JP5260906B2 - Volume control valve for variable capacity compressor - Google Patents

Abstract

A displacement control valve for a variable displacement compressor, in which a solenoid portion is reduced in size and weight without a change in the area of a valve body seal. The displacement control valve has a valve housing (301), a valve body (304), and a solenoid unit (315). The valve housing (301) has a valve hole (302) communicating with a discharge chamber (142) of the variable displacement compressor (100) in a vehicle air conditioning system, a valve chamber (303) communicating with the valve hole (302) and also communicating with a crank chamber (105) of the compressor (100), and a first pressure-sensing chamber (306) separated from the valve chamber (303) and communicating with a suction chamber (140) of the compressor (100). The valve body (304) has a large-diameter section (304a) for opening and closing the valve hole (302), subjected to the pressure of the discharge chamber (142), and also subjected, on the first pressure-sensing chamber (306) side, to the pressure of the suction chamber (140). The solenoid unit (315) applies force to the valve body (304), which force acts against the pressure of the discharge chamber (142). The displacement control valve further has a second pressure-sensing chamber (309) communicating with either the suction chamber (140) or the crank chamber (105), and also has a rod (304b) for causing the pressure of the second pressure-sensing chamber (309) to act on the valve body (304).

Description

  The present invention relates to a capacity control valve of a variable capacity compressor applied to an air conditioning system, particularly a vehicle air conditioning system.

  For example, a reciprocating variable displacement compressor used in a vehicle air conditioning system includes a housing in which a discharge chamber, a crank chamber, a suction chamber, and a cylinder bore are defined, and a piston disposed in the cylinder bore of the housing. And a drive shaft that is rotatably supported in the housing and rotates with the engine as a power source, and a conversion mechanism that converts the rotation of the drive shaft into a reciprocating motion of the piston. By reciprocating, the working fluid is sucked into the cylinder bore from the suction chamber, and the sucked working fluid is compressed and the compressed working fluid is discharged into the discharge chamber. It has become.

In this reciprocating variable displacement compressor, the stroke length of the piston, that is, the discharge capacity of the compressor is variable by changing the pressure (control pressure) of the crank chamber, and the capacity for controlling the discharge capacity. The control valve is disposed in an air supply passage that communicates the discharge chamber and the crank chamber, while a throttle is disposed in an extraction passage that communicates the crank chamber and the suction chamber.
The capacity control valve is controlled by a control device, and this control device targets a pressure difference (differential pressure) between the pressure in the discharge chamber (discharge pressure) and the pressure in the suction chamber (suction pressure). The discharge capacity is feedback-controlled so as to approach the value (see, for example, Patent Document 1).

Here, the capacity control valve applies a valve closing force opposite to the force due to the pressure of the discharge chamber by applying an electromagnetic force to the valve body that opens and closes the valve hole communicating with the discharge chamber. And a spring that constantly applies a force in the valve opening direction to the valve body. The force acting on the valve body is a discharge pressure Pd, a suction pressure Ps, and a substantial sectional area of the valve hole. If the valve seal area equal to Sv is Sv, the force in the valve opening direction always applied from the spring to the valve body is fs, and the electromagnetic force of the solenoid is F (I), this is expressed by Formula (1). ) Is transformed into equation (2).
fs + Sv.Pd-Sv.Ps-F (I) = Sv. (Pd-Ps) + fs-F (I) = 0
Formula (1)
Pd−Ps = (1 / Sv) · F (I) − (fs / Sv) Equation (2)
The cross-sectional area of the valve hole is determined on the assumption of the maximum flow rate of the working fluid that can flow through the capacity control valve. The determination of the cross-sectional area of the valve hole means that the valve body seal area Sv, that is, the sensitivity Therefore, the necessary electromagnetic force is determined on the basis of the required maximum pressure difference.
JP 2001-132650 A

In recent years, it has become an important technical issue to make the variable capacity compressor small and lightweight in order to improve vehicle fuel efficiency and to reduce the space for mounting the variable capacity compressor. Along with this, there is a demand for smaller and lighter capacity control valves.
In the case of a displacement control valve, the solenoid part, which is the drive unit, occupies a large proportion in both volume and weight. Therefore, reducing the size and weight of the solenoid part reduces the size and weight of the displacement control valve. It will contribute greatly.

  However, in the displacement control valve of the variable displacement compressor used in the above-described vehicle air conditioning system, in order to reduce the size and weight of the solenoid without changing the necessary maximum pressure difference, it can be seen from Equation (2). As described above, it is sufficient to increase the value of 1 / Sv, that is, to decrease the valve body seal area Sv (valve hole cross-sectional area). Therefore, it has been a conventional problem to solve this problem.

  The present invention has been made in order to solve the above-described problems. For example, when the present invention is used in a reciprocating variable displacement compressor in a vehicle air conditioning system, the maximum flow rate of a working fluid that can flow is assumed. It is an object of the present invention to provide a displacement control valve of a variable displacement compressor that can realize a reduction in size and weight of a solenoid portion without changing an important valve element seal area.

According to the first aspect of the present invention, the displacement of the variable capacity compressor having a discharge chamber, a suction chamber, and a control pressure chamber installed in a circulation path through which the working fluid circulates is changed. And a valve hole that communicates with the discharge chamber, a valve chamber that communicates with the valve hole and communicates with the control pressure chamber, and is partitioned from the valve chamber and the suction chamber A valve housing having a first pressure sensing chamber communicating with the valve chamber, and a valve housing supported by a partition portion between the valve chamber and the first pressure sensing chamber and formed on one end side located in the valve chamber. It has a first pressure receiving surface that opens and closes a hole to receive the pressure of the discharge chamber, and has a second pressure receiving surface that is formed on the other end side located on the first pressure sensing chamber side and receives the pressure of the suction chamber. An electromagnetic force is applied to the valve body and the valve body to oppose the force generated by the pressure in the discharge chamber. In the capacity control valve having a solenoid for applying a directional force, a second pressure sensing chamber communicating with the suction chamber or the control pressure chamber is provided, and the pressure of the second pressure sensing chamber is received by a third pressure receiving surface. A transmission part is provided that applies force due to this pressure to one end side of the valve body, and the area of the third pressure receiving surface in the transmission part that receives the pressure of the second pressure sensing chamber is the first pressure receiving surface of the valve body. It is characterized in that it is set smaller than the seal area defined in the state where the valve hole is closed, and the configuration of the capacity control valve of this variable capacity compressor is used as a means for solving the above-described conventional problems. .

