JP2572808Y2 - Anticorrosion pipe fittings - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrosion-resistant pipe joint, and more particularly to a seal structure for a corrosion-resistant pipe joint in which the inner surface of a joint body is covered with a synthetic resin body.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a main part of a conventional anticorrosion pipe joint. The anticorrosion pipe joint is the end of the metal joint body 2
A female screw 1 is formed on the inner surface of the body, and the inner surface of the main body except for the female screw 1 is covered with a synthetic resin body 3 .
A core part 5 is protruded from the end, and the core part 5 and the female screw
1 to form a gap for receiving the end of the connecting pipe 4
It was done. The anticorrosion pipe joint is formed so that the lining layer 4a on the inner surface of the pipe 4 is brought into contact with the core section 5 so as to prevent the fluid flowing inside from coming into contact with the pipe end face or the screw section.

However, due to variations in the diameters of the threaded portions of the joint body 2 and the pipe 4, the two cannot be sufficiently fitted,
The contact between the lining layer 4a and the core part 5 becomes incomplete,
In some cases, the fluid penetrated into the female screw 1 and corroded the joint body 2 and the pipe 4.

For this reason, conventionally, a sealant has been applied to the outer periphery of the core portion 5 (Japanese Patent Laid-Open No. Sho 60-231090), or a water-expandable rubber ring has been loaded (Japanese Utility Model Application Laid-Open No. 62-10).
No. 2085), the gap between the core portion 5 and the female screw 1
The sealing property has been improved by, for example, mounting and filling a foamed elastic body in which bubbles communicate with each other (Japanese Utility Model Laid-Open No. 1-146085).

[0005]

On the other hand, Japanese Industrial Standards (JIS) specify the range of variation in screw fitting in the above-described anticorrosion pipe joints and inner surface coated steel pipes according to the pipe diameter. For example, in the case of the size 15A, a variation of 8.2 mm is allowed at the tip of the tube. Furthermore, since the external thread on the pipe side is often installed with a threading machine at the piping site, the thread outer diameter generally varies depending on the setting state of the blade of the threading machine, etc.
Taking into account the tolerance of the screw at the actual piping site and the variation in the number of tightening ridges after manual tightening, it is necessary to cope with the above variation width of 8.2 mm or more. In some cases, performance could not be obtained.

Accordingly, an object of the present invention is to provide an anticorrosion pipe joint which can obtain a sufficient sealing performance even when the position of the pipe tip varies greatly.

[0007]

In order to achieve the above-mentioned object, the anticorrosion pipe joint according to the present invention comprises an end portion of a metal joint body.
A female screw is formed on the inner surface, the inner surface of the main body excluding the female screw is covered with a synthetic resin body , and a core is attached to an end of the synthetic resin body.
Projecting a portion to form a gap between the core portion and the female thread for receiving an end of a connecting pipe, and inside the gap.
In the anticorrosion pipe joint filled with an elastic foam , the foam
The non-foamed liquid agent injected into the gap is foam-hardened
Having closed closed cells, and the core portion
The ring body, which is slidably fitted in close contact with the outer peripheral surface of the
It is characterized in that it is disposed outside the foamed elastic body . In addition, the foamed elastic material has a 2 to 10 times expansion at room temperature.
It is preferable to use a foam-curable polysiloxane composition.
You.

[0008]

[Operation] According to the above configuration, the foamed elastic body is in contact with the core portion.
The unfoamed liquid agent injected into the gap between
It has closed cells that have been
It is filled without gaps and adheres tightly to the core and female thread.
Since the end of the tube to be connected abuts against the foamed elastic body,
Sealability from the tip of the pipe to the internal thread is improved
Connection, and even if the tip of the connecting pipe varies,
Since the foamed elastic body is pressed at the tip of the pipe to be compressed, sufficient sealing performance can be obtained due to the large compressive deformation rate of the foamed elastic body. Further, since the cells are closed cells, the fluid does not penetrate through the elastic body even when the fluid comes into contact with the foamed elastic body. In addition, since the ring body, which is slidably fitted in close contact with the outer peripheral surface of the core portion, is disposed on the outer side of the foamed elastic body, when the pipe connected to the joint body is screwed into the female thread. Thus, it is possible to reliably prevent the foamed elastic body from protruding from between the core portion and the lining layer on the inner surface of the pipe connected to the joint body.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a straight pipe type anticorrosion pipe joint, and FIG.
Is a cross-sectional view illustrating a main portion thereof, Fig. 3 is a schematic diagram of an apparatus for filling a foamed elastic body material.

