CN102913656A - Seal structure and a temperature expansion valve - Google Patents

Abstract

The sealing structure and the temperature expansion valve of the present invention seal between the valve casing (10) and the diaphragm device (20), so that high sealing performance can be obtained even when the pressure rises. An external thread portion (11) and a stepped portion (12) are formed on the outer periphery of the first cylindrical portion (1) of the valve housing. An internal thread portion (21) is formed on the inner periphery of the second cylindrical portion (2) of the lower cover (20b) of the diaphragm device. A protrusion (22) is formed at the opening end (2A) of the second cylindrical portion. The surfaces facing the stepped portion are respectively referred to as a first sealing surface (12A) and a second sealing surface (22A). Make the area of the second sealing surface smaller than the area of the first sealing surface. For example, make the second sealing surface a flat surface perpendicular to the axis (L), and make the first sealing surface a tapered surface. Inward stress is generated at the opening end of the second cylindrical portion by the thrust force generated by the tightening of the second cylindrical portion and the first cylindrical portion.

Description

Sealing structure and temperature expansion valve

technical field

The present invention relates to forming an external thread on the outer periphery of one of two cylindrical parts and forming an internal thread on the inner periphery of the other cylindrical part, and combining the external thread and the internal thread to combine the two cylindrical parts, And, in the device element in which the fluid is filled in the cylindrical part, there is a sealing structure that seals the joint portion of the two cylindrical parts, and a temperature expansion valve using the sealing structure.

Background technique

Conventionally, as a temperature expansion valve, there is, for example, a temperature expansion valve disclosed in JP-A-9-79703 (Patent Document 1). The thermal expansion valve (thermal expansion valve) of Patent Document 1 is provided with a temperature-sensing cylinder attached to the outlet pipe of the evaporator, and a diaphragm device (unit part 4') communicating with the temperature-sensing cylinder is attached to the valve casing ( cover part 40). The diaphragm device consists of a cover part 56 and a supporting part 55 stamped and formed of stainless steel, etc., to form a cover body, and a pressure sensitive chamber (first pressure chamber 50) and a pressure equalization chamber (second pressure chamber 50) divided by a diaphragm are arranged in the cover body. Room 51). The packaged gas of the temperature-sensing cylinder is introduced into the pressure-sensitive chamber, and the refrigerant pressure is introduced into the pressure-equalizing chamber.

The supporting part (lower cover) of the cover body of the diaphragm device has a cylindrical portion communicating with the pressure equalization chamber at its lower end, and the valve housing has a cylindrical portion leading from the diaphragm device side to the valve body. Furthermore, the cover is coupled to the valve case by screwing the internal thread portion and the external thread portion of the cylindrical portion of the valve case to the cylindrical portion of the receiving member. The sealing structure of the coupling portion is configured such that the lower end portion of the cylindrical portion of the receiving member abuts against the stepped portion of the cylindrical portion of the valve casing, and the sealing is performed by the surface contact between the lower end portion and the stepped portion. Combined part.

However, in such a temperature expansion valve, since the pressure inside the housing of the diaphragm device becomes high pressure, high sealing performance is required at the joining portion between the cylindrical portion of the housing and the cylindrical portion of the valve body.

In addition, as a technique for combining two cylindrical portions, there is, for example, a technique disclosed in Japanese Patent Application Laid-Open No. 4-503559 (Patent Document 2) as a sealing structure for sealing between the two cylindrical portions. The technology of this patent document 2 is to insert the sealing disk 69 into the outer cylindrical part 62 formed with the internal thread part, and screw the inner cylindrical part 71 formed with the external thread part to the outer cylinder. combined within the department. The inside of the outer cylindrical portion 62 and the inner cylindrical portion 71 pass through the tapered surface of the abutting portion 66 formed at the end of the sealing disk 69 and the tapered surface formed on the inner periphery of the outer cylindrical portion 62 . Surfaces (supporting surfaces 65) are in contact with each other to seal.