Further, in the invention according to claim 2, the area of the second pressure receiving surface of said valve body for receiving the pressure before Symbol suction chamber is supported by the partition portion between the valve chamber and the first pressure sensing chamber valve The area is defined based on the cross-sectional area of the body, and the area of the third pressure receiving surface in the transmission portion is set smaller than the area of the second pressure receiving surface of the valve body.

Furthermore, the invention according to claim 3, said second sense being inserted rotatably supported in the insertion hole communicating with the pressure chamber and the valve body at one end and disposed integrally or separately on the side rod of a configuration in which the said transmission unit Yes.
Furthermore, in the invention according to claim 4 , the area of the third pressure receiving surface that receives the pressure of the second pressure sensing chamber is the cross-sectional area of the rod that is supported so as to be able to be inserted into the insertion hole connected to the second pressure sensing chamber. It is configured.

Furthermore, in the invention according to claim 5 , the rod includes a portion supported so as to be able to be inserted into an insertion hole connected to the second pressure sensing chamber, and a portion located in the valve hole. The cross-sectional area of the portion to be positioned is set to be smaller than the area of the third pressure receiving surface.
Furthermore, the invention which concerns on Claim 6 is set as the structure provided with the provision means to give the force of the direction which goes to the said valve body with respect to the said transmission part.

Furthermore, the invention which concerns on Claim 7 is set as the structure provided with the adjustment member which adjusts the force of the direction which goes to the said valve body given to the transmission part from the said provision means.
Furthermore, in the invention according to claim 8 , the valve body and the rod as the transmission portion are coaxial, and the valve body support hole and the second in the partition portion between the valve chamber and the first pressure sensing chamber. The insertion hole connected to the pressure sensing chamber supports the valve body and the rod with a slight gap, and makes contact with the valve body and the rod when the valve body and the rod are inclined within the gap. It is configured to support it.

On the other hand, the invention according to claim 9 is a housing in which a discharge chamber, a crank chamber that is a control pressure chamber, a suction chamber, and a cylinder bore are partitioned and formed, a piston disposed in the cylinder bore, and a rotation to the housing A variable displacement compressor including a drive shaft supported by the shaft and a conversion mechanism that is housed in the crank chamber and converts rotation of the drive shaft into a reciprocating motion of the piston. The valve hole and the valve chamber of the capacity control valve described in any of 1 to 8 are communicated with each other, and the suction chamber or the crank chamber is communicated with the second pressure sensing chamber of the capacity control valve. .

And the invention which concerns on Claim 10 installs the variable capacity compressor described in Claim 9 with the heat radiator, the expander, and the evaporator in the circulation path through which the refrigerant circulates to constitute the refrigeration cycle of the air conditioning system, In a capacity control system for a variable capacity compressor that changes capacity based on a change in control pressure of a crank chamber in the variable capacity compressor, in a region from the discharge chamber of the variable capacity compressor to the expander in the refrigeration cycle. The refrigerant pressure is used as the discharge pressure, and the refrigerant pressure in the region from the expander of the refrigeration cycle to the suction chamber of the variable capacity compressor is used as the suction pressure. External information detection means for detecting external information, and discharge pressure and suction on the discharge chamber side based on the external information detected by the external information detection means Target differential pressure setting means for setting a target differential pressure with respect to the suction pressure on the side, and the variable capacity so as to bring the pressure difference between the discharge pressure on the discharge chamber side and the suction pressure on the suction chamber side closer to the target differential pressure The discharge capacity is changed by adjusting the energization amount to the solenoid of the capacity control valve in the compressor.

The invention according to claim 11, installed in the circulation passage in which the refrigerant so as to circulate constituting the refrigerating cycle of the air conditioning system, a variable displacement compressor according to claim 9 radiator, with expander and an evaporator, In a capacity control system for a variable capacity compressor that changes capacity based on a change in control pressure of a crank chamber in the variable capacity compressor, in a region from the discharge chamber of the variable capacity compressor to the expander in the refrigeration cycle. A discharge pressure detecting means for detecting the discharge pressure using the pressure of the refrigerant as a discharge pressure and the pressure of the refrigerant in the region from the expander of the refrigeration cycle to the suction chamber of the variable capacity compressor as the suction pressure. External information detection means for detecting one or more external information related to the refrigeration cycle, and external information detected by the external information detection means Target pressure setting means for setting one of the suction pressure and the control pressure based on the discharge pressure, the discharge pressure detected by the discharge pressure detection means and the target pressure set by the target pressure setting means Based on the above, the discharge capacity is changed by adjusting the energization amount to the solenoid of the capacity control valve in the variable capacity compressor.

  According to the capacity control valve of the variable capacity compressor according to claim 1 of the present invention, since it has the above-described configuration, for example, when used in a reciprocating variable capacity compressor in a vehicle air conditioning system, the suction chamber Alternatively, the maximum flow rate of the working fluid that can be flowed is assumed simply by bringing the cross-sectional area of the transmission section that receives the pressure of the second pressure sensing chamber communicating with the control pressure chamber and acts on one end side of the valve body close to the valve body seal area. In this case, the solenoid portion can be reduced in size and weight without changing the key valve seal area.

Further, according to the displacement control valve of a variable displacement compressor according to claim 1 of the present invention, the seal area defined in the state of closing the valve hole in the first pressure receiving surface of the valve body, the second pressure sensitive By setting the area of the third pressure receiving surface of the transmission part that receives the chamber pressure small, the discharge pressure can be applied in the valve opening direction, and the operation in the direction of decreasing the discharge capacity with respect to the increase in the discharge pressure. It can be done.

Furthermore, according to the capacity control valve of the variable capacity compressor according to claim 2 of the present invention, the variable capacity compressor is defined on the basis of the cross-sectional area of the valve body supported by the partition portion between the valve chamber and the first pressure sensing chamber. By setting the area of the third pressure receiving surface in the transmission part smaller than the area of the second pressure receiving surface, the suction pressure can be applied in the valve closing direction, and the discharge capacity is increased with respect to the increase of the suction pressure. It is possible to perform an operation in an increasing direction.

