阅读说明：本技术 容量控制阀及容量控制阀的控制方法 (Capacity control valve and control method for capacity control valve ) 是由 叶山真弘 小川义博 白藤启吾 福留康平 江岛贵裕 栗原大千 高桥涉 于 2018-12-26 设计创作，主要内容包括：本发明的目的在于提供一种与吸入室的压力无关地能够有效地排出液体制冷剂,并且在液体制冷剂排出运行中能够降低压缩机的驱动力的容量控制阀。容量控制阀(1)具备：阀主体(10),具有第1连通路(11)、第2连通路(12)、第3连通路(13)及主阀座(15a)；阀体(20),具有中间连通路(29)、主阀部(21c)及辅助阀部(23d)；螺线管(30),驱动具有辅助阀座(26c)的连杆(36)；及第1施力部件(43),向主阀部(21c)的闭阀方向施力,第1施力部件(43)的弹簧常数具有主阀部(21c)在开阀状态下大而在闭阀状态下小的特性。(The invention aims to provide a capacity control valve which can effectively discharge liquid refrigerant regardless of the pressure of a suction chamber and can reduce the driving force of a compressor in the liquid refrigerant discharge operation. A capacity control valve (1) is provided with: a valve main body (10) having a 1 st communication passage (11), a 2 nd communication passage (12), a 3 rd communication passage (13), and a main valve seat (15 a); a valve body (20) having an intermediate communication passage (29), a main valve portion (21c), and an auxiliary valve portion (23 d); a solenoid (30) that drives a link (36) having an auxiliary valve seat (26 c); and a 1 st biasing member (43) that biases the main valve portion (21c) in a valve closing direction, wherein the spring constant of the 1 st biasing member (43) has a characteristic that the main valve portion (21c) is large in an open state and small in a closed state.)

1. A capacity control valve for controlling a flow rate or a pressure of a variable capacity compressor according to a valve opening degree of a valve portion, the capacity control valve comprising:

a valve main body having a 1 st communication passage through which a 1 st pressure fluid flows, a 2 nd communication passage which is disposed adjacent to the 1 st communication passage and through which a 2 nd pressure fluid flows, a 3 rd communication passage through which a 3 rd pressure fluid flows, and a main valve seat disposed in a valve hole which communicates the 2 nd communication passage and the 3 rd communication passage;

a solenoid driving a link having an auxiliary valve seat;

a valve body having an intermediate communication passage for communicating the 1 st communication passage and the 3 rd communication passage, a main valve portion for opening and closing the valve hole by coming into contact with and coming out of the main valve seat, and an auxiliary valve portion for opening and closing the intermediate communication passage by coming into contact with and coming out of the auxiliary valve seat; and

a 1 st biasing member for biasing the main valve portion in a valve closing direction,

the 1 st urging member has a characteristic that the spring constant of the main valve portion is large in the valve-opened state and small in the valve-closed state.

2. The capacity control valve of claim 1,

the 1 st force application component is arranged between the connecting rod and the valve body.

3. The capacity control valve according to claim 1 or 2,

the 1 st biasing member has a communication passage communicating with the intermediate communication passage.

4. The capacity control valve according to any one of claims 1 to 3,

the solenoid further includes a plunger connected to the link, a core disposed between the plunger and the valve body, an electromagnetic coil, and a 2 nd urging member disposed between the plunger and the core.

5. The capacity control valve according to any one of claims 1 to 4,

the 1 st pressure is a suction pressure of the variable displacement compressor, the 2 nd pressure is a discharge pressure of the variable displacement compressor, and the 3 rd pressure is a pressure of a crank chamber of the variable displacement compressor.

6. The capacity control valve according to any one of claims 1 to 4,

the 1 st pressure is a pressure in a crank chamber of the variable displacement compressor, the 2 nd pressure is a discharge pressure of the variable displacement compressor, and the 3 rd pressure is a suction pressure of the variable displacement compressor.

7. A control method of a capacity control valve, characterized in that,

use of the capacity control valve according to any one of claims 1 to 6,

when the auxiliary valve portion is in the open state, the main valve portion is switched from the closed state to the open state.

Technical Field

The present invention relates to a capacity control valve used for controlling a flow rate or a pressure of a variable capacity compressor, and a method for controlling the capacity control valve.

Background

As a variable displacement compressor, for example, a swash plate type variable displacement compressor used in an air conditioning system of an automobile or the like includes: a rotating shaft rotationally driven by a rotational force of the engine; a swash plate connected to the rotary shaft so that an inclination angle thereof can be changed; and a compression piston connected to the swash plate, wherein the discharge amount of the refrigerant is controlled by changing the stroke of the piston by changing the inclination angle of the swash plate.