Patent Document 1: Japanese Patent Application Laid-Open No. 9-79703

Patent Document 2: Japanese Patent Application Publication No. 4-503559

As in Patent Document 1, in a temperature expansion valve, only the outer threaded part and the inner threaded part are used to screw the cover and the valve housing of the diaphragm device to ensure mutual airtightness. The cylindrical portion of the holder) deforms due to the pressure increase in the pressure equalization chamber, and the contact surface (sealing surface) between the lower end of the cylindrical portion and the step portion is misaligned, and there is a problem that the sealing performance cannot be maintained. In addition, if both sealing surfaces are tapered as in Patent Document 2, there is a similar problem in that if one cylindrical portion is deformed, the sealing surfaces will be displaced.

Contents of the invention

The problem to be solved by the present invention is to improve the sealing performance of the joint portion of the two cylindrical parts in a device element in which two cylindrical parts are connected by screwing together an external thread and a female thread, and the cylindrical part is filled with a fluid.

The sealing structure of the first aspect combines the first cylindrical part and the second cylindrical part, and seals the first cylindrical part and the second cylindrical part of the device element filled with fluid in the first cylindrical part and the second cylindrical part. The joint portion of the cylindrical portion is sealed, and the sealing structure is configured such that an external thread portion is formed on the outer circumference of the first cylindrical portion from the opening end of the first cylindrical portion, and an external thread portion is formed on the second cylindrical portion. An internal thread portion is formed on the inner periphery of the first cylindrical portion, and an annular ring centered on the axis of the first cylindrical portion is formed at a position opposite to the opening end of the external thread portion on the outer periphery of the first cylindrical portion. The first sealing surface is formed at the opening end of the second cylindrical portion in an annular shape with the axis of the second cylindrical portion as the center of rotation, and the area that can be accommodated in the first sealing surface is smaller than that of the first sealing surface. The second sealing surface of the sealing surface connects the first cylindrical portion and the second cylindrical portion by screwing the externally threaded portion and the internally threaded portion to press-contact the first sealing surface and the second sealing surface. At least one of the first sealing surface and the second sealing surface is formed as a tapered surface inclined to a plane perpendicular to the axis, so that the thrust force generated by the tightening of the external thread part and the internal thread part can The opening ends of the two cylindrical parts generate inward stress.

A sealing structure according to a second aspect is the sealing structure according to the first aspect, wherein the first sealing surface of the first cylindrical portion is the tapered surface, and the second sealing surface is a flat surface perpendicular to the axis.

A sealing structure according to a third aspect is the sealing structure described in the first aspect, wherein the first sealing surface of the first cylindrical portion is a flat surface perpendicular to the axis, and the second sealing surface is a tapered surface. .

A sealing structure according to a fourth aspect is the sealing structure according to any one of the first to third aspects, wherein the first cylindrical portion is made of brass, and the second cylindrical portion is made of stainless steel.

The temperature expansion valve according to the fifth aspect is provided with a valve main body that controls the flow of refrigerant by opening and closing a valve port formed on a valve casing by a valve body, and a diaphragm that divides the housing body by a diaphragm to form a pressure receiving chamber and a pressure equalizing chamber. device, which controls the valve opening of the valve port by using the diaphragm and the valve body that operate according to the pressure difference between the pressure receiving chamber and the pressure equalizing chamber, and is characterized in that it is configured to include the first In the sealing structure according to any one of the fourth aspect to the fourth aspect, the valve casing has the cylindrical first cylindrical portion for accommodating the valve body, and the cover of the diaphragm device has a The cylindrical second cylindrical portion is screwed together with the externally threaded portion and the internally threaded portion to press-contact the first sealing surface and the second sealing surface, thereby coupling the cover to the valve housing.

The effects of the present invention are as follows.

