JPH0532705Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to an improvement of the anti-corrosion core that seals the end of the lined steel pipe in the joint of resin-lined steel pipes used as water supply piping. be.

(Prior Art) For example, in a joint portion of a steel pipe with an internal resin lining, a pipe end anti-corrosion core is fitted to prevent metal from being exposed at the pipe end.

There are two types of joints using this pipe end anti-corrosion core: those with a structure in which the joint and the anti-corrosion core are separated, and those with a structure in which the anti-corrosion core is integrated into the joint. The target is the pipe end anti-corrosion core.

Pipe fittings to which this type of pipe end anti-corrosion core is applied are
As shown in the figure, it is composed of a joint main body 1 and a resin pipe end anti-corrosion core 3 that is inserted into the pipe end opening of an inner lining steel pipe 2 connected to the joint main body 1. The joint body 1 is provided with a tapered female thread 4 from its end, and is provided with a female thread 5 made of a resin material that is continuous with the tapered female thread 4 inside, while the pipe end anti-corrosion core 3 has the tapered female thread 4 on its outer periphery. 4 and a flange 7 having an annular wall surface 13 that contacts the end surface of the inner lining steel pipe 2, and a body 8 having a seal structure that is inserted into the inner lining steel pipe 2. .

In use, first, the body part 8 of the pipe end anticorrosive core 3 is inserted into the pipe end opening of the inner lining steel pipe 2, and the annular wall surface 13 is brought into contact with the pipe end of the steel pipe 2.
Next, the tapered male thread 9 provided on the outer periphery of the pipe end of the inner lining steel pipe 2 and the male thread 6 of the pipe end anti-corrosion core 3 are screwed into the tapered female thread 4 of the joint body 1, and then the male thread 6 of the pipe end anti-corrosion core 3 is screwed into the tapered female thread 4 of the joint body 1. By fitting and connecting to the female thread 5 portion of the joint body 1, the tube end of the inner lining steel pipe 2 and a part of the tapered female thread 4 of the joint body 1 are sealed and prevented from being exposed to running water.

(Problem to be solved by the invention) The conventional anti-corrosion core described above fully exhibits its original purpose of anti-corrosion, but it is easy to forget to attach the anti-corrosion core at the pipe installation site. However, after the pipe connection is completed, it is impossible to confirm its existence from the outside without using a super insulation meter or an ultrasonic flaw detector. However, the use of these special devices requires skill on the part of the operator and high costs, making them difficult to put to practical use.

The present invention was devised to solve this problem, and it is possible to visually identify the presence or absence of a pipe end anticorrosive core without changing the pipe construction method at all. The purpose is to obtain a pipe end corrosion protection core that can be embodied externally with physical evidence.

(Means for Solving the Problems) In order to achieve the above object, the pipe end anti-corrosion core of the present invention has its body inserted into the pipe end opening of the lined steel pipe, and is attached to the fitting body together with the lined steel pipe. A pipe end anti-corrosion core made of resin that is screwed into a tapered female thread of the pipe, comprising a body part to be fitted into the inner circumferential surface of a lining steel pipe, and a collar part having an annular wall surface that comes into contact with the end face of the steel pipe, A male thread is formed on the outer circumferential surface of the flange to be screwed into a tapered female thread provided on the joint body, and the body near the flange includes an inner ring that fits onto the body and is connected to the inner ring. An outer ring having a slightly larger diameter than the tip threaded portion of the tapered male thread provided at the end of the lining steel pipe is attached.

(Function) If the pipe end anti-corrosion core configured as described above is applied, when it is screwed into the joint body together with the lining steel pipe, the thin film supporting the outer ring or the connecting small struts will be affected by the screw's screw movement. Therefore, in a joint with an external resin coating, it is cut by the tensile force when the tube is inserted, and the outer ring is present on the male thread of the lining steel tube or on the outer diameter of the tube, demonstrating the attachment of the anticorrosion core.

Further, the inner ring remains between the annular wall surface of the tube end anticorrosion core and the end surface of the lining steel pipe, and is crimped into the gap between them to exert the anticorrosion effect.

(Example) An example of the present invention will be described below based on FIGS. 1 to 3 showing an example.

That is, the tube end anticorrosion core 3 is integrally molded from a resin material, and includes a flange portion 7 having a male thread 6 as described above, and an inner lining steel tube 2 or a flange portion 7 as shown in FIG. As shown in FIG. 3, it is comprised of a body part 8 having a sealing structure that is inserted into the end opening of the inner and outer lining steel pipe 2'.