The inclination angle of the swash plate can be continuously changed by using the suction pressure of a suction chamber for sucking a refrigerant, the discharge pressure of a discharge chamber for discharging the refrigerant pressurized by the piston, and the control chamber pressure of a control chamber (crank chamber) in which the swash plate is accommodated, and by using a capacity control valve that is driven to open and close by an electromagnetic force, the pressure in the control chamber can be appropriately controlled, and the balance state of the pressures acting on both surfaces of the piston can be adjusted.

An example of such a capacity control valve is shown in fig. 6. The capacity control valve 160 includes: a valve part 170 having a 2 nd valve chamber 182 communicating with the discharge chamber of the compressor via a 2 nd communication passage 173, a 1 st valve chamber 183 communicating with the suction chamber via a 1 st communication passage 171, and a 3 rd valve chamber 184 communicating with the control chamber via a 3 rd communication passage 174; a pressure-sensitive body 178 which is disposed in the 3 rd valve chamber, expands and contracts by the ambient pressure, and has a valve seat body 180 provided at a free end in the expansion and contraction direction; a valve body 181 having a 2 nd valve part 176 that opens and closes a valve hole 177 communicating the 2 nd valve chamber 182 and the 3 rd valve chamber 184, a 1 st valve part 175 that opens and closes the 1 st communication passage 171 and the flow groove 172, and a 3 rd valve part 179 that opens and closes the 3 rd valve chamber 184 and the flow groove 172 by engagement and disengagement with the valve seat body 180 in the 3 rd valve chamber 184; and a solenoid portion 190 for applying an electromagnetic driving force to the valve body 181.

In addition, in the capacity control valve 160, even if the clutch mechanism is not provided in the variable capacity compressor, when the control chamber pressure needs to be changed, the discharge chamber and the control chamber are communicated with each other, and the pressure (control chamber pressure) Pc and the suction pressure Ps (suction pressure) in the control chamber can be controlled. (hereinafter, referred to as "conventional art". The patent document 1, for example).

Prior art documents

Patent document

Patent document 1: japanese patent No. 5167121

Disclosure of Invention

Technical problem to be solved by the invention

In the conventional technology, when the swash plate type variable displacement compressor is stopped for a long time, a liquid refrigerant (a refrigerant that is cooled and liquefied during the discharge) is stored in the control chamber (crank chamber), and therefore, even when the compressor is started in this state, a set discharge amount cannot be secured. Therefore, in order to perform desired capacity control immediately after the start, it is necessary to discharge the liquid refrigerant in the control chamber (crank chamber) as quickly as possible.

Therefore, as shown in fig. 7, the conventional capacity control valve 160 has a liquid refrigerant discharge function for discharging the liquid refrigerant in the control chamber (crank chamber) as quickly as possible at the time of start-up. That is, when the variable displacement compressor is stopped and is left for a long time and then started, the high-pressure liquid refrigerant stored in the control chamber (crank chamber) flows from the 3 rd communication passage 174 into the 3 rd valve chamber 184. Then, the pressure sensitive body 178 contracts to open the valve between the 3 rd valve portion 179 and the valve seat body 180, so that the liquid refrigerant can be discharged from the 3 rd valve chamber 184 through the auxiliary communication passage 185, the communication passage 186, and the communication groove 172 from the control chamber (crank chamber) to the discharge chamber via the suction chamber, and quickly vaporized, and the cooling operation state can be set in a short time.

However, in the above-described conventional technique, the pressure in the control chamber is also high at the initial stage of the liquid refrigerant discharge process, and therefore the opening degree of the 3 rd valve portion 179 is also large, and the liquid refrigerant can be efficiently discharged. However, there is a problem in that it takes time to discharge the liquid refrigerant because the opening degree of the 3 rd valve portion becomes smaller as the discharge of the liquid refrigerant advances and the pressure of the control chamber decreases.

In addition, conventionally, when performing the liquid refrigerant discharge operation, attention has been paid only to how to complete the discharge of the liquid refrigerant in a short time, and therefore, when performing the liquid refrigerant discharge operation, control for reducing the engine load has not been performed. However, if the liquid refrigerant discharge operation is performed when the engine load is high, the engine load is further increased, which may result in a reduction in the energy efficiency of the entire vehicle.

The present invention has been made to solve the above-described problems occurring in the prior art, and an object of the present invention is to provide a capacity control valve and a method for controlling the capacity control valve, in which the flow rate or pressure of a variable capacity compressor is controlled according to the valve opening degree of a valve section, the opening degree of a main valve section is stably controlled at the time of control, liquid refrigerant can be efficiently discharged regardless of the pressure in a suction chamber, the operation is switched to a cooling operation in a short time, and the driving force of the compressor can be reduced in the liquid refrigerant discharge operation.

