JP2000230684A - Joint for soft synthetic resin pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operability at the time of production of a joint for a soft synthetic resin pipe showing high vibration resistance, and keep its connection strength for a long time. SOLUTION: This joint is composed of a connection socket 1, an extended socket 10 and an outer ring 20. Sawtooth connection meshing parts 4, 11 connected to each other are formed on a front of the connection socket 1 and a rear end of the extended socket 10. The extended socket 10 is made of corrosion resistant material, and has a softly tapered outer surface formed with minute unevenness, serving as an escape surface 12. A groove 21 is formed on an inner surface of the outer ring 20 for preventing escaping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a pipe joint having high seismic strength for use in a soft synthetic resin pipe such as a polyethylene pipe for water supply.

[0002]

2. Description of the Related Art In a joint for a soft synthetic resin pipe, a pipe joint which prevents local elongation when a sudden load is applied and has improved seismic strength has already been disclosed by the present inventor in Japanese Patent Application No. 9-27 / 1997.
No. 3951. This pipe joint is a type in which a soft synthetic resin pipe is sandwiched and fixed from inside and outside by a connection socket and an outer ring, and a relief surface with a gentle inclination is formed at the tip of the connection socket. By dispersing, local elongation is eliminated, and the pipe is stretched along its entire length to prevent breakage of the pipe in the event of an earthquake.

[0003]

However, in the above-mentioned conventional pipe joint, fine irregularities are formed on the relief surface of the outer surface to increase the sliding resistance value. When painting is applied, the eyes of these fine irregularities are clogged and the resistance value decreases, it becomes slippery and the stress can not be dispersed,
The intended purpose cannot be achieved. For this reason, after the powder coating, a post-treatment of removing the adhered coating by polishing the relief surface of the tip with sandpaper or the like is required, and there has been a problem that workability during manufacturing is poor. In addition, since the outer ring is press-fitted while squeezing at the time of fitting, the stress due to the stagnation accumulates in the polyethylene pipe at the connection end, and a force in a pulling direction is applied to the outer ring as it tries to return with time, and as time elapses, As a result, the outer ring gradually retreats, and finally the outer ring comes off, and the tightening holding force of the outer ring decreases, resulting in a problem that the pipe connection strength decreases.

SUMMARY OF THE INVENTION In view of the foregoing, an object of the present invention is to provide a pipe joint which does not require post-treatment after powder coating and has good workability in manufacturing. Another object of the present invention is to provide a pipe joint that eliminates the retreating movement of the outer ring with the passage of time and does not reduce the connection strength for a long time.

[0005]

The technical means of the joint for a soft synthetic resin pipe according to the present invention comprises a connecting socket, an extension socket and an outer ring, wherein the extension socket is made of a corrosion-resistant material and has a gently inclined outer surface. Thus, a relief surface having minute irregularities is formed and is connected to the tip of the connection socket.

[0006] A hook-shaped connecting and engaging portion may be formed at the front end of the connection socket and the rear end of the extension socket, and these may be connected to each other for connection. Further, it is preferable to form a groove on the inner surface of the outer ring for preventing the ring from coming off.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the pipe joint of the present invention is described below.
A description will be given based on an embodiment of the drawings. Reference numeral 1 denotes a metal connection socket, which is fixed to an end of one of the tubes to be connected. This tube may be made of synthetic resin or metal,
In addition to the pipe, it may be a connection port for equipment such as a valve,
In addition, it can be used by being integrally assembled with these devices, in which case the connection socket 1 becomes a part of the device.

[0008] On the outer surface of the pipe connection part 2 of the connection socket 1,
Relatively large irregularities 3 are formed to increase sliding resistance. In addition, a hook-shaped connection meshing portion 4 is provided at the tip of the pipe connection portion 2. The connection socket 1 is made of cast iron or the like, and after the completion of the production, powder coating is applied on the whole to prevent rust.

