JP2007077863A - Control valve for clutch type variable displacement compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control valve for an clutch type variable displacement compressor capable of improving response of the compressor at the time of start as compared to a conventional compressor. <P>SOLUTION: The control valve 50 for the clutch type variable displacement compressor 10 includes a liquid discharge passage for bleeding maintaining communication between a Pc port 58 and a Ps port 57. Communication and shut off of the liquid discharge passage for bleeding is controlled by movement of a pressure sensitive member constructing a pressure sensitive mechanism 66. When the compressor 10 is started from a stop condition, the pressure sensitive member positions to communicate the liquid discharge passage for bleeding while balance pressure in the compressor 10 at a time of stop of the compressor 10 is maintained, pressure in a suction pressure area drops with accompanying start of the compressor 10, and the pressure sensitive member moves in a direction shutting off the liquid discharge passage for bleeding when pressure in the suction pressure area reaches predetermined pressure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control valve, and more particularly, to a control valve provided in a clutch type variable displacement compressor.

Generally, a variable capacity compressor (hereinafter simply referred to as “compressor”) capable of variably controlling a discharge capacity is known as a compressor used in a vehicle air conditioner or the like.
This type of compressor has a cylinder block in which a cylinder bore is formed, a front housing joined to the front end of the cylinder block, and a rear housing in which a suction chamber and a discharge chamber are formed.
A control pressure chamber is formed inside the front housing, and a drive shaft is rotatably supported on the front housing. The drive shaft is connected to be driven to rotate by an external drive source such as an engine.
Incidentally, in a clutch type compressor, the power of an external drive source is transmitted or cut off via a clutch mechanism.

The control pressure chamber contains a swash plate that can be tilted with respect to the drive shaft. The swash plate rotates in synchronization with the drive shaft, and the piston accommodated in the cylinder bore has a piston stroke corresponding to the tilt state of the swash plate. To reciprocate.
The piston stroke is determined by the pressure difference between the pressure in the control pressure chamber and the suction pressure, but the swash plate approaches a right angle to the axis of the drive shaft as the pressure in the control pressure chamber increases (inclination angle of the swash plate). When the pressure in the control pressure chamber becomes low, the swash plate is inclined so as to approach the axis of the drive shaft (the inclination angle of the swash plate increases).
That is, when the pressure in the control pressure chamber is high and the swash plate tilt angle is small, the piston stroke is small. Conversely, when the control pressure chamber pressure is low and the swash plate tilt angle is large, the piston stroke is small. Is big.
Therefore, the discharge capacity decreases as the piston stroke decreases, and the discharge capacity increases as the stroke increases.

Control of the discharge capacity of the compressor is performed using a control valve.
The control valve controls the valve body based on the urging force of the pressure-sensitive member constituting the pressure-sensitive mechanism and the pressing force by the suction pressure, and the refrigerant that connects the control pressure chamber and the discharge pressure region by controlling the valve body There is a capacity control valve that opens and closes the passage and controls the pressure in the control pressure chamber.
For example, when the cooling load is low and the suction pressure is low, the refrigerant passage connecting the control pressure chamber and the discharge pressure region is communicated, and the pressure in the control pressure chamber is increased to control the discharge capacity to be reduced. .
This type of control valve is disclosed in Patent Document 1, for example.

In a clutch type compressor having a control valve, power from an external drive source is cut off by a clutch mechanism when cooling is not necessary.
When the stop time of the compressor becomes longer, the pressure inside the compressor becomes equal, and the refrigeration circuit including the compressor is gradually cooled by the outside air temperature.
Since the compressor is easy to cool, the refrigerant in the refrigeration circuit easily flows into the compressor. That is, when the refrigeration circuit is cooled and falls below the saturated vapor pressure temperature of the refrigerant, the refrigerant changes to a liquid state, but this liquid refrigerant (hereinafter referred to as “liquid refrigerant”) is likely to be stored in the compressor.
JP 2002-48058 A

In the conventional technology, when the stopped compressor is started via the clutch mechanism from the state where the refrigerant is stored as liquid in the control pressure chamber, the compressor tries to obtain a discharge capacity corresponding to the cooling load. The pressure in the pressure chamber cannot be reduced immediately.
This is because the liquid refrigerant is present in the control pressure chamber, so that the pressure in the control pressure chamber does not decrease depending on the saturated vapor pressure of the refrigerant.
In this state, the pressure in the control pressure chamber does not decrease unless at least the liquid refrigerant stored in the control pressure chamber is vaporized or discharged to the refrigeration circuit.
For this reason, at the time of starting the compressor, liquid refrigerant is stored in the control pressure chamber, so that the pressure in the control pressure chamber does not decrease immediately, and the inclination angle of the swash plate is controlled according to the required discharge capacity. There is a problem that it is not.
This phenomenon causes a reduction in the responsiveness of the compressor at the start-up such as “cooling delay” (also referred to as “return delay”).

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a control valve for a clutch-type variable displacement compressor that can improve the response of the compressor at the time of startup compared to the conventional one. It is in.