Means for solving the technical problem

In order to solve the above problem, a capacity control valve according to the present invention is a capacity control valve for controlling a flow rate or a pressure of a variable capacity compressor according to a valve opening degree of a valve section, the capacity control valve including:

a valve main body having a 1 st communication passage through which a 1 st pressure fluid flows, a 2 nd communication passage which is disposed adjacent to the 1 st communication passage and through which a 2 nd pressure fluid flows, a 3 rd communication passage through which a 3 rd pressure fluid flows, and a main valve seat disposed in a valve hole which communicates the 2 nd communication passage and the 3 rd communication passage;

a solenoid driving a link having an auxiliary valve seat;

a valve body having an intermediate communication passage for communicating the 1 st communication passage and the 3 rd communication passage, a main valve portion for opening and closing the valve hole by coming into contact with and coming out of the main valve seat, and an auxiliary valve portion for opening and closing the intermediate communication passage by coming into contact with and coming out of the auxiliary valve seat;

a 1 st biasing member for biasing the main valve portion in a valve closing direction,

the 1 st urging member has a characteristic that the spring constant of the main valve portion is large in the valve-opened state and small in the valve-closed state.

According to this feature, in the valve-opened state of the main valve portion in which the load acting on the 1 st urging member is reduced, the 1 st urging member is hardly deformed because the spring constant is increased. Therefore, the connecting rod is displaced integrally with the valve body in a state of maintaining the relative position, and therefore the capacity control valve can stably control the opening degree of the main valve portion. Further, in the closed state of the main valve portion in which the load acting on the 1 st biasing member is increased, the spring constant of the 1 st biasing member is decreased, so that the 1 st biasing member can be easily deformed by the link without excessively increasing the output of the solenoid, and the auxiliary valve portion can be forcibly opened. Thus, when the liquid refrigerant is discharged, the opening degree of the auxiliary valve portion is maintained in the fully open state, and the liquid refrigerant can be efficiently discharged regardless of the pressure in the suction chamber.

The capacity control valve of the present invention is characterized in that,

the 1 st force application component is arranged between the connecting rod and the valve body.

According to this feature, the driving force of the solenoid is transmitted to the main valve portion in the valve closing direction via the 1 st biasing member disposed between the link and the valve body, and the valve can be reliably closed.

The capacity control valve of the present invention is characterized in that,

the 1 st biasing member has a communication portion communicating with the intermediate communication passage.

According to this feature, the refrigerant passing through the intermediate communication passage does not interfere with the flow of the refrigerant.

The capacity control valve of the present invention is characterized in that,

the solenoid further includes a plunger connected to the link, a core disposed between the plunger and the valve body, an electromagnetic coil, and a 2 nd urging member disposed between the plunger and the core.

According to this feature, the 2 nd biasing member disposed between the plunger and the core can reliably bias the valve body in the valve opening direction of the main valve portion.

The capacity control valve of the present invention is characterized in that,

the 1 st pressure is a suction pressure of the variable displacement compressor, the 2 nd pressure is a discharge pressure of the variable displacement compressor, and the 3 rd pressure is a pressure of a crank chamber of the variable displacement compressor.

The 1 st pressure is a pressure in a crank chamber of the variable displacement compressor, the 2 nd pressure is a discharge pressure of the variable displacement compressor, and the 3 rd pressure is a suction pressure of the variable displacement compressor.

This feature can cope with various variable displacement compressors.

In order to solve the above problem, a control method of a capacity control valve according to the present invention is characterized in that,

when the auxiliary valve portion is in the open state, the main valve portion is set from the closed state to the open state.

According to this feature, when the liquid refrigerant is discharged, the main valve portion is opened in a state where the biasing force of the pressure sensitive body does not act on the valve body, and the flow rate from the discharge chamber to the control chamber is increased, whereby the load on the compressor can be reduced.

Drawings

Fig. 1 is a front sectional view of a capacity control valve according to the present invention.

Fig. 2 is a partially enlarged view of the valve body, and solenoid of fig. 1, showing the capacity control valve when the solenoid is "off".

Fig. 3 is a partially enlarged view of the valve body, and the solenoid of fig. 1, showing a control state of the capacity control valve.

Fig. 4 is a partially enlarged view of the valve body, and the solenoid of fig. 1, showing a state of the capacity control valve when the liquid refrigerant is discharged.

Fig. 5 is a view showing the 1 st biasing member.

Fig. 6 is a front cross-sectional view showing a conventional capacity control valve.

Fig. 7 is a diagram of a conventional capacity control valve, showing a state of the capacity control valve when liquid refrigerant is discharged.

Detailed Description

Hereinafter, modes for carrying out the present invention will be described by way of example according to embodiments with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative positions, and the like of the constituent elements described in the embodiments are not limited to those dimensions, materials, shapes, and relative positions unless otherwise explicitly stated.

A capacity control valve according to the present invention will be described with reference to fig. 1 to 5. In fig. 1, 1 is a capacity control valve. The capacity control valve 1 is mainly composed of a valve main body 10, a valve body 20, a pressure-sensitive body 24, and a solenoid 30.