Reference numeral 10 denotes an extension socket, which is provided at its rear end with a connecting meshing portion 11 for connecting the connecting meshing portions 4, 1 and 1.
The extension socket 10 is connected to the tip of the connection socket 1 by press-fitting the connection socket 1. This extension socket 10
The outer surface becomes a relief surface 12, and is gradually reduced in diameter toward the tip with a gentle inclination of about 10 to 30 °. Further, the relief surface 12 is formed with minute irregularities for increasing the sliding resistance. The extension socket 10 is made of a material having corrosion resistance, such as a copper alloy. As a result, powder coating becomes unnecessary, and the fine irregularities are not crushed.

Reference numeral 20 denotes a metal outer ring. A plurality of non-slip grooves 21 are formed in an annular shape on the inner surface of the outer ring 20. The groove 21 is preferably formed near the base of the enlarged diameter portion 22 at the ring end. The groove 21
Is preferably provided in the direction of biting against return.

Next, a method for connecting a pipe joint according to the present invention will be described. First, the extension socket 10 is connected to the tip of the connection socket 1. This is performed by press-fitting both connecting meshing parts 4 and 11. Since the connection meshing portion has a hook shape, once connected, it does not come off and is firmly fixed and held. The powder coating on the connection socket 1 is performed before the extension socket 10 is connected.

As described above, the distal end of the polyethylene pipe A is fitted to the outside of the connection portion 2 of the connection socket 1 to which the extension socket 10 is connected, and then the outer ring 20 is fitted to the outside thereof. Since these fitting operations require a considerable force, they are performed using appropriate tools. By fitting the outer ring 20, the polyethylene tube A is strongly tightened from the outside, and the inner wall of the tube bites into the unevenness 3 of the socket. For this reason, the connection strength is high, and even if a strong tensile force acts, the polyethylene tube does not come off.

Further, the outer surface of the extension socket 10 is a relief surface 12, which has a gentle slope, and has fine irregularities on the surface. Disperse without concentrating on. For this reason, local elongation does not occur, and the polyethylene pipe extends over its entire length, so that breakage of the pipe can be prevented. Further, a groove 21 is formed on the inner surface of the outer ring 20, and the outer surface of the polyethylene pipe A is digged into the groove 21. For this reason, even when the stress accumulated at the distal end of the polyethylene pipe returns over time due to the ironing when the outer ring 20 is fitted, the outer ring 20 does not retreat, and is stably fixed at a predetermined position. Therefore, the connection strength does not decrease.

The pipe joint of the present invention is not limited to the above embodiment, but can be freely modified within the scope of the claims. In particular, the connection method between the connection socket and the extension socket, the material of the extension socket and the shape of the fine irregularities on the outer surface, and the shape of the groove on the inner surface of the outer ring are freely determined.

[0015]

According to the joint for a soft synthetic resin pipe of the present invention, the socket has a two-body structure, and the extension socket may be connected after the powder coating of the connection socket body. No post-treatment is required to remove the adhered paint with sandpaper or the like, and workability during production can be improved.

Since the connection socket and the extension socket are connected to each other by the hook-shaped connection meshing portion, the connection socket can be reliably connected with a simple structure, and the connection operation is performed only by press-fitting. Therefore, on-site connection can be easily performed.

According to the third aspect of the present invention, since the outer surface of the soft synthetic resin pipe has a groove formed on the inner surface of the outer ring, the outer ring can be prevented from retreating with time, and the predetermined connection can be prevented. Strength can be stably maintained over a long period of time.

[Brief description of the drawings]

FIG. 1 is a sectional view of a connection state.

FIG. 2 is an enlarged sectional view of a main part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Connection socket 2 Pipe connection part 3 Irregularity 4 Connection mesh part 10 Extension socket 11 Connection mesh part 12 Relief surface 20 Outer ring 21 Groove

Claims (3)

[Claims] 1. A connection socket, an extension socket, and an outer ring, wherein the extension socket is made of a corrosion-resistant material, a gently inclined outer surface having a relief surface having minute irregularities, and connected to a tip of the connection socket. For flexible synthetic resin pipes. 2. The joint for a flexible synthetic resin pipe according to claim 1, wherein a hook-shaped coupling meshing portion to be connected to each other is formed at a front end of the connection socket and a rear end of the extension socket. 3. The joint for a flexible synthetic resin pipe according to claim 1, wherein a groove is formed on an inner surface of the outer ring to prevent the outer ring from coming off.