JP7146262B2 - control valve - Google Patents

Description

TECHNICAL FIELD The present invention relates to a control valve, and more particularly to a foreign object resistant structure.

An automobile air conditioner is generally configured by arranging a compressor, a condenser, an expansion device, an evaporator, etc. in a refrigeration cycle. As the compressor, a variable capacity compressor (simply referred to as a "compressor") is used that can vary the discharge capacity of the refrigerant so that a constant cooling capacity is maintained regardless of the number of revolutions of the engine. In this compressor, a piston for compression is connected to a swash plate attached to a rotating shaft driven by an engine, and the displacement of the refrigerant is adjusted by changing the angle of the swash plate to change the stroke of the piston. The angle of the swashplate is varied continuously by introducing a portion of the discharged refrigerant into the sealed control chamber to vary the pressure balance across the pistons. The pressure in the control chamber (hereinafter referred to as "control pressure") is, for example, a control valve for inlet control provided between the discharge chamber and the control chamber of the compressor, or a vent control valve provided between the control chamber and the suction chamber. It is regulated by a control valve (see Patent Document 1, for example).

JP 2017-89832 A

By the way, such a control valve is required to have foreign matter resistance performance. That is, the refrigerant discharged from the compressor may contain foreign matter such as metal powder. This is caused by abrasion around the piston of the compressor. If this foreign matter enters and gets caught in the sliding portion of the control valve, smooth operation may be hindered. Incidentally, such a problem may occur not only in the control valve of the compressor but also in the control valve having a sliding portion.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object of the present invention is to improve foreign matter resistance performance of a control valve.

One aspect of the invention is a control valve. This control valve has a first chamber communicating with the first port, a second chamber communicating with the second port, and is provided between the first chamber and the second chamber so as to separate them in the axial direction. a body having a guide hole; a valve actuating body slidably penetrating the guide hole; a solenoid for applying a driving force in the axial direction to the valve actuating body; a biasing member for imparting a At least one of the outer peripheral surface of the valve operating body and the inner peripheral surface of the guide hole is provided with a recessed portion, so that the contact surface between the valve operating body and the guide hole is intermittently formed in the axial direction. The recess is provided so that the axial length of each contact surface is smaller than the maximum axial stroke of the valve actuator.

According to this aspect, even if foreign matter enters the contact surface between the valve operating body and the guide hole, the valve operating body makes the maximum stroke to easily scrape out the foreign matter. Therefore, it is possible to prevent or suppress a situation in which a foreign object adheres to the contact surface.

ADVANTAGE OF THE INVENTION According to this invention, the foreign material resistance performance of a control valve can be improved.

It is a sectional view showing composition of a control valve concerning a 1st embodiment. 2 is a partially enlarged cross-sectional view corresponding to the upper half of FIG. 1; FIG. It is a figure showing operation|movement of a control valve. FIG. 4 is a partially enlarged cross-sectional view showing a foreign object resistant structure; FIG. 7 is a partially enlarged cross-sectional view around a valve operating body of a control valve according to a second embodiment; FIG. 4 is a partially enlarged cross-sectional view showing a foreign object resistant structure; FIG. 11 is a partially enlarged cross-sectional view of the periphery of a valve operating body of a control valve according to a modification; FIG. 11 is a partially enlarged cross-sectional view around a valve operating body of a control valve according to another modified example; FIG. 10 is a diagram showing a structure of a valve operating body and its surroundings according to another modified example;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, for the sake of convenience, the positional relationship of each structure may be expressed based on the illustrated state. Also, in the following embodiments and modifications thereof, substantially the same constituent elements are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

[First embodiment]
FIG. 1 is a cross-sectional view showing the configuration of the control valve according to the first embodiment.
A control valve 1 controls the displacement 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 through the refrigeration cycle and discharges it as a high-temperature, high-pressure gas refrigerant. The gas refrigerant is condensed by a condenser (external heat exchanger) and adiabatically expanded by an expansion device to become a low-temperature, low-pressure mist-like refrigerant. This low-temperature, low-pressure refrigerant evaporates in the evaporator, and the latent heat of evaporation cools the air inside the vehicle. The refrigerant evaporated by the evaporator is returned to the compressor and circulated through the refrigeration cycle.

The compressor has a rotating shaft that is rotationally driven by an automobile engine, and a compression piston is connected to a swash plate attached to the rotating shaft. By changing the angle of the swash plate to change the stroke of the piston, the discharge amount of the refrigerant is adjusted. The control valve 1 changes the angle of the swash plate and thus the displacement of the compressor according to the flow rate of refrigerant introduced from the discharge chamber of the compressor into the control chamber and the flow rate of refrigerant led out from the control chamber to the suction chamber. Although the control chamber in this embodiment consists of the crank chamber, in a modified example, it may be a pressure chamber separately provided in the crank chamber or outside the crank chamber.

The control valve 1 is configured as a so-called Ps sensing valve that controls the flow rate of refrigerant introduced from the discharge chamber into the control chamber so as to maintain the compressor suction pressure Ps at a set pressure. A control valve 1 is constructed by assembling a valve body 2 and a solenoid 3 in the axial direction. The valve body 2 includes a main valve 7 and a subvalve 8 . The opening of the main valve 7 is adjusted during operation of the compressor, and guides part of the discharged refrigerant to the control chamber. The auxiliary valve 8 is fully opened when the compressor is started, and functions as a so-called bleed valve that releases the refrigerant in the control chamber to the suction chamber. In this embodiment, the sub-valve 8 corresponds to the "first valve" and functions as a "breeding valve". Also, the main valve 7 corresponds to the "second valve" and functions as the "air supply valve".