Hereinafter, each constituent element of the displacement control valve 1 will be described with reference to fig. 1 and 2. The valve main body 10 is made of metal such as brass, iron, aluminum, and stainless steel, or a synthetic resin material. The valve body 10 is a hollow cylindrical member having a through hole penetrating in the axial direction, and a 1 st valve chamber 14, a 2 nd valve chamber 15 adjacent to the 1 st valve chamber 14, and a 3 rd valve chamber 16 adjacent to the 2 nd valve chamber 15 are continuously arranged in the region of the through hole.

The 2 nd communication passage 12 is connected to the 2 nd valve chamber 15. The 2 nd communication passage 12 is configured to communicate with a discharge chamber (not shown) of the variable displacement compressor, and fluid at a discharge pressure Pd (2 nd pressure according to the present invention) can flow from the 2 nd valve chamber 15 into the 3 rd valve chamber 16 by opening and closing the displacement control valve 1.

The 3 rd communication passage 13 is connected to the 3 rd valve chamber 16. The 3 rd communication passage 13 communicates with a control chamber (not shown) of the variable displacement compressor, and opens and closes the displacement control valve 1, so that the fluid at the discharge pressure Pd flowing from the 2 nd valve chamber 15 into the 3 rd valve chamber 16 flows out into the control chamber (crank chamber) of the variable displacement compressor, or the fluid at the control chamber pressure Pc (3 rd pressure according to the present invention) flowing into the 3 rd valve chamber 16 flows out into the suction chamber of the variable displacement compressor through an intermediate communication passage 29 described later and through the 1 st valve chamber 14.

The 1 st communication passage 11 is connected to the 1 st valve chamber 14. The 1 st communication passage 11 guides a fluid of a suction pressure Ps (1 st pressure according to the present invention) from a suction chamber of the variable displacement compressor to the pressure sensitive body 24 via an intermediate communication passage 29 described later, and controls the suction pressure of the compressor to a set value.

A hole 18 having a diameter smaller than the diameter of the 1 st valve chamber 14 and the 2 nd valve chamber 15 is continuously formed between these chambers, a labyrinth portion 21f described later is formed in the hole 18, and a seal portion for sealing between the 1 st valve chamber 14 and the 2 nd valve chamber 15 is formed. Further, a valve hole 17 having a diameter smaller than the diameters of the 2 nd valve chamber 15 and the 3 rd valve chamber 16 is connected between these chambers, and a main valve seat 15a is formed around the valve hole 17 on the 2 nd valve chamber 15 side. The main valve seat 15a is separated from and brought into contact with a main valve portion 21c described later to control opening and closing of the Pd-Pc flow path that communicates between the 2 nd communication path 12 and the 3 rd communication path 13.

A pressure-sensitive body 24 is disposed in the 3 rd valve chamber 16. In the pressure-sensitive body 24, one end of a metal bellows 24a is hermetically coupled to a partition adjustment portion 24 f. The bellows 24a is made of copper or stainless steel, etc., and its spring constant is designed to be a predetermined value. The inner space of the pressure-sensitive body 24 is vacuum or air exists. Then, the pressure acts on the effective pressure receiving area of the bellows 24a of the pressure sensitive body 24 to cause the pressure sensitive body 24 to perform the expansion and contraction operation. A flange portion 24d is disposed on the free end portion side of the pressure-sensitive body 24. The pressure-sensitive body 24 expands and contracts when the flange portion 24d is directly pressed by the engagement portion 26 of the link 36, which will be described later. That is, as will be described later, the pressure-sensitive body 24 expands and contracts in accordance with the suction pressure Ps guided by the pressure-sensitive body 24 via the intermediate communication passage 29, and also expands and contracts by the pressing force of the link 36.

The partition adjustment portion 24f of the pressure sensitive body 24 is fitted and fixed in a sealed manner so as to close the 3 rd valve chamber 16 of the valve main body 10. Further, when the partition adjustment portion 24f is screwed and fixed by a stopper screw (not shown), the compression spring arranged in parallel in the bellows 24a or the spring force of the bellows 24a can be adjusted to move in the axial direction.

The 1 st communication passage 11, the 2 nd communication passage 12, and the 3 rd communication passage 13 are each inserted through the circumferential surface of the valve body 10 at equal intervals of 2 to 6, for example. Further, 3O-ring mounting grooves are provided on the outer peripheral surface of the valve body 10 so as to be spaced apart in the axial direction. O-rings 47, 48, and 49 between the sealing valve main body 10 and a mounting hole (not shown) of the housing fitted to the valve main body 10 are mounted in the mounting grooves, and the respective passages of the 1 st communication passage 11, the 2 nd communication passage 12, and the 3 rd communication passage 13 are configured as independent passages.

