WO2015093502A1

WO2015093502A1 - Pressure control valve and variable displacement compressor using same

Info

Publication number: WO2015093502A1
Application number: PCT/JP2014/083334
Authority: WO
Inventors: 幸生風早; 栄林
Original assignee: 株式会社ヴァレオジャパン
Priority date: 2013-12-20
Filing date: 2014-12-17
Publication date: 2015-06-25
Also published as: DE112014005944T5; JP2015121097A

Abstract

Provided are: a pressure control valve capable of autonomously controlling the pressure (discharge capacity) of a control chamber, quickly following fluctuation of high pressure; and a variable displacement compressor using this pressure control valve. [Solution] A pressure control valve (2), for adjusting the amount of working fluid supplied from a discharge chamber to a control chamber and adjusting the pressure of the control chamber by adjusting the opening degree of an air supply passage connecting the discharge chamber and the control chamber, is configured to be capable of adjusting the opening degree of the air supply passage on the basis of only the pressure (Pd) of the discharge chamber, from among the pressure (Pd) of the discharge chamber, the pressure (Ps) of an intake chamber, and the pressure (Pc) of the control chamber. The pressure control valve is provided with a high-pressure inlet space (75) interconnected with the discharge chamber, a pressure adjustment space (77) interconnected with the control chamber, a valve port (80) for interconnecting the high-pressure inlet space (75) and the pressure adjustment space (77), and a valve body (61) capable of opening and closing the valve port (80), one end side of the valve body (61) in the operating direction being subjected, in a direction that opens the valve port (80), to the discharge chamber pressure (Pd) led into the high-pressure inlet space (75), and the other end side of the valve body (61) in the operating direction being subjected to atmospheric pressure or a vacuum pressure (Po).

Description

Pressure control valve and variable capacity compressor using the same

The present invention relates to a pressure control valve for a variable displacement compressor, which adjusts the supply amount of the working fluid flowing from the discharge chamber to the control chamber to adjust the pressure of the control chamber, thereby varying the discharge capacity. The present invention relates to the variable capacity compressor used.

In a variable capacity swash plate compressor using R134a as a refrigerant, when the suction pressure Ps is applied to a pressure sensitive member such as a bellows or a diaphragm, and Ps falls below a predetermined value, the pressure sensitive member is interlocked. The valve body increases the control chamber pressure by opening the air supply passage (passage that connects the discharge chamber and the control chamber) or closing the bleed passage (passage that connects the control chamber and the suction chamber). The discharge angle is autonomously controlled so that the inclination angle of the plate is reduced and Ps is maintained at the predetermined value (see Patent Document 1).

On the other hand, in the case of a supercritical cycle using carbon dioxide or the like as the refrigerant, if the outside air temperature is high, the refrigerant is not liquefied on the high pressure side of the cycle. When the amount becomes excessive with respect to the cooling load, the suction pressure gradually decreases, whereas the discharge pressure rapidly increases. For this reason, if a conventional control valve for controlling the suction pressure is used, the discharge pressure of the compressor is reduced because the suction pressure decreases slowly even though the discharge pressure suddenly increases when the rotational speed increases. May be delayed, leading to an increase in compressor driving torque.

In order to deal with such problems, a pressure control valve that controls the suction pressure to be controlled so as to increase as the discharge pressure increases, or a pressure control that controls the pressure difference between the discharge pressure and the suction pressure. A compressor using a valve has been proposed (see Patent Documents 2 and 3). According to the variable capacity compressor using these pressure control valves, the discharge pressure acts in the direction of increasing the opening degree of the valve body of the pressure control valve. The valve body of the pressure control valve is opened by the discharged pressure, and the control chamber pressure is increased to autonomously decrease the discharge capacity of the compressor, thereby promptly suppressing the increase in the discharge pressure.

Thus, the conventional pressure control valve causes the discharge pressure Pd to act on one side of the valve body and the suction pressure Ps to act on the other side, whereby the valve body operates based on the differential pressure between Pd and Ps. Therefore, by using a compressor using such a pressure control valve for a refrigeration cycle, autonomous control is performed so that the differential pressure between Pd and Ps becomes constant. Since the differential pressure between Pd and Ps can be adjusted by a solenoid that urges the external load on the valve body, when the cooling capacity is determined to be excessive, the set differential pressure between Pd and Ps is reduced. By adjusting the current of the solenoid, the discharge capacity of the compressor can be reduced and the cooling capacity can be reduced.