[0010] The main body of the anticorrosion pipe joint is made of gold as in the prior art.
Female threads 11 are formed on inner surfaces of both ends of a metal joint body 12
The inner surface of the main body excluding the female screw 11 is covered with a synthetic resin body 13 and a cylindrical core is attached to an end of the synthetic resin body 13.
A gap is formed between the core section 15 and the internal thread 11 so as to receive the end of the pipe 14 to be connected.

The joint body 12 is a metal joint defined by Japanese Industrial Standards. The synthetic resin body 13 is made of hard vinyl chloride, polyethylene, polybutene, nylon, ABS resin, polycarbonate, or other thermoplastic resin.
The synthetic resin body 13 can be prepared by a known method, for example,
As described in JP-A-129225 and the like, it is molded together with the core part 15 by injection molding.

The core 15 and the female screw 11
Inside the gap between the foamed elastic body 1 having closed cells
6 are filled. This foamed elastic body 16 is formed as described later.
In addition, the unfoamed liquid agent injected into the gap is foamed and cured.
Having closed cells. Further, as the foamed elastic body 16 having the closed cells, for example, it is preferable to use a polysiloxane composition which foams and cures at room temperature.

If necessary, fillers or reinforcements such as zinc oxide, magnesium oxide, calcium carbonate, fumed silica, precipitated silica, titanium dioxide, aluminum oxide, quartz powder, talc, bentonite, asbestos, glass fiber, etc. An agent can also be compounded. Furthermore, by blending a water-absorbing polymer, when water infiltrates due to water flow after pipe connection, the water-absorbing polymer absorbs water and expands, thereby closing gaps and more reliably stopping water. Further, by adding a rust preventive, rust prevention of the joint body can be achieved.

The foamed elastic body having closed cells obtained from the above composition is excellent in heat resistance, cold resistance, water resistance, weather resistance, compression restorability, and extremely high in safety to the human body. Furthermore, the foamed elastic body is a sponge-like cured product having extremely high foam-regulating properties and composed of fine and uniform independent cells.

The filling amount of the foamed elastic body 16 filled in the gap between the core portion 15 and the internal thread 11 is such that the tip of the tube 14 is the foamed elastic body 1 even with the minimum fitting amount in the variation width.
6 is set. In this filling amount, the foaming elastic body 16 has a foaming ratio of 2 to room temperature at room temperature so that the foamed elastic body 16 does not protrude from between the core portion 15 and the lining layer 14a on the inner surface of the pipe 14 even at the maximum fitting amount. 1
It is preferable to use a polysiloxane composition of about 0 times.

Further, as shown in FIG. 2, the outer core portion 15
A ring body 17 made of vinyl chloride, polyethylene, rubber, or the like, which is slidably fitted in close contact with the peripheral surface, is made of foam elastic.
It is arranged outside the body 16. Ring body like this
When the tube 17 is arranged, when the tube 14 is screwed into the female screw 11, the foamed elastic body 16 can be reliably prevented from protruding from between the core portion 15 and the lining layer 14a on the inner surface of the tube 14.

An unfoamed liquid agent, a foaming base material, and a hardening agent are mixed to form a mixture between the core portion 15 and the female screw 11 .
Filling the gap with the foamed elastic body 16 can be easily performed by using an apparatus as shown in FIG. This apparatus uses an articulated robot or the like, and is equipped with a two-liquid mixing / dispensing apparatus 21 at the tip thereof. The two-liquid mixing / dispensing device 21 includes a foaming main agent supply device 2.
2 and a curing agent supply device 23 are connected, and a predetermined amount of the foaming main agent and the curing agent are measured by the respective supply devices and supplied to the discharge device 21. In addition, the discharge device 21
Performs a circular motion according to the diameter of the joint, and injects a predetermined amount from the tip nozzle 21a into the gap between the core portion 15 and the internal thread 11 while stirring and mixing the foaming main agent and the curing agent.

