JPH029185Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] In order to maintain corrosion resistance, reduce weight, and reduce costs, the bodies of various types of valves, pumps, etc., and pipe joints, etc., are made of synthetic resin. This is widely practiced.

[Conventional technology]

The bodies of conventional valves, pumps, etc. usually have an outward flange at the open end of their fluid passageway, and in the case of pipe fittings, an outward flange at the end of the body, which connects to a similar mounting flange in the pipeline. It is attached by tightening both flanges with multiple bolts and nuts.

[Problem that the invention attempts to solve]

If the body or pipe joint is made of synthetic resin, which is inferior to metal in terms of rigidity and hardness, when the flange is tightened with bolts and nuts, the degree of pressure contact at the parts other than the tightened part may be somewhat insufficient. is unavoidable, and even if there is packing between both flanges, a good seal cannot be obtained.

In order to eliminate such concerns, the number of bolts and nuts may be increased, or the wall thickness of the flange may be increased, but if the nuts are tightened beyond a certain level, they may dig into the flesh of the mounting flange. Therefore, it is still not possible to obtain a tightening force above a certain level.

Therefore, conventional synthetic resin valve bodies or pipe joints have been considered to have a limited operating pressure.

The purpose of the present invention is to eliminate such problems with synthetic resin joints in pipelines.

[Means for solving problems]

In order to achieve the above purpose, in this invention,
The mounting flange integrally formed on the outer end of the synthetic resin cylindrical channel has an annular recessed step extending from the inner circumferential edge toward the outer circumference on the outer surface, and the inner and outer circumferential edges are slightly rounded. An annular core metal is embedded therein, and a bolt insertion hole that also passes through the annular core metal is bored in the mounting flange.

[Effect]

Due to the presence of the annular core metal, the deformation and compression of the synthetic resin mounting flange is suppressed, and the contact pressure with the mating mounting flange is maintained almost uniformly over its entire surface. The disadvantages of conventional synthetic resin joints are eliminated.

〔Example〕

FIG. 1 shows an example in which the present invention is applied to the body of a diaphragm valve.

Since the diaphragm valve itself is well known and has no direct relation to the present invention, a detailed explanation thereof will be omitted.

The body 1 of this valve is made by molding synthetic resin, and mounting flanges 5 facing in the circumferential direction are provided at the outer ends of the cylindrical flow passages 4, 4 that follow the wafer 3 against which the diaphragm 2 is to come into contact. , is integrally formed.

Each mounting flange 5 has an annular core metal 6 made of metal, preferably stainless steel or aluminum with low corrosion resistance, and having slightly larger roundness on the inner and outer peripheral edges.
is buried.

The outer diameter and thickness of this annular core bar 6 are determined so that a synthetic resin layer as thin as possible is formed around it, and the inner circumferential edge is formed at the mounting flange 5.
It is located at the base of the. In other words, the inner diameter of the annular core metal 6 is approximately equal to the outer diameter of the cylindrical flow path 4.

An annular recessed step portion 6a having an appropriate width and depth is provided on the outer surface of the annular core metal 6, extending from the inner circumferential edge toward the outer circumference.

Mounting flange 5 and annular core bar 6 embedded therein
A plurality of holes 8 for inserting tightening bolts 7 are provided at important points.

To embed the annular core bar 6 in the mounting flange 5,
It is better to do as follows.

As shown in FIG. 2, an annular core metal 6 with holes 8 pre-drilled at key locations is placed at key locations in the inner cavity 9a of the mold 9.
The positioning pins 10, 10 are inserted into mutually opposing holes 9b, 9b drilled at key points of the mold 9, while holding them appropriately without contacting the inner cavity 9a. ) is properly fitted into the hole 8 of the annular core metal 6, and then uncured synthetic resin is injected into the mold 9.

Then, the resin flows around the annular core bar 6,
It hardens when it is wrapped around it.

After solidification, the positioning pins 10, 10 are removed, and the finished body is taken out from the mold 9.

The procedure for attaching the valve body 1 of the present invention manufactured in this manner to a pipeline is the same as that of conventional valves.

For example, as shown in FIG. 3, an outward mounting flange 5' in which an annular core metal 6' similar to that in the body 1 is embedded is formed at the tip of the cylindrical flow path 4' in the mounting portion.

Both mounting flanges 5 and 5' are opposed to each other with packing 11 held between them, and bolts 7 are inserted into each hole 8 and tightened with nuts 12.

Mounting flange 5 at the inner peripheral edge of the annular core bar 6
In order to increase the yield strength of 6b in Fig. 3,
As shown in 6b', the inner circumferential edge of the annular core bar 6 may be extended to near the inner circumference of the cylindrical channels 4, 4'.

Note that the mating attachment portion shown in FIG. 3 may be a normal metal flange.

[Effect of idea]

According to the present invention, the presence of the annular core metal prevents deformation and compression of the synthetic resin mounting flange, and the contact pressure between opposing mounting flanges is maintained almost uniformly over the entire surface. Therefore, the drawbacks of the conventional synthetic resin body mentioned at the beginning are eliminated.

Since the outer surface of the annular mandrel is formed with a recessed step extending from the inner periphery toward the outer periphery, the thickness of the synthetic resin layer between the inner periphery of the annular mandrel and the outer surface of the mounting flange is , is larger than other parts, and despite the existence of the annular core metal, the bending stress and axial shearing force acting on the synthetic resin part at the base of the mounting flange are large.

Since the periphery of the annular core metal is completely covered with synthetic resin, there is no risk of corrosion or rusting, regardless of the material.

The inner and outer edges of the annular core are slightly rounded, so when the synthetic resin is molded, shrinkage due to solidification causes the parts of the synthetic resin that come into contact with the inner and outer edges of the annular core to A large stress is generated,
No cracks occur and the yield rate is good.

[Brief explanation of drawings]

FIG. 1 is a front view showing the right half of an example applied to the diaphragm valve of the present invention, taken longitudinally. FIG. 2 is a simplified longitudinal sectional view of the main part for explaining a preferred method of embedding the core metal in the mounting flange. FIG. 3 is an enlarged vertical cross-sectional view of a main part showing how to attach the diaphragm valve in FIG. 1 to a pipeline. 1...Body, 2...Diaphragm, 3...Wayer, 4...Cylindrical channel, 5...Mounting flange,
6... Annular core bar, 6a... Recessed step, 7... Bolt, 8... Hole, 9... Mold, 9a... Inner cavity, 9b
... hole, 10 ... positioning pin, 11 ... packing, 12 ... nut.

Claims (1)

[Scope of utility model registration request] The mounting flange integrally formed on the outer end of the synthetic resin cylindrical channel has an annular recessed step extending from the inner circumferential edge toward the outer circumference on the outer surface, and the inner and outer circumferential edges are slightly rounded. A synthetic resin joint for a pipeline, in which an annular core metal is buried and a bolt insertion hole that also passes through the annular core metal is bored in the mounting flange.