Japanese Examined Patent Publication No. 4-74549 JP 11-294328 A JP 2001-182666 A

However, in the case of a refrigeration cycle using a supercritical fluid such as carbon dioxide as a refrigerant, the pressure is very high compared to a refrigeration cycle using a fluorocarbon refrigerant such as R134a. However, it is necessary to consider so as not to cause problems due to abnormally high pressure.
For example, when the heat load on the evaporator side increases as the outside air temperature rises, Pd increases and Ps also increases. Therefore, the pressure difference between Pd and Ps is so large even though Pd is high. In other words, the detection of the high pressure abnormality may be delayed. For this reason, in the conventional configuration, a pressure sensor is separately provided on the high-pressure side of the refrigeration circuit to constantly monitor whether the detected high-pressure exceeds the predetermined pressure, and when the discharge pressure exceeds the predetermined pressure, the pressure is It was necessary to protect the refrigeration cycle by reducing the current applied to the control valve. Moreover, in the case of providing fail-safe control at the time of detecting a high pressure abnormality by such a high pressure sensor, if the high pressure sensor fails, the abnormal high pressure may be overlooked and the refrigeration circuit may be damaged.

The present invention has been made in view of such circumstances, and uses a pressure control valve capable of autonomously controlling the pressure (discharge capacity) of the control chamber by following the fluctuation of the high pressure quickly. The main problem is to provide a variable capacity compressor.

In order to achieve the above object, a pressure control valve according to the present invention includes a housing, a drive shaft provided in the housing, a swash plate that rotates with the drive shaft and has a variable inclination angle with respect to the drive shaft. And a plurality of cylinders provided in the housing and having an axis parallel to the drive shaft, and a plurality of cylinders slidably disposed in the cylinder and reciprocating in the cylinder as the swash plate rotates. Contains a piston, a compression chamber defined by the cylinder and the piston, a control chamber formed on the anti-compression chamber side of the piston, and a working fluid sucked into the compression chamber in the piston suction stroke And a discharge chamber into which the working fluid compressed in the compression chamber is discharged during the compression stroke of the piston, and discharge capacity is increased when the pressure in the control chamber increases. Used in a variable displacement compressor that decreases, and adjusts the supply amount of the working fluid from the discharge chamber to the control chamber by adjusting the opening of an air supply passage connecting the discharge chamber and the control chamber The pressure of the control chamber is adjusted, and the air supply passage is opened based on only the pressure of the discharge chamber among the pressure of the discharge chamber, the pressure of the suction chamber, and the pressure of the control chamber. It is characterized by adjusting the degree.

Here, adjusting the opening of the air supply passage based only on the pressure in the discharge chamber among the pressure in the discharge chamber, the pressure in the suction chamber, and the pressure in the control chamber means that the pressure in the suction chamber and the pressure in the control chamber are adjusted. It means that the opening of the air supply passage is adjusted by applying at least the pressure of the discharge chamber without acting.

Therefore, since the opening of the air supply passage is adjusted based only on the pressure in the discharge chamber, the pressure in the control chamber is quickly increased only on the basis of the pressure change in the discharge chamber regardless of the pressure change in the suction chamber or the control chamber. Will be adjusted.

That is, even in an environment where the high pressure side pressure of the system increases due to an increase in heat load or compressor speed, the opening of the air supply passage is adjusted based only on the pressure in the discharge chamber. The discharge capacity is autonomously controlled so as to maintain it, and it is possible to avoid a high pressure abnormality without performing a control to reduce the discharge capacity based on a signal from the outside by providing a pressure sensor on the high pressure side Become.

As a specific configuration of the pressure control valve, a high-pressure introduction space that communicates with the discharge chamber, a pressure adjustment space that communicates with the control chamber, a valve port that communicates the high-pressure introduction space and the pressure adjustment space, A valve opening / closing member that can be opened and closed, and the pressure of the discharge chamber introduced into the high-pressure introduction space acts on one end side of the operation direction of the valve opening / closing member in the direction of opening the valve opening, and the operation of the valve opening / closing member An atmospheric pressure or a vacuum pressure may be applied to the other end side in the direction.