  In order to achieve the above object, a first aspect of the present invention provides a Pd port communicating with a discharge pressure region of a compressor, a Pc port communicating with a control pressure chamber of the compressor, and a suction pressure of the compressor. A Ps port communicating with the region, a supply refrigerant passage connecting the Pd port and the Pc port, a valve body for opening and closing the supply refrigerant passage, and the valve according to the pressure in the suction pressure region A control valve of a clutch-type variable displacement compressor having a pressure-sensitive mechanism for controlling a body and a rod for opening and closing the valve body, wherein the extraction liquid discharge passage connects the Pc port and the Ps port The extraction and discharge passage of the extraction liquid discharge passage is controlled by movement of a pressure-sensitive member constituting the pressure-sensitive mechanism, and when the compressor is started from a stopped state, when the compressor is stopped. While the pressure equalization in the compressor is maintained The pressure-sensitive member is positioned so as to communicate with the extraction liquid discharge passage, and the pressure in the suction pressure region decreases with the start of the compressor, and the pressure in the suction pressure region is preset. When the pressure is reached, the pressure-sensitive member moves in a direction to block the extraction liquid discharge passage.

According to the first aspect of the present invention, when the compressor is started from the stopped state, the pressure sensing member has the extraction liquid discharge passage Pc while the pressure equalization in the compressor is maintained when the compressor is stopped. The communication port and the Ps port are positioned to communicate with each other.
The compressor is operated at the minimum discharge capacity at the time of startup, and while the extraction liquid discharge passage is in communication, the liquid refrigerant in the control pressure chamber is drawn through the extraction liquid discharge passage by the start of the compressor. Is discharged.
As the liquid refrigerant in the control pressure chamber is discharged, the pressure in the control pressure chamber decreases, and the swash plate is controlled to increase the discharge capacity.
Further, when the pressure in the suction pressure region decreases with the start of the compressor and the pressure in the suction pressure region reaches a preset pressure, the pressure sensitive member moves in a direction to block the extraction liquid discharge passage. Moving.
Therefore, even when liquid refrigerant is stored in the control pressure chamber at the time of starting the compressor, the liquid refrigerant is discharged to the suction pressure region after the start of the compressor, thereby reducing the pressure in the control pressure chamber more than before. Can be promoted.
Note that the larger the extraction fluid discharge passage, the better the returnability because the liquid refrigerant can be discharged from the control pressure chamber to the suction pressure region in a short time. When the discharge passage communicates the control pressure chamber and the suction pressure region, a large amount of refrigerant circulates from the control pressure chamber to the suction pressure region.
The refrigerant circulation in the compressor is necessary for lubrication of the sliding member inside the compressor, but does not contribute to the cooling due to the circulation of the refrigerant circuit, and thus the cooling capacity is reduced.
Blocking the extraction liquid discharge passage after the return of the compressor can prevent the cooling capacity from being lowered.

  According to a second aspect of the present invention, in the control valve of the clutch type variable displacement compressor according to the first aspect, the extraction liquid discharge passage is a recess formed in a side surface of the rod.

  According to the second aspect of the present invention, since the extraction liquid discharge passage only needs to form a recess on the side surface of the rod, the process of forming the recess becomes relatively simple.

  According to a third aspect of the present invention, in the control valve of the clutch type variable displacement compressor according to the first aspect, the extraction liquid discharge passage is a through-hole penetrating the inside of the rod.

According to the third aspect of the present invention, for example, even if the Pc port and the Ps port do not adjoin each other in the control valve, the extraction liquid discharge passage is formed by the through-hole penetrating the inside of the rod. Can do.
For this reason, the freedom degree of design of a control valve improves.

  According to the present invention, it is possible to provide a control valve for a clutch type variable displacement compressor that can improve the responsiveness of the compressor at the time of start-up as compared with the prior art.

(First embodiment)
Hereinafter, a control valve of a clutch variable displacement compressor (hereinafter simply referred to as “compressor”) according to a first embodiment will be described with reference to the drawings.
The compressor 10 shown in FIG. 1 includes a housing 11 that is an outer shell of the compressor 10. The housing 11 includes a cylinder block 12 having a plurality of cylinder bores 12 a and a cylinder block 12. The front housing 13 is joined to the front side, and the rear housing 14 is joined to the rear side of the cylinder block 12.
The front housing 13, the cylinder block 12, and the rear housing 14 are integrally fixed by fastening the through bolts 15 passed from the front housing 13 to the rear housing 14 in the front-rear direction, and the housing 11 is formed.

A control pressure chamber 16 is formed in the front housing 13 with the rear side closed by the cylinder block 12.
A rotatable drive shaft 17 is provided so as to penetrate the control pressure chamber 16 in the vicinity of the center. The drive shaft 17 is provided with a radial bearing 18 provided in the front housing 13 and another provided in the cylinder block 12. Are supported by a radial bearing 19.
A shaft sealing mechanism 20 is provided in front of the radial bearing 18 that supports the front portion of the drive shaft 17 so as to be in sliding contact with the circumferential surface of the drive shaft 17.
The shaft sealing mechanism 20 includes a lip seal member and the like, and prevents the refrigerant in the control pressure chamber 16 from leaking from between the front housing 13 and the drive shaft 17.

