KR20170092080A - Control valve for variable displacement compressor - Google Patents

Abstract

According to the present invention, applied is a control valve which senses the differential pressure between the refrigerant pressure and the atmospheric pressure, thereby enhancing control responsiveness while achieving the miniaturization of the control valve. A solenoid (3) comprises: a body (7) having an operation space (60) installed inside an electromagnetic coil (54), extending in an axial line direction, wherein the operation space (60) is opened to the atmosphere in a direction opposite to a valve main body (2); a core (64) fixated on the body (7) to be arranged in the operation space (60) and having a penetrating hole (66) formed in the axial line direction; a plunger (62) arranged in the operation space (60) to be disposed between the core (64) and a diaphragm (4) and supported to be able to slide to the body (7); and a spring (68) supported by the core (64) to be accommodated in the penetrating hole (66) as a coaxial shape, supporting the plunger (62) in the axial line direction, and biasing the plunger (62) in a direction being spaced from the core (64).

Description

[0001] CONTROL VALVE FOR VARIABLE DISPLACEMENT COMPRESSOR [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control valve for a variable capacity compressor that operates by detecting a differential pressure between a refrigerant pressure and an atmospheric pressure.

BACKGROUND ART [0002] As a compressor of an air conditioner for a vehicle, a variable displacement compressor capable of varying the discharge capacity of a refrigerant so that a constant cooling capacity is maintained irrespective of the number of revolutions of the engine is widely used. Generally, a solenoid-driven control valve is used for capacity control of the compressor. Such a control valve is constituted by assembling a valve body for accommodating a valve mechanism and a solenoid for driving the valve mechanism in the axial direction.

As such a control valve, there is one in which the opening degree of the valve portion is controlled autonomously such that the suction pressure and the atmospheric pressure differential pressure of the compressor are sensed and operated so that the suction pressure becomes a set pressure corresponding to the supply current value 1). In this control valve, a diaphragm is interposed between a valve body and a solenoid to divide them, and a suction pressure is introduced into a body (also referred to as a "valve body") on the valve body side and a solenoid body ) Is opened to the atmosphere. Thereby, the diaphragm can sense the differential pressure between the suction pressure and the atmospheric pressure to drive the valve portion.

In such a control valve, the core is fixed to the inside of the solenoid body, and the plunger is disposed between the core and the diaphragm. A shaft for supporting the plunger in the axial direction is provided so as to pass through the core. In this shaft, one end is fixed to the plunger, and the other end is supported by the solenoid body. Further, in the solenoid body, a spring is disposed for separating the plunger and the core when the energization is turned off. The solenoid body is provided with a ventilation passage for opening an operating space in which a plunger or the like is disposed to the atmosphere. From the viewpoint of waterproof and the like, this ventilation passage is formed at the end portion opposite to the valve body in the solenoid body.

Japanese Patent Application Laid-Open No. 2005-133556

However, in order to realize such a configuration, a space for accommodating the spring, a space for providing the bearing portion for supporting the shaft, etc. must be ensured separately from the core and the plunger in the solenoid body. In addition, the shaft is provided with a spring bearing for receiving the spring. For this reason, there has been a problem that the control valve is enlarged in the axial direction. Further, since the clearance between the shaft and the bearing portion is set to be relatively small in order to stably support the plunger, time is required until the pressure in the working space is again balanced with the atmospheric pressure. That is, when the temperature and the pressure of the operating space increase due to energization of the solenoid, there is a problem that the control responsiveness is lowered until the pressure in the working space becomes atmospheric pressure.

The object of the present invention is to realize a control valve that operates by detecting a differential pressure between a refrigerant pressure and an atmospheric pressure while maintaining a high control response.

An embodiment of the present invention is a control valve for a variable capacity compressor, which is constituted by assembling a valve body and a solenoid in an axial direction through a pressure reducing member and sensing a differential pressure between a refrigerant pressure and an atmospheric pressure to drive the valve portion. The valve body includes a valve body having a refrigerant flow passage, a valve hole provided in the flow passage, and a pressure chamber into which refrigerant pressure is introduced; A valve body that opens and closes the valve portion by being in contact with the valve hole; And a transmitting member provided between the valve body and the pressure-reducing member. The solenoid includes a solenoid body holding an electromagnetic coil, a working space formed inside the electromagnetic coil, the working space being open to the atmosphere on the opposite side of the valve body; A core fixed to the solenoid body so as to be disposed in the working space and having an axial through hole; A plunger disposed in the working space to be positioned between the core and the pressure-reducing member, the plunger slidably supported on the solenoid body; And a spring that is supported on the core so as to be inserted into the through hole in a coaxial shape, supports the plunger in the axial direction, and biases the plunger in a direction away from the core. The pressure-reducing member is interposed between the valve body and the solenoid body so as to partition the pressure chamber and the working space. The force generated by the differential pressure member sensing the differential pressure between the refrigerant pressure and the atmospheric pressure and the force of the solenoid is transmitted to the valve body through the transmitting member. The inner space of the spring inserted into the core is opened to the atmosphere.

