JP2642689B2 - Manufacturing method of synthetic resin valve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a valve made of synthetic resin, and more specifically, a heating wire is buried in an inner surface of a connection port of a valve to be connected to a pipe, and a pipe to be connected is connected to an electrofusion valve. The present invention relates to a synthetic resin valve to be attached and connected.

[Conventional technology]

The structure of the synthetic resin valve is described in Japanese Patent Publication No.
FIG. 8 according to the invention disclosed in Japanese Unexamined Patent Publication (Kokai) Publication. This fluid flows into an integrally formed valve box comprising a valve body holding portion for holding the spherical portion of the valve body and connection ports with pipes provided on both sides thereof in communication with the connection port. The valve body having a through hole that forms a passage is rotatably held, and the valve body has a spherical portion at both ends of the through hole with a repulsive force that expands toward the valve body holding portion of the valve box. It is a spherical valve held and enclosed in a valve box.

The most important point of the valve function is the sealing of the internal fluid,
As a result, the valve element retains the repulsive force and is held in the valve box, thereby increasing the sealing surface pressure between the valve box and the valve element and improving the sealing performance.

[Problems to be solved by the invention]

By the way, synthetic resin valves are generally sensitive to heat, and have a problem that they undergo deformation during the process of increasing the temperature at the time of connection with the pipe, resulting in a change in the initial sealing surface pressure and a decrease in sealing performance. Therefore, there is a synthetic resin valve in which a connection portion with a pipe line is connected using an adhesive or connected mechanically, but an electrofusion type valve is connected to a seal portion with a valve body by heat generated by connecting a pipe. It was not put to practical use due to its adverse effects.

An object of the present invention is to provide a synthetic resin valve having a connecting portion for connecting to a pipe by electrofusion while solving the above problems.

[Means for solving the problem]

Forming an inner portion of a resin body outside a main part of a valve having a valve body sandwiched between a metal packing case and a packing mounted on the inner surface of the case and a valve rod for rotating the valve body; A method for manufacturing a synthetic resin valve, characterized in that a heating wire is wound around the outer periphery of the portion, and then the outer portion of the resin body is formed outside the inner portion.

(Operation)

Since the present invention has the above configuration, the packing for sealing with the valve body is mounted on the inner surface of the metal packing case,
The deformation of the main body due to the heating of the heating wire winding portion of the connection portion is blocked by the metal packing case, so that the seal portion with the valve body is not affected. Therefore, good sealing performance can be ensured even after connection with the pipeline.

〔Example〕

The manufacturing method and structure will be described with reference to FIGS. 1, 2, and 3.

First, as shown in FIG. 1, the upper part 21 of the valve stem 20 is inserted into the hole 11 provided at the center of the cylindrical case 10 from the inside of the case, and is projected outside. Next, the spherical valve body 30 is inserted into the inside of the case 10, and the lower end portion 22 of the valve rod and the concave portion 31 of the spherical valve body 30 are engaged. Thereafter, the metal packing case 40 is screwed into both ends of the case 10, and the spherical valve body 30 is sandwiched from both sides. Thus, the main part 5 of the synthetic resin valve is constituted. The packing 41 is an elastic body such as rubber or synthetic resin, and is previously mounted on the metal packing case 40 by integral baking, bonding, or fitting.

Secondly, as shown in FIG. 2, cores 60, 60 'are inserted into the main part 5 from both right and left sides, and then set in an inner mold (not shown). The body inner part 70 is formed on the outside by injection molding.

Thirdly, grooves provided on the outer periphery of both ends of the inner portion 70
A heating wire 72 is wound around 71, a connector pin 73 for energization is attached, and the core metal 6 is attached to an outer molding die (not shown).
The entire inner portion 74 including the inner and outer portions 81 including 0,60 'is set to form the outer portion 81 of the main body. After that, remove the metal core 60,60 '
Assemble the O-ring 90 and the spacer 91 as shown in the figure,
The handle 92 is fixed to the upper end of the valve stem 20 with a set screw 93 to complete the process.