In this embodiment, the front end of the drive shaft 17 is connected to an external drive source via a clutch mechanism (not shown).
The clutch mechanism can transmit power from the external drive source to the drive shaft 17 or shut off.
A lug plate 21 is fixed to the drive shaft 17 in the control pressure chamber 16 so as to be integrally rotatable.
A swash plate 23 constituting a capacity changing mechanism 22 is supported on the drive shaft 17 behind the lug plate 21 so as to be slidable and tiltable in the axial direction of the drive shaft 17.
A hinge mechanism 24 is interposed between the swash plate 23 and the lug plate 21, and the swash plate 23 is connected to the lug plate 21 and the drive shaft 17 through the hinge mechanism 24 so as to be capable of synchronous rotation and tilting. ing.

A coil spring 25 is wound between the lug plate 21 and the swash plate 23 in the drive shaft 17, and a slidable cylindrical body 26 urged rearward by the pressing of the coil spring 25 is a drive shaft. 17 is inserted.
The swash plate 23 is always pressed backward, that is, in a direction in which the inclination angle of the swash plate 23 decreases, by the cylindrical body 26 that receives the urging force of the coil spring 25.
Here, the inclination angle of the swash plate 23 means an angle formed by a surface orthogonal to the drive shaft 17 and a surface of the swash plate 22.
A stopper portion 23a projects from the front portion of the swash plate 23, and the maximum inclined position of the swash plate 23 is regulated by the stopper portion 23a coming into contact with the lug plate 21, as shown in FIG. It has become. A retaining ring 27 is attached to the drive shaft 17 behind the swash plate 23, and a coil spring 28 is wound around the drive shaft 17 in front of the retaining ring 27.
The minimum inclination position of the swash plate 23 is regulated by contacting the front portion of the coil spring 28.

In each cylinder bore 12 a of the cylinder block 12, a single-headed piston 29 is accommodated so as to be able to reciprocate, and the necks of these pistons 29 are anchored to the outer periphery of the swash plate 23 via shoes 30.
When the swash plate 23 is rotationally moved with the rotation of the drive shaft 17, each piston 29 is reciprocated through the shoe 30.
On the other hand, as shown in FIG. 1, the front side of the rear housing 14 and the rear side of the cylinder block 12 are joined together. , 34 and a retainer 35 are interposed.
The rear housing 14 is a rear housing joined to the cylinder block 12. A suction chamber 38 is formed at the center of the rear housing 14, and the suction chamber 38 is provided in the valve plate 32. The suction port 36 communicates with the compression chamber 31 in the cylinder bore 12a.
Further, a discharge chamber 39 is formed on the outer peripheral side of the rear housing 14, and the discharge chamber 39 and the suction chamber 38 are separated from each other by a partition wall 14a.

The valve plate 32 is for forming the compression chamber 31 together with the piston 29 in the cylinder bore 12a, and has a suction port 36 communicating with the suction chamber 14a on the rear housing 14 side and a discharge port 37 communicating with the discharge chamber 39. is doing.
The valve body forming plate 33 is a suction valve forming plate that forms a suction valve (not shown) interposed between the compression chamber 31 and the suction chamber 38, while the valve body forming plate 34 is a discharge port 37. And a discharge valve forming plate for forming a lead type discharge valve 34 a interposed between the discharge chamber 39 and the discharge chamber 39.
The retainer 35 is for regulating the maximum opening of the discharge valve 34a.

By the way, the refrigerant in the suction chamber 38 is sucked into the compression chamber 31 through the suction port 36 and the suction valve by the movement of the piston 29 from the top dead center position to the bottom dead center position.
The refrigerant sucked into the compression chamber 31 is compressed to a predetermined pressure by moving from the bottom dead center position of the piston 29 to the top dead center position, and is discharged to the discharge chamber 39 through the discharge port 37 and the discharge valve 34a. The
The inclination angle of the swash plate 23 is determined based on a mutual balance with each moment such as a moment of rotational motion caused by the centrifugal force of the swash plate 23, a moment caused by the reciprocating inertia force of the piston 29, and a moment caused by the refrigerant pressure.
The moment due to the pressure of the refrigerant is a moment generated based on the correlation between the pressure in the compression chamber 31 and the pressure in the control pressure chamber 16 acting on the back surface of the piston 29, and corresponds to the pressure fluctuation in the control pressure chamber 16. This acts in an increasing or decreasing direction of the inclination angle.

Next, the external refrigerant circuit 42 will be described.
In this embodiment, the compressor 10 and the external refrigerant circuit 42 constitute a refrigeration circuit in which the refrigerant circulates.
The suction chamber 38 is connected to an external refrigerant circuit 42 via a suction passage 40 formed in the rear housing 14, and the refrigerant from the external refrigerant circuit 42 passes through the suction passage 40 and is supplied to the suction chamber 38.
In this embodiment, the suction chamber 38 and the suction passage 40 are included in the suction pressure region.
The discharge chamber 39 is connected to an external refrigerant circuit 42 through a discharge passage 41 formed in the rear housing 14, and the refrigerant in the discharge chamber 39 can be supplied to the external refrigerant circuit 42 through the discharge passage 41. it can.
The external refrigerant circuit 42 includes a heat exchanger 43 that takes heat from the refrigerant, an expansion valve 44, and a heat exchanger 45 that transfers heat to the refrigerant.

