JP2020193651A - Valve device - Google Patents

Abstract

To provide an improved valve device capable of suppressing abnormal noise while being inexpensive.SOLUTION: A valve device includes: a power element having a pressure detecting chamber into which a refrigerant enters, and a pressure operating chamber in which a gas is filled; a flexible diaphragm partitioning the pressure detecting chamber and the pressure operating chamber in the power element; an operating rod 5 that moves in a valve opening direction according to the displacement of the diaphragm; a valve body 2 that includes a valve seat 20 and is joined to the power element; and a valve element 3 that is installed to the valve body 2 so as to be capable of seating on the valve seat 20 and abuts on the operating rod 5. The valve element 3 is formed of a metal plate material and elastically deforms to separate from the valve seat 20 when force in the valve opening direction is applied from the operating rod 5. The valve element is restored from the deformation by own elastic force and seats on the valve seat 20 when force in the valve opening direction is not applied from the operating rod 5.SELECTED DRAWING: Figure 2

Description

The present invention relates to a valve device.

Mechanical constant pressure valves, expansion valves, and the like are known as valve devices that control the flow rate of refrigerant in air conditioners. For example, in Patent Document 1, when the driving force of the power element increases, the valve body which is a sphere is opened via the operating rod, and when the driving force of the power element decreases, the valve is urged by the coil spring. An expansion valve that closes the body is disclosed.

Japanese Unexamined Patent Publication No. 2019-011886

Further, in the expansion valve described in Patent Document 1, in order to suppress abnormal noise caused by the vibration of the operating rod, an anti-vibration spring for damping the vibration of the operating rod is provided.

However, it was confirmed that even if the vibration-proof spring suppresses the vibration of the operating rod, abnormal noise may occur. As a result of analysis by the present inventors, it was found that the vibration of the valve body is the cause of the abnormal noise. As a mechanism for generating abnormal noise, since the end of the operating rod that drives the sphere as a valve body is flat, the surface of the sphere and the end of the operating rod make point contact, and this is used as a fulcrum in the vicinity of the valve body. It is presumed that the valve body sways due to the disturbance when the refrigerant passes through the valve body, causing vibration.

In particular, in a type of expansion valve in which the valve body is urged in the valve closing direction by a coil spring arranged in the valve chamber as described in Patent Document 1, the coil spring is vibrated by the flow of the refrigerant, and the valve body It was also found to increase the vibration.

Therefore, an object of the present invention is to provide an improved valve device capable of suppressing abnormal noise at low cost.

In order to achieve the above object, the valve device according to the present invention
A case equipped with a pressure detection chamber into which the refrigerant enters and a pressure operating chamber filled with gas,
In the case, a flexible diaphragm that separates the pressure detecting chamber and the pressure operating chamber, and
A moving body that moves in the valve opening direction according to the displacement of the diaphragm, and
A valve body having a valve chamber formed with a valve seat and joined to the case,
It has a valve body that is arranged in the valve chamber so that it can be seated on the valve seat and that comes into contact with the moving body.
The valve body is formed of a metal circular plate material, and when a force in the valve opening direction is applied from the moving body, the valve body is elastically deformed toward the valve chamber to be separated from the valve seat. When a force in the valve opening direction is not applied from the moving body, the moving body recovers from the deformation by its own elastic force and is seated on the valve seat.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an improved valve device capable of suppressing abnormal noise at low cost.

FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve in the present embodiment is applied to a refrigerant circulation system. FIG. 2 is an enlarged perspective view showing a cross section of the lower end of the operating rod and the vicinity of the valve body. FIG. 3 is a perspective view of the valve body. FIG. 4 is a perspective view showing a ring spring. FIG. 5 is an enlarged cross-sectional view of the lower end of the operating rod and the vicinity of the valve body. FIG. 6 is an enlarged perspective view showing a cross section in the vicinity of the lower end of the operating rod, the valve body, and the holding plate. FIG. 7 is a perspective view of the valve body and the holding plate.

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

(Definition of direction)
In the present specification, the side from the valve body toward the diaphragm is defined as "upper", and the side from the diaphragm toward the valve body is defined as "downward".

An outline of the expansion valve 1 which is a valve device according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve 1 in the present embodiment is applied to the refrigerant circulation system 100. In this embodiment, the expansion valve 1 is fluidly connected to the compressor 101, the condenser 102, and the evaporator 103.

The expansion valve 1 includes a valve body 2 having a valve chamber VS, a valve body 3, an operating rod 5, a ring spring 6, and a power element 8. Let L be the axis of the expansion valve 1. The actuating rod 5 constitutes a moving body.