According to the sealing structure of the first aspect, since the second sealing surface of the second cylindrical portion is pressed against the first sealing surface of the first cylindrical portion by screwing the externally threaded portion and the internally threaded portion, the first circle is joined. The cylinder part and the second cylindrical part, and use the tapered surface of at least any one of the first sealing surface and the second sealing surface and utilize the thrust generated by the tightening of the external thread part and the internal thread part on the second cylindrical part. Stress toward the inside is generated at the opening end, so that the sealing surface composed of the first sealing surface and the second sealing surface can be prevented from moving due to the pressure rise of the fluid in the first cylindrical portion and the second cylindrical portion. Sealing is ensured even when the fluid becomes high pressure. If the hardness of the material of the second cylindrical portion is higher than that of the material of the first cylindrical portion, at least a part of the second sealing surface will sink into the first sealing surface, thereby further preventing the opening end of the second cylindrical portion from Move outward.

According to the sealing structure of the second aspect, the structure is such that the second sealing surface is a flat surface perpendicular to the axis, and when the first sealing surface of the first cylindrical part moves in the screwing direction, the outer surface of the second sealing surface The edge first abuts against the first sealing surface, and there is a part of the tapered surface of the first sealing surface on the outer side than the outer edge of the second sealing surface, so it can further prevent the second round from the mechanical point of view. The opening end of the cylindrical portion is moved outward to ensure sealing performance.

According to the sealing structure of the third aspect, the same effect as that of the first aspect can be obtained.

According to the sealing structure of the fourth aspect, the first cylindrical portion is made of brass, and the second cylindrical portion is made of stainless steel. Therefore, even if the inner or outer edge of the second sealing surface abuts against the first sealing surface, the inner or outer edge The fact that the outer edge portion is also difficult to deform allows the second sealing surface to be reliably inserted into the first sealing surface, and the opening end of the second cylindrical portion is reliably prevented from moving outward, thereby ensuring sealing performance.

According to the temperature expansion valve according to the fifth aspect, the sealing performance between the valve housing and the diaphragm device can be ensured by the action and effect described in any one of the first to fourth aspects.

Description of drawings

FIG. 1 is a partially enlarged cross-sectional view of a temperature expansion valve according to an embodiment of the present invention.

2 is an enlarged cross-sectional view of main parts showing a first embodiment of the sealing structure of the temperature expansion valve according to the embodiment of the present invention.

3 is an enlarged cross-sectional view of main parts showing a second embodiment of the sealing structure of the temperature expansion valve according to the embodiment of the present invention.

4 is an enlarged cross-sectional view of main parts showing a third embodiment of the sealing structure of the temperature expansion valve according to the embodiment of the present invention.

Fig. 5 is a longitudinal sectional view of the temperature expansion valve according to the embodiment of the present invention.

Symbol Description

1-first cylindrical part, 11-external thread part, 12-step part, 12A-first sealing surface, 2-second cylindrical part, 21-internal thread part, 22-protruding strip, 22A-second seal Surface, 22A1-inner edge, 22A2-outer edge, 10-valve housing, 10c-valve interface, 20-diaphragm device, 20a-upper cover, 20b-lower cover, 20c-diaphragm, 30-valve body.

Detailed ways

Embodiments of the sealing structure and the temperature expansion valve of the present invention will be described below with reference to the drawings. 1 is a partially enlarged cross-sectional view of a temperature expansion valve according to an embodiment, FIG. 2 is an enlarged cross-sectional view of a main part of a first embodiment showing a sealing structure of a temperature expansion valve according to an embodiment, and FIG. 3 is a seal showing a temperature expansion valve according to an embodiment. Fig. 4 is an enlarged sectional view of main parts of a third embodiment showing the sealing structure of the temperature expansion valve according to the embodiment, and Fig. 5 is a longitudinal sectional view of the temperature expansion valve according to the embodiment.