Reference numeral 10 denotes an inner ring fitted over the body 8 near the tsubabu 7, and an outer ring 12 is attached to the outside of the inner ring 10 via, for example, a small connecting post 11.
is integrally molded. The diameter of this outer ring 12 is determined to be slightly larger than the tip threaded portion of the tapered male thread 9 at the end of the inner lining steel pipe 2 and the inner and outer lining steel pipe 2'.

Incidentally, the installation procedure for the pipe end anti-corrosion core 3 of the present invention is similar to the conventional one. First, the inner ring 10, which has been integrally formed with the outer ring 12, is attached to the pipe end opening of the inner lining steel pipe 2. The body part 8 of the pipe end anti-corrosion core 3, which has been externally fitted from the part 8 side and brought into contact with the annular wall surface 13, is inserted and fitted to bring the annular wall surface 13 into contact with the pipe end of the inner lining steel pipe 2, and then The tapered male thread 9 provided on the outer periphery of the pipe end of the inner lining steel pipe 2 and the male thread 6 of the pipe end anti-corrosion core 3 are screwed into the tapered female thread 4 of the joint body 1, and the male thread 6 of the pipe end anti-corrosion core 3 is screwed into the joint. It is connected by fitting into the internal thread 5 at the back of the main body 1, and when the end of the inner lining steel pipe 2 starts to come into contact with the end surface of the joint main body 1, the connecting small A cutting force due to the screw threading begins to act on the strut 11, and the outer ring 12 is finally completely separated and remains on the outer diameter of the inner lining steel pipe 2 or at the cut-up portion of its tapered male thread 9 when the pipe connection is completed.

On the other hand, the inner ring 10 remains between the annular wall surface 13, which is the connection surface between the collar portion 7 and the body portion 8, and the end surface of the inner lining steel pipe 2.

In addition, the outer surface as shown in Fig. 3 is also coated with resin.
4, if the connecting small struts 11 are made easier to cut, when inserting the inner and outer lining steel pipes 2' into the outer resin coating 14, for example,
The inner ring 10 is restrained between the annular wall surface 13 of the pipe end anticorrosion core 3 and the tips of the inner and outer lining steel pipes 2',
In addition, the outer ring 12 has inner and outer lining steel pipes 2'.
Since the diameter is slightly larger than the tip thread of the tapered male thread, the end surface of the outer resin coating 14 allows the inner ring 1 to be
0 and is prevented from being inserted into the outer resin coating 14, the connecting small struts 11 are cut by the tensile force that acts when the inner and outer lining steel pipes 2' are inserted, and the outer ring 12 and the inner ring 10 are separated. Even when the pipes are separated and the pipe connection is completed, the outer ring 12 remains on the outer diameter portion of the inner and outer lining steel pipes 2'.

The inner ring 10, the outer ring 12, and the small connecting struts 11 may be made of extensible rubber, or may be made of synthetic resin or the like. Furthermore, in the case of a material that does not have extensibility, the inner ring 10 and the outer ring 12 may be partially cut out.

(Effects of the invention) The present invention is constructed as described above, and when the lining steel pipe connection is completed, the outer ring is inevitably left outside as physical evidence indicating that the pipe end anti-corrosion core has been attached. This allows visual confirmation and does not require any special inspection.

Furthermore, since the inner ring remains between the annular wall surface and the lining steel pipe, it exhibits a corrosion-preventing effect.

[Brief explanation of the drawing]

Fig. 1A is a partially sectional front view of an embodiment of the present invention, B is a side view thereof, and Figs. 2 and 3 show a pipe connection joint structure using the pipe end anti-corrosion core of the present invention. The sectional view shown in FIG. 4 is similar to FIG. 2 using a conventional pipe end anticorrosion core. 3 is a pipe end anticorrosion core, 6 is a male thread, 10 is an inner ring, 11 is a connecting small strut, and 12 is an outer ring.

Claims (1)

[Scope of utility model registration request] A pipe end corrosion-protective core made of resin whose body is inserted into the opening at the end of the lining steel pipe, and is attached together with the lining steel pipe to the tapered female thread of the joint body, and which is attached to the inner circumferential surface of the lining steel pipe. a body portion to be fitted into the pipe; and a collar portion having an annular wall surface that abuts the end surface of the steel pipe, and a male thread is formed on the outer peripheral surface of the collar portion to be screwed into a tapered female thread provided on the joint body, and The body near the section has an inner ring that fits onto the body, and an outer ring that is connected to the inner ring and has a slightly larger diameter than the threaded end of the tapered male thread provided at the end of the lining steel pipe. A pipe end anti-corrosion core that is characterized by being equipped with it.