Next, the valve body 20 will be explained. The valve body 20 is mainly composed of a main valve body 21 including a hollow cylindrical member and an adapter 23. First, the main valve body 21 will be explained. The main valve body 21 is a hollow cylindrical member, and a labyrinth portion 21f is formed at a substantially central portion in the axial direction of the outer peripheral portion thereof. The main valve body 21 is inserted into the valve body 10, and the labyrinth portion 21f slides in the hole portion 18 between the 1 st valve chamber 14 side and the 2 nd valve chamber 15 side to form a seal portion for sealing the 1 st valve chamber 14 and the 2 nd valve chamber 15. Thus, the 1 st valve chamber 14 communicating with the 1 st communication passage 11 and the 2 nd valve chamber 15 communicating with the 2 nd communication passage 12 are constituted as independent valve chambers.

The main valve body 21 is disposed on the 1 st communication passage 11 side and the 2 nd communication passage 12 side with a labyrinth 21f interposed therebetween. A main valve portion 21c is formed at an end portion of the main valve body 21 disposed on the 2 nd communication passage 12 side, and the main valve portion 21c is separated from and brought into contact with the main valve seat 15a to control opening and closing of the valve hole 17 communicating the 2 nd valve chamber 15 and the 3 rd valve chamber 16. The main valve portion 21c and the main valve seat 15a constitute a main valve 27 b. Here, the state in which the main valve portion 21c and the main valve seat 15a are brought into contact with each other and separated from each other is referred to as the state in which the main valve 27b is opened or the main valve portion 21c is opened, and the state in which the main valve portion 21c and the main valve seat 15a are brought into contact with each other is referred to as the state in which the main valve 27b is closed or the main valve portion 21c is closed. A shut-off valve portion 21a is formed at an end of the main valve body 21 disposed in the 1 st valve chamber 14. The blocking valve portion 21a contacts an end portion 32c of the core 32 when the solenoid 30 described later is turned "off" to block the communication between the intermediate communication passage 29 and the 1 st valve chamber 14. The block valve portion 21a and the end portion 32c of the core 32 constitute a block valve 27 a. The cut-off valve portion 21a and the main valve portion 21c of the valve body 20 are formed so as to be opened and closed in opposite directions to each other. The state in which the block valve portion 21a and the end portion 32c of the core 32 are brought into contact with each other is referred to as the state in which the block valve 27a is opened or the state in which the block valve portion 21a is opened, and the state in which the block valve portion 21a and the end portion 32c of the core 32 are brought into contact with each other is referred to as the state in which the block valve 27a is closed or the state in which the block valve portion 21a is closed.

Next, the adapter 23 constituting the valve body 20 will be described. The adaptor 23 is mainly composed of a large diameter portion 23c formed as a hollow cylindrical member and having a large diameter, and a cylindrical portion 23e formed as a smaller diameter than the large diameter portion 23 c. The cylindrical portion 23e is fitted to the open end of the main valve portion 21c of the main valve body 21 to constitute the valve body 20. Thereby, an intermediate communication passage 29 penetrating in the axial direction is formed inside the main valve body 21 and the adapter 23, that is, inside the valve body 20. An auxiliary valve portion 23d is formed in the large diameter portion 23c of the adapter 23, and the auxiliary valve portion 23d contacts and separates from an auxiliary valve seat 26c of the locking portion 26 of the connecting rod 36 to open and close an intermediate communication passage 29 that communicates the 1 st communication passage 11 and the 3 rd communication passage 13. The auxiliary valve portion 23d and the auxiliary valve seat 26c constitute an auxiliary valve 27 c. Here, the state in which the auxiliary valve portion 23d and the auxiliary valve seat 26c are brought into contact with each other and separated from each other is referred to as the state in which the auxiliary valve 27c is opened or the auxiliary valve portion 23d is opened, and the state in which the auxiliary valve portion 23d and the auxiliary valve seat 26c are brought into contact with each other and separated from each other is referred to as the state in which the auxiliary valve 27c is closed or the auxiliary valve portion 23d is closed.

Next, the solenoid 30 will be described. The solenoid 30 includes a link 36, a plunger cylinder 38, an electromagnetic coil 31, a core 32 including a center pillar 32a and a base member 32b, a plunger 35, a thin plate 34, and a solenoid case 33. The plunger cylinder 38 is a bottomed hollow cylindrical member having one side opened. The plunger 35 is disposed so as to be movable in the axial direction relative to the plunger cylinder 38 between the plunger cylinder 38 and the center pillar 32a disposed inside the plunger cylinder 38. The core 32 is fitted to the valve body 10 and disposed between the plunger 35 and the valve body 10. The link 36 is disposed so as to penetrate the center pillar 32a of the core 32 and the valve element 20 disposed in the valve body 10, and the link 36 is movable relative to the core 32 and the valve element 20 with a gap between the link 36 and the through hole 32e of the center pillar 32a of the core 32 and the intermediate communication passage 29 of the valve element 20. The plunger 35 is connected to one end 36e of the link 36, and the locking portion 26 is connected to the pressing portion 36h on the other end.