The temperature expansion valve of this embodiment has a brass valve case 10 and a diaphragm device 20 constituting a valve body. A first port 10a connected to a primary side connecting pipe 10a1 and a second port 10b connected to a secondary side connecting pipe 10b1 are formed on the valve case 10, and a valve is formed between the first port 10a and the second port 10b. interface 10c. In addition, a pressure equalizing passage 10d to which a pressure equalizing pipe 10d1 is connected is formed on the valve housing 10 . The primary side connection pipe 10a1 is connected to the outlet side pipe of the condenser, and the secondary side connection pipe 10b1 is connected to the inlet side pipe of the evaporator. In addition, the pressure equalizing pipe 10d1 is connected to an outlet-side pipe of the evaporator.

On the side of the diaphragm device 20 of the valve case 10, a cylindrical first cylindrical portion 1 is formed, and a guide hole 1a in which the first port 10a is opened on the side is formed in the first cylindrical portion 1. As shown in FIG. The guide hole 1a has a cylindrical shape with one end on the side of the valve port 10c and the central axis of the valve port 10c as the axis L, and opens into the diaphragm device 20 on the side opposite to the valve port 10c. The valve body 30 is arrange|positioned in the guide hole 1a. The valve body 30 has a valve portion 30a located on the second port 10b side with respect to the valve port 10c, and a cylindrical needle portion 30b fitted into the guide hole 1a with a clearance from the inner peripheral surface of the guide hole 1a. Thus, the valve body 30 is housed in the guide hole 1 a movably along the axis L, and the valve portion 30 a opens and closes the valve port 10 c by moving in the direction of the axis L. As shown in FIG.

A sealing member 40 is attached to the top of the needle portion 30b via a pressing member 40a, and a stopper 50 is attached to the end of the needle portion 30b, and the valve body 30 is connected to the diaphragm 20c of the diaphragm device 20 through the stopper 50. In addition, a substantially cylindrical mounting hole 10e having an axis L as an axis is formed at a lower portion of the valve port 10c, and an adjusting spindle 10f is mounted in the mounting hole 10e. Also, the force applied to the valve body 30 by the adjustment spring 10g can be adjusted by rotating the adjustment spindle 10f. This allows you to adjust the superheat setting.

The diaphragm device 20 constitutes a "cover" by an upper cover 20a and a lower cover 20b, both of which are made of stainless steel. A diaphragm 20c is provided between the upper cover 20a and the lower cover 20b, and the inside of the housing composed of the upper cover 20a and the lower cover 20b is divided into a pressure receiving chamber 20A and a pressure equalizing chamber 20B by the diaphragm 20c. The pressure equalization chamber 20B is connected to the outlet side pipe of the evaporator through the above-mentioned pressure equalization channel 10d of the valve casing 10, and the evaporating pressure is introduced into the pressure equalization chamber 20B.

The pressure receiving chamber 20A is connected to the thermosensitive cylinder 20e through the capillary 20d. In addition, for example, the same gas (and liquid) as the refrigerant of the refrigerating cycle is sealed in the thermosensitive cylinder 20e, the capillary tube 20d, and the pressure receiving chamber 20A, and the thermosensitive cylinder 20e is attached to the outlet side piping of the evaporator. Thereby, the internal pressure of 20 A of pressure receiving chambers changes according to the temperature detected by the temperature-sensitive cylinder 20e. Further, the diaphragm 20c is displaced in accordance with the pressure difference between the pressure receiving chamber 20A and the pressure equalizing chamber 20B, and the displacement is transmitted to the valve body 30 through the stopper 50 . With this structure, the opening degree of the valve port 10c that allows the refrigerant to flow from the primary pipe on the condenser side to the secondary pipe on the evaporator side is controlled according to the pressure difference between the temperature detected by the temperature sensing cylinder 20e and the evaporation pressure, and the refrigeration cycle is performed. Superheat control.

A cylindrical second cylindrical portion 2 is formed at the lower portion of the lower cover 20b. An external thread portion 11 is formed on the outer periphery of the first cylindrical portion 1 of the valve housing 10 . An internal thread portion 21 is formed on the inner periphery of the second cylindrical portion 2 . Further, the diaphragm device 20 is attached to the valve housing 10 by screwing the internal thread portion 21 of the second cylindrical portion 2 and the external thread portion 11 of the first cylindrical portion 1 .

