JP3556115B2 - Joint for soft synthetic resin pipe and connection method thereof - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint having high seismic strength used for a soft synthetic resin pipe such as a polyethylene pipe for water supply , and a method of connecting the pipe joint to the soft synthetic resin pipe.
[0002]
[Prior 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 proposed by the present inventors as Japanese Patent Application No. 9-273951. . 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 gently inclined relief surface is formed at the distal end of the connection socket. By dispersing, local elongation is eliminated, and the pipe is stretched over its entire length to prevent the pipe from breaking during an earthquake.
[0003]
[Problems to be solved by the invention]
However, in the conventional pipe joint, minute relief for increasing the slip resistance value is formed on the relief surface of the outer surface. The eyes are clogged, the resistance value is reduced, the slip is easy, the stress cannot be dispersed, and the intended purpose cannot be achieved. For this reason, after the powder coating, a post-treatment is required to remove the adhered coating by polishing the relief surface of the tip with sandpaper or the like, 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 over time, and as time passes. Therefore, there is a problem that the outer ring gradually retreats and finally the outer ring comes off, or the tightening holding force of the outer ring is reduced, thereby lowering the pipe connection strength.
[0004]
In view of the foregoing, the present invention provides a pipe joint that does not require post-treatment after powder coating and has good manufacturing workability , and a method for connecting the pipe joint to a soft synthetic resin pipe .
[0005]
[Means for Solving the Problems]
The technical means of the joint for a soft synthetic resin pipe of the present invention comprises a connection socket, an extension socket connected to the tip of the connection socket, and an outer ring for tightening the soft synthetic resin pipe fitted into the connection socket. The present invention is characterized in that the extension socket is provided with a relief surface having fine irregularities, and the minute irregularities are not coated with the powder .
[0006]
The technical means of the connection method of the present invention is a connection socket, an extension socket having a relief surface having minute irregularities, and a method of connecting a pipe joint having an outer ring and a soft synthetic resin pipe to the connection socket. After powder coating, the extension socket is connected to the connection socket, the tip of the soft synthetic resin tube is fitted into the connection portion of the connection socket to which the extension socket is connected, and the outer ring is fitted, so that the connection between the extension socket and the connection socket is established. It is characterized in that the synthetic resin tube is tightened .
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the pipe joint of the present invention will be described based on an example in the drawings. Reference numeral 1 denotes a metal connection socket, which is fixed to an end of one of the tubes to be connected. In addition, this pipe may be made of synthetic resin or metal, and in addition to the pipe, it may be a connection port of equipment such as a valve, and furthermore, it can be used by being integrally assembled with these equipment. In that case, the connection socket 1 becomes a part of the device.
[0008]
On the outer surface of the pipe connection portion 2 of the connection socket 1, relatively large irregularities 3 are formed to increase the sliding resistance. Further, a hook-shaped coupling meshing portion 4 is provided at the tip of the pipe connecting portion 2. The connection socket 1 is made of cast iron or the like, and after completion of the production, powder coating is applied entirely for rust prevention.
[0009]
Reference numeral 10 denotes an extension socket, which is provided with a connection meshing portion 11 at the rear end. The connection meshing portions 4 and 11 are press-fitted to connect the extension socket 10 to the tip of the connection socket 1. Since the outer surface of the extension socket 10 becomes the relief surface 12, the diameter of the extension socket 10 is reduced 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.
[0010]
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 root of the enlarged diameter portion 22 at the end of the ring. It is preferable that the groove 21 is provided in a direction in which the groove 21 bites against the return.
[0011]
Next, the connection method of the pipe joint of 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 mesh portions 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.
[0012]
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 an appropriate tool. 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 the polyethylene pipe does not come off even if a strong tensile force acts.
[0013]
In addition, since the outer surface of the extension socket 10 is a relief surface 12, the slope is gentle, and the surface has minute irregularities, so that stress is concentrated at one place even when it is subjected to sudden tension. Without dispersing. 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 buried therein. For this reason, even if the stress accumulated at the distal end of the polyethylene pipe returns with the lapse of time due to the ironing when the outer ring 20 is fitted, the outer ring 20 does not move backward and is stably fixed and held at a predetermined position. Therefore, the connection strength is not reduced.
[0014]
The pipe joint of the present invention is not limited to the above embodiment, and can be freely modified and implemented 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 minute irregularities on the outer surface, and the shape of the groove on the inner surface of the outer ring are freely determined.
[0015]
【The invention's effect】
The joint for a flexible synthetic resin pipe of the present invention has a two-piece structure in which the socket is provided with a powder-coated connection socket and a relief surface having minute irregularities, and the surface is provided with an extension socket that is not powder-coated. This is to connect the extension socket after applying powder coating to the connection socket.This eliminates the need for post-treatment to remove the paint adhering to the release surface with sandpaper etc. as in the conventional product, Workability can be improved.
[0016]
The connection method of the present invention is a method of connecting a connection socket, an extension socket provided with a relief surface having minute irregularities, a pipe joint provided with an outer ring, and a soft synthetic resin pipe, after powder coating on the connection socket. The extension socket is connected to the connection socket, the tip of the soft synthetic resin pipe is fitted into the connection portion of the connection socket to which the extension socket is connected, and the outer ring is fitted, so that the synthetic resin pipe is connected to the connection socket. Since it is tightened, workability during manufacturing is good and connection strength is high.
[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 (2)

It consists of a connection socket , an extension socket connected to the end of the connection socket, and an outer ring for tightening a soft synthetic resin tube fitted into the connection socket.The connection socket is powder-coated, and the extension socket has fine irregularities. A joint for a flexible synthetic resin pipe , characterized in that the joint has a relief surface and the fine irregularities are not powder-coated . A connection socket, an extension socket having a relief surface having minute irregularities, and a method of connecting a pipe joint having an outer ring to a soft synthetic resin pipe, wherein after the powder coating on the connection socket, the extension socket is attached to the connection socket. The connection is characterized in that the end of the soft synthetic resin pipe is fitted into the connection part of the connection socket to which the extension socket is connected, and the outer ring is fitted, thereby tightening the synthetic resin pipe with the connection socket. Method.

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