Here, the locking portion 26 constituting a part of the link 36 will be described. The locking portion 26 is a disc-shaped member, and is formed with a base portion 26a and flange portions provided on both sides in the axial direction from the base portion 26 a. One of the collar portions functions as an auxiliary valve seat 26c which is separated from and brought into contact with an auxiliary valve portion 23d of the adaptor 23, and the other thereof functions as a pressing portion 26d which is separated from and brought into contact with a flange portion 24d of the pressure sensitive body 24 to expand and contract the pressure sensitive body 24. A flow hole 26f through which the refrigerant flows is formed in the base portion 26a of the locking portion 26. The locking portion 26 may be formed integrally with the link 36, or the locking portion 26 may be fitted and fixed to the link 36 to be formed integrally therewith.

Further, a spring 37 (2 nd urging member according to the present invention) that urges the plunger 35 so as to be separated from the core 32 is disposed between the core 32 and the plunger 35. Thereby, the biasing force of the spring 37 acts in the direction of opening the main valve portion 21c of the valve body 20.

An open end of the plunger cylinder 38 is hermetically fixed to an inner peripheral portion of the base member 32b of the magnetic core 32, and the solenoid case 33 is hermetically fixed to an outer peripheral portion of the base member 32 b. Further, since the electromagnetic coil 31 is disposed in the space surrounded by the plunger cylinder 38, the base member 32b of the magnetic core 32, and the solenoid case 33 without contacting the refrigerant, it is possible to prevent a decrease in insulation resistance.

Next, the coil spring 43 (the 1 st urging member according to the present invention) will be described. As shown in fig. 5, the coil spring 43 is a circular plate having a conical shape, and has a hole 43d larger than the outer diameter of the link 36 in the center portion, and the hole 43d is formed with a plurality of protrusions extending toward the center of the coil spring 43. The adjacent convex portions function as a communication passage 43c through which the refrigerant flows, and the refrigerant flows through the communication passage 43c even in a state where the coil spring 43 is in contact with the connecting rod 36, and therefore the flow is not obstructed.

The coil spring 43 is disposed between the solenoid 30 and the valve body 20. Specifically, one end of the coil spring 43 contacts the stepped portion 36f of the link 36 formed at substantially the same position as the end portion 32c of the core 32, and the other end contacts the inner stepped portion 21h formed on the intermediate communication passage 29 side of the valve body 20. The coil spring 43 has a nonlinear spring constant such that the spring constant of the coil spring 43 increases when the applied load is small, and the spring constant of the coil spring 43 decreases when the applied load is large.

The operation of the displacement control valve 1 having the above-described configuration will be described. Hereinafter, the flow path from the 3 rd communication passage 13 to the 1 st communication passage 11 through the intermediate communication passage 29 will be referred to as a "Pc-Ps flow path". Hereinafter, the flow path leading from the 2 nd communication path 12 to the 3 rd communication path 13 through the valve hole 17 is referred to as "Pd — Pc flow path".

First, the operation of the connecting rod 36 and the operation of each valve portion of the valve body 20 will be described. First, in the non-energized state of the solenoid 30, as shown in fig. 1 and 2, the link 36 is pushed upward by the urging force of the pressure-sensitive body 24 and the urging force of the spring 37 (fig. 1), the adapter 23 that contacts the locking portion 26 of the link 36 is pushed upward, the main valve portion 21c is fully opened, and the blocking valve portion 21a contacts the end portion 32c of the core 32, and the blocking valve portion 21a is fully closed. In the non-energized state of the solenoid 30, the load acting on the coil spring 43 is almost zero, and the deflection of the coil spring is also zero.

Next, as shown in fig. 3, when the solenoid 30 starts to be energized from the non-energized state, the link 36 is gradually driven in the forward direction (the direction in which the link 36 projects outward from the end portion 32c of the core 32). At this time, the valve element 20 is pressed downward in fig. 3 via the coil spring 43, and the pressure-sensitive body 24 is pressed by the locking portion 26 of the link 36. Thereby, the shut valve portion 21a is separated from the end portion 32c of the core 32, the shut valve 27a is opened from the fully closed state, and the main valve 27b is gradually closed from the fully opened state. In the open state of the main valve 27b, the load acting on the coil spring 43 is small, and the spring constant of the coil spring 43 is large. Therefore, the coil spring 43 is hardly deformed, and therefore the rod 36 does not relatively displace with respect to the valve body 20, and the valve body 20 and the rod 36 displace integrally, so that the capacity control valve 1 can stably control the opening degree of the main valve 27 b.