The solenoid 3 generates a driving force for closing the main valve 7 and opening the sub valve 8 . The driving force is obtained with a magnitude corresponding to the supply current value. The valve body 2 has a stepped cylindrical body 5 in which a main valve 7 , a sub valve 8 and a power element 6 are accommodated. The power element 6 functions as a "pressure sensing section" and generates a counterforce to the solenoid 3 according to the magnitude of the suction pressure Ps.

The body 5 is provided with ports 12, 14 and 16 from its upper end side. Port 12 communicates with the suction chamber of the compressor. Port 14 communicates with the control room of the compressor. Port 16 communicates with the discharge chamber of the compressor. In this embodiment, the port 14 functions as a "first port", the port 12 functions as a "second port", and the port 16 functions as a "third port". An end member 13 is fixed so as to close the upper end opening of the body 5 .

In the body 5, a main passage for communicating the port 16 and the port 14 and a sub passage for communicating the port 14 and the port 12 are formed. A main valve 7 is provided in the main passage, and a sub valve 8 is provided in the sub passage. That is, the control valve 1 has a structure in which the power element 6, the sub valve 8, the main valve 7, and the solenoid 3 are arranged in order from one end side. A main valve hole 20 and a main valve seat 22 are provided in the main passage. A sub-valve seat 34 is provided in the sub-passage.

The port 12 communicates between the working chamber 23 defined in the upper portion of the body 5 and the suction chamber. The power element 6 is arranged in the working chamber 23 . The port 16 introduces refrigerant at a discharge pressure Pd from the discharge chamber. A main valve chamber 24 is provided between the port 16 and the main valve hole 20, in which the main valve 7 is arranged. A main valve seat 22 is formed at the lower end opening of the main valve hole 20 . The port 14 guides the refrigerant at the control pressure Pc to the control chamber via the main valve 7 during steady operation of the compressor, and discharges the refrigerant at the control pressure Pc from the control chamber when the compressor is started. to introduce A sub-valve chamber 26 is provided between the port 14 and the main valve hole 20, in which the sub-valve 8 is arranged. The port 12 guides the refrigerant at the suction pressure Ps through the auxiliary valve 8 to the suction chamber when the compressor is started. In this embodiment, the auxiliary valve chamber 26 functions as a "first valve chamber (first chamber)", the operating chamber 23 functions as a "second chamber", and the main valve chamber 24 functions as a "second valve chamber".

Cylindrical filter members 15 and 17 are attached to ports 14 and 16, respectively. Filter members 15 and 17 include meshes for suppressing entry of foreign matter into body 5 . When the main valve 7 is open, the filter member 17 suppresses foreign matter from entering the port 16 , and when the sub valve 8 is open, the filter member 15 suppresses foreign matter from entering the port 14 .

A guide hole 25 is provided between the auxiliary valve chamber 26 and the operating chamber 23 . A guide hole 27 is provided in the lower portion of the body 5 (on the opposite side of the main valve chamber 24 from the main valve hole 20). A valve driver 29 is slidably inserted through the guide hole 27 .

The valve driving body 29 has a stepped cylindrical shape, and its upper portion is reduced in diameter to form a dividing portion 33 that penetrates the main valve hole 20 and divides the inside and outside. The partition 33 functions as an "extension". A stepped portion formed in the valve driving body 29 serves as a main valve body 30 that opens and closes the main valve 7 by attaching to and detaching from the main valve seat 22 . The main valve 7 is opened and closed by attaching and detaching the main valve body 30 to and from the main valve seat 22 from the main valve chamber 24 side. An upper portion of the partition portion 33 is tapered upward, and a sub-valve seat 34 is formed at the upper end opening. The sub-valve seat 34 functions as a movable valve seat that displaces together with the valve driver 29 . In this embodiment, the valve driving body 29 and the main valve body 30 are distinguished, but the valve driving body 29 may be regarded as the "main valve body". The valve driver 29 may be regarded as a "valve seat member".

On the other hand, a cylindrical valve operating body 35 is slidably inserted through the guide hole 25 . A sub valve body 36 is integrally provided at the lower end of the valve operating body 35 . A plurality of communication passages 37 are provided so as to pass through the valve operating body 35 in the axial direction. The sub-valve element 36 and the sub-valve seat 34 are arranged to face each other in the axial direction. The sub-valve 8 is opened and closed by attaching and detaching the sub-valve element 36 to and from the sub-valve seat 34 in the sub-valve chamber 26 . In this embodiment, the valve actuating body 35 and the sub-valve 36 are distinguished, but the valve actuating body 35 may be regarded as the "sub-valve".

An elongated operating rod 38 is provided along the axis of the body 5 . The upper end of the operating rod 38 passes through the valve operating body 35 and is loosely fitted to the power element 6 . The valve actuation body 35 is operably connected to the power element 6 . A lower end of the operating rod 38 is connected to a plunger 50 of the solenoid 3 . The upper half of the operating rod 38 passes through the valve driver 29 and has a reduced diameter at its upper portion. A valve actuating body 35 is fitted over and fixed to the reduced diameter portion. The tip of the diameter-reduced portion is fitted to the power element 6 .

A ring-shaped spring bearing 40 is fitted to and supported by an axially intermediate portion of the operating rod 38 . A spring 42 (functioning as a "biasing member") is interposed between the valve driving body 29 and the spring bearing 40 to bias the valve driving body 29 in the closing direction of the main valve 7 and the sub valve 8. ing. When the main valve 7 is controlled, the elastic force of the spring 42 puts the valve driving body 29 and the spring bearing 40 in a tensioned state, and the main valve body 30 and the operating rod 38 move integrally.