  The expansion valve 44 is a temperature-sensing automatic expansion valve that controls the flow rate of the refrigerant in response to a change in the refrigerant temperature on the outlet side of the heat exchanger 45.

  In the compressor 10 of this embodiment, the pressure in the control pressure chamber 16 is adjusted using a control valve 50 described below, and the moment due to the refrigerant pressure is appropriately changed, so that the inclination angle of the swash plate 23 is minimized. An arbitrary angle between the inclination angle and the maximum inclination angle can be set.

As shown in FIG. 1, a control valve 50 for supplying air that supplies refrigerant in the discharge pressure region to the control pressure chamber 16 is provided in the rear housing 14.
As shown in FIG. 2, the control valve 50 is mainly formed of a valve housing 51 having a substantially cylindrical shape and having a plurality of chambers, a valve body 63 that opens and closes a passage in the control valve 50, and a suction chamber 38. It has a pressure-sensitive mechanism 66 that operates according to a change in pressure, and a rod 70 as a reciprocating body controlled by the pressure-sensitive mechanism 66.

As shown in FIG. 2, a pressure sensitive chamber 52, a communication chamber 53, and a valve chamber 54 are formed in the valve housing 51.
The pressure sensing chamber 52 is located at one end of the valve housing 51, the valve chamber 54 is located at the other end, and the communication chamber 53 is located between the pressure sensing chamber 52 and the valve chamber 54.
A separation member 55 having a shaft hole 55 a is mounted between the pressure sensing chamber 52 and the communication chamber 53, and the pressure sensing chamber 52 and the communication chamber 53 are isolated by the separation member 55.
The communication chamber 53 and the valve chamber 54 are isolated by a partition wall 51a which is a part of the valve housing 51, and a valve hole 56 is formed in the partition wall 51a.

The valve housing 51 is formed with a Ps port 57 that communicates with the pressure sensing chamber 52, a Pc port 58 that communicates with the communication chamber 53, and a Pd port 59 that communicates with the valve chamber 54.
As shown in FIG. 1, the Ps port 57 and the suction chamber 38 are connected by a passage 60, the Pc port and the control pressure chamber 16 are connected by a passage 61, and the Pd port 59 and the discharge chamber 39 are connected by a passage 62. Has been contacted by.

In the valve housing 51, an air supply refrigerant passage extending from the valve chamber 54 to the communication chamber 53 through the valve hole 56 is set, and the air supply refrigerant passage connects the Pd port 59 and the Pc port 58.
That is, the air supply refrigerant passage set between the Pd port 59 and the Pc port 58 includes the valve chamber 54, the communication chamber 53, and the valve hole 56.
The valve chamber 54 accommodates a spherical valve body 63 and a coil spring 64 as an urging member.
The valve body 63 has a diameter set larger than the diameter of the valve hole 56, and can block the valve hole 56.
The valve body 63 is always biased in the direction of closing the valve hole 56 by receiving the elastic force of the coil spring 64.

A pressure sensitive mechanism 66 is accommodated in the pressure sensitive chamber 52.
The pressure sensitive mechanism 66 includes a bellows 67 as a pressure sensitive member that partitions the pressure sensitive chamber 52 into a variable pressure chamber 52a and a constant pressure chamber 52b.
The fixed end of the bellows 67 is fixed to an end wall member 69 that covers the end of the valve housing 51.
The constant pressure chamber 52b in the bellows 63 is in a hermetically sealed state and is maintained at a predetermined constant pressure.
The variable pressure chamber 52a is set around the constant pressure chamber 52b, and the pressure in the variable pressure chamber 52a varies according to the variation in the pressure in the suction chamber 38. Therefore, when the pressure in the variable pressure chamber 52a is lower than the pressure in the constant pressure chamber 52b The bellows 67 expands, and conversely, if it is high, the bellows 67 contracts.
That is, a force is generated to move (expand / contract) the bellows 67 when there is a differential pressure between the constant pressure chamber 52b and the variable pressure chamber 52a.

A movable member 68 is fixed to the movable end of the bellows 67, and the movable member 68 is fixed to the end of the rod 70.
The rod 70 of this embodiment has a diameter corresponding to the shaft hole 55a. The length of the rod 70 is the valve element 63 against the urging force of the coil spring 64 when the bellows 67 is extended to the maximum. Is set to a length that can be separated from the valve hole 56.
A concave portion 70a is formed in the middle portion of the rod 70 along the length direction of the rod 70. For example, as shown in FIG. 3, the concave portion 70a is connected to the pressure sensitive chamber 52 when the bellows 67 contracts most. This is a recess for communicating the communication chamber 53.
That is, an extraction liquid discharge passage from the communication chamber 53 to the pressure sensing chamber 52 through the recess 70 a is set in the valve housing 51, and the extraction liquid discharge passage connects the Pc port 58 and the Ps port 57.
This extraction liquid discharge passage is mainly intended to discharge the liquid refrigerant stored in the control pressure chamber 16 to the suction chamber 38 mainly when the compressor 10 is started.
The extraction liquid discharge passage of this embodiment only forms the recess 70a on the side surface of the rod 70, so that the process of forming the recess 70a is relatively simple.
Incidentally, the cylinder block 12 is formed with a bleed passage 46 with a fixed throttle, and the control pressure chamber 16 and the suction chamber 38 are communicated with each other.
The bleed passage 46 with a fixed throttle is a passage that is provided with a fixed throttle in the middle of the passage to release the control pressure chamber 16.