Furthermore, according to the displacement control valve of the variable displacement compressor according to claim 3 of the present invention, since the rod arranged integrally or separately on one end side of the valve body is used as the transmission portion, the structure of the transmission portion is simplified. Since the valve body and the rod as the transmission part are respectively supported by the partition part between the valve chamber and the first pressure sensing chamber and the insertion hole connected to the second pressure sensing chamber. The stability of the valve body can be improved.

Furthermore, in the capacity control valve of the variable capacity compressor according to claim 4 of the present invention, the third cross section of the rod supported by the insertion hole connected to the second pressure sensing chamber receives the pressure of the second pressure sensing chamber. Since it is set as the area of a pressure receiving surface, a 3rd pressure receiving surface can be formed easily.
Furthermore, in the displacement control valve of the variable displacement compressor according to claim 5 of the present invention, the cross-sectional area of the portion located in the valve hole of the rod is set to be smaller than the area of the third pressure receiving surface. While ensuring the flow path area of the valve hole as a flow path, the gradient of the differential pressure between the discharge pressure and the suction pressure with respect to the change in the current supplied to the solenoid can be increased.

Furthermore, in the capacity control valve of the variable capacity compressor according to claim 6 of the present invention, the valve body can be quickly moved in the opening direction in a state where the solenoid is demagnetized, and according to claim 7 of the present invention. In the capacity control valve of the variable capacity compressor, the force applied from the applying means to the transmission unit can be adjusted.
Furthermore, according to the capacity control valve of the variable capacity compressor according to claim 8 of the present invention, since it is configured as described above, it is connected to the gap between the valve body and the valve body support hole and the rod and the second pressure sensing chamber. In addition to being able to suppress the inclination of the valve body caused by the gap with the insertion hole, it is possible to operate smoothly even if the valve body is inclined.

On the other hand, the variable capacity compressor according to claim 9 of the present invention has the above-described configuration, so that the size and weight of the compressor itself can be reduced as the capacity control valve can be reduced in size and weight. Can also be realized.
In the capacity control system for a variable capacity compressor according to claim 10 of the present invention, the solenoid part is reduced in size and weight without changing the valve seal area of the capacity control valve, and the discharge pressure and the suction pressure are reduced. It is possible to feedback control the discharge capacity so that the pressure difference between the pressure and the pressure becomes the target differential pressure set by the target differential pressure setting means.

In the capacity control system of the variable capacity compressor according to claim 11 of the present invention, the discharge capacity can be controlled so that the suction pressure or the control pressure maintains the target pressure set by the target pressure setting means. The control range of the suction pressure or the control pressure can be slid according to the level of the discharge pressure, and as a result, the control range of the suction pressure or the control pressure can be expanded.

Hereinafter, a capacity control valve of a variable capacity compressor according to the present invention will be described in detail with reference to the drawings.
1 to 3 show an embodiment of a capacity control valve of a variable capacity compressor according to the present invention. In this embodiment, the capacity control valve of the variable capacity compressor according to the present invention is used as a refrigeration cycle of a vehicle air conditioning system. The case where it is adopted is shown.
As shown in FIG. 1, the refrigeration cycle 10 of the vehicle air conditioning system includes a circulation path 12 through which a refrigerant as a working fluid circulates. In this circulation path 12, a variable capacity compressor 100, a radiator (condenser) 14, an expander (expansion valve) 16 and an evaporator 18 are sequentially arranged along the flow direction of the refrigerant, and the variable capacity compressor When a series of processes including a refrigerant suction process, a suction refrigerant compression process, and a compressed refrigerant discharge process are performed by operating 100, the refrigerant circulates in the circulation path 12.

In this case, the evaporator 18 also constitutes a part of the air circuit of the vehicle air conditioning system, and the air flow passing through the evaporator 18 is cooled by removing the heat of vaporization by the refrigerant in the evaporator 18. The
The variable capacity compressor 100 used in the capacity control system A of this embodiment is a swash plate type clutchless compressor, and includes a cylinder block 101 having a plurality of cylinder bores 101a. A front housing 102 is connected to one end of the cylinder block 101, and a rear housing (cylinder head) 104 is connected to the other end of the cylinder block 101 via a valve plate 103.

  An interior surrounded by the cylinder block 101 and the front housing 102 is formed as a crank chamber 105, and a drive shaft 106 is arranged longitudinally in the crank chamber 105. The drive shaft 106 passes through an annular swash plate 107 that is also disposed in the crank chamber 105, and the swash plate 107 is hinged to the rotor 108 fixed to the drive shaft 106 via a connecting portion 109. Yes. Accordingly, the swash plate 107 can tilt while moving along the drive shaft 106.

A coil spring 110 that urges the swash plate 107 toward the minimum inclination angle is attached to a portion of the drive shaft 106 positioned between the rotor 108 and the swash plate 107, while the opposite side of the swash plate 107 is sandwiched. A coil spring 111 that urges the swash plate 107 toward the maximum inclination angle is attached to the portion, that is, the portion located between the swash plate 107 and the cylinder block 101 of the drive shaft 106.
An end portion of the drive shaft 106 on the front housing 102 side protrudes outside through a boss portion 102a formed on the front housing 102 toward the outside, and an end portion of the drive shaft 106 is provided as a power transmission device. Pulley 112 is connected. The pulley 112 is rotatably supported by the boss portion 102a via a ball bearing 113, and a belt 115 is looped between the pulley 112 and an engine 114 as an external drive source.

A shaft seal device 116 is disposed inside the boss portion 102a to block the inside and the outside of the front housing 102 from each other. The drive shaft 106 is rotatably supported by bearings 117, 118, 119, and 120 in the radial direction and the thrust direction. Power from the engine 114 is transmitted to the pulley 112, and can rotate in synchronization with the rotation of the pulley 112.
A piston 130 is disposed in the cylinder bore 101a, and a tail portion protruding into the crank chamber 105 is integrally formed on the piston 130. A pair of shoes 132 are disposed in a recess 130 a formed in the tail portion, and these shoes 132 are in sliding contact with the outer peripheral portion of the swash plate 107 so as to be sandwiched therebetween. Therefore, the piston 130 and the swash plate 107 are interlocked with each other via the shoe 132, and the piston 130 reciprocates in the cylinder bore 101a by the rotation of the drive shaft 106.

