JPH08326969A - Pipe coupling - Google Patents

Abstract

PURPOSE: To prevent the removal of a pipe securely without using a metallic fastening ring. CONSTITUTION: A coupling main body to connect both fluid pipes 1 and 2 each other is formed of a glass fiber reinforced plastic, and by making the inner surfaces of fastening rings 4a and 4b provided outer side of the outer peripheral surface of the other side fluid pipe 2, in an uneven surface of a fiber reinforced plastic whose strength and the hardness are higher than the coupling main body 4 and the surface of the fluid pipe 2, a strong removal preventive function of both fluid pipes 1 and 2 each other by a removal preventive part 8 can be obtained without using a metallic fastening ring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint used in a joint portion of a fluid pipe at least the surface of which is made of synthetic resin or the like.

[0002]

2. Description of the Related Art Generally, a so-called slip-on type pipe joint is used for joining synthetic resin fluid pipes such as vinyl chloride pipes. This is to form an expanded inlet port on one pipe, accommodate the packing in the annular groove formed on the inner surface of the inlet port, and push the insertion port of the other pipe into the inlet port for both pipes. After making it watertight, a pair of semi-cylindrical tightening bodies that can be divided into two parts are attached to the outer peripheral surface of the receiving opening and the insertion opening, and a fixing part provided on the inner peripheral surface on the insertion opening side is attached to the outer peripheral surface of the insertion opening. Both pipes are prevented from coming off by biting into the surface and bolting.

Such a pipe joint has been formed of iron, ductile cast iron, or the like until now, but since it is made of metal, it is difficult to carry and work, and there is a problem in corrosion resistance.

As a solution to this problem, a pipe joint in which the entire tightening body is made of synthetic resin has been proposed (for example, see Japanese Utility Model Publication No. 58-53504).

[0005]

In the above-mentioned conventional pipe joint, since the metal tightening ring is used as the pipe retaining means, there is a limit to the weight reduction and the problem of corrosion resistance remains.

The present invention has been made in view of the above problems, and reliably prevents the pipe from coming off without using a metal tightening ring or the like, and is lightweight, and has excellent corrosion resistance and workability. It is intended to provide.

[0007]

In order to solve the above problems, according to the pipe joint of the present invention, the opening end of the other fluid pipe is sealed in the receiving port formed at the opening end of the one fluid pipe. Watertightness is inserted by a member, and the inlet and the outer peripheral surface of the other fluid pipe are fastened with a joint body having a pair of half-cylinder-shaped fastening rings that are fitted over the inlet and the other fluid pipe. By doing so, in a pipe joint in which both fluid pipes are connected to each other while preventing slip-off, the joint main body is made of plastic and is externally fitted to the outer peripheral surface of at least the other fluid pipe of the joint main body. The retaining part inside the tightening ring
It is characterized in that it is a layer of fiber reinforced plastic having higher strength and hardness than the joint body and the fluid pipe, and that a large number of irregularities are formed on the fixing surface of the retaining portion.

In the above pipe joint, it is preferable that the retaining portion is formed of carbon fiber reinforced plastic.

In the above-mentioned pipe joint, it is preferable that the retaining portion is made of aramid fiber strength plastic.

In the above pipe joint, the joint body is preferably made of glass fiber reinforced plastic.

In the above pipe joint, it is preferable that the retaining portion is integrally formed with the tightening ring of the joint body.

[0012]

[Operation] The joint body connecting both fluid pipes is molded of plastic, and the retaining portion on the inner surface side of the tightening ring fitted on the outer peripheral surface of the other fluid pipe is stronger than the joint body and the fluid pipe. And a layer of fiber-reinforced plastic with high hardness, and by gripping the fluid pipe with the uneven surface of this surface, without using a metal tightening ring as in the past,
The retaining ring provides a strong action of ejecting the fluid tubes from each other.

By forming the retaining portion of carbon fiber plastic or aramid fiber, irregularities on the fixing surface can be formed very easily by a mold or the like, and after curing, the retaining portion has high strength.

When the joint body is made of glass fiber reinforced plastic, the toughness of the joint as a whole is improved.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, the fluid pipes 1 and 2 to be connected to each other are formed of a synthetic resin material such as vinyl chloride. The opening end of one of the fluid pipes 1 is a reception port 1a having an enlarged diameter, and a packing 3 is fitted in a bulging portion 1b formed near the tip thereof.