The power element 6 includes a bellows 45 that is displaced by sensing the suction pressure Ps, and the displacement of the bellows 45 generates a force that opposes the solenoid force. This counterforce is also transmitted to the main valve body 30 via the actuation rod 38 and valve actuation body 35 . When the sub-valve element 36 is seated on the sub-valve seat 34 to close the sub-valve 8, refrigerant relief from the control chamber to the suction chamber is cut off. Further, the sub-valve body 36 is separated from the sub-valve seat 34 to open the sub-valve 8, thereby permitting the relief of the refrigerant from the control chamber to the suction chamber.

On the other hand, the solenoid 3 includes a stepped cylindrical core 46, a bottomed cylindrical sleeve 48 assembled to seal the lower end opening of the core 46, and a sleeve 48 that accommodates the core 46 in the axial direction. A stepped cylindrical plunger 50 disposed opposite to, a cylindrical bobbin 52 inserted over the core 46 and the sleeve 48, an electromagnetic coil 54 wound around the bobbin 52 and generating a magnetic circuit when energized, A cylindrical case 56 provided to cover the electromagnetic coil 54 from the outside, an end member 58 provided to seal the lower end opening of the case 56, and an end member 58 embedded below the bobbin 52. It has a collar 60 made of a magnetic material coated with it.

The valve body 2 and the solenoid 3 are fixed by press-fitting the lower end of the body 5 into the upper end opening of the core 46 . A working chamber 28 is formed between the body 5 and the core 46 . On the other hand, an operating rod 38 is inserted through the center of the core 46 in the axial direction. The working chamber 28 communicates with the working chamber 23 via the internal passages of the valve driving body 29 and the valve operating body 35, respectively. Therefore, the suction pressure Ps of the working chamber 23 is introduced into the working chamber 28 . This suction pressure Ps is also led to the inside of the sleeve 48 through the communication passage 62 formed by the gap between the operating rod 38 and the core 46 .

A spring 44 (functioning as a "biasing member") is interposed between the core 46 and the plunger 50 to bias them in a direction to separate them from each other. The spring 44 functions as a so-called off spring that fully opens the main valve 7 when the solenoid 3 is turned off. Actuating rod 38 is coaxially connected to each of valve actuation body 35 and plunger 50 . The operating rod 38 has its upper portion press-fitted into the valve operating body 35 and its lower end portion press-fitted into the upper portion of the plunger 50 . The actuating rod 38, the valve operating body 35 and the plunger 50 constitute a "movable body" that is integrally displaced with the valve driving body 29 when the main valve 7 is controlled.

The actuation rod 38 appropriately transmits the solenoid force, which is the attraction force between the core 46 and the plunger 50 , to the main valve body 30 and the subvalve body 36 . On the other hand, the operating rod 38 is loaded with a driving force (also referred to as a "pressure-sensitive driving force") due to the expansion and contraction of the power element 6 so as to oppose the solenoid force. That is, in the controlled state of the main valve 7 , the force adjusted by the solenoid force and the pressure-sensitive driving force acts on the main valve body 30 to appropriately control the opening of the main valve 7 . When the compressor is started, the operating rod 38 is displaced relative to the body 5 against the urging force of the spring 44 and the urging force of the power element 6 according to the magnitude of the solenoid force, closing the main valve 7. The sub-valve body 36 is pushed up to open the sub-valve 8 . Further, even during control of the main valve 7, if the suction pressure Ps rises considerably, the bellows 45 contracts and the operating rod 38 displaces relative to the body 5, closing the main valve 7 and then closing the sub-valve body. 36 is pushed up to open the sub valve 8. Thereby, the bleed function is exhibited.

The sleeve 48 is made of non-magnetic material. A communication groove 66 parallel to the axis is provided on the side surface of the plunger 50, and a communication hole 68 for communication between the inside and the outside is provided in the lower part of the plunger 50. As shown in FIG. With such a configuration, even if the plunger 50 is positioned at the bottom dead center as shown, the suction pressure Ps is led to the back pressure chamber 70 through the gap between the plunger 50 and the sleeve 48 .

A pair of connection terminals 72 connected to the electromagnetic coil 54 extend from the bobbin 52 and extend through the end member 58 to the outside. Only one of the pair is shown in the figure for convenience of explanation. The end member 58 is attached so as to seal the entire structure inside the solenoid 3 contained in the case 56 from below. The end member 58 is formed by molding (injection molding) a corrosion-resistant resin material, and the resin material is also interposed in the gap between the case 56 and the electromagnetic coil 54 . By interposing the resin material in the gap between the case 56 and the electromagnetic coil 54 in this manner, the heat generated by the electromagnetic coil 54 can be easily transferred to the case 56, thereby improving the heat radiation performance. A tip portion of a connection terminal 72 is drawn out from the end member 58 and connected to an external power source (not shown).

2 is a partially enlarged sectional view corresponding to the upper half of FIG. 1. FIG.
An annular groove 73 is provided around the sliding surface of the valve driver 29 with respect to the guide hole 27, and an O-ring 74 (seal ring) is fitted. This prevents the coolant from flowing through the gap between the two. Since the actuation rod 38 is provided integrally with the sub-valve element 36, the solenoid force can be transmitted directly to the sub-valve element 36.

The upper end portion of the valve driving member 29 (the sub valve seat 34) and the lower end portion of the valve operating member 35 (the sub valve member 36) are configured to be attached and detached at their tapered surfaces. As a result, the valve driving body 29 is stably driven in the axial direction by aligning the upper end and slidably supporting the lower half in the guide hole 27 .