  A suction chamber 140 and a discharge chamber 142 are defined in the rear housing 104, and the suction chamber 140 can communicate with the cylinder bore 101 a through a suction hole 103 a provided in the valve plate 103. The discharge chamber 142 communicates with the cylinder bore 101a through a discharge hole 103b provided in the valve plate 103. The suction hole 103a and the discharge hole 103b are opened and closed by a suction valve and a discharge valve (not shown), respectively.

  A muffler 150 is provided on the side of the cylinder block 101, and the muffler casing 152 is joined to a muffler base 101b formed integrally with the cylinder block 101 via a seal member (not shown). The muffler casing 152 and the muffler base 101b form a muffler space 154, and the muffler space 154 communicates with the discharge chamber 142 via a discharge passage 156 that passes through the rear housing 104, the valve plate 103, and the muffler base 101b. .

  A discharge port 152a is formed in the muffler casing 152, and a check valve 200 is disposed in the muffler space 154 so as to block between the discharge passage 156 and the discharge port 152a. Specifically, the check valve 200 opens and closes according to the pressure difference between the pressure on the discharge passage 156 side and the pressure on the muffler space 154 side, and closes when the pressure difference is smaller than a predetermined value, and the pressure difference is predetermined. If it is larger than the value, it opens.

Therefore, the discharge chamber 142 can communicate with the forward portion of the circulation path 12 via the discharge passage 156, the muffler space 154, and the discharge port 152a, and the muffler space 154 is interrupted by the check valve 200. On the other hand, the suction chamber 140 communicates with the return path portion of the circulation path 12 via a suction port 104 a formed in the rear housing 104.
A capacity control valve (electromagnetic control valve) 300 of the variable capacity compressor 100 is accommodated in the rear housing 104, and the capacity control valve 300 is disposed in the air supply passage 160. The air supply passage 160 is formed from the rear housing 104 to the cylinder block 101 through the valve plate 103 so as to communicate between the discharge chamber 142 and the crank chamber 105.

On the other hand, the suction chamber 140 communicates with the crank chamber 105 via the extraction passage 162. The bleed passage 162 includes a fixed orifice 103 c formed in the space 164 and the valve plate 103 including a gap between the drive shaft 106 and the bearings 119 and 120.
The suction chamber 140 is connected to the capacity control valve 300 independently of the air supply passage 160 through a pressure sensitive passage 166 formed in the rear housing 104.

  More specifically, as shown in FIG. 2, the displacement control valve 300 includes a valve unit and a drive unit that opens and closes the valve unit. The valve unit has a cylindrical valve housing 301, and a valve hole 302 is formed on one end side of the valve housing 301. The valve hole 302 communicates with the discharge chamber 142 via the inlet port 301 a and the upstream portion of the air supply passage 160, and opens to the valve chamber 303 defined inside the valve housing 301.

A cylindrical valve body 304 is accommodated in the valve chamber 303. The valve body 304 can move in the valve chamber 303 in the axial direction of the valve housing 301, and can close the valve hole 302 by contacting the end surface of the valve housing 301. That is, the end surface of the valve housing 301 functions as a valve seat.
Further, an outlet port 301 b is formed on the outer peripheral surface of the valve housing 301, and the outlet port 301 b communicates with the crank chamber 105 through a downstream portion of the air supply passage 160. The outlet port 301b also opens into the valve chamber 303, and the discharge chamber 142 and the crank chamber 105 can communicate with each other through the valve hole 302, the valve chamber 303, and the outlet port 301b.

Further, a first pressure sensing chamber 306 adjacent to the valve chamber 303 is formed on the other end side of the valve housing 301 with the partition member 305 interposed therebetween. The first pressure sensing chamber 306 includes a pressure sensing port 307 and a pressure sensing port 307. The suction chamber 140 communicates with the pressure sensitive passage 166.
In this case, the valve body 304 includes a large diameter portion (first pressure receiving surface, second pressure receiving surface) 304a that is a valve body main body and a small diameter that is formed integrally and coaxially with the large diameter portion 304a and protrudes toward the valve hole 302 side. The large diameter portion 304a is slidably supported in an insertion hole 305a formed in the partition member 305, and the small diameter rod 304b is continuous with the valve hole 302 in the valve housing 301. Is slidably supported by the insertion hole 301c formed.

  That is, by supporting the valve body 304 substantially at both ends, the inclination of the valve body 304 caused by the clearance between the large diameter portion 304a and the insertion hole 305a and the clearance between the small diameter rod 304b and the insertion hole 301c can be suppressed. Even if the valve body 304 is inclined, it is difficult to cause the valve body 304 to be galling by adopting a structure that supports at one point in each of the insertion holes 305a and 301c (two-point support structure), The operation of the valve body 304 is performed smoothly.

Furthermore, a recess 301 d is formed at one end of the valve housing 301, and a cap 308 is press-fitted and fixed in the recess 301 d, and an inner space closed by the end surface of the valve housing 301 and the cap 308 is formed. A second pressure sensing chamber 309 is formed.
A small diameter rod 304b of the valve body 304 protrudes from the second pressure sensing chamber 309, and the small diameter rod 304b extends from a spring 310 disposed in the second pressure sensing chamber 309 via a spring guide 311. A force in the always valve opening direction is applied. At this time, the end of the spring 310 is in contact with the cap 308, and the adjustment of the force applied from the spring 310 to the rod 304b is made by changing the amount of press-fitting of the cap 308 into the recess 301d. .

The second pressure sensing chamber 309 communicates with the suction chamber 140 via a communication hole 308a formed in the center of the cap 308 and a pressure sensing passage 166, and the small diameter rod 304b of the valve body 304 is connected to the second sensing chamber 309. It is a transmission part which makes the pressure in the pressure chamber 309 act on the valve body 304, and functions as a 3rd pressure receiving surface.
On the other hand, the drive unit is a solenoid unit 315 disposed on the other end side of the valve housing 301, a cylindrical solenoid housing 321 coaxially connected to the valve housing 301, and the valve housing 301 of the solenoid housing 321. Includes an end cap 322 that closes the opposite open end.

  A sleeve 323 having a bottomed cylindrical shape that opens on the valve housing 301 side is disposed on the axial center of the solenoid housing 321, and a fixed core 324 is provided at a portion from the open end to the center of the sleeve 323. A movable core 326 is accommodated in the core accommodating space 325 formed between the closed end of the sleeve 323 on the end cap 322 side and the fixed core 324 while being accommodated.