The insertion port 2a at the open end of the other fluid pipe 2
Is inserted into the receiving opening 1a to insert the insertion opening 2
The outer peripheral surface of a is in close contact with the packing 3, and watertightness is secured. The one fluid pipe 1 may be made of steel pipe or ductile.

Numeral 4 is a joint body which is divided into two along the pipe axis direction, and is a pair of upper and lower tightening rings 4a and 4b each having a half-cylindrical shape.
have.

One fluid pipe 1 is attached to each of the tightening rings 4a and 4b.
Large diameter portion 5 that is in close contact with the outer peripheral surface of the receiving port 1a having a large diameter and a small diameter portion 6 that is in close contact with the outer peripheral surface of the other fluid pipe 2.
And the flanges 7, 7 that are continuously provided at the opposite ends of each other are integrally molded, and the large diameter portion 5 and the small diameter portion 6 are largely opened. The inner diameter of the large-diameter portion 5 is slightly larger than the outer diameter of the receiving port 1a.

The joint body 4 is made of glass fiber reinforced plastic (GFRP) and has its respective tightening rings 4a, 4
On the inner peripheral surface of each small diameter portion 6 in b, a reinforcing layer of a required thickness made of carbon fiber reinforced plastic (CFRP),
That is, the retaining portion 8 is integrally formed. The inner surface (front surface) of the retaining portion 8 is a fixed surface 8a of an uneven strip that faces the circumferential direction (see FIG. 3), and when the joint body 4 is fastened to the connection portion of both fluid pipes 1 and 2, Since the fixed surface 8a bites into the outer peripheral surface of the fluid pipe 2 to prevent slippage, the fluid pipe 2 is prevented from slipping out of the receiving port 1a.

Fluid pipes 1 and 2 using the pipe joint of the above embodiment
In order to connect each other, first, with the packing 3 fitted in the bulging portion 1b of the receiving port 1a of the one fluid pipe 1, the insertion port 2a of the other fluid pipe 2 is inserted by a required length, Watertightness of both fluid pipes 1 and 2 is aimed at.

Then, the divided tightening rings 4a and 4b are covered from above and below, and the flanges 7 of both tightening rings 4a and 4b are fastened with bolts 9 and nuts 10. As a result, the fixing surface 8a of the retaining portion 8 formed integrally with the small-diameter portion 6 is extremely hard and therefore bites into the outer peripheral surface of the fluid pipe 2 to strongly grip the fluid pipe 2.

On the other hand, the large-diameter portion 5 has its inner diameter set to the receiving port 1a
Since the diameter is slightly larger than the outer diameter of the receiving port 1a, it is not strongly pressed against the outer peripheral surface of the receiving port 1a, and when both fluid pipes 1 and 2 expand or contract in the axial direction of the pipe, Entrance 1
These forces can be absorbed by the slip between the outer peripheral surfaces of a.

Further, when a large withdrawal force is applied due to fluid pressure or the like, the bulging portion 1b contacts the large diameter portion 5, so that both fluid pipes 1 and 2 will not come off.

As described above, in the pipe joint according to the embodiment of the present invention, the joint body 4 is molded from glass fiber reinforced plastic having high strength, and the direction stopping portion 8 is formed in the joint body 4.
Since it is integrally molded from carbon fiber reinforced plastic, which has even higher strength, not only the overall weight of the pipe joint can be reduced, but also the rust prevention effect is high. Further, when a conventional metal tightening ring is used, a screw or the like for fixing the tightening ring is necessary. Carbon fiber is used for the fixing surface 8a of the stopper 8 and its vicinity,
Since it has a structure that forms an integral reinforcing layer with the joint body 4,
It is possible to eliminate the risk of peeling between the joint body 4 and the retaining portion 8.

The embodiments of the present invention have been described above with reference to the drawings. However, the specific configuration is not limited to these embodiments, and even if there are changes and additions within the scope of the present invention, the present invention is not limited thereto. Included in the invention.

For example, the fixing surface 8a of the retaining portion 8 may be a large number of quadrangular pyramid-shaped projections 11 as shown in FIG. 5 or other rough surface having a locking function.