According to this embodiment, the core supports the spring to be inserted therethrough, and the biasing force of the spring is directly applied to the plunger. Therefore, the shaft for supporting the plunger and the bearing portion for supporting the shaft are unnecessary, so that the control valve can be made compact in the axial direction. Further, since the entrance and exit of the working space are not narrowed by such a shaft or bearing portion, the pressure of the working space can easily be taken in and out, and even if the pressure is changed, it can be brought close to the atmospheric pressure quickly. That is, according to this embodiment, it is possible to achieve miniaturization while maintaining high control response of the control valve.

According to the present invention, in a control valve that operates by detecting a differential pressure between a refrigerant pressure and an atmospheric pressure, it is possible to achieve miniaturization while maintaining high control responsiveness.

1 is a sectional view showing a configuration of a control valve according to an embodiment.
2 is an enlarged view of part A of Fig.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. On the other hand, in the following description, for convenience, the positional relationship of each structure may be expressed up and down based on the illustrated state.

1 is a cross-sectional view showing a configuration of a control valve according to an embodiment.

The control valve 1 is configured as a solenoid valve for controlling the discharge capacity of a variable displacement compressor (simply referred to as "compressor") installed in a refrigeration cycle of an automotive air conditioner. This compressor compresses the refrigerant flowing in the refrigeration cycle and discharges it as gas refrigerant of high temperature and high pressure. The gas refrigerant is condensed by a condenser (external heat exchanger), and further expanded adiabatically by the expansion device to become a low temperature / low pressure mist type refrigerant. The low-temperature and low-pressure refrigerant evaporates by the evaporator, and the vehicle interior air is cooled by the latent heat of evaporation. The refrigerant evaporated in the evaporator is returned to the compressor again to circulate the refrigeration cycle.

The compressor includes a rotation shaft that is rotationally driven by an automobile engine, and a compression piston is connected to a swing plate mounted on the rotation shaft. By changing the angle of the swing plate to change the stroke of the piston, the discharge amount of the refrigerant is adjusted. The control valve 1 controls the flow rate of the refrigerant introduced into the control chamber from the discharge chamber of the compressor to change the angle of the swing plate and thus the displacement of the compressor. For example, alternative refrigerant (HFC-134a) is used as the refrigerant, but other refrigerant (HFO-1234yf, etc.) may be used. On the other hand, the control chamber of the present embodiment is formed of a crank chamber, but in the modified example, it may be a pressure chamber separately provided in the crank chamber or the crank chamber.

The control valve 1 operates by detecting the suction pressure Ps of the compressor and the differential pressure between the atmospheric pressure (i.e., the gauge pressure of the suction pressure) and introduces the suction pressure Ps from the discharge chamber into the control chamber So-called " Ps " sensing valve. The control valve 1 is constituted by assembling the valve body 2 and the solenoid 3 via the diaphragm 4 in the axial direction. The valve body 2 includes a valve portion for opening and closing the refrigerant passage for introducing a part of the discharge refrigerant into the control chamber during the operation of the compressor. The solenoid (3) drives the valve portion in the opening and closing direction to adjust its opening degree and controls the flow rate of the refrigerant introduced into the control chamber. The valve body 2 includes a cylindrical body 5 having a stepped portion, a valve portion provided inside the body 5, and the like. The diaphragm 4 is interposed between the body 5 of the valve body 2 and the body 7 of the solenoid 3 and senses the differential pressure between the suction pressure Ps and the atmospheric pressure to be displaced in the axial direction. The body 5 functions as a "valve body", the body 7 functions as a "solenoid body", and the diaphragm 4 functions as a "pressure reducing member".