Next, the operation of the control valve 50 according to this embodiment will be described.
For example, when the stop time of the compressor 10 is long, the pressure inside the compressor 10 is equalized, and the refrigeration circuit including the compressor 10 is gradually cooled by the outside air temperature.
Since the compressor 10 is easy to cool, the refrigerant in the refrigeration circuit easily flows into the compressor 10.
That is, when the refrigeration circuit is cooled and falls below the saturated vapor pressure temperature of the refrigerant, the refrigerant changes to a liquid state, but this liquid refrigerant is easily stored in the compressor 10.
When the compressor 10 is stopped for a long time, the pressure equalization in the refrigeration circuit is much higher than the pressure in the suction pressure region when the compressor 10 is driven.
That is, the pressure in the variable pressure chamber 52 b is much higher than the pressure in the constant pressure chamber 52 a in the pressure sensitive chamber 52.

Therefore, in this state, as shown in FIG. 3, the bellows 67 is in the most contracted state, the concave portion 70 a of the rod 70 communicates the communication chamber 53 and the pressure sensing chamber 52, and the valve body 63 further includes the valve hole 56 is in a closed state.
This state indicates that in the control valve 50, the supply refrigerant passage is blocked while the extraction liquid discharge passage is communicated.

Next, when the necessity of cooling arises, power is transmitted to the compressor 10 by a clutch mechanism, and the compressor 10 in a stopped state is started.
At the start of startup, the swash plate 23 of the compressor 10 is in a state where the inclination angle is the smallest, that is, the compressor 10 is operated with the minimum capacity.
In the minimum capacity operation at the start of starting the compressor 10, the piston 29 reciprocates in the cylinder bore 12a with the minimum stroke.
In a state where the extraction liquid discharge passage communicates, the reciprocating motion of the piston 29 causes the refrigerant to circulate from the control pressure chamber 16 to the compression chamber 31 via the suction chamber 38.
At this time, liquid refrigerant is present in the control pressure chamber 16, but since the extraction liquid discharge passage is communicated, the liquid refrigerant in the control pressure chamber 16 passes through the passage 60, as the piston 29 reciprocates. 61 and the control valve 50 are all discharged into the suction chamber 38.

As all of the liquid refrigerant in the control pressure chamber 16 is discharged to the suction chamber 38, the pressure in the control pressure chamber 16 can be reduced below the saturated vapor pressure of the refrigerant.
As the pressure in the control pressure chamber 16 decreases, the inclination angle of the swash plate 23 increases, and the discharge capacity of the compressor 10 increases.
As the discharge capacity of the compressor 10 increases, the pressure in the variable pressure chamber 52a in the control valve 50 further decreases, and the bellows 67 extends as the pressure in the variable pressure chamber 52a decreases.
For example, during maximum capacity operation with a large cooling load, as shown in FIG. 2, the bellows 67 extends so that the rod 70 approaches the valve body 63 so as not to contact the valve body 63. The liquid discharge passage is blocked.
Incidentally, blow-by gas from the clearance between the piston 29 and the cylinder bore 12a always flows into the control pressure chamber 16 and tries to increase the pressure in the control pressure chamber 16.
At this time, the extraction liquid discharge passage in the control valve 50 is blocked by the rod 70, and in order to maintain the maximum capacity operation, the control pressure chamber 17 is released through the extraction passage 46 of the fixed throttle. Do.

In order to improve the efficiency during operation, it is desirable to block communication between the communication chamber 53 and the variable pressure chamber 52a when the liquid refrigerant in the control pressure chamber 16 is discharged. The pressure in the suction chamber 38 is gradually decreased from the saturated vapor pressure when the liquid refrigerant is discharged out of the compressor 10 and the inclination angle of the swash plate 23 is increased. The set pressure is desirable. That is, when the pressure in the suction chamber 38 reaches a preset pressure, the bellows 67 is extended, so that the rod 70 moves and the extraction liquid discharge passage is blocked.
However, since the saturated vapor pressure is a value that varies with temperature, it is difficult to determine uniquely. In the present embodiment, when chlorofluorocarbon (HFC-134a) is used as the refrigerant, the preset pressure is set to 0.4 to 0.45 MPa on the basis of a saturated vapor pressure of 0.49 MPa at 15 ° C. Since the suction pressure when the compressor 10 is operated at the maximum capacity or the intermediate capacity is about 0.2 to 0.4 MPa, the liquid for discharging is increased after the liquid refrigerant is discharged and the capacity of the compressor 10 is increased. The discharge passage can be blocked.