  A solenoid rod 327 is slidably provided in the insertion hole 324a located at the axial center of the fixed core 324, and one end of the solenoid rod 327 protruding into the valve chamber 303 is integrally connected to the valve body 304. The other end protruding into the core accommodating space 325 is fitted and fixed in a through hole formed in the movable core 326, whereby the movable core 326 and the solenoid rod 327 operate integrally.

  A coil 329 formed by being wound around a bobbin 328 and disposed around the sleeve 323 in the solenoid housing 321 is disposed. The solenoid housing 321, the end cap 322, the fixed core 324, and the movable core 326 are all magnetic. The sleeve 323 is made of a non-magnetic stainless steel material.

  The fixed core 324 is provided with a flange portion 324b, and a communication hole 324c that connects the first pressure sensing chamber 306 of the valve housing 301 and the insertion hole 324a of the fixed core 324 is formed in the flange portion 324b. Thus, the suction chamber 140 and the movable core housing space 325 are communicated with each other through the first pressure sensing chamber 306, the communication hole 324c, and the insertion hole 324a. It acts on 304 as a force in the valve closing direction.

The solenoid unit 315 is connected to a control device 400A provided outside the variable capacity compressor 100. When a control current I is supplied from the control device 400A, an electromagnetic force F (I) is generated. The electromagnetic force F (I) of the solenoid unit 315 attracts the movable core 326 to the fixed core 324 side and causes the valve body 304 to perform a valve closing operation.
In the refrigeration cycle 10 of the vehicle air conditioning system including the variable capacity compressor 100 having the capacity control valve 300, when the air conditioner is not operated in the engine operating state, the solenoid unit of the capacity control valve 300 of the variable capacity compressor 100. Since no current flows to 315, the valve body 304 is forcedly separated from the valve hole 302 by the elastic force of the spring 310 and is in the valve open state, and the discharge capacity is minimized.

  At this time, since the check valve 200 is always applied with a force in the closing direction, the refrigerant circulation to the air conditioning system is blocked, and as a result, the refrigerant discharged into the discharge chamber 142 with the minimum discharge capacity. Flows into the crank chamber 105 via the air supply passage 160 between the discharge chamber 142 including the capacity control valve 300 and the crank chamber 105, and then the gap between the drive shaft 106 and the bearings 119, 120, the space 164, and the fixing. It circulates in an internal circulation circuit that returns from the crank chamber 105 to the suction chamber 140 via a bleed passage 162 formed of an orifice 103c.

  On the other hand, when the air conditioner is operated, a current flows to the solenoid unit 315 of the capacity control valve 300 of the variable capacity compressor 100, and the valve body 304 is brought into the elastic force of the spring 310 as shown in FIG. Accordingly, the valve chamber 302 is brought into contact with the valve hole 302 to be closed, and the air supply passage 160 between the discharge chamber 142 and the crank chamber 105 is shut off, so that the pressure in the crank chamber 105 is reduced to be equal to the suction pressure. Become.

As a result, the inclination angle of the swash plate 107 is increased and the stroke of the piston 130 is increased. Therefore, when the pressure in the discharge chamber 142 is increased and the differential pressure across the check valve 200 exceeds a predetermined value, the check valve 200 is opened. The compressed refrigerant flows to the air conditioning system side.
During the operation of the variable displacement compressor 100, the control device 400A supplies the control current I to the solenoid unit 315 of the displacement control valve 300 to generate the electromagnetic force F (I). The discharge capacity of the compressor 100 is controlled.

  Next, the control characteristics of the capacity control valve 300 of the variable capacity compressor 100 will be described. In the capacity control valve 300, the pressure of the discharge chamber 142 (hereinafter referred to as discharge pressure Pd) acts on the large diameter portion 304a as the first pressure receiving surface located on one end side of the valve body 304, while the transmission portion The second pressure receiving surface located on the other end side of the valve body 304 and the pressure of the second pressure sensing chamber 309 (hereinafter referred to as suction pressure Ps) acts on the small diameter rod 304b as the third pressure receiving surface. The pressure of the suction chamber 140 (hereinafter referred to as suction pressure Ps) acts on the large-diameter portion 304a, and thus the valve body 304 functions as a pressure-sensitive member.

Here, the pressure receiving area (referred to as seal area Sv) of the valve body 304 when the valve body 304 closes the valve hole 302 and the large diameter portion 304a of the valve body 304 supported by the insertion hole 305a of the partition member 305. If the cross-sectional area is equal, the pressure in the crank chamber 105 (hereinafter referred to as crank pressure) does not act on the valve body 304 in either the opening direction or the closing direction.
Therefore, the force acting on the valve body 304 in this situation is expressed by the following equation (3), where Sr is the cross-sectional area of the rod 304b of the valve body 304 and fs is the force in the valve opening direction that is always applied from the spring 310 to the small diameter portion 304b. The equation (3) is transformed into the equation (4).
fs + Sr * Ps + (Sv-Sr) * Pd-Sv * Ps-F (I) = 0 Formula (3)
Pd−Ps = (1 / (Sv−Sr)) · F (I) − (fs / (Sv−Sr))
(However, Sr <Sv) Formula (4)
Equation (4) indicates that the pressure difference between the discharge pressure Pd and the suction pressure Ps can be adjusted by the electromagnetic force F (I) generated by the solenoid unit 315, that is, the current I.

That is, when the current I is increased, the electromagnetic force F (I) generated by the solenoid unit 315 acts to move the valve body 304 in the valve closing direction, so that the discharge pressure Pd and the suction pressure are increased as the current I is increased. The pressure difference with Ps can be set large.
The control unit 400 sets the pressure difference (target differential pressure ΔP) between the target discharge pressure Pd and the suction pressure Ps based on various external information from the external information detection means, that is, the control current I Therefore, the discharge capacity is feedback-controlled so that the pressure difference between the discharge pressure Pd and the suction pressure Ps becomes the target differential pressure ΔP.

At this time, if the control current I is zero, the valve element 304 is moved in the valve opening direction by the force constantly applied from the spring 310 to the small diameter portion 304b, and the valve hole 302 is opened. Introduced into the crank chamber 105, the discharge capacity is kept to a minimum.
Here, the electromagnetic force F (I) on the right side of the above formula (4) is multiplied by 1 / (Sv−Sr) as a coefficient. That is, the coefficient of the electromagnetic force F (I) can be changed by changing the cross-sectional area Sr of the rod 304b without changing the seal area Sv.