When the link 36 is further driven in the forward direction, as shown in fig. 4, the block valve 27a is fully opened, the main valve portion 21c contacts the main valve seat 15a, and the main valve 27b is fully closed, whereby the operation of the valve body 20 is stopped. When the link 36 is driven in the forward direction in a state where the main valve 27b is fully closed, that is, in a state where the valve element 20 is stopped, a large load acts on the coil spring 43, and the spring constant of the coil spring 43 decreases. Thus, since the solenoid 30 can deform the coil spring 43 without outputting a driving force, the link 36 can easily move relative to the valve body 20 (the main valve body 21 and the adapter 23), and the auxiliary valve seat 26c of the locking portion 26 can be separated from the auxiliary valve portion 23d of the adapter 23 to open the auxiliary valve 27 c. When the link 36 is further driven, the coil spring 43 is further deformed, and the pressing portion 26d of the locking portion 26 presses the flange portion 24d to contract the pressure-sensitive body 24, so that the auxiliary valve 27c can be set to the fully open state. When the pressure-sensitive body 24 contracts by a predetermined amount, the convex portion 24h of the flange portion 24d comes into contact with a convex portion (not shown) provided in the partition adjustment portion 24f, the deformation of the pressure-sensitive body 24 is stopped, and the movement of the link 36 is also stopped.

Next, the control state of the displacement control valve 1 will be described with reference to fig. 3. The control state is a state in which the auxiliary valve 27c is closed, the opening degree of the main valve 27b is set to a predetermined opening degree, and the pressure in the suction chamber of the variable displacement compressor is set to a set value Pset. In this state, the fluid of the suction pressure Ps flowing from the suction chamber of the variable displacement compressor to the 1 st valve chamber 14 through the 1 st communication passage 11 passes through the intermediate communication passage 29, flows into the internal space 28 surrounded by the locking portion 26 of the connecting rod 36 and the pressure sensitive member 24, and acts on the pressure sensitive member 24. As a result, the main valve portion 21c is controlled so as to stop at a position where the force in the valve closing direction by the coil spring 43, the force in the valve opening direction by the spring 37, the force by the solenoid 30, and the force by the pressure sensitive body 24 that expands and contracts in accordance with the suction pressure Ps are balanced, and the pressure in the suction chamber of the variable displacement compressor becomes the set value Pset. However, even if the opening degree of the main valve 27b is set to a predetermined opening degree, the pressure Ps of the suction chamber may fluctuate from the set value Pset due to disturbance or the like. For example, when the pressure Ps in the suction chamber becomes higher than the set value Pset due to disturbance or the like, the pressure-sensitive body 24 contracts, and the opening degree of the main valve 27b decreases. As a result, the Pd — Pc flow path is narrowed, and therefore the amount of refrigerant at the discharge pressure Pd flowing from the discharge chamber into the crank chamber is reduced, and the pressure in the crank chamber is reduced. Conversely, when the pressure Ps in the suction chamber becomes lower than the set value Pset, the pressure-sensitive body 24 expands and the opening degree of the main valve 27b increases. As a result, the Pd — Pc flow path is enlarged, and therefore, the amount of refrigerant at the discharge pressure Pd flowing from the discharge chamber into the crank chamber is increased, and the pressure in the crank chamber is increased. In this way, the displacement control valve 1 can control the pressure in the suction chamber of the variable displacement compressor to be the set value Pset.

Next, a liquid refrigerant discharge state of the displacement control valve 1 will be described with reference to fig. 4. Since the liquid refrigerant (refrigerant that is cooled and liquefied during the discharge) is stored in the crank chamber after the compressor is stopped for a long time, the liquid refrigerant needs to be discharged as quickly as possible in order to ensure a predetermined discharge pressure and discharge flow rate from the start of the compressor. When the liquid refrigerant is discharged, the pressure in the 3 rd valve chamber 16 and the pressure Ps in the suction chamber communicating with the crank chamber become high pressure, and therefore the pressure-sensitive body 24 contracts, and the solenoid 30 is driven in the forward direction to press the pressure-sensitive body 24 via the locking portion 26 of the link 36, thereby forcibly setting the auxiliary valve 27c to the fully open state. Accordingly, the auxiliary valve portion 23d is kept in the fully open state, and therefore, the liquid refrigerant can be discharged from the crank chamber to the suction chamber through the Pc-Ps flow path in a short time without changing the opening degree of the auxiliary valve portion 23d until the liquid refrigerant is completely discharged from the start of the liquid refrigerant discharge.

In addition, conventionally, in the liquid refrigerant discharging operation, attention has been paid only to how to complete the discharge of the liquid refrigerant in a short time, and therefore, the engine load may become excessive during the liquid refrigerant discharging operation. The capacity control valve 1 according to the present invention can rapidly drive the valve body 20 even when the liquid refrigerant is discharged. The operation of the displacement control valve 1 when the engine load is reduced when the liquid refrigerant is discharged will be described.