Next, when the cooling load is reduced, the compressor 10 is operated so that the capacity is reduced from the maximum capacity operation.
Specifically, the compressor 10 tries to maintain the maximum capacity operation even when the cooling load is reduced. However, the pressure in the suction pressure region is further reduced by reducing the cooling load.
As the suction pressure region further decreases, the pressure in the variable pressure chamber 52a also decreases.
When the pressure in the variable pressure chamber 52a is reduced, the bellows 67 is further extended as compared with the maximum capacity operation, and the rod 70 pushes the valve body against the biasing force of the coil spring 64 by the extension of the bellows 67.

When the rod 70 presses the valve body 63, the valve hole 56 is opened as shown in FIG.
When the valve hole 56 is opened, a part of the high-pressure refrigerant in the discharge chamber 39 is introduced into the control pressure chamber 16 through the passages 60 and 62 and the control valve 50.
When the high-pressure refrigerant is supplied to the control pressure chamber 16, the inclination angle of the swash plate 23 is reduced, and the compressor 10 performs variable capacity operation according to the cooling load.
In the variable capacity operation, the extraction liquid discharge passage is maintained in a blocked state.
The opening and closing of the valve hole 56 by the valve body 63 is mainly determined by the balance between the biasing force of the coil spring 64 and the biasing force of the rod 70 by the pressure-sensitive mechanism 66.

The control valve 50 according to this embodiment has the following effects.
(1) When the compressor 10 is started, the refrigerant in the control pressure chamber 16 is discharged, so that the pressure in the control pressure chamber 16 is reduced and the swash plate 23 is controlled to increase the discharge capacity.
Further, the extraction liquid discharge passage is blocked when the pressure in the suction pressure region decreases with the start of the compressor 10 and the pressure in the suction pressure region reaches a preset pressure.
Therefore, even when liquid refrigerant is stored in the control pressure chamber 16 when the compressor 10 is started, the pressure of the control pressure chamber 16 is reduced by discharging the liquid refrigerant to the suction pressure region after the compressor 10 is started. Reduction can be promoted more than before.
(2) Since the pressure equalization in the compressor 10 is set by the saturated vapor pressure of the refrigerant with respect to the outside air temperature, the position of the rod 70 is maintained by maintaining the pressure equalization at the start of the compressor 10 and canceling the pressure equalization thereafter. And the opening / closing of the extraction liquid discharge passage can be controlled according to the position of the recess 70a of the rod 70.
(3) The larger the extraction liquid discharge passage, the better the returnability since the liquid refrigerant can be discharged from the control pressure chamber 16 to the suction pressure region in a short time. When the liquid discharge passage communicates the control pressure chamber 16 and the suction pressure region, a large amount of refrigerant circulates from the control pressure chamber 16 to the suction pressure region.
Refrigerant circulation in the compressor 10 is necessary for lubrication of the sliding member inside the compressor 10, but does not contribute to cooling due to circulation of the refrigeration circuit, thereby causing a reduction in cooling capacity.
For example, blocking the bleed liquid discharge passage after the compressor 10 is restored can prevent the cooling capacity from being lowered.

(Second Embodiment)
Next, a control valve 80 according to a second embodiment will be described with reference to FIGS.
In this embodiment, since most of the compressors except the control valve 80 are common to the first embodiment, common reference numerals are used for elements that are the same as or similar to those of the first embodiment, and the first The description of the embodiment is cited.
As shown in FIG. 5, the control valve 80 includes a valve housing 81, a rod 87, and a pressure sensitive mechanism 96.
Inside the valve housing 81, a pressure sensing chamber 82 that communicates with the control pressure chamber 16, a valve chamber 83 that communicates with the discharge chamber 39, and a communication chamber 84 that communicates with the suction chamber 38 are formed.
The pressure sensing chamber 82 is formed on one end side of the valve housing 81, the communication chamber 84 is formed on the other end side, and the valve chamber 83 is located between the pressure sensing chamber 82 and the communication chamber 84.
A first partition 81 a having a valve hole 85 is provided between the pressure sensing chamber 82 and the valve chamber 83, and a second partition 81 b having a shaft hole 86 is provided between the valve chamber 83 and the communication chamber 84. Is provided.

Inside the valve housing 81, a reciprocating rod 87 is accommodated.
The rod 87 has a large-diameter portion 87 a located in the communication chamber 84 and the valve chamber 83, a small-diameter portion 87 b located in the pressure-sensitive chamber 82, and a through hole 88 that penetrates the center of the rod 87 in the axial direction.
The large diameter portion 87 a has a diameter corresponding to the shaft hole 86, and the small diameter portion 87 b is set to have a smaller diameter than the valve hole 85.
An end surface 87c between the small diameter portion 87b and the large diameter portion 87a of the rod 87 functions as a valve body, and the end surface 87c abuts on or separates from the first partition wall 81a, so that the pressure sensitive chamber 82 and the valve chamber 83 are separated. I try to communicate.
Therefore, in this embodiment, the valve chamber 83, the valve hole 85, and the pressure sensing chamber 82 correspond to the supply refrigerant passage in the control valve 80, and the end surface 87c of the rod 87 opens and closes the supply refrigerant passage. Corresponds to the body.
A through hole 88 of the rod 87 is a through hole that communicates the communication chamber 84 and the pressure sensing chamber 82.
The rod 87 receives a biasing force of the coil spring 89 accommodated in the communication chamber 84 and acts toward the pressure-sensitive chamber 82 side.