According to such a configuration, the pressure in the direction of opening the valve opening acting on one end side of the valve opening / closing member (valve element) is the pressure of the discharge chamber, and the pressure acting on the other end side is atmospheric pressure or vacuum pressure. Thus, the valve opening / closing member can be opened / closed depending only on the pressure in the discharge chamber, and the pressure fluctuation of the discharge chamber pressure can be followed quickly.
For example, when the discharge chamber pressure increases, the valve opening increases and the pressure in the control chamber increases, so that the inclination angle of the swash plate decreases and the discharge capacity of the compressor decreases. It will be autonomously controlled to limit the rise in discharge pressure.

In order to realize the above-described configuration, for example, the valve opening / closing member has one end in the operation direction facing the valve opening, the valve opening can be opened / closed from the pressure adjustment space, and the discharge introduced into the high pressure introduction space. When the pressure of the chamber acts on one end side in the operation direction of the valve port opening / closing member via the valve port, the atmospheric pressure or the vacuum pressure acts on the other end side in the operation direction of the valve port opening / closing member. Good.

Moreover, you may make it further provide the external force provision means which provides the external force which can be adjusted to the direction which closes the said valve opening with respect to the said valve opening / closing member.
By applying an external force to the valve opening / closing member in the direction of closing the valve opening / closing member by the external force applying means, it is possible to counter the pressure of the discharge chamber acting in the direction of opening the valve opening / closing member from the valve opening. By adjusting this external force, it is possible to adjust the pressure of the discharge chamber that is autonomously controlled against this from the outside.

As described above, when the pressure regulating valve according to the present invention is used, the opening of the air supply passage is adjusted based only on the pressure of the discharge chamber among the pressure of the discharge chamber, the pressure of the suction chamber, and the pressure of the control chamber. Therefore, it is possible to quickly and autonomously adjust the pressure in the control chamber based only on the pressure change in the discharge chamber regardless of the pressure change in the suction chamber or the control chamber. It is possible to avoid a high-pressure abnormality without controlling the discharge capacity based on this signal.

FIG. 1 is a schematic configuration diagram of a refrigeration cycle according to an embodiment of the present invention. FIG. 2 is a sectional view of the variable capacity compressor according to the embodiment of the present invention. FIG. 3 is a cross-sectional view showing a configuration example of the pressure control valve according to the embodiment of the present invention. FIG. 4 is a flowchart showing a control example of the pressure control valve according to the present invention. FIG. 5 is a sectional view showing another configuration example of the pressure control valve according to the embodiment of the present invention. FIG. 6 is a sectional view showing still another configuration example of the pressure control valve according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 shows a refrigeration cycle 1 in which a variable capacity compressor 3 having a pressure control valve 2 according to the present invention is used. The refrigeration cycle 1 is suitable for the case where CO2 is used as a refrigerant, and has a pressure control valve 2 for changing the discharge capacity, and a variable capacity compressor (hereinafter referred to as a compressor) capable of compressing the refrigerant to a supercritical region. 3) a radiator 4 that cools the compressed refrigerant, an internal heat exchanger 5 that exchanges heat between the high-pressure line 9 and the low-pressure line 10, an expansion device 6 that decompresses the refrigerant, and evaporates the refrigerant. An evaporator 7 and an accumulator 8 for gas-liquid separation of the refrigerant flowing out of the evaporator 7 are provided.

In this refrigeration cycle 1, the discharge side of the compressor 3 is connected to the high-pressure passage 5 a of the internal heat exchanger 5 via the radiator 4, and the outflow side of the high-pressure passage 5 a is connected to the expansion device 6. A path from the discharge side to the inflow side of the expansion device 6 is a high pressure line 9. The outflow side of the expansion device 6 is connected to the evaporator 7, and the outflow side of the evaporator 7 is connected to the low-pressure passage 5 b of the internal heat exchanger 5 via the accumulator 8. The outflow side of the low pressure passage 5 b is connected to the suction side of the compressor 3, and the path from the outflow side of the expansion device 6 to the suction side of the compressor 3 is a low pressure line 10.

In such a refrigeration cycle 1, when carbon dioxide (CO ₂ ) is used as a refrigerant, the refrigerant compressed by the compressor 3 enters the radiator 4 as a high-temperature and high-pressure supercritical refrigerant, and releases heat here. And cool. Thereafter, the internal heat exchanger 5 exchanges heat with the low-temperature refrigerant flowing out from the evaporator 7, and is further cooled and sent to the expansion device 6 without being liquefied. Then, the pressure is reduced in the expansion device 6 to become low-temperature and low-pressure wet steam, and heat is exchanged with the air passing therethrough in the evaporator 7 to become a gaseous state. Thereafter, in the internal heat exchanger 5, Heat is exchanged and returned to the compressor 3.

