JP4316046B2 - Seal structure of heterogeneous joint of valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seal structure for a heterogeneous joint portion of a valve.
[0002]
[Prior art]
FIG. 3 shows the structure of a resin butterfly valve that is incorporated in the middle of a gas pipe and opens and closes the pipe. A metal cylindrical core 2 that houses the valve body 1 is placed in a polyethylene valve body 3. The disc-shaped valve body 1 is fixed to the valve shaft 4 that is inserted and supported by the core 2, and the operating portion 5 that rotates the valve body 1 via the valve shaft 4 is provided on the core 2. A gas pipe 6 made of polyethylene is connected to both ends of the valve body 3 by welding, and the pipe body is opened and closed by the rotation of the valve body 1.
[0003]
Since the valve body 3 covers the metal core 2 in the resin valve as described above, the metal core 2 can be effectively protected from electric corrosion and rust when embedded in the ground, and is durable. Has the advantage of being excellent.
[0004]
However, since the metal core 2 and the polyethylene valve body 3 covering the outer surface of the metal core 2 have poor adhesion at the joint surface, a gap is generated at the joint surface, and there is a risk of gas leaking from the gap. Adoption of a seal structure for the joint surface is necessary.
[0005]
FIG. 4 shows the sealing structure of the resin and insert metal joint in the resin valve as described above, and an O-ring groove 8 is provided in the outer diameter of the cylindrical portion 7 of the core 2 at the joint surface between the core 2 and the valve body 3. In the state where the O-ring 9 is incorporated in the O-ring groove 8, the resin body is injection-molded to form the valve body 3, and the O-ring 9 is pressurized with this injection-molding pressure, whereby the core 2 and the valve body are formed. 3 was sealed between the joint surfaces.
[0006]
[Problems to be solved by the invention]
By the way, since the conventional seal structure as described above obtains the seal pressure by crushing the O-ring 9 with the resin injection molding pressure, the crushing amount of the O-ring 9 depends on the resin injection molding pressure. There is a problem that it is fluctuating, it is difficult to manage the amount of crushing and the life, and the reliability of the seal is lacking.
[0007]
Therefore, the object of the present invention is to mechanically seal a heterogeneous joint such as a resin and a metal, and to easily manage the collapse amount and life of the O-ring and to provide a highly reliable seal structure for the heterogeneous joint of the valve. Is to provide.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention is a valve in which a core for accommodating a valve body is inserted into a valve body different from the core , and the core holds the upper and lower portions of the valve shaft. A cylindrical portion is formed on both sides of the portion, and the cylindrical portion of the valve body that covers the cylindrical portion is extended from the end of the cylindrical portion and has the same inner diameter as the cylindrical portion. is, the cylindrical portion respectively forming the O-ring groove to the inner diameter of the inner diameter and the cylindrical portion, the both O-ring state incorporating each O-ring into the groove, the cylindrical portion and the cylindrical stiffener formed in a cylindrical shape Incorporated into the O-ring in a bridging manner in both the O-rings, this stiffener is provided on the inner peripheral surface of the cylindrical portion and the retaining protrusion provided on the inner peripheral surface of the cylindrical portion in that it adopts the positioning holding structure A.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
FIG. 1 shows a resin-made butterfly valve adopting the seal structure of the present invention, and the basic structure of the valve is the same as that of FIG. 3 described in the prior art. Instead of the explanation.
[0011]
The metal core 2 of the resin valve has a cross-sectional shape in which a cylindrical portion 7 that forms a pipe line is provided on both sides of a portion that holds the upper and lower portions of the valve shaft 4, and the resin valve that covers the core 2 The main body 3 integrally covers the outer surface of the cylindrical portion 7 on both sides from the portion that holds the valve shaft 4, and the portion that covers the cylindrical portion 7 protrudes from the end portion of the cylindrical portion 7, and the inner diameter of the protruding portion Is the same as the inner diameter of the cylindrical portion 7 and is a cylindrical portion 10 for connecting gas pipes of the same material by welding.
[0012]
In the sealing structure of the present invention, an O-ring groove 11 is formed adjacent to the inner peripheral surface of the cylindrical portion 7 on both sides of the core 2 and the inner diameter surface of the cylindrical portion 10 of the valve body 3, and both O-rings are formed. A stiffener 13 formed in a cylindrical shape using a metal such as stainless steel or a hard synthetic resin or the like in a state where the O-rings 12 are incorporated in the grooves 11 is inserted into both O-rings 12 in a bridging manner.