The valve body 2 includes a first flow path 21 and a second flow path 22 in addition to the valve chamber VS. The first flow path 21 is a supply-side flow path, and a refrigerant (also referred to as a fluid) is supplied to the valve chamber VS via the supply-side flow path. The second flow path 22 is a discharge side flow path, and the fluid in the valve chamber VS is discharged to the outside of the expansion valve through the communication hole 27 through which the lower end of the operating rod 5 is inserted and the discharge side flow path. The first flow path 21 and the valve chamber VS are communicated with each other by a connecting path 21a having a smaller diameter than the first flow path 21. The lower end of the valve chamber VS is sealed by a plug 43.

FIG. 2 is an enlarged perspective view showing a cross section of the lower end of the operating rod 5 and the vicinity of the valve body 3. In the valve body 2, the annular recess 27a is formed by the annular recess around the lower end of the communication hole 27 at the upper end of the valve chamber VS. By forming the annular recess 27a, the lower edge of the communication hole 27 projects downward in an annular shape to form the protrusion 27b. The cross section of the protruding portion 27b has a semicircular shape on the lower end side, and the lowermost end thereof constitutes the valve seat 20.

The lower end of the operating rod 5 is a flat surface 5a, and the flat surface 5a abuts on the upper surface of the valve body 3.

FIG. 3 is a perspective view of the valve body 3. For example, a valve body 3 as a diaphragm can be formed by plastic working a circular plate material made of SUS having a plate thickness of about 1 mm so that the center protrudes by press molding. The valve body 3 connects the central circular portion 3a having a flat upper surface, the peripheral annular portion 3b shifted downward with respect to the circular portion 3a, and the outer circumference of the circular portion 3a and the inner circumference of the peripheral annular portion 3b. A plurality of (here, six) legs 3c extending diagonally downward in a radial pattern are connected in series. The opening 3d surrounded by the adjacent leg portion 3c, the circular portion 3a, and the peripheral annular portion 3b penetrates the valve body 3 in the plate thickness direction, and the opening 3d forms a flow path for the refrigerant. The circular portion 3a constitutes the contact portion, and the leg portion 3c constitutes the deformed portion.

In the valve body 3, the peripheral annular portion 3b may be deleted so that the radial outer end of each leg portion 3c is a free end. In such a case, the radial outer end of the leg portion 3c is attached to the valve chamber VS by caulking. Further, the valve body 3 preferably has a rotationally symmetric shape.

The process of assembling the valve body 3 to the valve body 2 will be described. The inner diameter of the valve chamber VS is slightly smaller than the outer diameter of the valve body 3 in the free state. Further, in FIG. 2, a peripheral groove 2c is formed on the inner circumference near the upper end of the valve chamber VS.

Before assembling the plug 43 (described later) that seals the lower end of the valve chamber VS, when the valve body 3 is inserted by pushing it into the valve chamber VS from below the valve body 2, the valve body 3 contracts due to elastic deformation. Diameter. Further, when the valve body 3 is pushed upward, the peripheral annular portion 3b fits into the peripheral groove 2c and recovers from the deformation, and the circular portion 3a comes into contact with the valve seat 20 of the valve body 2. Even in such a state, the valve body 3 can be attached to the valve body 2, but caulking is used in this embodiment in order to perform more firm fixing.

More specifically, a ridge is formed below the peripheral groove 2c, and the ridge is pressurized by using a tool (not shown) inserted into the valve chamber VS while holding the valve body 3. It causes plastic deformation and forms a crimped portion CK. As a result, the caulking portion CK presses the peripheral annular portion 3b, and as shown in FIG. 2, the valve body 3 can be fixed to the upper part of the valve chamber VS. In the attached state, the valve body 3 is preloaded in the plate thickness direction by the caulking portion CK, whereby the leg portion 3c is elastically deformed, and the state in which the circular portion 3a is pressed against the valve seat 20 is maintained. After that, the operating rod 5 is inserted from above to abut the circular portion 3a of the valve body 3, and the lower end of the valve chamber VS is sealed by the plug 43.

Next, the power element 8 will be described with reference to FIG. The power element 8 is attached to a recess 2a provided at the top of the valve body 2. The recess 2a communicates with the return passage 23 in the valve body 2 through which the refrigerant from the evaporator 103 passes through the communication passage 2b. The operating rod 5 passes through the communication passage 2b. A female screw is formed on the inner circumference of the recess 2a.