A lower end portion of the sub-valve element 36 has a tapered shape that decreases in outer diameter downward. In this embodiment, the tapered surface is a spherical surface (curved surface) having a predetermined curvature, and is seated in line contact with the tapered auxiliary valve seat 34 . As a result, when the sub valve 8 is closed, the valve driving body 29 and the valve operating body 35 are stably driven together.

The valve operating body 35 has an insertion hole 43 axially penetrating through its center. A plurality of communication paths 37 are provided around the insertion hole 43 . Each communication passage 37 communicates between the internal passage 39 of the valve driver 29 and the working chamber 23 . The communication passage 37 communicates the sub-valve chamber 26 and the working chamber 23 when the sub-valve 8 is opened.

An annular groove 90 is provided around the inner peripheral surface of the guide hole 25 . The annular groove 90 can be obtained, for example, by boring. The annular groove 90 functions as a "recess" and improves the foreign matter resistance performance of the control valve 1, the details of which will be described later.

The upper portion of the operating rod 38 extends through the insertion hole 43 to the power element 6 . The valve operating body 35 is positioned with respect to the operating rod 38 by engaging with a stepped portion 79 that is the proximal end of the diameter-reduced portion of the operating rod 38 . In the illustrated state in which the sub valve body 36 is seated on the sub valve seat 34, the operating rod 38 is arranged so that the top surface of the spring bearing 40 is separated from the bottom surface of the valve driving body 29 by at least a predetermined distance L. The position of the stepped portion 79 is set. The predetermined interval L functions as a so-called "play".

When the solenoid force is increased, the operating rod 38 can be displaced relative to the main valve body 30 (valve driving body 29) to push up the valve operating body 35. FIG. Thereby, the sub-valve 8 can be opened by separating the sub-valve element 36 and the sub-valve seat 34 . In addition, the solenoid force can be directly transmitted to the main valve body 30 in a state where the spring bearing 40 and the valve driving body 29 are engaged (abutted), and the main valve body 30 can be moved in the closing direction of the main valve 7 by a large force. It can be pressed with force. This configuration functions as an unlocking mechanism that unlocks the operation of the main valve body 30 when the operation of the main valve body 30 is locked due to foreign matter getting caught in the sliding portion between the valve driving body 29 and the guide hole 27 .

The main valve chamber 24 is provided coaxially with the body 5 and configured as a pressure chamber having a diameter larger than that of the main valve hole 20 . Therefore, a relatively large space is formed between the main valve 7 and the port 16, and a sufficient flow rate of refrigerant flowing through the main passage can be ensured when the main valve 7 is opened. Similarly, the auxiliary valve chamber 26 is also provided coaxially with the body 5 and configured as a pressure chamber having a diameter larger than that of the main valve hole 20 . Therefore, a relatively large space is formed between the sub valve 8 and the port 14 as well. As shown in the drawing, the detachable portion between the upper end of the valve driving body 29 and the lower end of the sub-valve body 36 is set to be positioned in the central portion of the sub-valve chamber 26 . That is, the movable range of the main valve body 30 is set so that the sub valve seat 34 is always positioned in the sub valve chamber 26 , and the sub valve 8 is opened and closed in the sub valve chamber 26 . Therefore, when the sub-valve 8 is opened, a sufficient flow rate of refrigerant flowing through the sub-passage can be ensured. That is, the bleeding function can be effectively exhibited.

The power element 6 is constructed by closing the upper end opening of the bellows 45 with a first stopper 82 and closing the lower end opening with a second stopper 84 . Bellows 45 functions as a "pressure sensitive member". The first stopper 82 is integrally molded with the end member 13 . The second stopper 84 is formed into a cylindrical shape with a bottom by press-molding a metal material, and has a flange portion 86 extending radially outward at its lower end opening. The bellows 45 is hermetically welded to the bottom surface of the end member 13 at the top end of the bellows-like body, and hermetically welded to the top surface of the flange portion 86 at the bottom opening of the body. The inside of the bellows 45 is a closed reference pressure chamber S. A spring 88 is arranged inside the bellows 45 . A spring 88 is interposed between the end member 13 and the flange portion 86 to bias the bellows 45 in the extension direction. The reference pressure chamber S is in a vacuum state in this embodiment.

The end member 13 serves as a fixed end of the power element 6 . By adjusting the amount of press-fitting of the end member 13 into the body 5, the set load of the power element 6 (the set load of the spring 88) can be adjusted. The central portion of the first stopper 82 extends downward toward the inside of the bellows 45 , the central portion of the second stopper 84 extends upward toward the inside of the bellows 45 , and the bellows 45 form the axis of The bellows 45 expands or contracts in the axial direction (the opening/closing direction of the main valve and the sub-valve) according to the pressure difference between the suction pressure Ps in the working chamber 23 and the reference pressure in the reference pressure chamber S. As the differential pressure decreases and the bellows 45 expands, a driving force is applied to the valve driver 29 in the direction of opening the main valve 7 and closing the sub valve 8 . Even if the pressure difference increases, when the bellows 45 contracts by a predetermined amount, the second stopper 84 contacts and locks with the first stopper 82, so the contraction is restricted.

In this embodiment, the effective pressure receiving diameter A of the bellows 45, the effective pressure receiving diameter B (seal portion diameter) of the main valve body 30 at the main valve 7, the sliding portion diameter C of the valve driver 29, and the valve operating body 35 is set equal to the diameter D of the sliding portion. It should be noted that the term "equal" as used herein may be considered to include not only the concept of being completely equal, but also the concept of being approximately equal (substantially equal). Therefore, when the valve driving body 29 and the power element 6 are operatively connected, the combined body of the main valve body 30 and the sub-valve body 36 is affected by the discharge pressure Pd, the control pressure Pc and the suction pressure Ps. Canceled. As a result, in the controlled state of the main valve 7 , the main valve body 30 opens and closes based on the suction pressure Ps that the power element 6 receives in the working chamber 23 . That is, the control valve 1 functions as a so-called Ps sensing valve.

