JPH04331897A - Pipe incorporating socket and pipe joint - Google Patents

Abstract

PURPOSE:To prevent occurrence of a lash of abrupt leakage by providing check mechanism without hindering the function of a pipe joint part using an adhesive. CONSTITUTION:A heat wire 4 is disposed in a circumferential groove 3 formed in the inner surface of a pipe socket 2, and one end part of the heat wire is led outside of the socket 2 by way of a hole or groove 31 which communicates the above-mentioned circumferential groove with the outside of the socket.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe or a pipe joint with a socket for joining plastic pipes, which is equipped with a retaining mechanism.

0002

[Prior art] When joining plastic pipes, especially vinyl chloride pipes, the pipe socket of a plastic pipe fitting or a pipe socket of a plastic pipe (pipe with a socket) formed by expanding the diameter of one end. Apply adhesive to the tapered inner surface (usually 1/30 to 1/45 taper) and the outer surface of the plastic tube end (tube insertion port), and then insert the plastic tube into the tube socket. In some cases, a so-called cold plug-in joining method is used.

In this joining method, the inner surface of the tube socket and the outer surface of the tube socket are swollen with an adhesive, and these swelling layers (the thickness of the swelling layer is approximately 0.1 mm) are used to attach the tube to the tube socket. As the tube is inserted into the tube, the distal end of the tube outlet is elastically pressed into contact with the inner part of the tube socket, and the gap between the tube socket and the tube outlet is bonded with an adhesive.

0004

[Problem to be Solved by the Invention] If there is poor adhesion in pipe joints made using this cold insertion joining method, the pipe fitting may escape from the pipe socket of the pipe with a socket or the pipe joint, and the water inside the pipe will flow out all at once. Because of this, water leakage accidents occur suddenly, and there is not enough time to deal with the problem, resulting in flooding, and the damage caused is serious.

Even if the above-mentioned adhesion failure occurs, if the tube inlet can be fixed in the tube with a socket or the tube socket of the pipe joint, the above-mentioned elastic contact between the tip of the tube inlet and the back of the tube socket can be maintained. Therefore, water can be stopped to a certain extent, and water leakage can be slowed down, allowing for sufficient time to be able to deal with the problem. During this time, the leakage location can be detected and repaired to prevent serious damage. It can be avoided. Therefore, it is effective to add a so-called slip-off prevention mechanism to the pipe joints formed by the above-mentioned cold insertion joining method.

[0006] Conventionally, it has been necessary to add a retaining mechanism to socket-equipped pipes and pipe fittings that have relatively low pull-out resistance, such as socket-insertion type socket-equipped pipes and pipe fittings that use rubber rings. However, when these retaining mechanisms are incorporated into pipe joints using the cold insertion method described above, elastic pressure contact between the inner part of the pipe socket and the tip of the pipe socket, and the connection between the pipe socket and It is difficult to adhere satisfactorily to the tube inlet, and the performance of the tube joint actually deteriorates.

An object of the present invention is to provide a pipe with a socket or a socket that can prevent water from suddenly leaking all at once by providing a retaining mechanism without impairing the performance of the above-mentioned adhesive-used pipe joints. Our goal is to provide pipe fittings.

[0008]

[Means for Solving the Problems] The pipe or pipe joint with a socket of the present invention has a heating wire housed in a circumferential groove on the inner surface of the pipe socket,
This structure is characterized in that the end of the heating wire is drawn out to the outside through a hole or groove that connects the circumferential groove to the outside of the tube socket.

[0009]

[Operation] After inserting the tube socket into the pipe socket of a pipe with a socket or a pipe fitting, the heating wire is heated by electricity and is heated, and the drawn end of the heating wire is pulled to enter the circumferential groove on the inner surface of the pipe socket. When the heating wire is put under tension, the heating wire bites into the outer circumferential surface of the tube insertion port in a semi-embedded state and exerts a locking action against the tube insertion port being pulled out.

[0010] Furthermore, the tube socket can be inserted into the tube socket while the heating wire is housed in the circumferential groove on the inner surface of the tube socket, thereby preventing adhesion between the pipe socket and the pipe socket. Elastic pressure contact between the inner part and the tip of the tube insertion port can be performed in the same manner as in the conventional cold insertion joining method.

[0011]

[Embodiments] Hereinafter, embodiments of the present invention will be explained with reference to the drawings. FIG. 1(a) is an explanatory diagram (partially cut away side view) showing an embodiment of the pipe joint of the present invention, and FIG.
It is a sectional view of Rollo in a).