A port 12 is provided at the top opening of the body 5 and ports 14 and 16 are provided at the side from above. The port 12 functions as a "discharge chamber communication port " and communicates with the discharge chamber of the compressor. The port 14 functions as a "control chamber communication port " and communicates with the control chamber of the compressor. The port 16 functions as a "suction chamber communication port " and communicates with the suction chamber of the compressor. The valve body 2 and the solenoid 3 are fixed by pressing the lower end portion of the body 5 into the upper end portion of the solenoid 3.

The body 5 is formed with a flow passage 18 for communicating the port 14 and the port 12 and a pressure chamber 20 communicating with the port 16. A valve hole (22) is provided in the middle of the flow path (18), and a valve seat (24) is provided at an upstream end of the valve hole (22). The port 12 functions as an "introduction port" for introducing the refrigerant of the discharge pressure Pd from the discharge chamber. The port 14 functions as an "outlet port" for leading the refrigerant of the control pressure Pc via the valve portion toward the control chamber. The port 16 functions as an "introduction port" for introducing the refrigerant of the suction pressure Ps from the suction chamber. A cylindrical filter member 15 having a bottom portion is attached to the port 12. The filter member (15) includes a mesh for suppressing intrusion of foreign matter into the interior of the body (5).

A guide hole 28 is provided in the body 5 so as to pass through the partition wall between the flow path 18 and the pressure chamber 20. [ The valve hole (22) and the guide hole (28) are formed coaxially along the axis of the body (5). The pressure chamber 20 is widely opened toward the lower side of the body 5 and its lower end opening is sealed by the diaphragm 4. [ In the pressure chamber 20, a cylindrical connection member 30 having a bottom portion is disposed coaxially with the body 5. [ A communication passage 32 is provided outside the guide hole 28. The communication passage 32 extends parallel to the guide hole 28 to communicate the port 16 and the pressure chamber 20.

A valve chamber 34 is formed between the port 12 and the valve hole 22 and a ball-shaped valve body 36 is disposed in the valve chamber 34. The valve seat 24 is formed in a concave spherical shape having a slightly larger radius of curvature than that of the valve element 36 to facilitate detachment of the valve element 36. [ And the valve body is opened and closed by removing the valve body from the upstream side to the valve seat. A spring bearing 38 is fixed to the upper end of the body 5 and a spring 40 is interposed between the valve body 36 and the spring bearing 38. [ The spring 40 biases the valve body 36 in the valve closing direction. The load of the spring 40 is adjusted by the fixing position of the spring bearing 38 in the body 5. [

A shaft 42 is provided so as to pass through the valve hole 22 and the guide hole 28 in the axial direction. The shaft 42 has a stepped cylindrical shape, and is slidably supported by the guide hole 28. The upper end of the shaft 42 is reduced in diameter and passes through the valve hole 22 to support the valve body 36 on the downstream side. The lower end of the shaft 42 protrudes into the pressure chamber 20. The connecting member 30 is interposed between the shaft 42 and the diaphragm 4 such that the lower end of the shaft 42 is received in a coaxial shape. On the other hand, the shaft 42 and the connecting member 30 function as "transmitting members. &Quot;

On the other hand, the solenoid 3 is constituted by housing a drive mechanism in the inside of the body 7. [ That is, the body 7 includes a cylindrical case 50, a cylindrical bobbin 52 housed in the case 50, an electromagnetic coil 54 wound around the bobbin 52, a bobbin 52, An end member 58 provided so as to substantially seal the lower end opening of the case 50 and a cylindrical member 58 which is provided at the lower end of the bobbin 52 and which is embedded in the end member 58, (Not shown).

The plunger 62 and the core 64 are disposed in the working space 60 formed on the inner side of the body 7. The sleeve 56 is made of a non-magnetic material and holds the electromagnetic coil 54 between the case 56 and the case 50. The sleeve 56 has a flange portion 57 extending radially outward from the top opening and the flange portion 57 is sandwiched between the body 5 and the case 50. The core 64 has a stepped cylindrical shape and is fixed by allowing the upper half of the core 64 to be inserted into the lower end of the sleeve 56. The core 64 has a through hole 66 in the axial direction. The through hole 66 is formed by a stepped hole whose upper half is slightly enlarged in diameter, and a spring 68 is accommodated in the large diameter portion. The core 64 is a member for supporting the plunger 62, and only the spring 68 is inserted therethrough. On the other hand, the case 50 and the collar 59 constitute a yoke. The spring 68 is placed in the magnetic circuit produced by the electromagnetic coil 54. [