In this embodiment, the diameters B, C, and D are thus made equal, and the internal passage of the valve body (main valve body 30 and subvalve body 36) is vertically penetrated, so that the pressure acting on the valve body ( Pd, Pc, Ps) can be canceled. That is, the pressures before and after (up and down in the drawing) the combined body of the valve operating body 35, the valve driving body 29, the operating rod 38 and the plunger 50 can be made the same pressure (suction pressure Ps), thereby realizing pressure cancellation. be done. Thereby, the diameter of each valve body can be set without depending on the diameter of the bellows 45, and the degree of design freedom is high. In a modification, the diameters B, C, and D may be made equal, while the effective pressure receiving diameter A may be made different. That is, the effective pressure receiving diameter A of the bellows 45 may be smaller than the diameters B, C, and D, or larger than the diameters B, C, and D.

On the other hand, in this embodiment, the seal diameter E of the sub valve 8 of the sub valve body 36 is made smaller than the effective pressure receiving diameter B of the main valve 7 of the main valve body 30, and the difference between the control pressure Pc and the suction pressure Ps is A pressure (Pc-Ps) acts on the valve driver 29 in the direction of opening the sub valve 8 . This pressure receiving structure and the biasing structure by the spring 42 realize a "differential pressure opening mechanism" that opens the sub valve 8 when the differential pressure (Pc-Ps) exceeds the set differential pressure ΔPset. ing.

Next, the operation of the control valve will be explained.
In this embodiment, a PWM (Pulse Width Modulation) method is employed for controlling the energization of the solenoid 3 . This PWM control is performed by supplying a pulse current of about 400 Hz set to a predetermined duty ratio, and is executed by a control section (not shown). This control unit has a PWM output unit that outputs a pulse signal with a designated duty ratio, but since a known configuration is employed for the configuration itself, detailed description thereof will be omitted.

FIG. 3 is a diagram showing the operation of the control valve. FIG. 2, already described, shows the state of the control valve during minimum displacement operation. FIG. 3 shows the state when the bleed function is exhibited during maximum capacity operation (when the air conditioner is started, etc.). The following description will be made based on FIG. 1 with appropriate reference to FIGS. 2 and 3. FIG.

When the solenoid 3 in the control valve 1 is not energized (OFF), that is, when the air conditioner is not operating, no attraction force acts between the core 46 and the plunger 50 . On the other hand, the biasing force of spring 44 is transmitted to valve driver 29 via plunger 50 , operating rod 38 and valve operating body 35 . As a result, as shown in FIG. 2, the main valve body 30 is separated from the main valve seat 22 and the main valve 7 is fully opened. At this time, the sub valve 8 maintains the closed state.

On the other hand, when a control current (starting current) is supplied to the solenoid 3 such as when the air conditioner is started, the core 46 attracts the plunger 50 . As a result, the operating rod 38 is pushed up. At this time, the biasing force of the spring 44 pushes up the valve driving body 29, and the main valve body 30 is seated on the main valve seat 22 to close the main valve 7, as shown in FIG. On the other hand, the operating rod 38 is displaced relative to the valve driving body 29 and further pushed up, and the operating rod 38 pushes up the valve operating body 35 . As a result, the sub-valve body 36 is separated from the sub-valve seat 34 to open the sub-valve 8 . As a result, a predetermined flow rate of refrigerant is released from the control chamber to the suction chamber, the control pressure Pc is lowered, and the compressor operates at maximum capacity. That is, the bleed function is exhibited, and the compressor is quickly started.

When the suction pressure Ps becomes sufficiently low in this way, the power element 6 expands to close the auxiliary valve 8 . At this time, when the control current supplied to the solenoid 3 is reduced in accordance with the set temperature of the air conditioner, the valve driving body 29 and the power element 6 operate together, and the main valve 7 is set to a predetermined degree of opening. be.

When the current value supplied to the solenoid 3 is within the control current value range of the main valve 7, the opening of the main valve 7 is autonomously adjusted so that the suction pressure Ps becomes the set pressure Pset set by the supply current value. be. In this controlled state of the main valve 7, the sub-valve element 36 is seated on the sub-valve seat 34, and the sub-valve 8 maintains the closed state. The main valve body 30 stops at the valve lift position where the force in the valve opening direction by the spring 44, the solenoid force in the valve closing direction, and the force in the valve opening direction by the power element 6 corresponding to the suction pressure Ps are balanced. .

At this time, when the refrigerating load increases and the suction pressure Ps becomes higher than the set pressure Pset, the bellows 45 shrinks and the main valve element 30 relatively displaces upward (in the valve closing direction). As a result, the valve opening degree of the main valve 7 becomes smaller, and the compressor operates to increase the displacement. As a result, the suction pressure Ps decreases. Conversely, when the refrigerating load decreases and the suction pressure Ps becomes lower than the set pressure Pset, the bellows 45 expands. As a result, the power element 6 biases the main valve body 30 in the valve opening direction to increase the valve opening degree of the main valve 7, and the compressor operates to reduce the displacement. As a result, the suction pressure Ps is maintained at the set pressure Pset.

