JPH056284U - Anticorrosion pipe fitting - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an anticorrosion pipe joint that can obtain sufficient sealing performance even if there is a large variation in the position of the pipe tip where the screw fits. [Structure] An inner surface of a main body of a metal joint body 12 having an internal thread 11 on an inner surface of an end excluding the internal thread 11 is covered with a synthetic resin body 13, and a core portion 15 from the synthetic resin body 13 to an end side. In the anticorrosion pipe joint with the protruding portion, a foamed elastic body 16 having closed cells is filled between the female screw 11 and the core portion 15.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an anticorrosion pipe joint, and more particularly to a seal structure for an anticorrosion pipe joint in which the inner surface of the joint body is covered with a synthetic resin body.

[0002]

[Prior Art]

 FIG. 4 is a sectional view showing a main part of a conventional anticorrosion pipe joint. The anticorrosion pipe joint covers the inner surface of the main body of the metallic joint body 2 having the female thread 1 on the inner surface at the end excluding the female thread 1 with the synthetic resin body 3 and from the synthetic resin body 3 to the end side. In addition, a core portion 5 having a gap for receiving the end portion of the connecting pipe 4 is projected between the female screw 1 and the female screw 1. This anticorrosion pipe joint is formed so as to prevent the fluid flowing inside from coming into contact with the pipe end face and the screw portion by contacting the lining layer 4a on the inner surface of the pipe 4 with the core portion 5. ..

However, due to variations in the diameters of the joint body 2 and the threaded portion of the pipe 4, the two cannot be fitted sufficiently, and the contact between the lining layer 4a and the core portion 5 becomes incomplete, so that the fluid female thread The joint body 2 and the pipe 4 may be corroded by invading one portion.

Therefore, conventionally, a sealant has been applied to the outer periphery of the core portion 5 (Japanese Patent Laid-Open No. 60-231090) or a water-expandable rubber ring has been loaded (Japanese Utility Model Laid-Open No. 62-102085). ), A foamed elastic body in which air bubbles communicate with each other is attached between the core portion 5 and the female screw 1 (Japanese Utility Model Laid-Open No. 1-146085) to improve the sealing performance.

[0005]

[Problems to be solved by the device]

 On the other hand, in the Japanese Industrial Standard (JIS), the variation range of the screw fitting in the above corrosion-resistant pipe joint and inner surface coated steel pipe is defined according to the pipe diameter. For example, in the case of size 15A, a variation of 8.2 mm is allowed at the tip position of the pipe. Further, since the male thread on the pipe side is often constructed by a thread cutting machine at the piping site, the outer diameter of the screw generally varies depending on the setting condition of the blade of the thread cutting machine, etc. Considering the tolerance and the variation of the number of tightening peaks after manual tightening, it is necessary to cope with the variation width of 8.2 mm or more, but the conventional seal structure described above may not provide sufficient sealing performance. there were.

Therefore, an object of the present invention is to provide an anticorrosion pipe joint that can obtain sufficient sealing performance even if there is a large variation in the pipe tip position.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the anticorrosion pipe joint of the present invention is such that the inner surface of a metal joint body having an internal thread at its inner end except for the internal thread is covered with a synthetic resin body. In an anticorrosion pipe joint in which a core portion having a gap for receiving the end portion of a pipe connected between the female thread and the synthetic resin body is projected from the synthetic resin body to the end side, the corrosion-resistant pipe joint is provided between the female thread and the core It is characterized by being filled with a foamed elastic body having closed cells.

[0008]

[Work]

 According to the above configuration, sufficient sealing performance can be obtained even if the tube tip position varies due to the large compression deformation rate of the foamed elastic body. In addition, since the cells are closed cells, the fluid does not penetrate into the elastic body even when the fluid comes into contact with the foamed elastic body.

[0009]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. 1 is a cross-sectional view of a straight pipe type anticorrosion pipe joint, FIG. 2 is a cross-sectional view showing a main part of another embodiment, and FIG. 3 is a schematic diagram of an apparatus for filling a foamed elastic material.

In the main body of the anticorrosion pipe joint, as in the conventional case, the inner surface of the main body of the metallic joint body 12 having internal threads 11 at both ends except the internal thread 11 is covered with the synthetic resin body 13. At the same time, a cylindrical core portion 15 is provided on the end portion side of the synthetic resin body 13 with a gap formed between the synthetic resin body 13 and the female screw 11 for receiving the end portion of the pipe 14 to be connected. ..

The joint body 12 is a metal joint defined by Japanese Industrial Standards, and the synthetic resin body 13 is hard vinyl chloride, polyethylene, polybutene, nylon, ABS resin, polycarbonate, or other thermoplastic resin, The synthetic resin body 13 is molded by injection molding together with the core portion 15 as described in a known method, for example, JP-A-60-129225.