In addition, a stepped portion 12 having a larger diameter than the externally threaded portion 11 is formed at a position on the outer periphery of the first cylindrical portion 1 on the opposite side to the opening end 1A of the externally threaded portion 11 . And, the surface of the stepped portion 12 facing the second cylindrical portion 2 forms an annular first sealing surface 12A whose rotation center is the axis L of the first cylindrical portion 1 . A ring-shaped protrusion 22 is formed at the opening end 2A of the second cylindrical portion 2 . And the opposite surface of the protrusion 22 on the side of the first sealing surface 12A forms an annular second sealing surface 22A whose rotation center is the axis L of the second cylindrical portion 2 . In addition, as shown in FIG. 2 and FIG. 3 , the radial width D1 of the first sealing surface 12A is larger than the radial width D2 of the second sealing surface 22A, and the second sealing surface 22A is located in the first sealing surface 12A. s position. Accordingly, the area of the second sealing surface 22A is smaller than the area of the first sealing surface 12A. In addition, the axis L is an axis common to the first cylindrical portion 1 and the second cylindrical portion 2 .

Embodiments of sealing configurations according to the first sealing surface 12A and the second sealing surface 22A will be described below. In addition, although FIGS. 2 to 4 are enlarged views of the dotted line portion on the left side in FIG. 1, the overall structure is that of a rotating body when the section of FIGS. 2 to 4 is rotated with the axis L as the rotation axis. . Fig. 2 is a diagram showing the first embodiment, showing a state in which the second cylindrical part 2 is gradually screwed into the first cylindrical part 1 in the order of Fig. 2(A), Fig. 2(B) and Fig. 2(C) . As for the first embodiment, the second sealing surface 22A of the second cylindrical portion 2 is a flat surface perpendicular to the axis L. As shown in FIG. Moreover, the first sealing surface 12A is a tapered surface so that the outer edge portion 22A2 ( FIG. 2(B) ) of the second sealing surface 22A first moves in the direction of screwing in the second cylindrical portion 2 (arrow R direction). The first sealing surface 12A abuts against.

If the outer edge portion 22A2 of the second sealing surface 22A first abuts against the first sealing surface 12A and starts to advance in the direction of screwing in, since the first sealing surface 12A is made into a tapered surface, the protrusion 22 (opening end) 2A) Stress toward the inside is generated, and at least the outer edge portion 22A2 of the second sealing surface 22A sinks into the first sealing surface 12A, thereby preventing the opening end 2A of the second cylindrical portion 2 from moving outward. Thereby, sealing performance can be ensured. In addition, as shown in FIG. 2(C), if the second sealing surface 22A is completely sunk into the first sealing surface 12A, it is possible to more reliably prevent the opening end 2A of the second cylindrical portion 2 from moving outward, and it is possible to Ensure tightness.

FIG. 3 is a diagram showing a second embodiment, showing a state in which the second cylindrical portion 2 is gradually screwed into the first cylindrical portion 1 in the order of FIG. 3(A), FIG. 3(B), and FIG. 3(C). . As for the second embodiment, the first sealing surface 12A of the first cylindrical portion 1 is a flat surface perpendicular to the axis L. As shown in FIG. Moreover, the second sealing surface 22A is a tapered surface so that the inner edge portion 22A1 ( FIG. 3(B) ) of the second sealing surface 22A first contacts with the screwing direction (arrow R direction) of the second cylindrical portion 2 . The first sealing surface 12A abuts against.