At the downstream end of the ventilation portion of the evaporator 7, a post-evaporation temperature sensor 11 for detecting the air temperature immediately after the evaporator 7 is provided. A signal corresponding to the actual air temperature immediately after the evaporator (actual post-evaporation temperature) detected by the actual post-evaporation temperature sensor 11 is detected by the outside air temperature (Ta) detected by the external air temperature sensor and the vehicle interior temperature sensor. The vehicle interior temperature (Tinc), the amount of solar radiation detected by the solar radiation amount detection sensor 16 (Qsun), and the like are input to the control unit 12 together with signals corresponding to each.

The control unit 12 inputs the above-described various signals (sensor values) as data, a memory unit composed of a read-only memory (ROM) or a random access memory (RAM), and calls a program stored in the memory unit. A central processing unit (CPU) that calculates control data based on the data, and determines and supplies a current to be supplied to an excitation coil 58 of a pressure control valve 2 described later based on the control data calculated by the central processing unit. An output circuit is provided.

The compressor 3 is, for example, a variable displacement swash plate type compressor as shown in FIG. 2, and is assembled to a cylinder block 21 and a rear side (right side in the drawing) of the cylinder block 21 via a valve plate 22. The rear head 23 and the front head 24 assembled so as to close the front side (left side in the drawing) of the cylinder block 21 are configured. The front head 24, the cylinder block 21, the valve plate 22, and the rear head 23 軸 are fastened in the axial direction by fastening bolts (not shown) to constitute a housing of the entire compressor.

A control chamber 26 defined by the front head 24 and the cylinder block 21 accommodates a drive shaft 27 having one end protruding from the front head 24. A drive pulley connected to a vehicle engine (not shown) through a belt is fixed to a portion of the drive shaft 27 突出 protruding from the front head 24 、 so that the rotation of the engine is transmitted.

Further, one end side of the drive shaft 27 is hermetically sealed with the front head 24 through a seal member 28 provided between the front shaft 24 and is rotatably supported by

radial bearings

29 and 30. The other end of the drive shaft 27 is rotatably supported by

radial bearings

31 and 32 accommodated in the cylinder block 21.

A thrust flange 33 that rotates integrally with the drive shaft 27 is fixed to the drive shaft 27 in the control chamber 26. The thrust flange 33 is rotatably supported by a front head 24 via a thrust bearing 34 and is connected to a swash plate 36 via a link member 35.

The swash plate 36 is attached so as to be tiltable about the drive shaft 27, and is rotated integrally with the rotation of the thrust flange 33. The swash plate 36 is disposed in a state of being pressed from both axial sides by an elastic member 37 such as a coil spring interposed between the thrust flange 33 and an elastic member 38 such as a coil spring disposed on the opposite side. Therefore, the drive shaft 27 is allowed to move in the axial direction.

The cylinder block 21 is formed with a support recess 39 in which the

radial bearings

31, 32 are accommodated, and a plurality of cylinder bores 40 配 arranged at equal intervals on the circumference around the support recess 39. And piston 41 is inserted in each cylinder bore 40 so that reciprocating sliding is possible.

The piston 41 is configured by joining a head portion 41a inserted into the cylinder bore 40 and an engaging portion 41b protruding into the control chamber 26 in the axial direction. The engaging portion 41b is connected to a pair of shoes 42. It is moored to the peripheral portion of the swash plate 36 via

The thrust flange 33, the swash plate 36, and the piston 41 constitute a compression mechanism that converts the rotation of the drive shaft 27 into the compression action of the working fluid. When the drive shaft 27 rotates, the swash plate is synchronized with the compression mechanism. 36 rotates integrally, and this rotational motion is converted into a reciprocating linear motion of the piston 41 via the shoe 42, and is formed between the piston 41 and the valve plate 22 in the cylinder bore 40 by the reciprocating motion of the piston 41. The volume of the compression chamber 43 is changed.