In FIG. 1, reference numeral 1 denotes a pipe joint body made of plastic (for example, made of vinyl chloride), and is provided with a pipe socket 2. As shown in FIG. The inner surface 21 of this tube socket 2 is 1/30 to 1/4
5 tapered surface. 3 is a circumferential groove provided on the inner surface 21 of the tube socket, and 31 is a hole through which the circumferential groove 3 is led out to the outside of the tube socket 2. Reference numeral 4 denotes a heating wire housed in the circumferential groove 3, and in the illustrated embodiment, an insulated resistance wire is used. Both ends 41, 41 of the heating wire 4 are drawn out to the outside of the tube socket 2 through the hole 31.

FIG. 2 is a partially cutaway side view of a main part of a pipe with a socket according to another embodiment. In FIG. 2, 1a is a tube body with a socket, and a tube socket 2a is formed by expanding the diameter of one end of a plastic pipe (for example, a vinyl chloride pipe). In the pipe socket 2a of the pipe main body 1a with a socket, the taper of the inner surface 21a is the same as the inner surface 21 of the pipe socket 2, and the circumferential groove 3
, a hole 31 that guides this circumferential groove 3 to the outside of the pipe socket 2a.
The configuration of the heating wire 4 accommodated in the circumferential groove 3 is substantially the same as the configuration of the pipe socket 2 of the pipe joint body 1, so a detailed explanation will be omitted and the same figure as FIG. 1 will be omitted. It is indicated by the number.

The pipe with a socket and the pipe fitting of the present invention are used for joining plastic pipes, and since there is no difference in the joining method between the pipe with a socket and the pipe joint, the method shown in FIG. Taking as an example a case where a pipe fitting 1 is used, the joining procedure will be explained with reference to FIGS. 3A to 3C.

In FIG. 3, A represents the pipe joint of the present invention, and B represents the pipe joint of the present invention.
indicates the tube inlet. To join plastic pipes using the pipe joint A of the present invention, first, (
As shown in a), adhesive 5 is applied to the inner surface 21 of the tube socket 2 of the pipe joint A and the outer surface of the tube socket B of the plastic pipe, and the tube socket B is inserted into the tube socket 2.

In this case, the heating wire 4 is housed in the circumferential groove 3 on the inner surface 21 of the tube socket, and there is no problem with its insertion, and the inner surface 21 of the tube socket has a tapered surface. Since the inner surface 21 of the tube socket and the outer surface of the tube socket B are swollen by the adhesive 5, the insertion can be easily performed. By this insertion, the space between the tube socket 2 and the tube socket B is bonded with the adhesive 5, and the tip of the tube socket B is elastically moved toward the back of the tube socket 2, as shown in FIG. pipe socket 2.
The gap between and the tube insertion port B is filled with adhesive 5.

Next, after waiting for the adhesive 5 to dry, the heating wire 4 is energized from the drawn-out ends 41, 41 to generate heat, and the temperature of the heating wire 4 is heated to the thermal softening temperature of the tube insertion port B. Pull both ends 41, 41 of the heating wire 4, and
As shown in FIG.
is put into a tensioned state, and the heating wire 4 is partially embedded in the outer peripheral surface of the tube insertion port B, and the outer peripheral portions b, b on both sides of the heating wire 4 are raised (see FIG. 4).

After that, the power to the heating wire 4 is cut off, the lead-out ends 41, 41 of the heating wire 4 are cut off, and the heating wire half-embedded in the outer surface of the tube insertion opening is cooled after the power is cut off. 4 is fixed to the tube inlet B, the raised tube inlet outer circumferential portion b is solidified, and these heating wires 4 and the tube inlet outer circumferential portion b have a locking action against the tube inlet B being pulled out. This completes the pipe joining work.

The heating wire 4 may be energized before the adhesive between the tube socket 2 and the tube socket B dries. In the above, the heating wire 4 must have high electrical resistance and excellent tensile strength; for example, nichrome, iron chromium, pneumatic, etc. are used. The diameter of the heating wire is preferably 1/4 to 1/5 of the thickness of the pipe to be connected.