For example, if the cross-sectional area Sr of the rod 304b is brought close to the seal area Sv, the coefficient 1 / (Sv−Sr) increases, and the pressure difference between the discharge pressure Pd and the suction pressure Ps with respect to the change in the current supplied to the solenoid unit 315. The inclination of becomes larger.
Therefore, as shown in FIG. 4, in the graph of the formula (4) in the capacity control system A of the present embodiment, the current supplied to the solenoid unit 315 is compared with the graph of the formula (2) in the conventional capacity control system. The inclination of the pressure difference between the discharge pressure Pd and the suction pressure Ps with respect to the change can be increased, and the current value for obtaining the target differential pressure ΔP can be reduced to I ′ smaller than I in the graph of the equation (2). it can.

This means that if the required maximum pressure difference is not changed, it means that the electromagnetic force generated in the solenoid unit 315 can be kept small, so that the solenoid unit 315 can be reduced in size and weight.
In this embodiment, as partially shown in FIG. 5, the valve hole 302 of the valve body 304 is larger than the area of the rod 304b supported by the insertion hole 301c of the valve housing 301, that is, the area of the third pressure receiving surface. If the cross-sectional area of the portion 304c located inside is set small, the flow passage area of the valve hole 302 as a fluid flow passage can be secured, so that the discharge pressure Pd and the suction pressure with respect to the change in the current supplied to the solenoid unit 315 The slope of the differential pressure with Ps can be increased.

FIG. 6 shows another embodiment of the capacity control valve of the variable capacity compressor according to the present invention. In this embodiment as well, the capacity control valve of the variable capacity compressor according to the present invention is used as the refrigeration cycle of the vehicle air conditioning system. The case where it is adopted is shown.
As shown in FIG. 6, in the capacity control valve 300, the second pressure sensing chamber 309 and the crank chamber 105 communicate with each other via a communication hole 308 a formed at the center of the cap 308 and a downstream portion of the air supply passage 160. Also in this case, the small-diameter rod 304b of the valve body 304 is a transmission portion that causes the pressure in the second pressure sensing chamber 309 to act on the valve body 304 and functions as a third pressure receiving surface. Yes.

  The control characteristics of the displacement control valve 300 will be described. In the capacity control valve 300, the pressure of the discharge chamber 142 (hereinafter referred to as discharge pressure Pd) acts on the large diameter portion 304a as the first pressure receiving surface located on one end side of the valve body 304, while the transmission portion And the pressure of the second pressure sensing chamber 309 (hereinafter referred to as the crank pressure Pc) acts on the small-diameter rod 304b as the third pressure receiving surface and is located on the other end side of the valve body 304. The pressure of the suction chamber 140 (hereinafter referred to as suction pressure Ps) acts on the large-diameter portion 304a, and thus the valve body 304 functions as a pressure-sensitive member.

Here, the pressure receiving area (referred to as seal area Sv) of the valve body 304 when the valve body 304 closes the valve hole 302 and the large diameter portion 304a of the valve body 304 supported by the insertion hole 305a of the partition member 305. If the cross-sectional area is equal, the crank pressure Pc of the crank chamber 105 acts on the valve body 304 in the opening direction.
Therefore, the force acting on the valve body 304 in this situation is expressed by the equation (5) where Sr is the cross-sectional area of the rod 304b of the valve body 304 and fs is the force in the valve opening direction that is always applied from the spring 310 to the small diameter portion 304b. In this equation (5), if it is modified as Pc = Ps + α, equation (6) is obtained.
fs + Sr * Pc + (Sv-Sr) * Pd-Sv * Ps-F (I) = 0 Formula (5)
If Pc = Ps + α,
Pd−Ps = (1 / (Sv−Sr)) · F (I) − (fs + Sr · α) / (Sv−Sr)
(However, Sr <Sv) Formula (6)
Equation (6) also shows that the pressure difference between the discharge pressure Pd and the suction pressure Ps can be adjusted by the electromagnetic force F (I) generated by the solenoid unit 315, that is, the current I, and the current I is increased. Accordingly, the pressure difference between the discharge pressure Pd and the suction pressure Ps can be set large.

As in the previous embodiment, the electromagnetic force F (I) on the right side of Equation (6) is multiplied by 1 / (Sv−Sr) as a coefficient, and the cross-sectional area Sr of the rod 304b is set to the seal area Sv. As the values approach, the coefficient 1 / (Sv−Sr) increases, and the slope of the pressure difference between the discharge pressure Pd and the suction pressure Ps with respect to the change in the current supplied to the solenoid unit 315 increases.
Therefore, also in this embodiment, compared with the conventional capacity control system, the gradient of the pressure difference between the discharge pressure Pd and the suction pressure Ps with respect to the change in the current supplied to the solenoid unit 315 can be increased, and the target differential pressure is increased. The current value for obtaining ΔP may be small.

That is, if the required maximum pressure difference is not changed, the electromagnetic force generated in the solenoid unit 315 can be suppressed to a small value, and as a result, the solenoid unit 315 can be reduced in size and weight.
In each of the above-described embodiments, energization of the solenoid unit 315 of the capacity control valve 300 in the variable capacity compressor 100 is performed so that the pressure difference between the discharge pressure on the discharge chamber side and the suction pressure on the suction chamber side approaches the target differential pressure. Although the case where control is performed so as to change the discharge capacity by adjusting the amount is shown, the present invention is not limited to this. In the present invention, the discharge pressure acts on one end side and the suction pressure on the other end side. The present invention can be applied to all discharge amount control systems that use a so-called pressure-sensitive structure capacity control valve.

  As another capacity control system, for example, as shown in FIG. 1 used in the description of the above embodiment, a sensor (discharge pressure detecting means) 500a for detecting the discharge pressure Pd and one or more related to the refrigeration cycle 10 are used. External information detecting means (not shown) for detecting external information and target pressure setting means for setting one target pressure of the suction pressure Ps and the control pressure Pc based on the external information detected by the external information detecting means. And a solenoid unit 315 of the capacity control valve 300 in the variable capacity compressor 100 based on the discharge pressure Pd detected by the sensor 500a and the target pressure set by the target pressure setting means of the control apparatus 400B. There is a capacity control system B that changes the discharge capacity by adjusting the amount of current supplied to the.