The power element 8 has a stopper 81, an upper lid member 82, a diaphragm 83, a stopper member 84, and a receiving member 86.

The upper lid member 82 has a central conical portion 82a and an annular flange portion 82b extending from the lower end of the conical portion 82a to the outer periphery. An opening 82c is formed at the top of the conical portion 82a and can be sealed by a stopper 81.

The diaphragm 83 is made of a thin plate material in which a plurality of concentric uneven shapes are formed. The stopper member 84 has a fitting hole 84a at the center of the lower end.

The receiving member 86 includes a flange portion 86a having an outer diameter substantially the same as the outer diameter of the flange portion 82b of the upper lid member 82, a stepped portion 86c having an annular support surface 86b substantially orthogonal to the axis L, and a hollow cylindrical portion 86d. have. A male screw is formed on the outer circumference of the hollow cylindrical portion 86d.

The procedure for assembling the power element 8 will be described. The upper lid member 82, the diaphragm 83, the stopper member 84, and the receiving member 86 are arranged so as to have a positional relationship as shown in FIG.

Further, in a state where the flange portion 82b of the upper lid member 82, the diaphragm 83, and the flange portion 86a of the receiving member 86 are overlapped with each other, the outer peripheral portion is peripherally welded by, for example, TIG welding, laser welding, plasma welding, or the like. And integrate. The case is composed of the upper lid member 82 and the receiving member 86.

Subsequently, from the opening 82c formed in the upper lid member 82, the working gas is sealed in the space (pressure operating chamber PO) surrounded by the upper lid member 82 and the diaphragm 83, and then the opening 82c is sealed with the stopper 81. Further, the stopper 81 is fixed to the upper lid member 82 by projection welding or the like.

At this time, since the diaphragm 83 receives pressure in a form of projecting toward the receiving member 86 due to the working gas sealed in the pressure operating chamber PO, the space (pressure detection chamber PD) surrounded by the diaphragm 83 and the receiving member 86 is filled. It is supported in contact with the upper surface of the arranged stopper member 84.

When assembling the power element 8, with the upper end of the operating rod 5 fitted in the fitting hole 84a of the stopper member 84, the male screw of the hollow cylindrical portion 86d of the receiving member 86 is replaced with the female screw of the recess 2a of the valve body 2. By screwing, the power element 8 is fixed to the valve body 2. In such a state, the pressure detection chamber PD of the power element 8 communicates with the return flow path 23, that is, the same internal pressure is obtained. The receiving member 86 and the upper surface of the valve body 2 are sealed by the packing PK.

Next, the ring spring 6 will be described. The ring spring 6 is installed in the cylindrical recess 26 of the valve body 2 in FIG. 1. FIG. 4 is a perspective view showing the ring spring 6.

The ring spring 6 is formed by bending a plate-shaped member into a cylindrical shape as shown in FIG. 4 and bending the first elastic piece 61, the second elastic piece 62, and the third elastic piece 63 inward. Will be done.

The first elastic piece 61, the second elastic piece 62, and the third elastic piece 63 are bent so as to be cut up inward, and the first convex contact portion 61a and the first convex contact portion 61a provided near the tip, respectively. The convex contact portion 62a of No. 2 and the third convex contact portion 63a are designed so as to be positioned so that the circumference is divided into three equal parts. Then, in the plane orthogonal to the axis L (FIG. 1), the inscribed circle connecting the tops of the first convex contact portion 61a, the second convex contact portion 62a, and the third convex contact portion 63a. The diameter dimension of the circle is formed to be smaller than the outer diameter of the operating rod 5. As a result, a predetermined pressing force is applied to the outer circumference of the operating rod 5 from the first convex contact portion 61a, the second convex contact portion 62a, and the third convex contact portion 63a. It becomes.

(Operation of expansion valve)
An operation example of the expansion valve 1 will be described with reference to FIG. The refrigerant pressurized by the compressor 101 is liquefied by the condenser 102 and sent to the expansion valve 1. Further, the refrigerant adiabatically expanded by the expansion valve 1 is sent to the evaporator 103, and the evaporator 103 exchanges heat with the air flowing around the evaporator. The refrigerant returning from the evaporator 103 is returned to the compressor 101 side through the expansion valve 1 (more specifically, the return flow path 23).

A high-pressure refrigerant is supplied to the expansion valve 1 from the condenser 102. More specifically, the high-pressure refrigerant from the condenser 102 is supplied to the valve chamber VS via the first flow path 21.