A foam elastic body 16 having closed cells is filled between the core portion 15 and the female screw 11. As the foamed elastic body 16 having the closed cells, for example, a polysiloxane composition that foams and cures at room temperature is preferably used.

In addition, if necessary, fillers and reinforcements such as zinc oxide, magnesium oxide, calcium carbonate, fumed silica, precipitated silica, titanium dioxide, aluminum oxide, quartz powder, talc, bentonite, asbestos, and glass fiber. It is also possible to mix agents. Furthermore, by blending the water-absorbing polymer, when water is infiltrated by water passage after the pipe connection, the water-absorbing polymer absorbs the water and expands, thereby closing the gap and more reliable water stopping. By adding a rust preventive agent, the joint body can be prevented from rusting.

The foamed elastic body having closed cells obtained by the above composition is excellent in heat resistance, cold resistance, water resistance, weather resistance and compression recovery, and is very safe for humans. Further, the foamed elastic body is a sponge-like cured product having extremely high foam control properties and composed of fine and uniform independent cells.

The filling amount of the foam elastic body 16 to be filled between the core portion 15 and the female screw 11 is such that the tip of the tube 14 contacts the foam elastic body 16 even with the minimum fitting amount in the variation width. Is set to. In addition, in this filling amount, the foaming elastic body 16 has a foaming expansion ratio of about 2 to 10 times so that the foaming elastic body 16 does not stick out between the core portion 15 and the lining layer 14a on the inner surface of the pipe 14 even at the maximum fitting amount. The body 16 may be used.

At this time, as shown in FIG. 2, when the ring body 17 made of vinyl chloride, polyethylene, rubber or the like is brought into close contact with the outer peripheral surface of the core portion 15 and slidably fitted therein, the pipe 14 It is possible to reliably prevent the foamed elastic body 16 from protruding from between the core portion 15 and the lining layer 14a on the inner surface of the tube 14 when screwed into the female screw 11.

In order to fill the foaming elastic body 16 between the core portion 15 and the female screw 11 by mixing the foaming main agent and the curing agent, it is easy to use a device as shown in FIG. Can be done. This device uses an articulated robot or the like, and is equipped with a two-liquid mixed constant-volume discharge device 21 at its tip. A foaming base agent supply device 22 and a curing agent supply device 23 are connected to the two-liquid mixing / dispensing device 21, and a predetermined amount of the foaming base agent and the curing agent is measured by each supply device and discharged. It is supplied to the device 21. Further, the discharge device 21 performs a circular motion according to the diameter of the joint, and while stirring and mixing the foaming main agent and the curing agent, injects a predetermined amount between the core portion 15 and the female screw 11 from the tip nozzle 21a. To do.

One of the joints A is held by a proper gripper 24 so that the filling portion is vertical and is conveyed to a predetermined position. Further, by providing a plurality of grippers 24 on an appropriate transport device, for example, a turntable, the joint A can be continuously transported to the filler injection position and the filling step can be performed.

At the time of filling, in order to promote foaming and hardening of the filler, a temperature within a range that does not thermally affect 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]

[Effect of the device]

 As described above, the anticorrosion pipe joint of the present invention is filled with the foamed elastic body having independent air bubbles between the female thread and the core portion, so that the sealing property between the lining layer on the inner surface of the pipe and the core portion is improved. Even if the fitting amount of the joint and the pipe varies, and the tip position of the pipe that enters between the female thread and the core part also varies, sufficient sealing performance can be obtained due to the large compression deformation rate of the foamed elastic body. Be done. Further, since the closed cells are used, the fluid does not penetrate into the elastic body even when the fluid comes into contact with the foamed elastic body, so that the fluid can be prevented from coming into contact with the joint body or the pipe end surface.

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

[Brief description of drawings]

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

FIG. 2 is a sectional view of an essential part showing another embodiment of the present invention.

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]

DESCRIPTION OF SYMBOLS 11 ... Female screw 12 ... Joint main body 13 ... Synthetic resin body 14 ... Pipe 14a ... Lining layer 15 ... Core part 16 ... Foamed elastic body having closed cells

Front page continuation (72) Hiroshi Kataoka 5-8 Mitsuyacho, Nagahama-shi, Shiga Mitsubishi Plastics Co., Ltd. Nagahama Plant (72) Creator Nobuhiro Katsuno 1456, Sakamachi, Hachioji-shi, Tokyo Inside ThreeBond Co., Ltd.

Claims (1)

[Claims for utility model registration] [Claim 1] The inner surface of the main body of the metal joint body having internal threads on the inner surface excluding the internal thread is covered with a synthetic resin body, and the synthetic resin body is connected to the end section. In the anticorrosion pipe joint in which a core portion having a gap for receiving the end portion of the pipe connected to the female thread is projected on the side, foam elasticity having independent bubbles between the female thread and the core portion An anticorrosion pipe joint filled with a body.