JP5535997B2 - Seal structure and temperature expansion valve - Google Patents

Description

  In the present invention, a male screw is formed on the outer periphery of one of the two cylindrical portions, and a female screw is formed on the inner periphery of the other cylindrical portion. The male screw and the female screw are screwed together to connect both cylindrical portions. The present invention relates to a seal structure that seals a joint portion of two cylindrical portions in a device element that is filled with fluid in the cylindrical portion, and a temperature expansion valve to which the seal structure is applied.

  Conventionally, as a temperature expansion valve, for example, there is one disclosed in JP-A-9-79703 (Patent Document 1). The temperature expansion valve (temperature type expansion valve) of Patent Document 1 includes a temperature sensing cylinder attached to an outlet pipe of an evaporator, and a diaphragm device (element part 4 ') communicated with the temperature sensing cylinder is a valve body. It is attached to the valve housing (housing member 40). In the diaphragm device, a case body is constituted by a lid member (56) and a receiving member (55) that are press-molded with stainless steel or the like, and a pressure sensing chamber (first pressure chamber 50) partitioned by a diaphragm in the case body. A pressure chamber (second pressure chamber 51) is provided. The pressure in the temperature sensing cylinder is introduced into the pressure sensing chamber, and the refrigerant pressure is introduced into the pressure equalizing chamber.

  The receiving member (lower lid) of the case body of the diaphragm device has a cylindrical portion communicating with the pressure equalizing chamber at the lower end thereof, and the valve housing has a cylindrical portion communicating with the valve body from the diaphragm device side. And the case body is couple | bonded with the valve housing by screwing together the external thread part and the external thread part of the cylindrical part of a valve housing to the cylindrical part of a receiving member. The sealing structure of the coupling portion is a structure in which the lower end portion of the cylindrical portion of the receiving member is brought into contact with the step portion of the cylindrical portion of the valve housing, and the coupling portion is sealed by surface contact between the lower end portion and the step portion. Yes.

  However, in such a temperature expansion valve, since the pressure in the case body of the diaphragm device becomes high, a high sealing performance is required for the joint portion between the cylindrical portion of the case body and the cylindrical portion of the valve body.

  In addition, in what joins two cylindrical parts, as a sealing structure which seals between both of these cylindrical parts, there exists what was disclosed by Japanese translations of PCT publication No. 4-503559 (patent document 2), for example. In the technique of Patent Document 2, a closing disk (69) is inserted into an outer cylindrical portion (62) in which a female screw portion is formed, and an inner cylindrical portion (71) in which a male screw portion is formed is inserted into an outer cylinder. It is screwed into the part and connected. Between the inside of the outer cylindrical portion (62) and the inner cylindrical portion (71), the tapered surface of the contact portion (66) formed at the end of the closing disk (69) and the outer cylindrical portion (62). ) Is sealed by surface contact with a tapered surface (support surface 65) formed on the inner periphery.

JP-A-9-79703 JP-T-4-503559

  As in Patent Document 1, in the temperature expansion valve, the case body of the diaphragm device and the valve housing are only screwed together by the male screw portion and the female screw portion, so that the airtightness of each other is ensured. When the cylindrical part on the case body side (cylindrical part of the receiving member) is deformed by this, the contact surface (seal surface) between the lower end part of the cylindrical part and the step part is displaced, and there is a problem that the sealing performance cannot be maintained. In addition, when both sealing surfaces are made into a taper surface like patent document 2, there exists the same problem that a sealing surface will shift | deviate if one cylindrical part deform | transforms.

  It is an object of the present invention to improve the sealing performance of a connecting portion of two cylindrical portions in an apparatus element in which two cylindrical portions are coupled by screwing a male screw and a female screw and fluid is filled in the cylindrical portion. .