When the load on the engine increases while such steady control is being performed and it is desired to reduce the load on the air conditioner, the solenoid 3 in the control valve 1 is switched from on to off. As a result, no suction force acts between the core 46 and the plunger 50, so that the main valve body 30 is separated from the main valve seat 22 by the biasing force of the spring 44, and the main valve 7 is fully opened. At this time, since the sub-valve element 36 is basically seated on the sub-valve seat 34, the sub-valve 8 is closed. As a result, the refrigerant at the discharge pressure Pd introduced from the discharge chamber of the compressor to the port 16 passes through the fully open main valve 7 and flows from the port 14 to the control chamber. Therefore, the control pressure Pc becomes higher, and the compressor comes to perform the minimum capacity operation.

Next, the details of the foreign matter resistant structure in this embodiment will be described.
FIG. 4 is a partially enlarged cross-sectional view showing the foreign object resistant structure. The left side corresponds to the enlarged view of part a in FIG. 2, and shows the state where the solenoid 3 is turned off and the valve operating body 35 is at the bottom dead center. The right side corresponds to the enlarged view of part a in FIG. 3, and shows the state where the solenoid 3 is turned on and the valve operating body 35 is at the top dead center. Therefore, s1 in the drawing indicates the maximum stroke of the valve operating body 35. As shown in FIG.

In this embodiment, a seal ring (O-ring 74) is provided between the valve driver 29 and the guide hole 27 as shown in FIG. not set in This is to minimize sliding resistance of the valve operating body 35 against the driving force of the solenoid 3 . Further, the differential pressure (Pc-Ps) generated between the sub-valve chamber 26 and the working chamber 23 is smaller than the differential pressure (Pd-Ps) generated between the main valve chamber 24 and the working chamber 28 . This is also because the need for sealing between the valve operating body 35 and the guide hole 25 is less than that between the valve driving body 29 and the guide hole 27 .

However, especially when the solenoid 3 is switched from ON to OFF and the main valve 7 is fully opened, even the differential pressure (Pc-Ps) increases. For this reason, foreign matter in the refrigerant may enter the sliding portion between the valve operating body 35 and the guide hole 25 and hinder the smooth operation of the valve operating body 35 . There is also a concern that the operation of the valve operating body 35 may be locked if foreign matter adheres to the sliding portion.

Therefore, in this embodiment, as shown in FIG. 4, a relatively large annular groove 90 is provided on the inner peripheral surface of the guide hole 25 . The guide hole 25 slidably supports the valve actuating body 35 on upper side surfaces 92 and lower side surfaces 94 adjacent to the annular groove 90 thereof. That is, the upper side surface 92 and the lower side surface 94 constitute "contact surfaces" that contact the valve actuation body 35 . The upper side surface 92 corresponds to the "first contact surface" and the lower side surface 94 corresponds to the "second contact surface".

As shown in the drawing, an annular groove 90 is provided so that the axial lengths l1 and l2 of each contact surface are both smaller than the maximum stroke s1 of the valve operating body 35. As shown in FIG. Therefore, even if foreign matter enters the sliding surface between the valve operating body 35 and the guide hole 25, the valve operating body 35 operates with the maximum stroke, so that the foreign matter can be pushed out of the contact surface. . That is, even if a foreign substance tries to adhere to the contact surface, it can be peeled off and scraped out of the space formed by the annular groove 90 or out of the sliding portion. As a result, the foreign matter resistance performance of the control valve 1 can be enhanced.

[Second embodiment]
FIG. 5 is a partially enlarged cross-sectional view of the periphery of the valve operating body of the control valve according to the second embodiment. FIG. 5(A) shows the state where the valve operating body is at the bottom dead center, and FIG. 5(B) shows the state where the valve operating body is at the top dead center. FIG. 6 is a partially enlarged cross-sectional view showing the foreign object resistant structure. The left stage corresponds to the enlarged view of part a in FIG. 5A, and the right stage corresponds to the enlarged view of part a in FIG. 5B. The following description will focus on differences from the first embodiment.

As shown in FIGS. 5A and 5B, no concave portion is provided on the inner peripheral surface of guide hole 225 in body 205 . On the other hand, a plurality of annular grooves 290 are provided on the outer peripheral surface of the valve operating body 235 . In this embodiment, six annular grooves 290 are arranged at equal intervals in the axial direction of the valve operating body 235 to form a so-called labyrinth structure. Each annular groove 290 functions as a "recess".

As also shown in FIG. 6, narrow annular grooves 290 are arranged on the outer peripheral surface of the valve operating body 235 at small intervals. Thereby, a narrow sliding surface 292 is formed between adjacent annular grooves 290, and a contact surface between the valve operating body 235 and the guide hole 225 is intermittently formed in the axial direction. The annular grooves 290 are provided such that both the contact surface length l21 between the adjacent annular grooves 290 and the contact surface length l22 outside the annular groove region are smaller than the maximum stroke s21 of the valve operating body 235. there is Therefore, even if foreign matter enters the sliding surface between the valve operating body 235 and the guide hole 225, it can be scraped out without being retained on the contact surface. That is, this embodiment can also improve the foreign matter resistance performance of the control valve.

Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to those specific embodiments, and that various modifications are possible within the scope of the technical idea of the present invention. do not have.

FIG. 7 is a partially enlarged cross-sectional view of the periphery of the valve operating body of the control valve according to the modification. FIG. 7(A) shows the state where the valve operating body is at the bottom dead center, and FIG. 7(B) shows the state where the valve operating body is at the top dead center.
In this modification, the upper end of the valve actuating body 335 has a flange-like shielding portion 340 projecting radially outward. The shielding portion 340 has an outer diameter larger than the inner diameter of the guide hole 25 . The shielding part 340 is seated on the bottom of the working chamber 23 when the solenoid 3 is turned off, and closes the open end of the gap between the valve operating body 335 and the guide hole 25 .