In FIG. 1, a pressure operating chamber PO and a pressure detecting chamber PD partitioned by a diaphragm 83 are provided inside the power element 8. Therefore, when the working gas in the pressure working chamber PO is liquefied, the working rod 5 is displaced upward (referred to as the valve closing direction), and when the liquefied working gas is vaporized, the working rod 5 moves downward. Displace in the valve opening direction.

When the operating rod 5 is displaced upward, as shown by the solid line in FIG. 5, the valve body 3 is maintained in a state in which the circular portion 3a is seated on the valve seat 20 by the elastic force of the leg portion 3c. The refrigerant in the valve chamber VS enters the annular recess 27a through the opening 3d (FIG. 3), but cannot enter the communication hole 27 because the circular portion 3a is seated in the valve seat 20. That is, when the valve body 3 is seated on the valve seat 20, the first flow path 21 and the second flow path 22 are in a non-communication state.

On the other hand, when the operating rod 5 moves downward, the circular portion 3a of the valve body 3 is pressed downward toward the inside of the valve chamber VS, and the leg portion 3c is elastically deformed as shown by the dotted line in FIG. As a result, the circular portion 3a is separated from the valve seat 20, so that the refrigerant flows from the annular recess 27a toward the communication hole 27, as shown by the arrow. That is, when the valve body 3 is separated from the valve seat 20, the first flow path 21 and the second flow path 22 are in a communicating state.

As a result, the refrigerant supplied to the valve chamber VS is sent out to the evaporator 103 through the communication hole 27 and the second flow path 22. The valve switching is performed by the actuating rod 5 connected to the power element 8.

The pressure detection chamber PD of the power element 8 communicates with the return flow path 23. Therefore, the phase (gas phase, liquid phase, etc.) of the working gas in the pressure working chamber PO changes according to the temperature and pressure of the refrigerant flowing through the return flow path 23, and the working rod 5 is driven. In other words, in the expansion valve 1 shown in FIG. 1, the amount of the refrigerant supplied from the expansion valve 1 to the evaporator 103 is automatically adjusted according to the temperature and pressure of the refrigerant returning from the evaporator 103 to the expansion valve 1. It will be adjusted.

According to the present embodiment, the refrigerant flows around the valve body 3 when the valve is opened, but since the flat surface 5a at the lower end of the operating rod 5 is in contact with the circular portion 3a, the valve body 3 is held. The property is enhanced and the vibration can be effectively suppressed. Further, since the valve body 3 as the diaphragm itself has an elastic force, it is not necessary to provide a coil spring for urging the valve body 3 in the valve chamber VS. As a result, it is possible to eliminate the vibration generated by the flow of the refrigerant when the coil spring is provided. However, even if the operating rod 5 moves downward with the maximum stroke, the valve body 3 does not reverse. Further, it is preferable that the valve seat 20 and the valve body 3 are used in a linear relationship with respect to the stroke of the operating rod 5.

In the present embodiment, the coil spring is not accommodated in the valve chamber VS, but by securing a large capacity valve chamber VS, it is possible to exert a muffler effect when the refrigerant passes and reduce noise. Further, by arranging a filter, a strainer, or the like in the valve chamber VS, it is possible to capture foreign matter mixed in the refrigerant in addition to reducing noise. The filter, strainer, etc. can be replaced or cleaned by removing the plug 43.

(Modification example)
Next, a modified example of the present embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is an enlarged perspective view showing a cross section of the lower end of the operating rod 5, the valve body 3A, and the vicinity of the holding plate 9. FIG. 7 is a perspective view of the valve body 3A and the holding plate 9. In this modification, the valve body 3A is attached to the valve chamber VS of the valve body 2A via the holding plate 9. Since the other configurations are the same as those in the above-described embodiment, the same reference numerals are given and duplicate description will be omitted.

The valve body 3A has a shape in which a conical tapered portion 3e is continuously provided around a circular portion 3a, and constitutes a diaphragm. The valve body 3A can be formed, for example, by plastic working a plate material made of SUS having a plate thickness of about 1 mm so that the center protrudes by press molding. It should be noted that an opening may be provided in the tapered portion 3e as in the above-described embodiment. The tapered portion 3e constitutes the deformed portion.

The holding plate 9 is made of, for example, aluminum, and has an inner annular portion 9a, an outer annular portion 9b arranged around the inner annular portion 9a, and three beam portions 9c connecting the inner annular portion 9a and the outer annular portion 9b. Has. An arcuate slit 9d, which is an opening that communicates with the upper and lower surfaces, is formed between the adjacent beam portions 9c. The arcuate slit 9d constitutes the flow path of the refrigerant.