The rear head 23 is joined to the cylinder block 21 via the valve plate 22, thereby defining a discharge chamber 44 and a suction chamber 45 formed around the discharge chamber 44. The valve plate 22 has a suction hole 46 that communicates the suction chamber 45 and the compression chamber 43 via a suction valve (not shown), and a discharge hole 47 that communicates the discharge chamber 44 and the compression chamber 43 via a discharge valve (not shown). And are formed.

The discharge capacity of the compressor is determined by the stroke of the piston 41. This stroke is the pressure applied to the front surface of the piston 41, that is, the pressure in the compression chamber 43 (pressure in the cylinder bore 40) and the pressure applied to the back surface of the piston 41. That is, it is determined by the pressure difference with the pressure in the control chamber 26 (control chamber pressure Pc). Specifically, if the pressure in the control chamber 26 is increased, the differential pressure between the compression chamber 43 and the control chamber 26 is reduced, so that the inclination angle (swing angle) of the swash plate 36 is reduced. If the stroke of the piston 41 is reduced and the discharge capacity is reduced. Conversely, if the pressure in the control chamber 26 is lowered, the differential pressure between the compression chamber 43 and the control chamber 26 is increased. (Swinging angle) is increased, and therefore, the stroke of the piston 41 is increased and the discharge capacity is increased.

In such a compressor, an air supply passage 48 that connects the discharge chamber 44 and the control chamber 26 is formed in the cylinder block 21, the valve plate 22, and the rear head 23, and a pressure control valve is provided on the air supply passage 48. 2 is provided. The pressure control valve 2 is mounted in a control valve mounting hole 49 formed in the rear head 23, and the pressure in the control chamber 26 (control chamber pressure Pc) is adjusted by adjusting the opening of the air supply passage 48. Is controlling.

In FIG. 3, a specific configuration example of the pressure control valve 2 is shown, and the pressure control valve 2 will be described in detail below.
The pressure control valve 2 includes a drive unit 51 and a tip block unit 52. The drive unit 51 includes a fixed iron core 53 that is screwed to the tip block 52, a plate-like upper case member 54 that is locked to the fixed iron core 53, and a cylindrical cylindrical case 55 that is screwed to the upper case member 54. A lower case member 56 that is caulked and fixed to the lower end of the cylindrical case 55, a cylindrical cylinder 56 that is housed in the cylindrical case 55 and fixed to the fixed iron core 53, and is fixed around the cylinder 56. A bobbin 57, an exciting coil 58 wound around the bobbin 57, a plunger 59 arranged coaxially with the fixed iron core 53 and slidably inserted into the cylinder 56, and the plunger 59 and shaft A rod-shaped valve body 61 that is fixed to the plunger 59 with its center aligned and is inserted through a shaft hole 60 provided in the center of the fixed iron core 53, and an opening on the lower case member side of the cylinder 56. A sealing block 63 that is airtightly fitted to the end portion via an O-ring 62 and screwed into the lower case member 56, and a spring 64 that is elastically mounted between the fixed iron core 53 and the plunger 59. Configured.

The end portion of the valve body 61 is slidably inserted into a rod insertion hole 65 formed in the sealing block 63, and the insertion portion of the sealing block 63 is airtight by an O-ring 66. .

A back pressure chamber 69 defined by the valve body 61 inserted therein is formed in the rod insertion hole 65 of the sealing block 63, and the back pressure chamber 69 is formed in the sealing block 63. Atmospheric pressure or vacuum pressure Po is introduced through the communication hole 70. Reference numeral 67 denotes a support member that supports the upper portion of the valve body 61 at several locations in the circumferential direction, and 68 denotes a lead wire that supplies current to the exciting coil 58.

The distal end block portion 52 includes a block body 71 that is engaged with the fixed iron core 53 on the proximal end side in the axial direction, and a valve seat member 72 that is engaged with the distal end side of the block body 71. Therefore, a filter mounting member 74 containing a filter 73 is assembled at the tip of the block main body 71 of the tip block 52, and the filter 73 is interposed between the filter 73 and the valve seat member 72. A high-pressure introduction space 75 communicating with the discharge chamber 44 is formed.