The plunger 62 has a stepped cylindrical shape and is slidably supported by the sleeve 56. [ The plunger 62 is disposed in the working space 60 so as to be positioned between the core 64 and the diaphragm 4 and faces the core 64 in the axial direction. Between the core 64 and the plunger 62, a disk-shaped spacer 70 made of a non-magnetic material is disposed. The spacers 70 can easily be spaced apart by the biasing force of the spring 68 when the value of the current supplied to the electromagnetic coil 54 falls to a value at which the core 64 and the plunger 62 must be separated from each other So that they are positioned between the two. The spring 68 is a coil spring having a larger load than the spring 40 and interposed between the stepped portion provided in the through hole 66 and the spacer 70. The spring 68 axially supports the plunger 62 through the spacer 70 and biases the plunger 62 away from the core 64.

An O-ring 72 for sealing is mounted on the lower end surface of the body 5. [ The body 5 is press-fitted into the upper end of the case 50 so that the outer peripheral portion of the diaphragm 4 and the O-ring 72 are sandwiched between the flange portion 57 of the sleeve 56 and the body 5 . Thereby, the diaphragm 4 divides the pressure chamber 20 on the valve body 2 side and the operating space 60 on the solenoid 3 side so as to be interposed between the body 5 and the body 7, do. On the other hand, the diaphragm 4 is made of a resin material in the form of a thin film such as a polyimide film in the present embodiment, but may be made of a thin metal plate. However, the resin film is preferable in that a deformation stroke larger than that of the metal film can be obtained. Particularly, in realizing the miniaturization of the control valve 1, when it is necessary to reduce the hydraulic pressure of the diaphragm 4 or to reduce the size of the solenoid 3, it is possible to increase the stroke of the diaphragm 4 .

A pair of connection terminals 74 connected to the electromagnetic coil 54 extend from the bobbin 52 and extend through the end member 58 to the outside. For convenience of explanation, only one of the pairs is shown in Fig. The end member 58 is mounted so as to seal the entire structure in the solenoid 3 contained in the case 50 from below. The end member 58 is formed by molding (injection molding) of a resin material having corrosion resistance, and the resin member is provided so as to cover the electromagnetic coil 54 from the outside. The distal end portion of the end member 58 becomes the connector connecting portion 76 and the distal end portion of the connecting terminal 74 is drawn out from the connector connecting portion 76. [ A connector (not shown) connected to an external power source is connected to the connector connecting portion 76.

The end member 58 is provided with a ventilation passage 78 for communicating the inside and the outside of the working space 60. One end of the ventilation passage 78 is opened in the working space 60 and the other end is opened in the connector connection portion 76. The outside atmosphere is introduced into the working space 60 through the ventilation passage 78.

2 is an enlarged view of part A of Fig.

The plunger 62 has a ring-shaped wall 80 projecting in a circular ring shape along the periphery of the surface facing the core 64. Then, the spacer 70 is assembled to the plunger 62 so as to be disposed inside the ring-shaped wall 80. On the other hand, the core 64 has a shape cut in a circular ring shape so that the peripheral portion of the face opposed to the plunger 62 is complementary to the ring-shaped wall 80. That is, a circular concave portion 82 is provided on the lower surface of the plunger 62, and a circular protruding portion 84 is provided on the upper surface of the core 64. Since the height of the ring-shaped wall 80 is sufficiently larger than the thickness of the spacer 70, the protruding portion 84 and the recessed portion 82 are overlapped radially in the valve closed state. The inner shape of the ring-shaped wall 80 and the outer shape of the spacer 70 are complementary to each other so that the spacer 70 is fitted to the ring-shaped wall 80 movably The ring-shaped wall 80 also has a function of stably holding the spacer 70 on the plunger 62 side.

As described above, the plunger 62 is made larger in the axial direction by the ring-shaped wall 80, so that the plunger 62 is not easily tilted with respect to the axis of the sleeve 56. Thereby preventing or suppressing the uneven wear caused by the abutment of the plunger 62 against the sleeve 56 and the increase of the hysteresis in the operation of the plunger 62. That is, the control valve 1 does not include the shaft for supporting the plunger or the bearing portion of the shaft as described in Patent Document 1, but by increasing the length in the axial direction of the plunger 62, And stable operation is ensured. On the other hand, even if the axial length of the outer circumferential surface of the plunger 62 is increased, the axial length of the outer peripheral surface of the core 64 becomes smaller. Therefore, the miniaturization of the solenoid 3 realized in the present embodiment is not hindered. However, if the height of the concave-convex shape of the opposed faces of the plunger 62 and the core 64 is made large, there is a possibility of changing the suction force characteristics of the both, so that the height of the ring- As shown in Fig.