In the case where the engine load is rapidly reduced at the time of liquid refrigerant discharge, the solenoid 30 is set to "off", and the magnetic attraction force Fsol between the core 32 and the plunger 35 is operated to zero. Since the upward pressure and the downward pressure acting on the valve element 20 are set to cancel each other out, the resultant force of the biasing force of the spring 37 acting on the valve opening direction of the main valve 27b, the biasing force of the coil spring 43 acting on the valve closing direction of the main valve 27b, and the magnetic attraction force Fsol of the solenoid 30 is balanced with respect to the main force acting on the valve element 20 at the time of discharging the liquid refrigerant. Here, when the magnetic attraction force Fsol of the solenoid 30 becomes zero, the urging force of the spring 37 acting on the main valve 27b in the valve opening direction becomes dominant, the link 36 moves upward, and the coil spring 43 returns to the natural state. As a result, the link 36 is quickly pushed up, the locking portion 26 comes into contact with the adapter 23, the valve body 20 is driven in the valve opening direction of the main valve 27b, and the main valve 27b is quickly fully opened. When the main valve 27b is fully opened, the amount of refrigerant flowing from the discharge chamber of the compressor into the crank chamber through the Pd — Pc flow path increases, the pressure Pc in the crank chamber increases, and the compressor is operated at the minimum capacity. In this way, even when the auxiliary valve 27c is in the open state and a force does not act on the valve body 20 from the pressure-sensitive body 24 as in the case of discharging the liquid refrigerant, the load on the compressor can be reduced, and the load on the engine can be reduced also in the case of discharging the liquid refrigerant.

In a state where the pressure in the suction chamber of the compressor is controlled to be the set value Pset by the displacement control valve 1, when the load of the engine is to be reduced, the solenoid 30 is in the non-energized state and the main valve 27b is in the fully open state, so that the amount of the Pd pressure refrigerant flowing from the discharge chamber of the compressor into the crank chamber through the Pd-Pc flow path is increased, and the compressor is operated at the minimum displacement, thereby enabling the operation of reducing the engine load.

The coil spring 43 has a nonlinear characteristic in which the spring constant becomes large in a state where the load is small and becomes small in a state where the load is large. Thus, in the valve-opened state of the main valve 27b in which the load acting on the coil spring 43 is small, the coil spring 43 is hardly deformed because the spring constant is large. Therefore, the connecting rod 36 is displaced integrally with the valve body 20 in a state of maintaining the relative position, and therefore the capacity control valve 1 can stably control the opening degree of the main valve 27 b. In the closed state of the main valve 27b in which the load acting on the coil spring 43 is large, the spring constant of the coil spring 43 is small, and therefore the link 36 can forcibly open the auxiliary valve 27c by largely deforming the coil spring 43 without excessively increasing the output of the solenoid 30. Accordingly, when the liquid refrigerant is discharged, the auxiliary valve 27c can be maintained in the fully open state regardless of the pressure in the 3 rd valve chamber 16 and the pressure Ps in the suction chamber, and therefore the liquid refrigerant can be discharged from the crank chamber to the suction chamber through the Pc-Ps flow path in a short time.

While the embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and modifications and additions that do not depart from the spirit and scope of the invention are also included in the present invention.

For example, in the above embodiment, one end of the coil spring 43 contacts the step portion 36f of the link 36, and the other end contacts the inside step portion 21h of the valve body 20, but is not limited thereto. For example, as shown in fig. 5, one end of the spring 44 may be in contact with the end portion 32c of the core 32, and the other end may be in contact with the inner step portion 21h of the valve body 20.

In the above embodiment, the 1 st pressure in the 1 st valve chamber 14 is set as the suction pressure Ps of the variable displacement compressor, the 2 nd pressure in the 2 nd valve chamber 15 is set as the discharge pressure Pd of the variable displacement compressor, and the 3 rd pressure in the 3 rd valve chamber 16 is set as the pressure Pc of the crank chamber of the variable displacement compressor, but the present invention is not limited thereto, and the various variable displacement compressors can be dealt with by setting the 1 st pressure in the 1 st valve chamber 14 as the pressure Pc of the crank chamber of the variable displacement compressor, the 2 nd pressure in the 2 nd valve chamber 15 as the discharge pressure Pd of the variable displacement compressor, and the 3 rd pressure in the 3 rd valve chamber 16 as the suction pressure Ps of the variable displacement compressor.

Description of the symbols

1-capacity control valve, 10-valve body, 11-1 st communication passage, 12-2 nd communication passage, 13-3 rd communication passage, 14-1 st valve chamber, 15-2 nd valve chamber, 15 a-main valve seat, 16-3 rd valve chamber, 17-valve hole, 20-valve body, 21-main valve body, 21 a-block valve portion, 21 c-main valve portion, 23-adapter, 23 d-auxiliary valve portion, 24-pressure sensitive body, 24 a-bellows, 24 d-flange portion, 26-locking portion, 26 c-auxiliary valve seat, 26 d-pressing portion, 27 a-block valve, 27 b-main valve, 27 c-auxiliary valve, 29-intermediate communication passage, 30-solenoid portion, 31-electromagnetic coil, 32-magnetic core, 35-plunger, 36-link, 37-spring (2 nd forcing member), 43-coil spring (1 st forcing member), Fsol-magnetic attraction force, Ps-suction pressure (1 st pressure) (3 rd pressure), Pd-discharge pressure, Pc-control chamber pressure (3 rd pressure) (1 st pressure), Pset-suction pressure set value.