 The material of each component is as follows.

The main body is made of a synthetic resin that can be fused, such as polyethylene, with the outer portion 81 of the inner portion 70, and the packing case 40 and the cylindrical case 10 are made of a metal that is not easily deformed by the heat of fusion of pipe connection. The spherical valve body 30 and the valve stem 20 may be made of either synthetic resin or metal, but shall not easily be thermally deformed at the temperature at which the main body is molded.

FIG. 4 shows a main part 5 'of another embodiment according to the present invention.
In this example, after the spherical valve element 30 and the valve rod 21 are combined, a state is shown in which metal packing cases 40 'and 40 "are sandwiched from the left and right of the spherical valve element 30, and in this state, as in the first embodiment. The cores 60, 60 'are inserted into the spherical valve body 30 and then set in an inner mold, and the inner part of the main body is formed outside the main part 5' by injection molding.

FIG. 5 shows a third embodiment of the present invention, which is a completed butterfly valve made of synthetic resin.

An elastic packing 43 made of rubber, synthetic resin, or the like is mounted on the inner surface of the packing case 40 'in advance by integral baking, bonding, fitting, or the like. Packing 43
Is an outer periphery of the valve body 32 and the valve stem 23 as shown in FIG.
Seal the outer periphery of.

The manufacturing method is as follows. First, the valve element 32 and the valve stem 23 are assembled inside the packing case 40 'in which the packing 43 is mounted in advance, and the main part is completed.

Second, the core is packed in a packing case as in the first embodiment.
Insert the main part and the core metal into the inner mold and insert the main body inner part 75 outside the main part.
Is formed by injection molding.

Thirdly, similarly to the first embodiment, a heating wire 72 is wound around the outer periphery of both ends of the inner portion 75, and
73 is attached, and the entire inner portion including the core metal of the outer mold is set to form the main body outer portion 83. Thereafter, the core is removed and the O-ring 9 is inserted as shown in FIG.
Attach 0 'and handle 94 to complete.

When connecting the synthetic resin valve according to the present invention to the pipeline,
After inserting a synthetic resin tube into the connection port 82 on both sides of the main body, when current is applied to the connector pin 73, the winding part of the heating wire 72 is heated and the connection port inner surface and the tube outer surface are fused and fused together. Is done. At this time, the entire body is also heated by the heating of the connection port 82, but since the sealing portion between the spherical valve body 39 and the packing 41 is provided inside the strong metal packing case 40, deformation of the body due to heat is prevented. The influence is prevented and good sealing performance can be maintained.

〔The invention's effect〕

As described above, according to the method for manufacturing a synthetic resin valve of the present invention, it is possible to obtain a synthetic resin valve that can be easily connected to a pipe only by passing a current without lowering the sealing performance.

[Brief description of the drawings]

1 and 2 are longitudinal sectional views showing an embodiment of a manufacturing method according to the present invention, FIG. 3 is a longitudinal sectional view showing an embodiment of a finished product according to the present invention, and FIG. FIG. 5 is a longitudinal sectional view showing a third embodiment according to the present invention, FIG. 6 is a sketch showing a packing of a third embodiment according to the present invention, and FIG. 7 is a present invention. And FIG. 8 is a sectional view showing a conventional example.

Claims (3)

(57) [Claims] An inner part of a resin body is formed outside a main part of a valve having a metal packing case, a packing mounted on an inner surface of the case, a valve body, and a valve rod for rotating the valve body. A method of manufacturing a synthetic resin valve, comprising: wrapping a heating wire around an outer periphery of an inner portion, and thereafter forming an outer portion of the resin body outside the inner portion. 2. A method for manufacturing a synthetic resin valve according to claim 1, wherein the valve body is spherical, and has a pair of metal packing cases and a valve rod. 3. A method for manufacturing a synthetic resin valve according to claim 1, wherein said valve body is of a butterfly type.