JPS5810059Y2 - Joint structure - Google Patents

Description

[Detailed description of the invention] The present invention relates to the structure of a joint between a metal tube and a synthetic resin tube that are joined via a backing, and more specifically, relates to the structure of a joint in a so-called mechanical joint. 〇As a means of joining a synthetic resin pipe to the socket of a cast iron pipe, a so-called mechanical joint that uses a sealing backing and a flange on the socket is widely used.

FIG. 1 is a sectional view of a main part showing a typical joining method. According to the general joining method, a sealing backing 4 is attached to the socket 2 of the socket pipe 1.

The insertion tube 5 with the press ring 6 inserted loosely is inserted into the socket tube.

After the flange portion 3 of the socket pipe 1 and each through hole of the press ring 6 are opposed to each other, they are screwed together using a fastening rod member 7 such as a bolt to obtain a complete joint state.

However, in such a joint structure, the gap t formed between the inner periphery of the socket 2 and the outer periphery of the inlet tube 5 becomes excessively large in some parts due to poor ground conditions, etc. The contact surface pressure of No. 4 may decrease and the sealing performance may be impaired.

The present invention was developed in view of the above circumstances, and its purpose is to provide a joint structure that enhances the sealing effect in the mechanical joint and provides a stable joint state. be.

The structure of the present invention that achieves this purpose is that a synthetic resin socket is inserted into the socket of a metal tube equipped with a sealing banking, and a push ring loosely inserted into the outer layer of the socket and the In a joint part in which a flange formed on a socket part is joined by a fastening rod member, the inner surface of the socket part is gradually reduced in diameter from the tip of the socket toward the back side by a first tapered part and a second tapered part. and an intermediate part parallel to the tube axis is interposed between the first tapered part and the second tapered part, and the backing to be attached to the socket has its distal end side in the insertion direction facing the second tapered part. The gist is that the portion to be loaded between the tapered portion and the outer periphery of the insertion tube is formed to have a circular cross section, and the outer peripheral surface behind the circular portion is formed as a tapered surface having an angle corresponding to the first tapered portion. It is something to do.

The configuration and effects of the present invention will be explained below in detail based on the drawings which are examples. However, the following example is only one specific example, and it is of course possible to make various changes to the design in keeping with the spirit described above and below. All of these are included in the technical scope of the present invention.

FIG. 2 is a vertical sectional view of a suction part showing an example of the joint structure according to the present invention, and a banking 4 as shown in FIG. 3 is attached to the inner surface of the socket part 2 of the socket pipe 1.

That is, on the inner surface of the socket part 2 of the present invention, a first tapered part 10 and a second tapered part 11 are formed, the inner diameters of which are gradually reduced from the tip on the open side of the socket toward the back side of the socket. A parallel intermediate portion 12 along the tube axis is provided between the tapered portion 10 and the second tapered portion 11.

The sealing backing 4 applied to such a socket part 2 has a circular sealing part 8 on the tip side, and a tapered part 9 corresponding to the first tapered part next to the circular sealing part 8 as a locking part.

Further, the backing 4 is pushed in with a push ring 6 as illustrated in FIG.

Socket part 2 and sealing backing 4 configured in this way
The sealing effect is explained below.

That is, the circular seal part 8 is strongly pressed and compressed into the gap between the second tapered part 11 and the outer circumferential surface of the insertion tube 5, and the deformation of the first circular seal part 8 escapes into the intermediate part 12, and a uniform compressive force is applied to the circular seal part 8. It comes to act on the seal portion 8.

Further, since the circular seal portion 8 receives a wedge effect from the second tapered portion 11, the backing 4 inserted between the socket portion 2 and the insertion tube 5 receives a strong contact pressure at this portion, and its adhesion becomes extremely tight. expensive.

In addition, since the tapered part 9 also receives the wedge effect of the first tapered part 10 formed on the side where the socket is open from the second taper part, the entire backing 4 is brought into close contact with the socket part 2 and stabilized, and the sealing effect of the backing 4 is improved. becomes extremely high.

FIG. 4 is an explanatory diagram showing an eccentric state when a local load such as earth pressure is applied to the joint of the present invention, and shows a state in which the insertion tube 5 is eccentric in the direction of arrow B.

That is, since the insertion tube 5 is pushed downward in the drawing, one gap t1 is narrowed and the other gap t2 is widened, and the compressive surface pressure of the upper part of the backing 4 is reduced.

However, in the joint structure of the present invention, as described above, the circular seal part 8 in contact with the second tapered part 11 and the intermediate part 12 exerts a sealing action independently of the tapered part 9, so the restorability of the circular seal part 8 is good. , the fluid pressure A in the pipe is backing 4
The circular seal portion 8 in contact with the second tapered portion 11 and the intermediate portion 12 can prevent water leakage even if the water leakage occurs.

In addition, since the inside of the backing 4 is sufficiently compressed by the first tapered portion 10, the circular seal portion 8 resists the force of pushing the socket portion 2 toward the open side due to the fluid pressure A. This can be prevented at this point, and even if the gap between the push ring 6 and the inlet tube 5 is eccentric, there is no fear of escape.

In this manner, the present invention does not reduce the sealing effect of the sealing backing even if the pipe line is eccentric or bent at the joint.

The illustrated joint structure can be applied not only to joints for long pipes, but also to pipe joints such as socket-type joints, cheese-type joints, and band-type joints, as well as to connections with devices such as pumps.

The present invention is structured as described above.

■ Extremely high sealing performance.

■ Even if the joint part is eccentric or bent, the sealing performance will not be impaired.

■ Highly practical due to its simple structure.

■ Can be applied to any type of joint.

Various effects can be enjoyed.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the main part showing a known joint part, Fig. 2 is a cross-sectional view of the main part showing the structure of the joint part of the present invention, and Fig. 3 is a cross-sectional view showing the sealing backing applied to the present invention. 4 are explanatory diagrams showing the eccentric state of the joint portion of the present invention. 1...Socket pipe, 2...Socket part, 3...
...Flange. 4... Seal backing, 5... Insertion tube, 6... Push ring, 7... Fastening rod member, 8... Circular seal part, 9...Tapered part, 10...First tapered part, 11...
・Second tapered part, 12... intermediate part.

Claims (1)

[Scope of Claim for Utility Model Registration] A synthetic resin socket is inserted into the socket of a metal pipe fitted with a sealing backing, and a push ring loosely inserted into the outer layer of the socket and formed in the socket. At a joint where flanges are joined by a fastening rod member. The diameter of the inner surface of the socket is gradually reduced in the back direction by a first taper part and a second taper part formed from the tip of the socket towards the back, and a space between the first taper part and the second taper part is formed. has an intermediate part parallel to the tube axis, and the backing attached to the socket is connected to the second part on the distal end side in the insertion direction.
The distal end portion loaded between the tapered portion and the outer periphery of the insertion tube is formed to have a circular cross section, and the outer circumferential surface behind the circular portion is formed as a tapered surface having an angle corresponding to the first tapered portion. The structure of the joint.