the first step portion 100 is set. A tapered surface 102 is formed over the entire surface.
The formation of the tapered surface 102 facilitates the insertion of the valve housing 91 fitted with the O-ring 72 into the space in which the inner peripheral diameter set by the formation of the first step portion 100 is set.

The inner peripheral diameter that is set to be the smallest by the formation of the second step portion 101 in the second storage chamber 59 is set slightly larger than the outer peripheral diameter of the valve housing 91.
Accordingly, only the valve housing 91 can be inserted while the O-ring 72 is attached to the valve housing 91 in a space in which the inner peripheral diameter set by the formation of the second stepped portion 101 is set. The ring 72 cannot be inserted.
A step surface 103 is formed on the second step portion 101 between the first step portion 100.
The O-ring 72 is in contact with the step surface 103, so that the movement of the valve housing 91 toward the bottom wall portion 93 is restricted and positioned.
According to this modification, the valve housing 91 with the O-ring 72 attached thereto can be easily inserted into the second storage chamber 59.

  The above embodiment shows an embodiment of the present invention, and the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the invention as described below. Is possible.

In the above embodiment (including the modification), the back pressure chamber of the check valve is communicated with the suction chamber that is the suction pressure region through the back pressure introduction hole, the second space, and the suction communication passage. However, the present invention is not limited to this, and the back pressure chamber may be communicated with the suction passage. Alternatively, instead of the suction communication path, a communication path that connects the second space and the control pressure chamber is formed, and the back pressure introduction hole, the second space, and the second space are connected via a communication path that connects the control pressure chamber. Thus, the refrigerant gas in the control pressure chamber may be introduced into the back pressure chamber. In this case, the differential pressure between the valve hole side and the back pressure chamber when the check valve is opened is smaller than when the refrigerant gas in the suction chamber is used. The urging force in the valve closing direction can be relatively reduced.
In the above embodiment (including modifications), the circular elastic body is an O-ring having a circular cross section formed of a rubber-based material. However, the circular elastic body is not limited to the O-ring. For example, a ring member having a rectangular cross section formed of an elastic resin material may be used.
In the above embodiment (including the modified example), the cylindrical wall provided on the bottom wall portion of the valve housing is used as a stopper that restricts the movement of the valve body toward the bottom wall portion side. May be the bottom wall instead of the cylindrical wall.
In the above embodiment (including modifications), the material of the valve housing and the valve body was not specified, but the valve housing and the valve body may be formed of resin, or one of the valve housing and the valve body may be The other may be formed of an aluminum material. When both the valve housing and the valve body are formed of resin, there is a possibility that the clearance of the sliding surface between the peripheral wall portion and the valve body may be increased. Therefore, the valve body in the peripheral wall portion as in the first embodiment. It is preferable to mount the annular elastic body at a position corresponding to the moving range. Further, when one of the valve housing and the valve body is formed of resin and the other is formed of an aluminum material, the clearance of the sliding surface between the peripheral wall portion and the valve body can be set small. For this reason, it is preferable to attach an annular elastic body closer to the bottom wall portion side than the moving range of the valve body in the peripheral wall portion as in the second embodiment. In addition, it does not prevent that both the valve housing and the valve body are formed of an aluminum-based material. In addition, when forming with an aluminum-type material, you may provide a coating layer in the surface.
In the above embodiment (including modifications), the check valve is provided in the rear housing as the housing, but the check valve is not limited to being provided in the rear housing. A check valve may be provided in the discharge passage in the housing other than the rear housing. For example, a check valve may be provided in the muffler housing provided on the outer periphery of the cylinder block for silencing the refrigerant gas. Good.
In the first embodiment, the annular groove is provided in the peripheral wall portion of the valve housing as the restricting portion that restricts the movement of the annular elastic body, but the restricting portion is not limited to the groove. The restricting portion may be a protrusion provided in an annular shape on the peripheral wall portion.

11 Cylinder block 12 Front housing 13 Rear housing 16 Control pressure chamber 18 Drive shaft 23 Engine 26 Swash plate 28 Cylinder bore 29 Piston 35 Suction chamber 36 Discharge chamber 44 External refrigerant circuit 46 Suction passage 48 Discharge passage 50, 90 Check valve 56 Capacity control Valve 57 First housing chamber 58 Valve seat forming body 59 Second housing chamber 60, 91 Valve housing 64 Valve hole 65 Valve seat 67, 92 Peripheral wall portion 68, 93 Bottom wall portion 70, 95 Communication hole 71 An annular groove (as a regulating portion) of)
72 O-ring (as an annular elastic body)
76 Valve body 79 Sealing portion 80 Pressure receiving portion 81 Coil spring (as urging member)
82 Back pressure chamber 97 Inlet communication hole 98 Stepped portion 99, 103 Stepped surface 100 First stepped portion 101 Second stepped portion 102 Tapered surface 103 Stepped surface S Space portion S1 First space S2 Second space

Claims (4)

A discharge pressure region and a suction pressure region are connected to an external refrigerant circuit, obtain a rotational drive force of the drive shaft from an external drive source via a power transmission mechanism, and accommodate a swash plate that rotates integrally with the drive shaft. In the variable displacement swash plate compressor having a check valve in the discharge passage between the discharge pressure region and the external refrigerant circuit in the housing, the discharge capacity can be changed by controlling the pressure in the chamber.
The check valve is
A valve seat forming body having a valve hole and a valve seat;
A valve housing fixed to the valve seat forming body;
A valve body movably accommodated in the valve housing and contacting and separating from the valve seat;
A biasing member that acts on the valve body with a biasing force in a direction in which the valve body is brought into contact with the valve seat;
An annular elastic body disposed between the valve housing and the housing and supporting the valve housing with respect to the housing;
In the valve housing, a back pressure chamber is defined in the back portion of the valve body,
The back pressure chamber communicates with the suction pressure region or the control pressure chamber,
The variable capacity swash plate compressor, wherein the annular elastic body seals between the discharge passage and the back pressure chamber.   2. The variable capacity swash plate compressor according to claim 1, wherein the valve housing or the valve seat forming body is supported by the housing on the discharge passage side from a position where the annular elastic body is disposed. The valve housing has a peripheral wall portion on which the valve body slides,
The variable capacity swash plate compressor according to claim 1, wherein the annular elastic body is disposed on the peripheral wall portion.   The variable capacity swash plate compressor according to any one of claims 1 to 3, wherein the valve housing or the housing includes a restricting portion that restricts movement of the annular elastic body.

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