JPH0433517Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to the structure of a pipe end joint provided with anti-corrosion means, and particularly relates to an improvement of a built-in anti-corrosion pipe end joint.

(Prior art) Figures 2a and 2b show examples of commonly used joints that are equipped with a type of anti-corrosion core 2 built into the joint body 1. The lip portion 2a of the end anti-corrosion core 2 is connected to the joint body 1.
The structure is such that it is located inside the end surface 4 of the female thread 3. In addition, in FIG. 2, 5 is a tube screwed into the joint main body 1 having the above-mentioned tube end anticorrosive core 2 installed therein, and 9 is a sealant.

(Problem to be solved by the invention) In the above-mentioned conventional pipe end anti-corrosion joint, the lip part of the pipe end anti-corrosion core exists inside the end face of the female thread of the joint body when it is installed. The inner diameter is small or there is distortion,
Furthermore, due to factors such as eccentricity of the pipe end anti-corrosion core, the tip of the lip portion 2a of the pipe end anti-corrosion core 2 may come into contact with the end surface of the pipe 5 during piping construction, as shown in FIGS. 3a and 3b. As the pipe 5 spirals, the lip portion 2a is compressed and deformed, resulting in a so-called crushed state (Fig. 3a), or in extreme cases, a state in which it hangs down into the internal water passage space (Fig. 3). b), which may lead to the formation of red water or a situation where water cannot pass. Moreover, the piping installer has no way of checking whether or not the above-mentioned crushing deformation has occurred, and there is a problem in that the piping is left as is, assuming that the piping has been properly constructed.

By the way, the factors that cause this phenomenon of crushing of the lip part include variations in the inner diameter of the pipe, diameter reduction due to external force during thread cutting at the piping construction site, burr deformation of the cut end of the pipe due to poor cutting of the pipe, and deformation of the resin after injection molding. There are many examples such as eccentricity of the core due to cooling sink. In order to prevent this crushing, reducing the outer diameter of the lip may be a temporary measure, but if this method is adopted, the head loss will be reduced by reducing the inner diameter. This is undesirable because it is accompanied by significant quality defects such as expansion, freezing deformation accidents due to gaps between the pipe and the lip, and generation of red water.

The present invention was developed to solve the above-mentioned problems, and it accurately prevents crushing without reducing the outer diameter of the lip part, allowing the anti-corrosion joint to perform its original function. The purpose is to provide a joint that makes it possible to

(Means for Solving the Problems) The pipe end anti-corrosion joint according to the present invention has a lip portion of the pipe end anti-corrosion core provided inside the joint to a length that protrudes from the female threaded end surface of the joint body when it is installed. At the same time, the end of the joint body is formed into a protective sleeve having an inner diameter larger than the outer diameter of the male threaded part of the tube end screwed into the joint body and protruding from the lip part.

(Function) The present invention forms the lip portion of the pipe end anti-corrosion core provided inside the joint to a length that projects from the female threaded end surface of the joint body when it is installed, and
Since the end of the fitting body is constructed as a protective sleeve to prevent the lip from being deformed by external force, the lip protrudes further from the female threaded end surface of the fitting body, and therefore the piping In this case, the normal screwing operation cannot be performed unless the lip portion of the core is first accommodated in the pipe, and the fear of crushing the core is inevitably eliminated. In addition, the lip part is protected from deformation due to external force due to the protective sleeve.
Damage is prevented.

(Example) The present invention will be explained below based on the example shown in FIGS. 1a to 1c.

That is, in the first embodiment shown in FIG. 1a, the pipe end anticorrosion core 2 is connected by screwing to the end of the lining resin molded part 6 that is joined to the inner inner wall of the inner part except for the three female threads provided at the end of the joint body 1. However, at the time of connection, the lip portion 2a of the pipe end anticorrosive core 2 is made to protrude longer than the end surface 4 of the female thread 3 of the joint body 1 by a length l, and a protective sleeve 7 is further formed at the tip of the joint body 1. ing. The protective sleeve 7 has an inner diameter larger than the outer diameter of the male threaded portion of the tube end, and maintains enough space to prevent damage to the male threaded portion of the tube end when the tube end is screwed into the joint body 1. is also outstanding.
The purpose of forming the protective sleeve 7 is to prevent damage to the tube end anti-corrosion core 2 due to external force during transportation and carrying.

In addition, in the second embodiment shown in FIG. 1b, the pipe end anti-corrosion core 2 is molded integrally with the lining resin molded part 6, and the tip of the joint body 1 is provided with a protection integral with the joint body 1. 7 parts of the sleeve. Furthermore, the third embodiment shown in FIG. 1c shows an application of the present invention to a joint whose main body is, for example, a bronze valve. They are screwed together. The protective sleeve 7 has an outer diameter larger than the outer diameter of the joint body 1 to keep the inner diameter of the sleeve 7 large, thereby increasing the gap between the sleeve end and the pipe end to which the joint is screwed. The fit is loose.

In each of the above embodiments, the tip of the protective sleeve 7 is made to protrude slightly from the tip of the lip portion 2a, and the length of the protrusion of the lip portion 2a from the end surface 4 of the female thread 3 of the joint body 1 is determined by the ease of pipe insertion. From the test results, it was confirmed that around 10 mm is the most appropriate.
However, the above-mentioned protrusion length may be selected and determined as appropriate and is not limited in any way.

In addition, in the embodiments of the present invention, pipe joints were mainly described, but the same applies to valves, water faucets, etc. In other words, as long as the core exists inside the internal thread of the main body, It goes without saying that any of these methods can be applied, and the desired objectives and effects will be achieved.

(Effects of the invention) The present invention forms the lip part of the pipe end anticorrosion core provided inside the joint to a length that protrudes from the female threaded end surface of the joint body when it is installed, and
It has a structure in which a protective sleeve is formed at the end of the joint body to prevent the lip from deforming due to external force. is provided at the end of the joint body, so when connecting the pipe by screwing it, it can be done reliably without crushing the lip of the pipe end anti-corrosion core, so the function as an anti-corrosion joint is not impaired. Not at all. Furthermore, damage to the pipe end anti-corrosion core during transport and handling of the joint can be completely prevented.

[Brief explanation of the drawing]

FIGS. 1a to 1c are cross-sectional views showing embodiments of the present invention,
FIGS. 2a and 2b are sectional views showing a conventional joint structure, and FIGS. 3a and 3b are sectional views showing a core crushed state in a conventional joint. 1 is a joint body, 2 is a tube end anticorrosive core, 2a is a lip portion, 3 is a female thread, 4 is an end face of the female thread 3, and 7 is a protective sleeve.

Claims (1)

[Scope of utility model registration request] The lip part of the pipe end anti-corrosion core provided inside the joint is formed to a length that protrudes from the female threaded end surface of the joint body when it is installed, and the end of the joint body is formed with a male thread on the pipe end that is screwed into the joint body. A pipe end anti-corrosion joint characterized by a protective sleeve having an inner diameter larger than the outer diameter of the lip and protruding from the lip.