[0013]
In the example shown in FIG. 1B, an annular contact 14 on which the inner end of the stiffener 13 abuts is provided at a position closer to the inner side than the O-ring groove 11 on the inner peripheral surface of both side cylindrical portions 8 in the core 2. The stiffener 13 fitted into the cylindrical portion 7 and the cylindrical portion 10 can be positioned.
[0014]
Further, a retaining protrusion 16 having a diameter slightly smaller than the outer diameter of the stiffener 13 is provided in the vicinity of the O-ring groove 11 on the inner diameter surface of the tubular portion 10 of the valve body 3, and the stiffener 13 is connected to both O-rings. When the stiffener 13 is inserted into both the O-rings 12, the material of the valve body 3 is used to force the stiffener 13 to pass through the retaining protrusion 16. It is designed so that it can be secured.
[0015]
The downstream cylindrical portion 7 in the core 2 is separated from the seat ring 15 that the valve body 1 is in contact with the valve body 1 in the closed position, and is fitted and fixed in the cylindrical portion 7, and the O-ring is attached to the seat ring 15. A groove 11 is formed.
[0016]
The seal structure of the present invention is configured as described above, and the O-ring groove 11 is disposed close to the inner peripheral surface of the cylindrical portions 7 on both sides of the core 2 and the inner surface of the cylindrical portion 10 of the valve body 3. O-rings 12 are formed in both O-ring grooves 11 and cylindrical stiffeners 13 are formed across the inner peripheral surface of the cylindrical portion 7 and the inner surface of the cylindrical portion 10 of the valve body 3. The O-ring 12 is inserted into the bridge 12 so as to be compressed in the O-ring groove 11.
[0017]
By compression of both O-rings 12 by the insertion of the stiffener 13, the joint surface between the core 2 and the valve body 3 is mechanically sealed at the joint portion between the end of the cylindrical portion 7 and the tubular portion 10, and gas leakage occurs. Occurrence can be reliably prevented.
[0018]
In such a seal structure, by measuring the dimensions of the O-ring groove 11 and the outer diameter of the stiffener 13, the amount of crushing of the O-ring 12 can be managed, and the long-term life can be easily predicted.
[0019]
In the above embodiment, the valve is a butterfly valve, but the valve may be of other types such as a ball valve, and the core 2 is a metal and the valve body 3 is a synthetic resin. As the combination of the materials of the valve body 3 and the valve body 3, for example, a combination of different kinds of materials such as a material having different strength and a material having different heat shrinkability can be freely selected.
[0020]
【The invention's effect】
As described above, according to the present invention, an O-ring groove is formed in each of the inner diameter of the core and the inner diameter of the valve body, and the stiffener is bridged between the O-rings in a state in which the O-rings are incorporated in both the O-ring grooves. Since the inner diameter of the core, which is a heterogeneous joint, and the inner diameter of the valve body can be mechanically sealed with an O-ring, it is easy to manage the collapse amount and life of the O-ring. A highly reliable seal structure for the joint is obtained.
[Brief description of the drawings]
FIG. 1 (a) is a longitudinal sectional view of a resin valve adopting the sealing structure of the present invention, and FIG. 1 (b) is an enlarged longitudinal sectional view of a main part of the sealing structure. Fig. 3 is a vertical cross-sectional view of a resin valve employing a conventional seal structure. Fig. 4 is an enlarged vertical cross-sectional view of the same seal structure.
DESCRIPTION OF SYMBOLS 1 Valve body 2 Core 3 Valve main body 4 Valve shaft 5 Operation part 7 Cylindrical part 10 Cylindrical part 11 O ring groove 12 O ring 13 Stiffener 14 per 15

Claims (1)

The core for accommodating the valve body, a valve inserted in said core and heterogeneity of the valve body, wherein the core is formed by providing a cylindrical portion on both sides of the portion holding the top and bottom of the valve shaft, the valve A portion of the main body that covers the cylindrical portion is provided with a cylindrical portion that extends from the end portion of the cylindrical portion and has an inner diameter that is the same as that of the cylindrical portion. Each of the O-ring grooves is formed, and the O-rings are assembled in both O-ring grooves, and the cylindrical stiffener is formed inside the cylindrical portion and the cylindrical portion, and is bridged in the O-rings. A seal structure of a heterogeneous joint portion of a valve, which is assembled in a state of being inserted, and is positioned and held by a stopper provided on the inner peripheral surface of the cylindrical portion and a stopper provided on the inner peripheral surface of the cylindrical portion .

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