The radial outer upper surface of each beam portion 9c is at the same level as the upper surface of the outer annular portion 9b, and the radial inner upper surface is at the same level as the upper surface of the inner annular portion 9a. On the other hand, since the upper surface level of the inner annular portion 9a is lower than the upper surface level of the outer annular portion 9b, each beam portion 9c is provided with a stepped surface 9e in the middle to connect the upper surfaces on both sides. The stepped surface 9e is a part of a cylindrical surface whose axis is the axis L of the holding plate, and the inner diameter of the cylindrical surface substantially coincides with the outer diameter of the valve body 3A.

A male screw 9f is formed on the outer circumference of the outer annular portion 9b. On the other hand, in FIG. 6, a female screw SC is formed on the upper inner circumference of the valve chamber VS.

At the time of assembly, the outer circumference of the valve body 3A is fitted to the stepped surface 9e of the holding plate 9, and the male screw 9f is screwed into the female screw SC of the valve chamber VS, and the three screws protruding from the tool (not shown). The claw is engaged with the arcuate slit 9d. From this state, by rotating the tool around the axis L, the holding plate 9 rises while turning with respect to the valve chamber VS, and the circular portion 3a of the valve body 3A comes into contact with the valve seat 20. Due to the reaction force at that time, the outer circumference of the tapered portion 3e abuts on the stepped surface 9e and is deformed, whereby an elastic force is exerted (FIG. 6). By adjusting the screwing amount of the holding plate 9 with respect to the valve chamber VS, the preload acting between the circular portion 3a and the valve seat 20 can be adjusted.

When the operating rod 5 is displaced upward, the state in which the circular portion 3a is seated on the valve seat 20 is maintained by the elastic force of the tapered portion 3e of the valve body 3A. As shown by the arrow in FIG. 6, the refrigerant in the valve chamber VS enters the annular recess 27a through the inside of the arcuate slit 9d of the holding plate 9 and the outside of the tapered portion 3e, and the circular portion 3a enters the valve seat. Since he is seated at 20, he cannot enter the communication hole 27.

On the other hand, when the operating rod 5 moves downward, the circular portion 3a of the valve body 3A is pressed downward, whereby the circular portion 3a is separated from the valve seat 20, so that the annular recess 27a is directed toward the communication hole 27. The refrigerant will flow (see FIG. 5).

In the modification described above, the holding plate 9 is screwed to the valve chamber VS, but it can also be fixed by caulking or press fitting, for example. Further, the present invention is applicable not only to expansion valves but also to various valve devices such as constant pressure valves.

The present invention is not limited to the above-described embodiment. Within the scope of the present invention, any component of the above-described embodiment can be modified, and any component of the above-described embodiment can be added or omitted.

1: Expansion valve 2, 2A: Valve body 3, 3A: Valve body 5: Operating rod 8: Power element 9: Holding plate 100: Refrigerant circulation system 101: Compressor 102: Condenser 103: Evaporator

Claims (6)

A case equipped with a pressure detection chamber into which the refrigerant enters and a pressure operating chamber filled with gas,
In the case, a flexible diaphragm that separates the pressure detecting chamber and the pressure operating chamber, and
A moving body that moves in the valve opening direction according to the displacement of the diaphragm, and
A valve body having a valve chamber formed with a valve seat and joined to the case,
It has a valve body that is arranged in the valve chamber so that it can be seated on the valve seat and that comes into contact with the moving body.
The valve body is formed of a metal circular plate material, and when a force in the valve opening direction is applied from the moving body, the valve body is elastically deformed toward the valve chamber to be separated from the valve seat. When a force in the valve opening direction is not applied from the moving body, it recovers from the deformation by its own elastic force and sits on the valve seat.
A valve device characterized by that. The valve body is a diaphragm plastically processed so that the center protrudes.
The valve device according to claim 1. The diaphragm of the valve body has a flow path that penetrates in the plate thickness direction and allows the refrigerant to pass through.
The valve device according to claim 2. It has a holding plate for attaching the diaphragm of the valve body to the valve body.
The valve device according to claim 2. The holding plate has a flow path that penetrates in the plate thickness direction and allows the refrigerant to pass through.
The valve device according to claim 4. The valve body has a central contact portion that comes into contact with the moving body and a deformed portion that extends radially outward from the contact portion, and the valve body is attached to the valve chamber and described as described above. When a force in the valve opening direction is applied from the moving body to the contact portion, the deformed portion is deformed to generate an elastic force.
The valve device according to claim 1.

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