The communication chamber 84 is located on the end side of the large-diameter portion 87 a, has a Ps port 90, and a passage 93 that connects the Ps port 90 and the suction chamber 38 is formed in the rear housing 14.
The valve chamber 83 is formed around the large-diameter portion 87 a, has a Pd port 91, and a passage 94 that connects the Pd port 91 and the discharge chamber 39 is formed in the rear housing 14.
The pressure sensing chamber 82 is located on the end side of the small diameter portion 87 b, has a Pc port 92, and a passage 95 connecting the Pc port 92 and the control pressure chamber 16 is formed in the rear housing 14.

A pressure sensitive mechanism 96 is accommodated in the pressure sensitive chamber 82.
The pressure sensitive mechanism 96 includes a bellows 97 as a pressure sensitive member that partitions the pressure sensitive chamber 82 into a variable pressure chamber 82a and a constant pressure chamber 82b.
The fixed end of the bellows 97 is fixed to an end wall member 98 that covers the end of the valve housing 81.
The constant pressure chamber 82b in the bellows 97 is in a hermetically sealed state and is maintained at a predetermined constant pressure.
The variable pressure chamber 82a is set around the constant pressure chamber 82b, and the pressure in the variable pressure chamber 82a varies according to the fluctuation in the pressure in the suction chamber 38. Therefore, when the pressure in the variable pressure chamber 82a is lower than the pressure in the constant pressure chamber 82b. The bellows 97 expands, and conversely, when the pressure in the variable pressure chamber 82a is high, the bellows 97 contracts.
That is, a force is generated to expand and contract the bellows 97 when there is a differential pressure between the constant pressure chamber 82b and the variable pressure chamber 82a.

A movable member 99 is fixed to the movable end of the bellows 97, and an annular valve member 100 for opening and closing the pressure sensitive chamber 82 and the through hole 88 is attached to the rod 87 side of the movable member 99.
The valve member 100 has a tapered surface 100a that decreases in diameter toward the bellows 97 side on the inner diameter side.
The bellows 97 extends, and the outer diameter edge at the end of the small diameter portion 87b and the tapered surface 100a come into contact with each other, whereby communication between the communication chamber 84 and the pressure sensitive chamber 82 is blocked.
When the bellows 97 contracts, the valve member 100 and the small diameter portion 87b of the rod 87 are separated, and the pressure sensing chamber 82 and the communication chamber 84 are communicated with each other through the through hole 88.
That is, in this embodiment, the variable pressure chamber 82 a, the through hole 88, and the communication chamber 84 correspond to the extraction liquid discharge passage in the control valve 80.

The operation of the control valve 80 of this embodiment will be described.
When the stop time of the compressor is long, the liquid refrigerant is stored in the compressor, the pressure of the refrigeration circuit is almost equalized, and the pressure equalization of the refrigeration circuit is the suction pressure region when the compressor is driven It is in a state far higher than the pressure.
That is, the pressure in the variable pressure chamber 82a is much higher than the pressure in the constant pressure chamber 82b in the pressure sensitive chamber 82.

For this reason, in this state, as shown in FIG. 6A, the bellows 97 is in the most contracted state, the rod 87 and the valve member 100 are separated, and the rod 87 is energized by the coil spring 89. The valve hole 85 is in a closed state.
This state indicates that, in the control valve 80, the supply refrigerant passage is blocked while the extraction liquid discharge passage is communicated.

Next, when the necessity for cooling occurs, power is transmitted to the compressor by the clutch mechanism, and the stopped compressor is started.
In the minimum capacity operation when starting the compressor, the piston 29 reciprocates in the cylinder bore 12a with a minimum stroke.
In a state where the extraction liquid discharge passage communicates, the reciprocating motion of the piston 29 causes the refrigerant to circulate from the control pressure chamber 16 to the compression chamber 31 via the suction chamber 38.
At this time, liquid refrigerant is present in the control pressure chamber 16, but since the extraction liquid discharge passage is in communication, the liquid refrigerant in the control pressure chamber 16 passes through the passage 93, as the piston 29 reciprocates. 95 and the control valve 80 are all discharged into the suction chamber 38.

As all of the liquid refrigerant in the control pressure chamber 16 is discharged to the suction chamber 38, the pressure in the control pressure chamber 16 can be reduced below the saturated vapor pressure of the refrigerant.
As the pressure in the control pressure chamber 16 decreases, the inclination angle of the swash plate 23 increases, and the discharge capacity of the compressor increases.
As the discharge capacity of the compressor increases, the pressure in the variable pressure chamber 82a in the control valve 80 further decreases, and the bellows 97 expands as the pressure in the variable pressure chamber 82a decreases.
For example, during maximum capacity operation with a large cooling load, as shown in FIG. 5, the bellows 97 extends so that the valve member 100 abuts against the rod 87, and at this position of the rod 87, the extraction liquid discharge passage is blocked. Is done.