The inner diameter of the large diameter portion 92 of the through hole 66 is made substantially equal to the outer diameter of the spring 68 so that the rattling of the spring 68 in the core 64 can be suppressed Prevention or suppression. The inner diameter of the small diameter portion 94 is set to be approximately equal to the inner diameter of the spring 68 so that the pressure between the plunger 62 and the core 64 can be easily opened to the outside air.

Next, the operation of the control valve 1 will be described.

In the control valve 1, when the solenoid 3 is non-energized, no attraction force acts between the core 64 and the plunger 62. [ On the other hand, since the load of the spring 68 is set to be considerably larger than the load of the spring 40, the plunger 62 is displaced upward and the diaphragm 4, the connecting member 30, And the valve body 36 is opened. As a result, the refrigerant of the discharge pressure Pd introduced into the port 12 from the discharge chamber passes through the valve portion in the unfolded state, and flows from the port 14 to the control chamber. Therefore, the control pressure Pc rises and the compressor performs the minimum capacity operation.

On the other hand, when a control current is supplied to the solenoid 3, such as when the automotive air conditioner is started, the core 64 sucks the plunger 62 against the biasing force of the spring 68. As a result, the valve body 36 is pushed down by the spring 40 and seated on the valve seat 24, so that the control valve 1 is closed.

When the suction pressure Ps of the suction chamber is sufficiently lowered in this manner, the diaphragm 4 senses the differential pressure between the suction pressure Ps and the atmospheric pressure and is displaced upward. At this time, if the control current supplied to the solenoid 3 is made smaller according to the set temperature of the air conditioner, the force due to the differential pressure between the discharge pressure Pd and the control pressure Pc The force due to the differential pressure between the control pressure Pc and the suction pressure Ps (i.e., the force due to the differential pressure acting on the shaft 42) The force generated by the diaphragm 4 sensing the differential pressure between the suction pressure Ps and the atmospheric pressure) and the combined force of the spring 40 and the spring 68 and the suction force of the solenoid 3 are balanced . Thereby, the valve body 36 is pushed up, and is set at a predetermined opening spaced from the valve seat 24. [ Therefore, the refrigerant of the discharge pressure Pd is controlled at a flow rate corresponding to the opening degree and is introduced into the control room, and the compressor shifts to the operation of the capacity corresponding to the control current.

When the control current supplied to the electromagnetic coil 54 of the solenoid 3 is constant, the diaphragm 4 senses the differential pressure between the suction pressure Ps and the atmospheric pressure to control the valve opening degree. The valve body 36 is integrally formed with the shaft 42, the connecting member 30, the diaphragm 4, and the plunger 62 when the refrigerant load is large and the suction pressure Ps and the atmospheric differential pressure are large, So that the valve opening degree is reduced and the compressor operates to increase the discharge capacity. As a result, the suction pressure Ps is lowered and becomes close to the set pressure. On the other hand, when the refrigeration load becomes small and the differential pressure between the suction pressure Ps and the atmospheric pressure becomes small, the valve body 36 is displaced upward to increase the valve opening degree, so that the compressor operates so as to reduce the discharge capacity. As a result, the suction pressure Ps rises and approaches the set pressure. In this way, the control valve 1 controls the discharge capacity of the compressor so that the suction pressure Ps becomes the set pressure Pset set by the solenoid 3.

As described above, according to the present embodiment, the core 64 supports the spring 68 to be inserted therethrough, and the biasing force of the spring 68 is transmitted directly to the plunger 62 through the spacer 70 . Therefore, the shaft for supporting the plunger 62 and the bearing portion for supporting the shaft are unnecessary, and the control valve 1 can be made compact in the axial direction. Further, since the entrance and exit of the working space are not narrowed by such a shaft or bearing portion, the pressure in the working space 60 can easily be taken in and out, and even if the pressure is changed, it can be brought close to the atmospheric pressure quickly. In other words, according to the present embodiment, it is possible to achieve miniaturization while maintaining high control responsiveness of the control valve 1. [

Although the preferred embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the specific embodiments, and various modifications are possible within the scope of the technical idea of the present invention.