If the inner edge portion 22A1 of the second sealing surface 22A first comes into contact with the first sealing surface 12A and starts to advance in the screwing direction, the second sealing surface 22A is tapered as shown in FIG. 3(B). Therefore, an inward stress is generated on the ridge 22 (opening end 2A), and at least a part of the second sealing surface 22A sinks into the first sealing surface 12A, thereby preventing the opening end 2A of the second cylindrical portion 2 from moving outward. . Thereby, sealing performance can be ensured. In addition, as shown in FIG. 3(C), if the second sealing surface 22A is completely sunk into the first sealing surface 12A, it is possible to more reliably prevent the opening end 2A of the second cylindrical portion 2 from moving outward, and Can ensure sealing.

In the above embodiments, an example is shown in which either one of the first sealing surface 12A and the second sealing surface 22A is a flat surface perpendicular to the axis L, but both the first sealing surface 12A and the second sealing surface 22A may be, for example, A tapered surface like the third embodiment shown in FIG. 4 . In this case, the second sealing surface 22A of the second cylindrical portion 2 is made into a slightly inclined tapered surface, and the first sealing surface 12A is a tapered surface so that the outer edge portion 22A2 of the second sealing surface 22A ( FIG. 4(B) ) first comes into contact with the first sealing surface 12A as the second cylindrical portion 2 moves in the screwing direction (arrow R direction).

In the above embodiments, although the sealing structure of the present invention has been described in the case of sealing between the valve casing of the temperature expansion valve and the diaphragm device, when the two cylindrical members are screwed and combined, the joint position The structures of the first cylindrical portion and the second cylindrical portion of the embodiment may also be applied.

Claims (5)

1. A sealing structure that couples the first cylindrical portion and the second cylindrical portion of a device element that combines the first cylindrical portion and the second cylindrical portion and fills the fluid in the first cylindrical portion and the second cylindrical portion. The joint part of the cylindrical part is sealed, and it is characterized in that, An external thread portion is formed on the outer periphery of the first cylindrical portion from an opening end portion of the first cylindrical portion, and an internal thread portion is formed on the inner periphery of the second cylindrical portion, An annular first sealing surface centered on the axis of the first cylindrical portion is formed at a position on the outer periphery of the first cylindrical portion opposite to the opening end of the external thread portion, At the opening end of the second cylindrical portion, an annular second seal having a smaller area than the first sealing surface and capable of being accommodated in the first sealing surface is formed with the axis of the second cylindrical portion as the center of rotation. noodle, The first cylindrical portion and the second cylindrical portion are joined by screwing the externally threaded portion and the internally threaded portion to press-contact the first sealing surface and the second sealing surface, At least one of the first sealing surface and the second sealing surface is formed as a tapered surface inclined to a plane perpendicular to the axis, so that the thrust generated by the tightening of the external thread portion and the internal thread portion The opening end of the second cylindrical portion generates inward stress. 2. The sealing structure according to claim 1, wherein: The first sealing surface of the first cylindrical portion is the tapered surface, and the second sealing surface is a flat surface perpendicular to the axis. 3. The sealing structure according to claim 1, wherein: The first sealing surface of the first cylindrical portion is a flat surface perpendicular to the axis, and the second sealing surface is the tapered surface. 4. The sealing structure according to any one of claims 1 to 3, characterized in that, The first cylindrical portion is made of brass, and the second cylindrical portion is made of stainless steel. 5. A temperature expansion valve comprising a valve main body that uses a valve body to open and close a valve port formed on a valve housing to control the flow of refrigerant, and a diaphragm that divides the housing body by a diaphragm to form a pressure receiving chamber and a pressure equalizing chamber device, which controls the valve opening of the valve port by using the diaphragm and the valve body that operate according to the pressure difference between the pressure receiving chamber and the pressure equalizing chamber, and is characterized in that Constructed to have the sealing structure described in any one of claims 1 to 4 above, The valve housing has the cylindrical first cylindrical portion for housing the valve body, and the cover of the diaphragm device has the cylindrical second cylindrical portion communicating with the pressure equalization chamber, The cover body is coupled to the valve housing by screwing the external thread portion and the internal thread portion to press-contact the first sealing surface and the second sealing surface.

Images