The seal structure according to claim 1 connects the first cylindrical portion and the second cylindrical portion, and the first cylindrical portion and the second cylindrical portion of the device element in which fluid is filled in the first cylindrical portion and the second cylindrical portion. A sealing structure for sealing a coupling portion, wherein a male screw portion is formed on an outer periphery of the first cylindrical portion from an opening end portion of the first cylindrical portion, and a female screw is provided on an inner periphery of the second cylindrical portion. An annular first seal surface centering on the axis of the first cylindrical portion is formed on the outer periphery of the first cylindrical portion at a position opposite to the opening end of the male screw portion. The opening end portion of the second cylindrical portion has an annular second seal surface with the axis of the second cylindrical portion as a center of rotation, and the first seal surface fits within the first seal surface. A second seal surface having a small area is formed, and the male screw portion and the female screw portion are screwed together to form the first seal surface and the second seal surface. The first cylindrical portion and the second cylindrical portion are coupled by crimping the control surface, and the thrust generated by tightening the male screw portion and the female screw portion is directed inward to the opening end portion of the second cylindrical portion. The first seal surface is a tapered surface such that the outer edge portion of the second seal surface first comes into contact with the first seal surface due to the movement of the second cylindrical portion in the screwing direction. characterized in that there.

Seal structure according to claim 2, a seal structure according to claim 1, wherein the pre-Symbol second sealing surface is perpendicular flat surface to the axis.

Seal structure of claim 3 is a seal structure according to claim 1, before Symbol second sealing surface is characterized by a tapered surface.

  The seal structure according to claim 4 is the seal structure according to any one of claims 1 to 3, wherein the first cylindrical portion is brass and the second cylindrical portion is stainless steel. To do.

  According to a fifth aspect of the present invention, there is provided a temperature expansion valve comprising: a valve body for controlling a refrigerant flow by opening and closing a valve port formed in a valve housing; and a pressure receiving chamber and a pressure equalizing chamber divided by a diaphragm in the case body. A temperature of which the valve opening degree of the valve port is controlled by the diaphragm and the valve body that operate according to a differential pressure between the pressure of the pressure receiving chamber and the pressure equalizing chamber. The expansion valve includes the seal structure according to any one of claims 1 to 4, wherein the valve housing includes the cylindrical first cylindrical portion that accommodates the valve body, and the diaphragm device includes: The case body has the cylindrical second cylindrical portion communicating with the pressure equalizing chamber, and the male screw portion and the female screw portion are screwed together to crimp the first seal surface and the second seal surface. The valve housing Characterized in that it is configured to couple the casing body against.

According to the seal structure of the first aspect, the male screw portion and the female screw portion are screwed together, and the second seal surface of the second cylindrical portion is pressure-bonded to the first seal surface of the first cylindrical portion, thereby the first cylindrical portion and the first cylindrical portion. Since the two cylindrical portions are coupled and the taper surface of the first seal surface causes an inward stress to be generated at the opening end portion of the second cylindrical portion due to the thrust generated by tightening the male screw portion and the female screw portion, the first cylinder It is possible to prevent the seal surface composed of the first seal surface and the second seal surface from moving due to an increase in the pressure of the fluid in the part and the second cylindrical part, and to ensure a sealing property even when the fluid becomes a high pressure. . If the second cylindrical portion is made of a material harder than the first cylindrical portion, at least part of the second sealing surface bites into the first sealing surface, and further prevents the opening end of the second cylindrical portion from moving outward. can do.

  According to the seal structure of claim 2, the second seal surface is a flat surface perpendicular to the axis, and the first seal surface of the first cylindrical portion is an outer edge portion of the second seal surface when moving in the screwing direction. Is a structure that first contacts the first seal surface, and since a part of the tapered surface of the first seal surface exists outside the outer edge portion of the second seal surface, the opening end portion of the second cylindrical portion is the outer side. Can be further prevented mechanically, and sealing performance can be secured.

  According to the seal structure of claim 3, the same effect as that of claim 1 can be obtained.

  According to the seal structure of claim 4, even if the first cylindrical portion is brass and the second cylindrical portion is stainless steel, and the inner edge portion or the outer edge portion of the second seal surface is in contact with the first seal surface, the inner edge portion or Since the outer edge portion is less likely to be deformed, the second sealing surface can be surely bited into the first sealing surface, and the opening end of the second cylindrical portion can be reliably prevented from moving outward, Sealability can be secured.

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

It is a partial expanded sectional view of the temperature expansion valve of embodiment of this invention. It is a principal part expanded sectional view which shows the 1st Example of the seal structure of the temperature expansion valve of embodiment of this invention. It is a principal part expanded sectional view which shows the reference example of the seal structure of the temperature expansion valve of embodiment of this invention. It is a principal part expanded sectional view which shows the 2nd Example of the seal structure of the temperature expansion valve of embodiment of this invention. It is a longitudinal cross-sectional view of the temperature expansion valve of embodiment of this invention.