Further, a valve body 61 inserted through the shaft hole 60 protrudes between the valve seat member 72 and the fixed iron core 53 and communicates with the control chamber 26 via a communication hole 76 formed in the block body 71 in the radial direction. A communicating pressure adjusting space 77 is formed. The pressure adjusting space 77 communicates with a space 78 in which a spring 64 between the fixed iron core 53 and the plunger 59 is accommodated via a gap between the shaft hole 60 and the valve body 61. And a space 79 between the plunger 59 and the sealing block 63 via a clearance between the pressure adjusting space 77 and the space 78 between the fixed iron core 53 and the plunger 59. The space 79 between the plunger 59 and the sealing block 63 has a control chamber pressure Pc.

The valve seat member 72 is formed with a valve port 80 that communicates the high-pressure introduction space 75 and the pressure adjustment space 77, and the valve port 80 moves the valve body 61 from the pressure adjustment space 77 to the valve port 80. It is possible to open and close by separating and contacting the peripheral edge. The rod-shaped valve element 61 constitutes a valve opening / closing member that opens and closes the valve opening 80.

In the above configuration, when the pressure acting on the valve body 61 is viewed, the control chamber pressure Pc does not act directly on the axial direction of the valve body 61, and also on the plunger 59 fixed to the valve body 61. Since the front and rear in the axial direction becomes the control chamber pressure Pc, the control chamber pressure Pc does not act in the axial direction of the valve body 61 via the plunger 59. In contrast, the discharge chamber pressure Pd acts on the tip of the valve body 61 in the opening direction via the valve port 80, and the atmospheric pressure or vacuum introduced into the back pressure chamber 69 at the end of the valve body 61. Pressure acts. Further, an elastic force (spring pressure) by the spring 64 acts in the opening direction of the valve body 61 via the plunger 59, and an electromagnetic force induced by the excitation coil 58 acts in the closing direction of the valve body 61. Therefore, among the pressure in the discharge chamber 44 (discharge chamber pressure Pd), the pressure in the suction chamber 45 (suction chamber pressure Ps), and the pressure in the control chamber 26 (control chamber pressure Pc), the valve body 61 acts in the axial direction. The pressure is only the pressure of the discharge chamber 44 (discharge chamber pressure Pd), and the valve body moves to a position where the discharge chamber pressure Pd and back pressure Po (atmospheric pressure or vacuum pressure), spring pressure, and electromagnetic force are balanced. It will be. Since the spring pressure and the back pressure are constant, the valve opening pressure of the valve body 61 is adjusted by electromagnetic force, and the valve body 61 having this valve opening pressure is opened and closed according to the discharge chamber pressure Pd.

As shown in FIG. 4, the current supplied to the excitation coil 58 is input when each sensor value (outside air temperature, vehicle interior temperature, solar radiation amount, actual post-evaporation temperature, etc.) is input in the control unit 12 ( Step 90), calculate the air temperature immediately after the target evaporator (target post-evaporation temperature) (step 92), and based on the difference between the actual air temperature immediately after the evaporator (actual post-evaporation temperature) and the target post-evaporation temperature, The supply current value of the exciting coil 58 is determined so that the actual post-evaporation temperature approaches the target post-evaporation temperature (step 94).

Therefore, by using such a pressure control valve 2, only the discharge chamber pressure Pd acts on the valve body 61 among the discharge chamber pressure Pd, the suction chamber pressure Ps, and the control chamber pressure Pc, and the valve opening degree is autonomous. Therefore, by arbitrarily adjusting the current of the exciting coil 58, the discharge capacity of the compressor 3 is controlled so that the discharge pressure corresponds to the current. For this reason, as described above, it is possible to obtain preferable air conditioning by adjusting the current of the exciting coil 58 so that the actual post-evaporation temperature approaches the target temperature (target post-evaporation temperature).

Also, even when the high pressure on the system side increases due to an increase in heat load or compressor speed, the discharge chamber pressure directly acts on the valve body, so the discharge pressure corresponding to the current should be maintained. The discharge capacity is controlled autonomously. Accordingly, it is possible to quickly avoid a high pressure abnormality without providing a pressure sensor or the like for measuring the pressure on the high pressure side of the refrigeration cycle 1 and performing control for reducing the discharge capacity based on an external signal.