  Since the capacity control system B controls the suction pressure Ps, when the suction pressure Ps decreases due to a lack of refrigerant, the discharge capacity is decreased so as to maintain the suction pressure Ps at the target suction pressure, and finally Move to minimum capacity. As a result, even if the structure is as simple as the capacity control valve 300 described above, the variable capacity compressor 100 is protected by avoiding the maximum discharge capacity when the refrigerant is insufficient.

In addition, the capacity control system B described above has a wide control range of the suction pressure Ps while the suction pressure Ps is a control target. This is due to the following reason.
In this capacity control valve 300, the force acting on the valve body 304 is as follows: Sr is the cross-sectional area of the rod 304b of the valve body 304, and fs is the force in the valve opening direction that is always applied from the spring 310 to the small diameter portion 304b. Equation (4) is obtained.
Ps = − (1 / (Sv−Sr)) · F (I) + Pd + (fs / (Sv−Sr))
(However, Sr <Sv) Formula (7)
Expression (7) indicates that the suction pressure Ps can be adjusted by the electromagnetic force F (I) generated by the solenoid unit 315, that is, the current I and the discharge pressure Pd.

  Based on such a relationship, if the target suction pressure is determined in advance and information on the changing discharge pressure Pd is known, the electromagnetic force F (I), that is, the value of the control current I to be generated can be calculated. Then, when the energization amount to the solenoid unit 315 is adjusted based on the calculated control current I, the valve body 304 operates so that the suction pressure Ps maintains the target suction pressure, and the crank pressure Pc is adjusted. That is, the discharge capacity is controlled so that the suction pressure Ps maintains the target suction pressure.

  In such control that maintains the suction pressure Ps at the target suction pressure, as shown in FIG. 7, the suction pressure Ps can be controlled in the range from Pdmin to Pdmax according to the level of the discharge pressure Pd. The control range of the suction pressure Ps at an arbitrary discharge pressure Pdh can be slid higher than the control range of the suction pressure Ps at a discharge pressure Pdl lower than the discharge pressure Pdh.

  Also in this case, if the cross-sectional area Sr of the rod 304b is brought close to the seal area Sv, the coefficient 1 / (Sv−Sr) increases, and the target suction at an arbitrary discharge pressure Pd with a small electromagnetic force F (I). The control range of the pressure can be expanded, and the control range of the target suction pressure can be greatly expanded by exhibiting the synergistic effect of the slide of the control range of the target suction pressure and the expansion of the control range. .

In the above-described embodiment, the case where the valve body 304 includes the large-diameter portion 304a and the small-diameter rod 304b formed integrally and coaxially with the large-diameter portion 304a has been described, but the large-diameter portion 304a and the rod 304b are illustrated. May be separate from each other.
In addition to the discharge pressure and the suction pressure, a pressure in the crank chamber may be applied to the valve body 304 of the capacity control valve. Further, as a configuration different from the capacity control valve described above, for example, a small bellows is used. Adopted as a pressure-sensitive member, the valve body is connected to one end of the bellows to receive the discharge pressure, the suction pressure is applied to the inside of the bellows, and the solenoid rod is connected to the end surface of the bellows. It is also possible.

Furthermore, an elastic body that applies a force in the valve closing direction to the movable core 326 of the solenoid rod unit 315 after setting a large force to be applied from the spring 310 disposed in the second pressure sensing chamber 309 to the small diameter portion 304b. It is also possible to adopt a configuration for installation.
Furthermore, although the case where the variable displacement compressor 100 is a clutchless compressor has been described in the above-described embodiment, it may be a variable displacement compressor equipped with an electromagnetic clutch.

Furthermore, in the above-described embodiment, the variable capacity compressor 100 is a swash plate type reciprocating compressor. However, the variable capacity compressor 100 may be a swing plate type variable capacity compressor, and may include an electric motor. A hermetic variable capacity compressor may be used.
Furthermore, in the variable capacity compressor 100 in the above-described embodiment, the fixed orifice 103c formed in the valve plate 103 is employed as a throttle element of the extraction passage 162 that regulates the flow rate so as to increase the pressure in the crank chamber 105. However, the present invention is not limited to this, and as another configuration, for example, a variable throttle or a valve may be employed to regulate the flow rate.

  Furthermore, the capacity control valve of the variable capacity compressor of the present invention can be applied to refrigeration cycles in general, such as refrigeration cycles for indoor air conditioning systems other than vehicle air conditioning systems, and refrigeration cycles for refrigeration equipment such as refrigeration / refrigerators. In addition, in addition to the refrigeration cycle using R134a and carbon dioxide as a refrigerant, the present invention can be applied to a refrigeration cycle using a new refrigerant other than R134a and carbon dioxide.

It is explanatory drawing which shows schematic structure of the refrigerating cycle of a vehicle air conditioning system with the longitudinal cross-section of a variable capacity compressor. FIG. 2 is a cross-sectional explanatory view showing a valve open state of a capacity control valve in the variable capacity compressor of FIG. FIG. 2 is an explanatory cross-sectional view showing a closed state of a capacity control valve in the variable capacity compressor of FIG. It is a graph which shows the relationship of the pressure difference of the target discharge pressure with respect to control current, and suction pressure. It is an expanded sectional explanatory view of the 2nd pressure sensing room part showing other examples of composition of a capacity control valve in the variable capacity compressor of Drawing 1. FIG. 6 is a cross-sectional explanatory view of a valve opening state showing a capacity control valve according to another embodiment of the variable capacity compressor in FIG. 1. It is a graph which shows the relationship of the target suction pressure with respect to the control current of the other capacity | capacitance control system using the capacity | capacitance control valve of the variable capacity compressor in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Variable capacity compressor 101 Housing 101a Cylinder bore 105 Crank chamber 106 Drive shaft 130 Piston 140 Suction chamber 142 Discharge chamber 300 Capacity control valve 301 Valve housing 301c Insertion hole 302 Valve hole 303 Valve chamber 304 Valve body 304a Large diameter part (first pressure receiving pressure) Surface, second pressure receiving surface)
304b Small-diameter rod (transmission part; third pressure-receiving surface)
306 First pressure sensing chamber 308 Cap (adjusting member)
308a Insertion hole
309 Second pressure sensing chamber 310 Spring (applying means)
315 Solenoid unit (solenoid)

