JPH0439501Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a synthetic resin flare male joint for connecting synthetic resin pipes.

[Conventional technology]

In general, flare joints, as shown in Figure 4,
Insert the flare female fitting nut 2 into the pipe 1 whose tip is flared, and attach the flare seal portion 1a of the pipe 1 to the flare male seal portion 3a at the tip.
The female screw 2a of the flare female joint nut 2 is screwed into the male screw 3b provided on the outer periphery of the flare male joint 3. The flare seal portion 1a and the flare male seal portion 3a are brought into close contact and connected.

In recent years, the use of synthetic resin for tanks, pumps, piping, etc. has progressed because it is easy to mold and process and has excellent corrosion resistance, and attached fittings are also made of synthetic resin, and the flare fittings mentioned above are also made of synthetic resin. It is beginning to be used.

[Problem that the invention attempts to solve]

By the way, in the flare joint, the flare male seal part 3a and the flare seal part 1a are tightly abutted to prevent the internal fluid from leaking to the outside, so the flare male joint 3 and the cap nut 2 are tightly screwed together. must match. However, since both synthetic resins have lower strength than metals, they cannot be tightened strongly and stress relaxation occurs during long-term use.
There was a drawback that the internal fluid leaked from the connection part due to loosening of the fastened screws.

Therefore, as shown in Fig. 5, the flare joint is made of metal, the cap nut 2 is made of metal, the flare male joint 3 is connected to a base 4 made of synthetic resin, and a male screw 3b is provided on the outer periphery. , and a metal insert whose tip is a flared male seal part 3a, and the flared male seal part 3a and the flared seal part 1a are brought into close contact with each other by screwing together the metal screws to prevent a decrease in fastening force. I tried. However, it is difficult to seal between the synthetic resin base 4 of the flared male joint 3 and the metal insert 5, and leakage may occur if the internal fluid is a high-pressure gas. Furthermore, the cap nut 2 may be made of metal since it does not come into contact with fluid, but since the metal insert 5 of the flare male joint 3 comes into contact with the internal fluid, a metal that does not corrode with the fluid must be selected. There is an unavoidable inconvenience.

In view of the above circumstances, it is an object of the present invention to provide a flare male joint made of synthetic resin that does not impair the advantages of synthetic resin and does not reduce the fastening force.

[Means for solving problems]

The present invention was made to achieve the above object, and its gist is to connect a synthetic resin pipe to which a flare seal is provided at the tip and a metal flare female coupling nut is attached. , a flared male joint made of synthetic resin that has a flared male seal at the tip and a male threaded part on the body that screws into the flared female fitting nut; The male threaded portion is formed by an insert, and the cylindrical metal insert abuts against the rear stepped portion of the convex portion formed by surrounding the tip of the flared male joint made of synthetic resin. Synthetic resin flare male fitting.

[Specific structure and function of the device]

The present invention will be explained below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of a synthetic resin flared male joint according to the present invention, and the same parts as in FIG. 4 are given the same reference numerals and their explanation will be omitted.

The flare male fitting 3 has a male seal part 3 at the tip.
a, and a metal cylindrical insert 7 having a male thread 3b on its surface, which is embedded integrally by surrounding the outer periphery of the tubular body 6.
It is composed of:

To connect a synthetic resin pipe 1 using this flared male joint 3, the flared seal portion 1a is brought into contact with the flared male sealed portion 3a, and the metal bag nut 2 is inserted into the metal cylindrical insert of the flared male joint 3. 7 and tighten. In that case, the metal cylindrical insert contacts the rear step portion 3d of the convex portion 3c formed by bending the tip of the synthetic resin flare male joint. In addition, the male screw 3b and the female screw 2a have high strength because they are metal screws screwed together, and the metal cylindrical insert 7 is prevented from moving in the direction of the male seal portion 3a with respect to the synthetic resin tubular body 6. Therefore, the flare seal portion 1a and the flare male seal portion 3a are strongly adhered to each other, and a strong connection is possible without damaging the screws during tightening or loosening the fastening over time.
Furthermore, since the metal bag nut 2 and the metal cylindrical insert 7 do not come into contact with the fluid flowing inside the pipe, there is no need to select the metal material depending on the type of fluid to be used.

Further, in the above description, the metal cylindrical insert 7 is embedded in the outer periphery of the synthetic resin tubular body 6, but the metal cylindrical insert 7 Since it is only necessary to prevent movement in the direction of , as shown in FIG. The shaped insert 7 may be attached to the tubular body 6 for use. In addition, in order to prevent the metal cylindrical inserts from rotating together when the cap nut 2 is screwed into the cylindrical insert, they are shaped to prevent mutual rotation, as shown in an example in Fig. 3. You can also do that.

〔effect〕

As described above, the synthetic resin flare male joint according to the present invention clamps and fastens the flare seal part between the flare male seal part and the metal bag nut by threading the metal screw, so it is difficult to tighten. Since there is no damage to the internal screws or loosening over time, the connection is strong, and the fluid does not come into contact with metal, reliable piping is possible without sacrificing the advantages of synthetic resin piping.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing one embodiment of the synthetic resin flare male joint according to the present invention, Fig. 2 is a longitudinal cross-sectional view showing another example, and Fig. 3 is a synthetic resin tubular body and a metal tube. A cross-sectional view corresponding to the - line arrow in Fig. 2 showing the joined state of shaped inserts, Fig. 4 is an explanatory view of a flare joint, and Fig. 5 is a longitudinal cross-sectional view of a conventional synthetic resin flare joint with a metal threaded part. It is. 1...Pipe, 1a...Flare seal part, 2
...Flare female joint gloves nut (bag nut), 3
...Flare male joint, 3a...Flare male seal part, 3b...Male thread, 3c...Protrusion, 3d
...Stepped portion, 6...Synthetic resin tubular body, 7...Metal cylindrical insert.

Claims (1)

[Scope of utility model registration request] A flare male seal is provided at the tip, which connects to a synthetic resin pipe to which a flare female fitting nut made of metal is attached, and a flared female fitting nut is attached to the body. In a flare male joint made of synthetic resin that is provided with a male threaded portion to be screwed together, only the male threaded portion is formed of a cylindrical metal insert, and the male threaded portion is formed of a cylindrical metal insert. is a flared male joint made of synthetic resin, which comes into contact with a rear stepped portion of a convex portion formed by surrounding the tip of the flared male joint made of synthetic resin.