Note that the pressure control valve 2 described above is not limited to the above configuration example as long as the same purpose can be achieved, and may be modified as shown in FIG. 5, for example.
In the modification shown in FIG. 5, a communication hole is formed in a bellows 81 in which atmospheric pressure or vacuum pressure acting on the end of the valve body 61 is interposed between the sealing block 3 and the end of the valve body 61. 70 may be supplied via the bellows 81, and atmospheric pressure or vacuum pressure may be applied to the valve body 61 via the bellows 81. The bellows 81 is fixed to the end of the valve body 61 and the sealing block 63, and the control chamber pressure Pc in the space 79 between the plunger 59 and the sealing member 63 acts on the end of the valve body 61 in the axial direction. It is attached so as not to.

Therefore, even in such a configuration, the control chamber pressure Pc does not act in the axial direction of the valve body, and the pressure of the discharge chamber 44 (discharge chamber pressure Pd), the pressure of the suction chamber 45 (suction chamber pressure Ps), Of the pressure in the control chamber 26 (control chamber pressure Pc), the pressure acting in the axial direction of the valve body 61 can be only the pressure in the discharge chamber 44 (discharge chamber pressure Pd). It is possible to achieve the same effect.

Further, the pressure control valve 2 may be configured as shown in FIG.
The pressure control valve 2 shown here includes a drive portion 51 and a tip block portion 52 as in the case of the pressure control valve. The drive unit 51 includes a fixed iron core 101, a lower case member 102 that is screwed to the end side of the fixed iron core 101, a cylindrical cylindrical case 103 that is caulked and fixed to the lower case member 102, and the cylindrical case 103 A cylindrical cylinder 104 that is housed inside and fixed to the distal end side of the fixed iron core 101, a bobbin 105 that is fixed around the fixed iron core 101 and the cylinder 104, and an excitation coil 106 that is wound around the bobbin 105. A plunger 107 that is slidably inserted into the cylinder 104, a valve body 108 that is fixed to the plunger 107 with its axis aligned with the plunger and that protrudes into the end block 52, and a fixed iron core. The sealing member 110 that is secretly fitted to the opening end on the distal end side of the 101 via the O-ring 109 and the opening end on the front end side of the fixed iron core 101 are fixed. A spring receiver 111 which is is configured by a spring 112 which is elastically interposed between the spring receiving 111 and the valve body 108.

The distal end block portion 52 includes a block main body 115 that is locked and fixed to the cylinder 104 via the O-ring 113 and the spacer 114 on the base end side in the axial direction. The block main body 115 includes the block main body 115. A high-pressure introduction space 117 that communicates with the discharge chamber 44 via a communication passage 116 that is formed in a radial direction and accommodates the plunger 107, and a communication passage that is formed in the high-pressure introduction space 117 and the block body 115 in the axial direction. 118, the valve head housing space 120 closed by a lid 119 provided at the tip of the block main body 115, and the communication passage 121 formed in the block main body 115 in the radial direction. A pressure adjustment space 122 communicating with the control chamber 26 is formed.

The valve body 108 is slidably inserted into a shaft hole 123 formed in the block body 115 from the high-pressure introduction space 117 to the valve head housing space 120. The valve head 108a of the valve body 108 is It is accommodated in the head accommodating space 120, and the shaft hole 123 can be opened and closed from the valve head accommodating space 120. The pressure adjustment space 122 is formed between the inner peripheral surface of the shaft hole 123 and the small diameter portion 108b formed by reducing the diameter in front of the valve head portion 108a of the valve body 108. Between the space 122 and the valve head housing space 120 where the high pressure introduction space 117 communicates, the valve body 108 (the valve head 108a) is opened and closed (separated from the opening periphery of the shaft hole 123). It has become.

In the valve head housing space 120, a bellows 124 is interposed between the lid 119 and the valve body 108 (valve head 108a). The bellows 124 is fixed to the lid 119 and the valve head 108a, and the inside thereof is set to atmospheric pressure or vacuum pressure Po. The discharge chamber pressure Pd of the valve head housing space 120 is set to the valve head 108a. It is attached to the tip of the so as not to act in the axial direction.