According to this modification, when the solenoid 3 is turned off, that is, when the main valve 7 is fully open and the differential pressure (Pc-Ps) is maximized, the gap between the valve operating body 335 and the guide hole 25 is blocked. be. That is, it is possible to prevent or suppress the entry of foreign matter into the sliding portion in a state of greatest concern. In this modified example, an example in which the shielding section is applied to the configuration of the first embodiment is shown, but a similar shielding section may be applied to the second embodiment and other configurations.

It should be noted that even if the concave portion of the guide hole is omitted in this modified example, the effect of improving foreign matter resistance performance can be obtained. The control valve of this modified example may be broadly understood as follows. The control valve includes a first chamber communicating with a first port, a second chamber communicating with a second port, and a space between the first chamber and the second chamber in the axial direction. a valve actuating body slidably penetrating the guide hole; a solenoid for applying an axial driving force to the valve actuating body; a biasing member for applying a biasing force opposing the force. The valve actuator has a shield projecting radially outward. The shield closes the open end of the gap between the valve operating body and the guide hole when the solenoid is turned off.

FIG. 8 is a partially enlarged cross-sectional view of the periphery of a valve operating body of a control valve according to another modification.
In this modification, a stepped portion 350 is provided around the guide hole 25 in the auxiliary valve chamber 26 . The stepped portion 350 is an annular recess formed in the upper surface of the sub-valve chamber 26 in the body 305 .

According to this modified example, by providing the stepped portion 350 in the vicinity of the opening end of the gap between the valve operating body 335 and the guide hole 25, foreign matter can be received. That is, it is possible to suppress the fact that the foreign matter entering from the port 14 is led to the sliding portion. In this modified example, an example in which the stepped portion is applied to the configuration of the first embodiment is shown, but a similar stepped portion may be applied to the configuration of the second embodiment and other configurations.

It should be noted that even if the concave portion of the guide hole is omitted in this modified example, the effect of improving foreign matter resistance performance can be obtained. The control valve of this modified example may be broadly understood as follows. The control valve includes a first port for introducing fluid, a first chamber communicating with the first port, a second port for leading out the fluid, a second chamber communicating with the first port, and the first port. a body having a guide hole axially spaced between the chamber and the second chamber; a valve actuating body slidably penetrating the guide hole; A solenoid for applying an axial driving force and a biasing member for applying a biasing force opposing the driving force to the valve actuator. A stepped portion is provided around the guide hole in the first chamber for receiving foreign matter entering from the first port.

FIG. 9 is a diagram showing the structure of a valve operating body and its surroundings according to another modification. FIG. 9(A) is a partially enlarged cross-sectional view of the periphery of the valve operating body. FIG. 9B is a plan view of the valve operating body, and FIG. 9C is a side view of the valve operating body.

In this modified example, a foreign matter discharging structure is provided in addition to the configuration of the second embodiment. That is, a discharge groove 450 is provided on the outer peripheral surface of the valve operating body 435 so as to traverse the annular groove 290 . Two discharge grooves 450 are provided at positions circumferentially offset by 180 degrees on the valve actuation body 435 . The lower end of the discharge groove 450 communicates with the lowermost annular groove 290 , and the upper end of the discharge groove 450 is open to the working chamber 23 .

According to this modification, it becomes easier to discharge foreign matter scraped into the annular groove 290 by the sliding surfaces 292 and 294 (see FIG. 6) into the working chamber 23 via the discharge groove 450 . In this modified example, an example in which the discharge groove is applied to the configuration of the second embodiment is shown, but a similar discharge groove may be applied to the first embodiment and other configurations. Also, the number of discharge grooves is not limited to two, and can be set as appropriate. The discharge groove may intersect the annular groove at an angle other than 90 degrees.

In the above-described second embodiment, an example in which six annular grooves 290 are provided in the valve operating body 235 was shown, but the number of annular grooves is not limited to this and can be set as appropriate. Also, the widths of the plurality of annular grooves may be varied, or the intervals between adjacent annular grooves may be appropriately varied. However, the axial length of each contact surface should be smaller than the maximum stroke of the valve operating body.

In the above embodiment, the stroke of the valve operating body when the solenoid is turned on from off is exemplified as the "maximum stroke". However, depending on the external environment, such as when the outside air temperature is low, there are cases where the valve operating body does not make a full stroke even when the solenoid is turned on from off. Therefore, the "maximum stroke" may be defined as a full stroke in specifications so as not to make the definition ambiguous.

In the above-described embodiment, a configuration in which a foreign matter-resistant structure (recess) is provided between the sliding portion between the auxiliary valve chamber 26 and the operating chamber 23, that is, between the valve operating body and the guide hole has been exemplified. In a modification, the seal ring may be omitted in the sliding portion between the main valve chamber 24 and the working chamber 28, and a foreign matter resistant structure (recess) may be provided. That is, a foreign matter-resistant structure (recess) may be provided between the valve driver 29 and the guide hole 27 . In that case, the valve driving body can also be regarded as a "valve operating body." At least one of the outer peripheral surface of the valve driving body and the inner peripheral surface of the guide hole is provided with a recessed portion so that the contact surface between the valve driving body and the guide hole is intermittently formed in the axial direction. A recess is provided so that the axial length of each contact surface is smaller than the maximum stroke of the valve driver. The recess may consist of a single annular groove that is elongated in the axial direction. Alternatively, it may be composed of a plurality of annular grooves.

In the above embodiment, the configuration in which the control valve includes the main valve 7 and the sub valve 8 is exemplified. That is, the body has an inlet port (port 16) for introducing fluid, an inlet/outlet port (port 14) for introducing and leading out fluid, and an outlet port (port 12) for leading out fluid. In a modified example, the foreign matter resistant structure (concave portion) may be applied to a control valve that does not have an inlet/outlet port, that is, a control valve that has a single valve portion.