As shown in FIG. 5(A), the heating wire ends 41, 41 are drawn out by diagonally intersecting holes 31, 31.
Alternatively, as shown in FIG.
You can also use

The length of the circumferential groove 3 on the inner surface 2 of the tube socket does not necessarily have to be the entire circumference, but a length of ⅓ or more is sufficient. For example, as shown in FIG. Alternatively, it can be half-circular, and in this case, there is no cross-contact of the heating wire 4, so a bare resistance wire piece can be used as the heating wire 4.

One end of the heating wire 4 may be fixed to the tube socket 2, and only the other end may be drawn out of the tube socket 2 through a hole or groove. The position of the circumferential groove 3 on the inner surface 2 of the tube socket is such that even if the amount of tube insertion is insufficient, the above-mentioned locking effect can be achieved by the heating wire 4 biting into the outer surface of the tube socket B. It is preferable to provide it considerably nearer than the rear end of 2.

[0023] The number of the circumferential grooves is plural, a heating wire is housed in each circumferential groove, and the end of each heating wire is drawn out through a hole or groove that connects each circumferential groove with the outside of the pipe socket. Good too. In this case, it is also possible to provide a plurality of half-circumferential grooves as shown in FIG.

The depth of the circumferential groove 3 is set to a depth that accommodates the heating wire 4 and does not interfere with the insertion when the tube insertion port B is inserted into the tube socket 2. It is preferable to make the depth slightly deeper than the diameter of.

[0025] Also, the heating wire 4 is lightly adhesively fixed in the circumferential groove 3 (adhesive strength is such that it can be peeled off by the above-mentioned tension).
It is also possible to embed and fix the heating wire 4 in the circumferential groove 3 using a resin whose softening temperature is lower than the heating temperature of the heating wire 4.

[0026] For the pipe joint main body 1, the pipe main body 1a with a socket, and the plastic pipes to be joined, use plastics that have excellent adhesive properties and can be easily softened by heating with the heating wire, especially for the plastic pipes to be joined. Vinyl chloride is preferred, but it is also possible to use poorly adhesive plastics, such as polyethylene, for the above-mentioned locking effect.

The pipe joint of the present invention can be applied to any type of joint as long as it is a plastic pipe joint that has a pipe socket.For example, it can be applied to sockets, elbows, cheeses, reducers, etc. can.

[0028]

[Effects of the Invention] The pipe and pipe fitting with a socket of the present invention have the above-mentioned configuration, and are installed without any heating wire protruding from the inner surface of the pipe socket, so the pipe socket can be inserted into the pipe socket. It can be inserted smoothly under the application of adhesive, and the performance of the cold insertion bonding method can be well maintained. In addition, since both ends of the heating wire are pulled out of the tube socket, after the tube insertion port is inserted, the heating wire is heated with electricity to be pulled, and the heating wire is inserted into the outside surface of the tube socket in a semi-embedded state. , a locking mechanism can be easily provided. Therefore, the performance of the cold insertion joining method can be well maintained, and a slip-off prevention mechanism can be provided to the adhesively joined portion of the plastic pipe.

[0029] Furthermore, since the pulling force can be borne by both adhesion and locking, difficult-to-adhesive plastic pipes,
For example, even polyethylene pipes can be joined with sufficient reliability.

[0030] Even if there is poor adhesion at the adhesive joint of the plastic pipe, it is possible to prevent the pipe inlet from escaping from the pipe socket, thereby avoiding sudden water leakage accidents and allowing sufficient time. It is possible to repair the water leakage point and prevent serious damage such as flooding inside the building.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view (a) of a pipe joint showing an embodiment of the present invention, and a cross-sectional view (b) of the pipe joint in (b).
.

FIG. 2 is a partially cutaway side view of a main part of a pipe with a socket showing another embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a procedure for connecting plastic pipes using the pipe joint of the present invention.

FIG. 4 is a sectional view showing a locking structure of a plastic pipe joint using the pipe joint of the present invention.

FIG. 5 is an explanatory view showing each example of a pull-out hole or groove at the end of the heating wire in the pipe joint of the present invention.

[Explanation of symbols]

1 Pipe fitting body 1a　　　Pipe body with socket 2, 2a pipe socket 3 Circumferential groove 31 Hole or groove ４　　　　　　Heating wire

Claims (1)

[Claims] Claim 1: A heating wire is housed in a circumferential groove on the inner surface of the pipe socket, and an end of the heating wire is drawn out through a hole or groove that connects the circumferential groove to the outside of the pipe socket. A pipe or pipe fitting with a socket.