Claims (11)

A displacement control valve comprising a discharge chamber, a suction chamber, and a control pressure chamber, wherein the displacement of a variable displacement compressor installed in a circulation path through which a working fluid circulates is changed based on a change in pressure of the control pressure chamber. ,
A valve having a valve hole communicating with the discharge chamber, a valve chamber communicating with the valve hole and communicating with the control pressure chamber, and a first pressure sensing chamber partitioned from the valve chamber and communicated with the suction chamber A housing;
A first pressure receiving pressure that is supported at a partition portion between the valve chamber and the first pressure sensing chamber and that is formed on one end side located in the valve chamber to open and close the valve hole and receive the pressure of the discharge chamber. A valve body having a second pressure receiving surface that is formed on the other end side that has a surface and is located on the first pressure sensing chamber side and that receives the pressure of the suction chamber;
In a capacity control valve provided with a solenoid that applies an electromagnetic force to the valve body to apply a force in a direction opposite to the force due to the pressure of the discharge chamber,
A second pressure sensing chamber communicating with the suction chamber or the control pressure chamber is provided, and the pressure of the second pressure sensing chamber is received by the third pressure receiving surface, and the force caused by this pressure is applied to one end side of the valve body. Set up a section ,
The area of the third pressure receiving surface in the transmission portion that receives the pressure of the second pressure sensing chamber is set to be smaller than the seal area defined in a state where the valve hole is closed by the first pressure receiving surface of the valve body. A capacity control valve for a variable capacity compressor. The area of the second pressure receiving surface of the valve body that receives the pressure of the suction chamber is an area that is defined based on the cross-sectional area of the valve body that is supported by a partition portion between the valve chamber and the first pressure sensing chamber. The capacity control valve of the variable capacity compressor according to claim 1, wherein an area of the third pressure receiving surface in the transmission unit is set smaller than an area of the second pressure receiving surface of the valve body. Of the variable displacement compressor according to claim 1 or 2 rods arranged integrally or separately and said transmitting portion at one end of the second sensitive inserted rotatably supported in the insertion hole communicating with the pressure chamber and the valve body Capacity control valve. 4. The variable capacity compressor according to claim 3 , wherein the area of the third pressure receiving surface that receives the pressure of the second pressure sensing chamber is a cross-sectional area of a rod that is supported so as to be able to be inserted into an insertion hole connected to the second pressure sensing chamber. Capacity control valve. The rod includes a portion supported so as to be able to be inserted into an insertion hole connected to the second pressure sensing chamber and a portion located in the valve hole, and a cross-sectional area of the portion located in the valve hole is the third area. The capacity control valve of the variable capacity compressor according to claim 4 , wherein the capacity control valve is set to be smaller than an area of the pressure receiving surface. The displacement control valve for a variable displacement compressor according to any one of claims 1 to 5 , further comprising applying means for applying a force in a direction toward the valve body to the transmission portion. The displacement control valve for a variable displacement compressor according to claim 6 , further comprising an adjustment member that adjusts a force in a direction toward the valve body that is applied from the applying unit to the transmission unit. The valve body and the rod as the transmission part are coaxial, and the insertion hole connected to the valve body support hole and the second pressure sensing chamber in the partition portion between the valve chamber and the first pressure sensing chamber is the valve with the body and the rod support respectively with a slight gap, any claim 3 to 7 wherein the valve body and the rod is supported by contact with a point to each of the valve body and the rod in a state inclined in the range of the gap A capacity control valve for a variable capacity compressor according to claim 1. A housing having a discharge chamber, a crank chamber as a control pressure chamber, a suction chamber and a cylinder bore defined therein, a piston disposed in the cylinder bore, a drive shaft rotatably supported by the housing, and the crank In a variable capacity compressor having a conversion mechanism housed in a chamber and converting the rotation of the drive shaft into a reciprocating motion of the piston,
The discharge chamber and the crank chamber communicate with the valve hole and the valve chamber of the capacity control valve according to any one of claims 1 to 8 , and the suction chamber or the crank chamber is a second feeling of the capacity control valve. A variable capacity compressor characterized by communicating with a pressure chamber. A variable capacity compressor according to claim 9 is installed together with a radiator, an expander and an evaporator in a circulation path through which a refrigerant circulates to constitute a refrigeration cycle of an air conditioning system, and control of a crank chamber in the variable capacity compressor In a capacity control system of a variable capacity compressor that changes capacity based on a change in pressure,
The refrigerant pressure in the region from the discharge chamber of the variable capacity compressor in the refrigeration cycle to the expander is used as the discharge pressure, and the region from the expander in the refrigeration cycle to the suction chamber of the variable capacity compressor The pressure of the refrigerant at the suction pressure,
An external information detecting means for detecting one or more external information related to the refrigeration cycle, and a discharge pressure on the discharge chamber side and a suction pressure on the suction chamber side based on the external information detected by the external information detecting means; Target differential pressure setting means for setting the target differential pressure of
In order to make the pressure difference between the discharge pressure on the discharge chamber side and the suction pressure on the suction chamber side closer to the target differential pressure, the discharge capacity is changed by adjusting the energization amount to the solenoid of the capacity control valve in the variable capacity compressor. A capacity control system for a variable capacity compressor. A variable capacity compressor according to claim 9 is installed together with a radiator, an expander and an evaporator in a circulation path through which a refrigerant circulates to constitute a refrigeration cycle of an air conditioning system, and control of a crank chamber in the variable capacity compressor In a capacity control system of a variable capacity compressor that changes capacity based on a change in pressure,
The refrigerant pressure in the region from the discharge chamber of the variable capacity compressor in the refrigeration cycle to the expander is used as the discharge pressure, and the region from the expander in the refrigeration cycle to the suction chamber of the variable capacity compressor The pressure of the refrigerant at the suction pressure,
A discharge pressure detecting means for detecting the discharge pressure; an external information detecting means for detecting one or more external information related to the refrigeration cycle; and the suction pressure based on the external information detected by the external information detecting means. And target pressure setting means for setting one target pressure of the control pressure,
Based on the discharge pressure detected by the discharge pressure detecting means and the target pressure set by the target pressure setting means, the amount of current supplied to the solenoid of the capacity control valve in the variable capacity compressor is adjusted to reduce the discharge capacity. A capacity control system of a variable capacity compressor characterized by being changed.

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