JPH08210568A - Different type pipe joint - Google Patents

Abstract

PURPOSE: To provide a different type pipe joint that will not leak any pipe fluid even if it is used for a transport pipeline available in a high pressure fluid. CONSTITUTION: A notch step part 2 is installed around the end inner surface of a metal cylinder 2, and this notch step part 22 is covered with a plastic body 121 integrally extended out of a plastic joint body 1, while an external thread 21 continuing to an internal thread 21 installed on an inner surface of the metal cylinder 2 is installed on the inner surface. Accordingly any possible seepage and leakage of a pipe fluid can be prevented with certainty in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dissimilar pipe joint used for connecting a synthetic resin pipe and a metal pipe of different materials.

[0002]

2. Description of the Related Art Conventionally, a dissimilar pipe joint as shown in a sectional view of FIG. 2 has been used for connecting a synthetic resin pipe and a metal pipe. This pipe joint has a structure in which a metal cylinder 2 having an internal thread 21 is embedded in the inner surface of an end of a synthetic resin joint body 1, and a male thread provided at the end of the metal tube 4 is screwed into the internal thread 21. I was connected.

[0003]

However, when the conventional pipe joint is used for the high-pressure fluid transportation pipe, the fluid in the pipe may leak. That is, since the joint body 1 made of synthetic resin and the cylindrical body 2 made of metal have poor adhesiveness, the high-pressure fluid may exude and leak from the boundary surface between the joint body 1 and the metal cylinder 2 as indicated by an arrow X in the figure. .

[0004] In order to solve this problem
No. 8211 has a joint body 1 as shown by a broken line in FIG.
Although a pipe joint in which a reinforcing ring a is fitted on the outer peripheral side is proposed, an increase in the cost of the product cannot be avoided because the number of parts increases.

The present invention has solved the structural problem of the conventional pipe joint, and is intended to reduce the product cost and prevent the fluid in the pipe from leaking even when used in the transportation pipe for high-pressure fluid. A pipe joint is provided.

[0006]

DISCLOSURE OF THE INVENTION The heterogeneous pipe joint of the present invention is a synthetic resin joint body in which a metal cylinder having an internal thread is embedded in the inner surface of the end, and a notch is formed in the inner surface of the end of the cylinder. The stepped portion is provided around the cutout portion, the cutout stepped portion is covered with a synthetic resin body integrally extending from the joint body, and an internal thread continuous with the internal thread provided on the inner surface of the metal tubular body is provided on the inner surface thereof. And

[0007]

As described above, since the internal thread of the synthetic resin body covering the notched step portion of the metal cylinder body is provided with the female thread continuous with the female thread of the metal cylinder body, the male thread provided at the end of the metal pipe is provided on the female thread. When screwed in, the metal pipe and the pipe joint are screwed together. Then, when the metal tube is further screwed in, the diameter of the synthetic resin body having a female thread is expanded, and the outer peripheral surface is pressed against the notched step portion of the metal cylinder body to be sealed.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a heterogeneous pipe joint showing an embodiment of the present invention. In the figure, reference numeral 1 is a synthetic resin joint body made of vinyl chloride resin or the like, 2 is a metal tube made of cast iron, gun metal or the like. It is the body.

The joint body 1 has a receiving port 11 at one end, and the synthetic resin pipe 3 can be fitted into the receiving port 11 for adhesive bonding. A metal cylinder 2 having a tapered female screw 21 is embedded in the inner surface of the other end 12 of the joint body 1. A notched step portion 22 is provided around the inner surface of the end of the tubular body 2, and the notched step portion 22 is covered with a synthetic resin body 121 integrally extending from the joint body 1.

Further, on the inner surface of the synthetic resin body 121, there are provided taper-shaped female threads 21 which are continuous with the female threads 21 provided on the inner surface of the cylindrical body 2, and each of the female threads 21 is attached to the end of the metal tube 4. The provided male screw can be screwed and connected. This pipe joint is integrally manufactured by injection molding, and the outer peripheral surface of the metal tubular body 2 is subjected to an annular groove or knurling to form the joint body 1 and the tubular body 2.
It is possible to enhance the adhesiveness with and the sealing property.

When the synthetic resin pipe 3 and the metal pipe 4 are connected using this dissimilar pipe joint, the synthetic resin pipe 3 is adhesively bonded to the receptacle 11 provided at one end of the joint body 1 and the other end is joined. The ends of the metal tube 4 are screwed together. When connecting the metal tube 4,
When the male screw provided at the end of the metal pipe 4 is screwed into the female screw 21 of the pipe joint, the synthetic resin body 121 having the female screw 21 expands in diameter, and its outer peripheral surface is pressed against the cutout step portion 22 of the metal tubular body 2. Will be sealed. Therefore, even if this dissimilar pipe joint is used for a high-pressure fluid transportation pipe, the pipe fluid does not seep out or leak.

Although a socket joint is illustrated in FIG. 1 showing an embodiment of the present invention, a metal cylinder may be embedded in the inner surface of the end of the joint body made of synthetic resin such as elbow and cheese. Further, the notch step portion 22 may be provided only at one of the end portions on the opening side or the back side of the metal tubular body 2.

[0013]

As described in detail above, according to the present invention, since the internal thread of the synthetic resin body covering the notched step portion of the metal cylinder body is provided with the female thread continuous with the female thread of the metal cylinder body, the metal pipe is attached to the female thread. When the male screw provided at the end portion of the is screwed in, the diameter of the synthetic resin body is expanded, and the outer peripheral surface thereof is pressed against the notched step portion of the metal cylindrical body to be sealed. For this reason, even when the dissimilar pipe fitting of the present invention is used in a high-pressure fluid transportation pipe, the pipe fluid does not exude or leak.

[Brief description of drawings]

FIG. 1 is a sectional view of a heterogeneous pipe joint showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a conventional pipe joint.

[Explanation of symbols]

 1 Synthetic Resin Joint Body 2 Metal Cylindrical Body 21 Female Thread 22 Notch Step 121 Synthetic Resin Body

Claims (1)

[Claims] 1. A heterogeneous pipe joint in which a synthetic resin joint body (1) is embedded with a metal cylinder (2) having an internal thread (21) on the inner surface of the end, the end of the cylinder (2). A notched step portion (22) is provided around the inner surface, and the notched step portion (22) is covered with a synthetic resin body (121) integrally extending from the joint body (1) and a metal cylinder ( A dissimilar pipe joint characterized in that a female screw (21) continuous with the female screw (21) provided on the inner surface of (2) is provided.