Next, embodiments of a seal structure and a temperature expansion valve of the present invention will be described with reference to the drawings. FIG. 1 is a partially enlarged sectional view of a temperature expansion valve of the embodiment, FIG. 2 is an enlarged sectional view of a main part showing a first example of the seal structure of the temperature expansion valve of the embodiment, and FIG. 3 is a temperature expansion valve of the embodiment. enlarged sectional view showing a reference example of the seal structure, FIG. 4 is a fragmentary enlarged sectional view showing a second embodiment of the sealing arrangement of the temperature expansion valve embodiment, FIG 5 is a longitudinal temperature expansion valve embodiments FIG.

The temperature expansion valve of this embodiment has a brass valve housing 10 and a diaphragm device 20 that constitute a valve body. The valve housing 10 is formed with a first port 10a to which the primary side joint pipe 10a1 is connected and a second port 10b to which the secondary side joint pipe 10b1 is connected, between the first port 10a and the second port 10b. A valve port 10c is formed at the end. The valve housing 10 is formed with a pressure equalizing path 10d to which a pressure equalizing pipe 10d1 is connected. The primary side joint pipe 10a1 is connected to the outlet side pipe of the condenser, and the secondary side joint pipe 10b1 is connected to the inlet side pipe of the evaporator. The pressure equalizing pipe 10d1 is connected to the outlet side piping of the evaporator.

  A cylindrical first cylindrical portion 1 is formed on the diaphragm housing 20 side of the valve housing 10, and the first cylindrical portion 1 is formed with a guide hole 1 a in which the first port 10 a is opened to the side. . The guide hole 1a has a cylindrical shape with the valve port 10c side as one end and the central axis of the valve port 10c as the axis L, and the side opposite to the valve port 10c opens into the diaphragm device 20. . A valve body 30 is disposed in the guide hole 1a. The valve body 30 has a clearance with respect to the valve portion 30a located on the second port 10b side with respect to the valve port 10c and the inner peripheral surface of the guide hole 1a, and is a cylindrical shape that is inserted into the guide hole 1a. Needle portion 30b. Thereby, the valve body 30 is accommodated in the guide hole 1a so as to be movable in the axis L direction, and the valve portion 30a opens and closes the valve port 10c by the movement in the axis L direction.

  A seal member 40 is attached to the upper portion of the needle portion 30b by a presser member 40a. Further, an abutment 50 is attached to an end of the needle portion 30b, and the valve body 30 is a diaphragm through the abutment 50. The diaphragm 20c of the device 20 is connected. A substantially cylindrical mounting hole 10e with the axis L as an axis is formed in the lower part of the valve port 10c, and an adjusting spindle 10f is mounted in the mounting hole 10e. And the urging | biasing force to the valve body 30 by the adjustment spring 10g is adjusted by rotating the adjustment spindle 10f. Thereby, the superheat degree setting is adjusted.

  In the diaphragm device 20, a “case body” is constituted by an upper lid 20 a and a lower lid 20 b made of stainless steel. A diaphragm 20c is provided between the upper lid 20a and the lower lid 20b, and the inside of the case body composed of the upper lid 20a and the lower lid 20b is partitioned as a pressure receiving chamber 20A and a pressure equalizing chamber 20B by the diaphragm 20c. The pressure equalizing chamber 20B is connected to the outlet side piping of the evaporator via the pressure equalizing passage 10d of the valve housing 10, and the evaporation pressure is introduced into the pressure equalizing chamber 20B.

  The pressure receiving chamber 20A is connected to the temperature sensing cylinder 20e through the capillary tube 20d. The temperature sensing cylinder 20e, the capillary tube 20d, and the pressure receiving chamber 20A are filled with, for example, the same gas (and liquid) as the refrigerant of the refrigeration cycle, and the temperature sensing cylinder 20e is connected to the outlet side piping of the evaporator. It is attached. Thereby, the internal pressure of the pressure receiving chamber 20A changes according to the temperature sensed by the temperature sensing cylinder 20e. The diaphragm 20c is displaced according to the pressure difference between the pressure receiving chamber 20A and the pressure equalizing chamber 20B, and this displacement is transmitted to the valve body 30 by the metal 50. With this configuration, the opening degree of the valve port 10c for flowing the refrigerant from the condenser-side primary pipe to the evaporator-side secondary pipe is controlled in accordance with the pressure difference between the temperature sensed by the temperature sensing cylinder 20e and the evaporation pressure. Perform superheat control of the refrigeration cycle.