In the above-described embodiment, the main configuration is the so-called inlet control that controls the flow rate of refrigerant flowing from the discharge chamber to the control chamber. It is good also as the composition which carried out. The control valve for discharge control is configured as a Ps sensing valve that adjusts the flow rate of refrigerant discharged from the control chamber to the suction chamber so as to keep the compressor suction pressure Ps (corresponding to the "sensed pressure") at the set pressure. . Alternatively, the configuration may be such that both the insertion control and the removal control are appropriately controlled.

In the above embodiment, the so-called Ps sensing valve that operates by directly sensing the suction pressure Ps is exemplified as the control valve. That is, the pressure sensed by the pressure sensing portion (also referred to as "sensed pressure") was defined as the suction pressure Ps. In a modification, it may be a so-called Pc sensing valve that operates by sensing the control pressure Pc as the sensed pressure.

In the above embodiment, the spring is used as the biasing member, but other biasing member such as rubber may be used.

In the above embodiment, the configuration in which the valve operating body functions as a valve body has been exemplified. In a modified example, the valve operating body itself may be configured so as not to have a valve function. For example, the valve operating body may be configured as an operating rod (shaft) and slidably supported by a guide hole. The foreign object resistant structure (recess) may be provided between the valve operating body and the operating rod.

Although not described in the above embodiment, the valve operating body may be made of a material with lower hardness than the body. As a result, it becomes easier to scrape off the foreign matter adhering to the outer peripheral surface of the valve actuating body into the recess or scrape it out of the sliding portion.

It should be noted that the present invention is not limited to the above-described embodiments and modifications, and can be embodied by modifying constituent elements without departing from the scope of the invention. Various inventions may be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments and modifications. Also, some constituent elements may be deleted from all the constituent elements shown in the above embodiments and modifications.

1 control valve, 2 valve body, 3 solenoid, 5 body, 6 power element, 7 main valve, 8 auxiliary valve, 12 port, 14 port, 16 port, 20 main valve hole, 22 main valve seat, 23 working chamber, 24 Main valve chamber 25 Guide hole 26 Sub valve chamber 27 Guide hole 28 Operating chamber 29 Valve driver 30 Main valve element 32 Sub valve hole 34 Sub valve seat 35 Valve operating element 36 Sub valve element , 37 communicating passage, 38 operating rod, 39 internal passage, 42 spring, 44 spring, 90 annular groove, 90 concave portion, 92 upper surface, 94 lower surface, 205 body, 225 guide hole, 235 valve operating body, 290 annular groove, 292 sliding surface, 305 body, 335 valve operating body, 340 shielding portion, 350 stepped portion, 435 valve operating body, 450 discharge groove.

Claims (8)

a first chamber communicating with the first port, a second chamber communicating with the second port, and a guide hole provided between the first chamber and the second chamber so as to separate them in the axial direction. a body having
a valve operating body slidably penetrating the guide hole;
a solenoid for applying an axial driving force to the valve actuator;
a biasing member for applying a biasing force opposing the driving force to the valve operating body;
with
At least one of the outer peripheral surface of the valve operating body and the inner peripheral surface of the guide hole is provided with a recessed portion so that the contact surface between the valve operating body and the guide hole is intermittently formed in the axial direction,
The control valve, wherein the recess is provided such that the axial length of each contact surface is smaller than the maximum axial stroke of the valve actuator. the concave portion is composed of one annular groove provided on the inner peripheral surface of the guide hole,
2. The control valve according to claim 1, wherein the contact surfaces comprise a first contact surface and a second contact surface adjacent to the annular groove. 2. The control valve according to claim 1, wherein the recess is a plurality of annular grooves provided on the outer peripheral surface of the valve actuator. the valve actuator has a shield projecting radially outward;
The control valve according to any one of claims 1 to 3, wherein the shield closes an open end of a gap between the valve operating body and the guide hole when the solenoid is turned off. said first port introducing fluid while said second port outflowing fluid;
4. The control valve according to claim 2, wherein said valve operating body further has a discharge groove opening from said annular groove to said second chamber. said first port introducing fluid while said second port outflowing fluid;
6. The control valve according to any one of claims 1 to 5, wherein a stepped portion is provided around the guide hole in the first chamber for receiving foreign matter entering from the first port. Applied to a variable displacement compressor having a suction chamber, a discharge chamber and a control chamber, wherein the discharge displacement is variable by adjusting the pressure of the control chamber,
a valve seat disposed in the first chamber;
a valve body that can be displaced integrally with the valve operating body and that opens and closes the valve portion by attaching to and detaching from the valve seat;
with
the first port communicates with the control chamber while the second port communicates with the suction chamber;
7. The control valve according to any one of claims 1 to 6, wherein the valve portion is a bleed valve that is opened to release part of the refrigerant in the control chamber to the suction chamber. a third port communicating with the discharge chamber; a first valve chamber as the first chamber; a second valve chamber communicating with the third port; a valve hole in directional communication;
a first valve body provided integrally with the valve actuation body as the valve body;
a second valve body that contacts and separates from the valve hole from the side of the second valve chamber to open and close an air supply valve;
an extension portion extending from the second valve body through the valve hole to the first valve chamber;
an operating rod that transmits the driving force of the solenoid to the first valve body;
a first biasing member as the biasing member;
a second biasing member for biasing the second valve body in the valve closing direction;
with
The valve seat is provided integrally with the extension portion in the first valve chamber,
8. The control valve according to claim 7, wherein the operating rod penetrates the second valve body and the extension portion and is provided integrally with the first valve body.

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