Next, when the cooling load is reduced, the compressor is operated so that the capacity is reduced from the maximum capacity operation. However, the compressor tries to maintain the maximum capacity operation even when the cooling load is reduced.
As the cooling load decreases, the pressure in the suction pressure region further decreases, and the pressure in the variable pressure chamber 82a further decreases.
As the pressure in the variable pressure chamber 82a further decreases, the bellows 97 is further extended as compared with the maximum capacity operation, and the valve member 100 presses the rod 87 against the urging force of the coil spring 89 by the extension of the bellows 97.

When the valve member 100 presses the rod 87 toward the communication chamber 84, the valve hole 85 is opened as shown in FIG. 6B, and a part of the high-pressure refrigerant in the discharge chamber 39 is passed through the passage 92, 94 and the control valve 80 are introduced into the control pressure chamber 16.
When the high-pressure refrigerant is supplied to the control pressure chamber 16, the inclination angle of the swash plate 23 is reduced, and the compressor 10 performs variable capacity operation according to the cooling load.
In the variable capacity operation, the extraction liquid discharge passage is maintained in a blocked state.
The opening / closing of the valve hole 85 by the rod 87 is mainly determined by the balance between the biasing force of the coil spring 89 and the biasing force of the valve member 100 by the pressure-sensitive mechanism 96.

According to the control valve 80 of this embodiment, substantially the same effect as that of the first embodiment, even when liquid refrigerant is stored in the control pressure chamber 16 when the compressor 10 is started, the compressor 10 By discharging the liquid refrigerant to the suction pressure region after the activation of the control, the pressure drop in the control pressure chamber 16 can be promoted more than before.
Even if the Pc port and the Ps port are not adjacent to each other in the control valve 80, the extraction liquid discharge passage can be formed by the through-hole 88 that penetrates the inside of the rod. The degree is improved.
By setting the diameter of the through hole 88 to be relatively large, the amount of liquid refrigerant passing from the control pressure chamber 16 passing through the through hole 88 can be increased.
Thereby, the refrigerant can be quickly discharged from the control pressure chamber 16 when the compressor is started.
That is, the through hole 88 is more advantageous than the control valve 50 of the first embodiment in that a large amount of liquid refrigerant can be passed.

The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the invention. For example, the following modifications may be made.
In the first and second embodiments, the extraction liquid discharge passage is configured to be closed during the maximum capacity operation. However, the extraction liquid discharge passage may be opened except during the variable capacity operation. Good.

It is sectional drawing which shows the outline | summary of the control valve in the variable displacement compressor which concerns on 1st Embodiment. It is sectional drawing which shows the control valve (at the time of maximum capacity | capacitance driving | operation) which concerns on 1st Embodiment. It is sectional drawing which shows the control valve (at the time of a stop) which concerns on 1st Embodiment. It is sectional drawing which shows the control valve (at the time of variable displacement driving | operation) which concerns on 1st Embodiment. It is sectional drawing which shows the control valve (at the time of maximum capacity | capacitance driving | operation) in the variable capacity type compressor which concerns on 2nd Embodiment. It is sectional drawing which shows the control valve (at the time of a stop and variable displacement operation) which concerns on 2nd Embodiment.

Explanation of symbols

10 Compressor 16 Control pressure chamber 17 Drive shaft 23 Swash plate 29 Piston 38 Suction chamber 39 Discharge chamber 50, 80 Control valve 51, 81 Valve housing 52, 82 Pressure sensing chamber 53, 84 Communication chamber 54, 83 Valve chamber 56, 85 Valve hole 57, 90 Ps port 58, 92 Pc port 59, 91 Pd port 66, 96 Pressure sensitive mechanism 67, 97 Bellows 70, 87 Rod 70a Recess 88 Through hole 100 Valve member

Claims (3)

A port for Pd communicating with the discharge pressure region of the compressor, a port for Pc communicating with the control pressure chamber of the compressor, a port for Ps communicating with the suction pressure region of the compressor, a port for Pd, and for Pc An air supply refrigerant passage that communicates with the port; a valve body that opens and closes the air supply refrigerant path; a pressure-sensitive mechanism that controls the valve body in accordance with the pressure in the suction pressure region; and the valve body that opens and closes. A control valve of a clutch type variable displacement compressor having a rod,
An extraction liquid discharge passage connecting the Pc port and the Ps port;
Communication and blocking of the extraction liquid discharge passage are controlled by movement of a pressure-sensitive member constituting the pressure-sensitive mechanism,
When the compressor is started from a stopped state, the pressure sensitive member is positioned so as to communicate with the extraction liquid discharge passage while the pressure equalization in the compressor is maintained when the compressor is stopped.
Furthermore, when the compressor starts, the pressure in the suction pressure region decreases, and when the pressure in the suction pressure region reaches a preset pressure, the sensation in a direction to block the extraction liquid discharge passage. A control valve for a clutch type variable displacement compressor, wherein the pressure member moves. 2. The control valve for a clutch-type variable displacement compressor according to claim 1, wherein the extraction liquid discharge passage is a recess formed in a side surface of the rod. 2. The control valve for a clutch type variable displacement compressor according to claim 1, wherein the extraction liquid discharge passage is a through-hole penetrating the inside of the rod.

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