  A cylindrical second cylindrical portion 2 is formed at the lower portion of the lower lid 20b. A male screw portion 11 is formed on the outer periphery of the first cylindrical portion 1 of the valve housing 10. A female screw portion 21 is formed on the inner periphery of the second cylindrical portion 2. The diaphragm device 20 is attached to the valve housing 10 by screwing the female screw portion 21 of the second cylindrical portion 2 and the male screw portion 11 of the first cylindrical portion 1 together.

  Further, on the outer periphery of the first cylindrical portion 1, a step portion 12 having a diameter larger than that of the male screw portion 11 is formed at a position opposite to the opening end portion 1 </ b> A of the male screw portion 11. The surface of the step portion 12 that faces the second cylindrical portion 2 is an annular first seal surface 12A that has the axis L of the first cylindrical portion 1 as the center of rotation. A ring-shaped protrusion 22 is formed at the opening end 2 </ b> A of the second cylindrical portion 2. And the opposing surface by the side of the 1st seal surface 12A of this protrusion 22 becomes the cyclic | annular 2nd seal surface 22A which makes the axis line L of the 2nd cylindrical part 2 the rotation center. 2 and 3, the radial width D1 of the first seal surface 12A is larger than the radial width D2 of the second seal surface 22A, and the second seal surface 22A is the first seal surface 22A. It is located within the seal surface 12A. As a result, the area of the second seal surface 22A is smaller than the area of the first seal surface 12A. The axis L is common to the first cylindrical portion 1 and the second cylindrical portion 2.

  Next, each embodiment of the seal structure by the first seal surface 12A and the second seal surface 22A will be described. 2 to 4 are enlarged views of the portion of the dashed line on the left side in FIG. 1, but the entire structure is a structure of a rotating body in which the cross section of FIGS. 2 to 4 is rotated about the axis L as a rotation axis. It has become. FIG. 2 is a view showing the first embodiment. The second cylindrical portion 2 is gradually screwed into the first cylindrical portion 1 in the order of FIGS. 2 (A), 2 (B), and 2 (C). It shows the state to go. In the first embodiment, the second sealing surface 22A of the second cylindrical portion 2 is a flat surface perpendicular to the axis L. Then, the first seal surface 12A is moved in the screwing direction (arrow R direction) of the second cylindrical portion 2 so that the outer edge portion 22A2 (FIG. 2 (B)) of the second seal surface 22A first contacts the first seal surface 12A. It is a tapered surface that comes into contact.

  When the outer edge portion 22A2 of the second seal surface 22A first contacts the first seal surface 12A and then proceeds in the screwing direction, the first seal surface 12A becomes a tapered surface, and thus the ridge 22 (opening) The end portion 2A) is stressed inward, and at least the outer edge portion 22A2 of the second seal surface 22A bites into the first seal surface 12A, so that the open end portion 2A of the second cylindrical portion 2 moves outward. Can be prevented. Thereby, sealing performance can be secured. Further, as shown in FIG. 2 (C), when the second seal surface 22A is completely bited into the first seal surface 12A, the opening end portion 2A of the second cylindrical portion 2 is reliably moved outward. Can be prevented, and sealing performance can be secured.

FIG. 3 is a diagram showing a reference example, in which the second cylindrical portion 2 is gradually screwed into the first cylindrical portion 1 in the order of FIGS. 3 (A), 3 (B), and 3 (C). Is shown. In the second embodiment, the first sealing surface 12A of the first cylindrical portion 1 is a flat surface perpendicular to the axis L. When the second seal surface 22A is moved in the screwing direction (arrow R direction) of the second cylindrical portion 2, the inner edge portion 22A1 (FIG. 3B) of the second seal surface 22A is first placed on the first seal surface 12A. It is a tapered surface that comes into contact.