Even in such a configuration, the control chamber pressure Pc does not act in the axial direction of the valve body 108, and the discharge chamber pressure Pd is applied to the valve body 108 from between the plunger 107 and the spring receiver 111 in the high pressure introduction space 117. Further, the atmospheric pressure or the vacuum pressure Po sealed in the bellows 124 acts on the tip of the valve body 108. Further, an elastic force (spring pressure) by the spring 112 acts in the opening direction of the valve body 108 and an electromagnetic force induced by the exciting coil 106 acts in the closing direction of the valve body 108 via the plunger 107. Therefore, among the pressure in the discharge chamber 44 (discharge chamber pressure Pd), the pressure in the suction chamber 45 (suction chamber pressure Ps), and the pressure in the control chamber 26 (control chamber pressure Pc), the valve body 108 acts in the axial direction. The pressure is only the pressure of the discharge chamber 44 (discharge chamber pressure Pd), and the valve is placed at a position where the discharge chamber pressure Pd and the pressure in the bellows 124 (atmospheric pressure or vacuum pressure Po), spring pressure, and electromagnetic force are balanced. The body 108 (valve head 108a) moves. Since the spring pressure and the internal pressure of the bellows 124 are constant, the valve element 108 adjusts the valve opening pressure of the valve element 108 by electromagnetic force, and the valve element 108 having this valve opening pressure opens and closes according to the discharge chamber pressure Pd. It has come to be.

Therefore, also in such a pressure control valve 2, only the discharge chamber pressure Pd among the suction chamber pressure Ps, the control chamber pressure Pc, and the discharge chamber pressure Pd acts on the valve body 108, and the valve opening degree is controlled autonomously. Therefore, by arbitrarily adjusting the current of the exciting coil 106, the discharge capacity of the compressor is controlled so that the discharge pressure corresponds to the current.

Even when the high pressure on the system side increases due to an increase in the heat load or the compressor rotation speed, the discharge pressure corresponding to the current is maintained because the pressure in the discharge chamber 44 acts directly on the valve element 108. In this way, the discharge capacity is controlled autonomously, so that a high pressure abnormality can be achieved without providing a pressure sensor or the like for measuring the pressure on the high pressure side of the refrigeration cycle 1 and controlling the discharge capacity based on an external signal. Can be promptly avoided.

2 Pressure control valve 26 Control chamber 27 Drive shaft 36 Swash plate 40 Cylinder 41 Piston 43 Compression chamber 44 Discharge chamber 45 Suction chamber 48

Air supply passage

61, 108

Valve body

75, 117 High

pressure introduction space

77, 122 Pressure adjustment space 80 Valve port

Claims

A housing, a drive shaft provided in the housing, a swash plate that rotates together with the drive shaft and has a variable inclination angle with respect to the drive shaft, and an axis provided in the housing and parallel to the drive shaft. A plurality of cylinders, a plurality of pistons slidably disposed in the cylinders and reciprocating in the cylinders as the swash plate rotates, and a compression chamber defined by the cylinders and the pistons A control chamber formed on the anti-compression chamber side of the piston, a suction chamber for storing a working fluid sucked into the compression chamber in the piston suction stroke, and compressed in the compression chamber in the piston compression stroke. A discharge chamber into which the working fluid is discharged, and is used in a variable capacity compressor whose discharge capacity decreases when the pressure in the control chamber increases, A pressure control valve for adjusting the pressure of the control chamber by adjusting the supply amount of the working fluid to the control chamber from the discharge chamber by adjusting the opening degree of the supply passage connecting the control chamber,
A pressure control valve that adjusts the opening degree of the air supply passage based only on the pressure of the discharge chamber among the pressure of the discharge chamber, the pressure of the suction chamber, and the pressure of the control chamber.
A high-pressure introduction space communicating with the discharge chamber, a pressure adjustment space communicating with the control chamber, a valve port communicating the high-pressure introduction space and the pressure adjustment space, and a valve opening / closing member capable of opening and closing the valve port And
The pressure of the discharge chamber introduced into the high-pressure introduction space on one end side in the operation direction of the valve opening / closing member acts in a direction to open the valve opening, and on the other end side in the operation direction of the valve opening / closing member. The pressure control valve according to claim 1, wherein atmospheric pressure or vacuum pressure acts.
The valve port opening / closing member has one end side in the operation direction facing the valve port, and the valve port can be opened / closed from the pressure adjustment space,
The pressure of the discharge chamber introduced into the high pressure introduction space acts on one end side of the valve opening / closing member via the valve opening,
The pressure control valve according to claim 2, wherein atmospheric pressure or vacuum pressure acts on the other end side in the operation direction of the valve opening / closing member.
4. The pressure control valve according to claim 2, further comprising external force applying means for applying an external force adjustable in a direction of closing the valve port to the valve port opening / closing member.
A variable capacity compressor using the pressure control valve according to any one of claims 1 to 4.