Meanwhile, joint hands A by appropriate gripper 24,
The filling section is held vertically and conveyed to a predetermined position. In addition, by providing a plurality of grippers 24 on a suitable transport device, for example, a turntable, the joint A can be continuously transported to the filler injection position and the filling process can be performed.

At the time of filling, in order to promote foaming and hardening of the filler, a temperature within a range not thermally affecting the synthetic resin body 13, for example, 50 to 50 when the synthetic resin body 13 is hard vinyl chloride. It can also be heated to 100 ° C.

[0020]

As described above, the anticorrosion pipe joint of the present invention has a foamed elasticity having closed cells formed by foaming and hardening the injected unfoamed liquid agent inside the gap between the female screw and the core. Since the foam is filled, the foamed elastic body has no gap in the gap.
Is filled well and adheres tightly to the core and female thread.
Since the tip of the connecting pipe abuts the body, the connecting pipe
The sealing performance of the part from the tip of the
Even if the fitting amount between the joint and the pipe varies, and even if the tip position of the pipe entering between the female screw and the core part varies, the foamed elastic body is pressed at the tip of the connecting pipe, so that the foaming is performed. Sufficient sealing performance can be obtained by a large compressive deformation rate of the elastic body. Further, since the closed cells, it is possible to prevent the fluid it is rather name that fluid be in contact with the foamed elastic body penetrates into the elastic member, the fluid comes into contact with the joint body and the pipe end face. In addition, since the ring body, which is slidably fitted in close contact with the outer peripheral surface of the core portion, is disposed on the outer side of the foamed elastic body, when the pipe connected to the joint body is screwed into the female thread. Thus, it is possible to reliably prevent the foamed elastic body from protruding from between the core portion and the lining layer on the inner surface of the pipe connected to the joint body.

Therefore, an anticorrosion pipe joint having extremely excellent corrosion resistance can be obtained, and can be suitably used for water supply, water supply and hot water supply pipes, or pipes for plants of chemical and chemical factories.

[Brief description of the drawings]

FIG. 1 is a sectional view of an anticorrosion pipe joint according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part thereof .

FIG. 3 is a schematic view of an apparatus for filling a foamed elastic material.

FIG. 4 is a sectional view showing a main part of a conventional anticorrosion pipe joint.

[Explanation of symbols]

11 female thread, 12 joint body, 13 synthetic resin body, 1
4 ... tube, 14a ... lining layer, 15 ... core part, 16 ...
Elastic foam with closed cells

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) creator Hiroshi Kataoka 5-8, Mitsuya-cho, Nagahama-shi, Shiga Prefecture In the Nagahama Plant of Mitsubishi Plastics Co., Ltd. (72) creator Norihiro Katsuno 1456 Hamaoji-cho, Hachioji-shi, Tokyo Three Bond Co., Ltd. (56) References JP-A 1-146085 (JP, U) JP 2-33872 (JP, U) JP-A 3-62284 (JP, U)

Claims (2)

(57) [Scope of request for utility model registration] 1. A female screw is provided on an inner surface of an end of a metal joint body.
And forming an inner surface of the main body excluding the female screw with a synthetic resin body , and projecting a core portion from an end of the synthetic resin body.
A gap is formed between the core and the female thread to receive the end of the pipe to be connected, and a foamed elastic body is formed inside the gap.
In the filled anticorrosion pipe joint, the foamed elastic body is
Independent air created by foaming and curing the unfoamed liquid agent injected into the gap
It has foam and is tightly attached to the outer peripheral surface of the core portion.
The ring body which is slidably fitted by being brought into contact with the foamed elastic body
An anticorrosion pipe joint, which is disposed on the outside of the pipe. 2. The foamed elastic material is 2 to 10 times at room temperature.
Characterized by being a foam-curable polysiloxane composition
The anticorrosion pipe joint according to claim 1.