  When the inner edge portion 22A1 of the second seal surface 22A first contacts the first seal surface 12A and then proceeds in the screwing direction, the second seal surface 22A becomes a tapered surface as shown in FIG. 3B. Therefore, the inward stress is generated in the protrusion 22 (opening end 2A), and at least a part of the second seal surface 22A bites into the first seal surface 12A. It is possible to prevent the open end portion 2A of the outer side from moving outward. Thereby, sealing performance can be secured. Further, as shown in FIG. 3 (C), when the second seal surface 22A is completely bited into the first seal surface 12A, the opening end portion 2A of the second cylindrical portion 2 is reliably moved outward. Can be prevented, and sealing performance can be secured.

In the first embodiment and the reference example described above, an example in which one of the first seal surface 12A and the second seal surface 22A is a flat surface perpendicular to the axis L is shown. For example, the second embodiment shown in FIG. As described above, both the first seal surface 12A and the second seal surface 22A may be tapered surfaces. In this case, the second seal surface 22A of the second cylindrical portion 2 is slightly tapered, and the first seal surface 12A is moved in the second direction by the movement of the second cylindrical portion 2 in the screwing direction (arrow R direction). The outer peripheral portion 22A2 (FIG. 4B) of the seal surface 22A is a tapered surface that first comes into contact with the first seal surface 12A.

  In the above embodiment, the seal structure of the present invention has been described for sealing between the valve housing of the temperature expansion valve and the diaphragm device. However, when two cylindrical members are screwed together, the joint portion is implemented. You may apply the structure of the 1st cylindrical part of a form, and a 2nd cylindrical part.

DESCRIPTION OF SYMBOLS 1 1st cylindrical part 11 Male thread part 12 Step part 12A 1st sealing surface 2 2nd cylindrical part 21 Female thread part 22 Projection 22A 2nd sealing surface 22A1 Inner edge part 22A2 Outer edge part 10 Valve housing 10c Valve port 20 Diaphragm apparatus 20a Upper cover 20b Lower lid 20c Diaphragm 30 Valve body

Claims (5)

A seal structure for connecting the first cylindrical portion and the second cylindrical portion, and sealing the connecting portion between the first cylindrical portion and the second cylindrical portion of the device element in which fluid is filled in the first cylindrical portion and the second cylindrical portion. Because
A male screw part is formed on the outer periphery of the first cylindrical part from the opening end of the first cylindrical part, and a female screw part is formed on the inner periphery of the second cylindrical part,
On the outer periphery of the first cylindrical portion, an annular first sealing surface centering on the axis of the first cylindrical portion is formed at a position opposite to the opening end portion of the male screw portion,
An opening end portion of the second cylindrical portion is an annular second seal surface whose center of rotation is the axis of the second cylindrical portion, and has an area larger than that of the first seal surface that fits within the first seal surface. A small second sealing surface is formed,
The male screw part and the female screw part are screwed together, and the first cylindrical surface and the second cylindrical part are joined by crimping the first seal surface and the second seal surface,
The first seal surface is formed in the screwing direction of the second cylindrical portion so as to generate an inward stress at the opening end portion of the second cylindrical portion by a thrust generated by tightening the male screw portion and the female screw portion . A seal structure, wherein the outer edge of the second seal surface is a tapered surface that first contacts the first seal surface by movement . The seal structure of claim 1, prior Symbol second sealing surface is characterized by a perpendicular flat surface to the axis. The seal structure of claim 1 prior Symbol second sealing surfaces, characterized in that a tapered surface.   The seal structure according to any one of claims 1 to 3, wherein the first cylindrical portion is brass, and the second cylindrical portion is stainless steel. A valve body for controlling the flow of refrigerant by opening and closing a valve port formed in the valve housing by a valve body, and a diaphragm device in which a case body is partitioned by a diaphragm to form a pressure receiving chamber and a pressure equalizing chamber, In the temperature expansion valve in which the valve opening degree of the valve port is controlled by the diaphragm and the valve body that operate in accordance with a differential pressure between the pressure in the pressure receiving chamber and the pressure in the pressure equalizing chamber, Comprising the seal structure according to any one of 4;
The valve housing has the cylindrical first cylindrical portion that houses the valve body, and the case body of the diaphragm device has the cylindrical second cylindrical portion that communicates with the pressure equalizing chamber,
The case body is coupled to the valve housing by screwing the male screw portion and the female screw portion and crimping the first seal surface and the second seal surface. Temperature expansion valve.

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