Further, as shown in FIG. 6, the retaining portion 12 is formed separately from the joint body 4, and the retaining portion 12 is closely packed in the concave groove 13 formed on the inner surface of the small diameter portion 6 of the tightening rings 4a and 4b. It may be fitted and fixed with an adhesive. In some cases, the groove 13 may not be used.

Further, as the material of the retaining portions 8 and 12, aramid fiber (Kevlar fiber) reinforced plastic or fiber reinforced plastic made of composite fiber of carbon fiber and aramid fiber may be used.

Although the fiber-reinforced plastic layer of the retaining portions 8 and 12 is expressed as a thick wall, a carbon or aramid fiber sheet is used depending on the strength of the fluid pipe.
It is also possible to form a thin layer together with the resin by using about 3 sheets.

[0030]

According to the present invention, the following effects can be obtained.

(A) According to the invention of claim 1, since the entire joint is made of plastic, and at least the inner side of the tightening ring is made of fiber-reinforced plastic having high strength, it is as strong as an ordinary iron joint. Yes, and because it is lightweight,
Good workability and excellent corrosion resistance. Furthermore, since the retaining portion has greater strength and hardness than the joint body and the fluid pipe, it is not necessary to use a metallic tightening ring as in the conventional case, and the retaining pipe strongly digs into the outer peripheral surface of the fluid pipe. It is possible to reliably prevent slipping out.

(B) According to the invention of claim 2 or 3,
By forming the retaining portion of carbon fiber plastic or aramid fiber, irregularities on the fixing surface can be formed very easily by a mold or the like, and after curing, the retaining portion has high strength and hardness.

(C) According to the invention of claim 4, since the joint body is made of glass fiber reinforced plastic, the toughness of the entire joint is improved.

(D) According to the invention of claim 5, it is possible to save the labor of separately molding the retaining portion, reduce the cost, eliminate the need for an adhesive, and facilitate the management of parts.

[0035]

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a pipe joint of the present invention and an example of joining pipes by the pipe joint.

FIG. 2 is a cross-sectional plan view taken along the line II-II in FIG.

FIG. 3 is a plan view of the inner surface side of the joint body.

4 is a vertical plan view taken along the line IV-IV in FIG.

FIG. 5 is a plan view of an essential part showing another embodiment of the fixing surface.

FIG. 6 is a vertical sectional view showing another embodiment of the retaining portion and its mounting example.

[Explanation of symbols]

 1 one fluid pipe 1a receiving port 1b bulging part 2 other fluid pipe 2a insertion port 3 packing (seal member) 4 joint body 4a, 4b tightening ring 5 large diameter part 6 small diameter part 7 flange 8 retaining part 8a fixing Surface 9 Bolt 10 Nut 11 Protrusion 12 Fall-out prevention portion 13 Recessed groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ryoichi Ishida, Inventor Ryoichi Shimbashi 2-16-16, Minato-ku, Tokyo, No. 701, No. 701 New Shimbashi Building, Room 706, Cosmo Koki Co., Ltd. (72) Inventor Toshio Saito Inagi, Tokyo 2283 Ichisakahama Super Resin Industry Co., Ltd.

Claims (5)

[Claims] 1. A receiving port formed in the opening end of one fluid pipe, the opening end of the other fluid pipe being inserted while maintaining watertightness by a sealing member, and the receiving port and the other fluid pipe. 1 of the half-cylindrical shape which is fitted over the outer peripheral surface of
A pipe joint in which both fluid pipes are connected by preventing them from coming off by fastening with a joint body having a pair of tightening rings, wherein the joint body is made of plastic, and at least the other side of the joint body The retaining portion inside the tightening ring that is fitted onto the outer peripheral surface of the fluid pipe is a layer of fiber reinforced plastic that has higher strength and hardness than the joint body and the fluid pipe. A pipe joint characterized in that a large number of irregularities are formed on the fixed surface. 2. The pipe joint according to claim 1, wherein the retaining portion is made of carbon fiber reinforced plastic. 3. The pipe joint according to claim 1, wherein the retaining portion is made of aramid fiber reinforced plastic. 4. The pipe joint according to claim 1, wherein the joint body is made of glass fiber reinforced plastic. 5. The pipe joint according to claim 1, wherein the retaining portion is integrally formed with the tightening ring of the joint body.