In the above-described embodiment, a so-called Ps sensing valve which operates by detecting the suction pressure Ps as the refrigerant pressure and the pressure difference between the atmospheric pressure is exemplified as the control valve. In the modified example, a so-called Pc sensing valve may be used, which operates by sensing the differential pressure between the control pressure Pc as the refrigerant pressure and the atmospheric pressure. In this case, the control pressure Pc may be introduced into the pressure chamber 20.

In the above embodiment, the shaft 42 and the connecting member 30 are shown as examples of functioning as "transmitting member ". In a modified example, the valve body may be directly connected to the pressure-reducing member. In that case, a part of the valve body functions as a "transmitting member ".

In the above-described embodiment, the diaphragm is exemplified as the pressure-reducing member, but may be a bellows or other pressure-reducing member. However, it is preferable to employ a diaphragm of a thin film type in realizing the miniaturization of the control valve.

In the above-described embodiment, a so-called introduction control valve for adjusting the flow rate or pressure of the refrigerant introduced into the crank chamber from the discharge chamber of the variable displacement compressor is proposed. However, in the modified example, the refrigerant discharged from the crank chamber to the suction chamber Or a control valve of so-called derivation control for adjusting the flow rate or pressure.

On the other hand, the present invention is not limited to the above-described embodiments and modifications, and can be embodied by modifying the constituent elements without departing from the gist. Various inventions may be formed by suitably combining a plurality of constituent elements disclosed in the above-described embodiment or modified examples. Furthermore, some of the constituent elements may be deleted from all the constituent elements shown in the above-described embodiment or modified examples.

1: Control valve
2:
3: Solenoid
4: Diaphragm
5: Body
7: Body
12: Port
14: Port
16: Port
18: Distribution channel
20: Pressure chamber
22: valve hole
36: Valve body
42: Shaft
54: electromagnetic coil
60: working space
62: plunger
64: Core
66: Through hole
68: spring
70: Spacer
78: vent passage
80: ring-shaped wall

Claims (4)

A control valve for a variable capacity compressor, comprising a valve body and a solenoid assembled in an axial direction through a pressure reducing member, for sensing a differential pressure between a refrigerant pressure and an atmospheric pressure to drive the valve portion,
Wherein the valve body comprises:
A valve body having a refrigerant flow passage, a valve hole provided in the flow passage, and a pressure chamber into which the refrigerant pressure is introduced;
A valve body that opens and closes the valve portion by being in contact with the valve hole; And
And a transmitting member provided between the valve body and the pressure-reducing member,
The solenoid includes:
A solenoid body which holds an electromagnetic coil, in which an operating space is formed in the inside of the electromagnetic coil, the working space of which is open to the atmosphere on the opposite side of the valve body;
A core fixed to the solenoid body so as to be disposed in the operating space and having an axial through hole;
A plunger disposed in the operating space to be positioned between the core and the pressure-reducing member, the plunger slidably supported on the solenoid body; And
And a spring supported on the core so as to be inserted into the through hole in a coaxial manner to support the plunger in an axial direction and to bias the plunger in a direction away from the core,
Wherein the pressure-reducing member is interposed between the valve body and the solenoid body so as to partition the pressure chamber and the working space,
The force generated by the differential pressure member sensing the differential pressure between the refrigerant pressure and the atmospheric pressure and the force of the solenoid is transmitted to the valve body through the transmission member,
And an inner space of the spring inserted into the core is opened to the atmosphere. The method according to claim 1,
Wherein the plunger has a ring-shaped wall protruding axially along a periphery of a surface facing the core and being slidably supported by the solenoid body,
Wherein the core has a shape cut in an annular shape such that the peripheral portion of the surface facing the plunger has a complementary shape to the ring-shaped wall. 3. The method of claim 2,
The solenoid further comprises a nonmagnetic spacer disposed between the core and the plunger,
The spring supports the plunger axially through the spacer,
Wherein the spacer is assembled with respect to the plunger so as to be disposed inside the ring-shaped wall. 4. The method according to any one of claims 1 to 3,
And a diaphragm as the pressure-reducing member,
The suction pressure of the variable displacement compressor is introduced into the pressure chamber as the refrigerant pressure,
The diaphragm senses a differential pressure between the suction pressure and the atmospheric pressure, generates a force corresponding to the magnitude of the differential pressure,
Wherein the opening degree of the valve portion is controlled so that the suction pressure becomes a set pressure corresponding to a supply current value to the solenoid.

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