JP2676500B2 - Method for forming locking end forming material for steel pipe connection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a steel pipe connecting locking end forming material for forming a locking end portion on a connecting edge of a steel pipe when connecting a steel pipe for fluid transportation. .

[0002]

2. Description of the Related Art In addition to flange joints and screw joints, pipes for supplying gas and powder, such as water supply and water distribution, are known to have a connecting means such as a Victrick type pipe joint that is fitted around the abutting surfaces. Has been. In order to use this Victaulic type pipe joint, it is necessary to form a large-diameter stepped portion around the connection end edge of the steel pipe for locking the joint member. This step portion is usually formed by welding a stepped ring-shaped locking end portion forming material to the connection end surface.

[0003]

It is rational to cut the outer periphery of a thick ring-shaped material having the same inner diameter as the steel pipe to be joined as the material for forming the locking end. Such a material is formed by cutting a thick-walled steel pipe material to a predetermined thickness in the longitudinal direction, but the applicable thick-walled steel pipe material is out of the scope of the standard product and is difficult to obtain. However, if you place a special order for it, you will end up with a large amount of money and an enormous amount of inventory even with the lowest demand. Further, since the large-diameter portion is thick, it is expected that the total weight will exceed the design value and the design change will be unavoidable in the case of a complicated pipe having many joints. Therefore, an object of the present invention is to provide a method of forming a locking end portion forming material having a rational structure.

[0004]

In order to solve the above-mentioned problems, the present invention firstly cuts the same steel pipe material as the steel pipe to be connected to a predetermined thickness in the longitudinal direction, and then cuts the cut ring. It is to expand at least the other surface side of the strip-shaped material, and finally to cut the outer periphery to form a large-diameter step portion on the outer periphery of the other surface side. In the present invention, the term “steel pipe” is not limited to steel and stainless steel, and is broadly understood to include copper and aluminum pipes.

[0005]

By increasing the inner diameter on the other surface side, a step can be formed, and the other surface side can be made thin and lightweight.
Also, since the same steel pipe material as the steel pipe to be connected is used efficiently, it is easy to obtain the starting material, and it is cheap.
It becomes easier to meet small demand.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for forming a steel pipe connecting locking end forming material according to the present invention will be described with reference to the drawings. First, the forming step will be described. In the first step, the mass-produced standard long steel pipe material 1 is cut into a ring shape having a thickness of about 5 cm in the longitudinal direction, which is used as a material 2 (Fig. 1). Next, the cut material 2 is set in the press machine 3, and the tapered punch 3 is press-fitted into the ring hole to expand the punch press-fitting side (FIG. 2). Finally, the outer circumference is cut to form the large-diameter step portion 4 on the expanded diameter side (FIG. 3).

The steel pipe connecting locking end forming member thus formed is light in weight because the inside of the ring hole is the tapered surface F due to the press-fitting of the tapered punch 3, and the smaller diameter side is equal to the diameter of the steel pipe. Therefore, it can be welded to the end surface of the steel pipe so as to be continuous on its extension. By doing so, a large diameter step portion for locking can be integrally formed around the end edge portion of the steel pipe as shown in FIG. it can.

In the above embodiment, the inner diameter has a tapered surface due to the pressure of the tapered punch. However, by using a punch having a taper only at the tip, a non-tapered steel pipe connecting locking end forming material can be obtained. It is also possible to form.

In the step of expanding the diameter, it is desirable to restrain the outer circumference to correct the large-diameter step portion, and the cutting portion can be reduced.

[0010]

According to the present invention, since the inner diameter of the other surface side is made thicker, the other surface side becomes thinner and lighter in weight, and the same steel pipe material as the steel pipe to be connected is efficiently used for the formation. , It is easy to obtain starting materials, it is cheap, and it is easy to meet small demand.

[Brief description of the drawings]

FIG. 1 is an explanatory view of cutting out a raw material of a steel pipe connecting locking end forming material according to the present invention from a long steel pipe.

FIG. 2a is an explanatory diagram in which the cut material is set in a press.

FIG. 2b is an explanatory view showing a state in which the material is expanded in diameter by press fitting of a tapered punch of a press machine.

FIG. 3a is a cross-sectional view of the expanded material.

FIG. 3b is a cross-sectional view of a steel pipe connecting engagement end forming material completed by cutting the outer circumference of the expanded material to form a large diameter step.

FIG. 4 is a perspective view of a locking end portion completed by welding a steel pipe connecting locking end portion forming material to the end edge portion of the steel pipe.

FIG. 5 is an explanatory cross-sectional view when the steel pipes shown in FIG. 4 are connected to each other by a Victaulic pipe joint.

[Explanation of symbols]

1 ... long steel pipe material, 2 material, 2 '... expanded material, 3 taper punch for press, 4 large diameter step, F taper

Claims (1)

(57) [Claims] 1. First, the same steel pipe material as the steel pipe to be connected is cut into a predetermined thickness in the longitudinal direction, and then at least the other surface side of the cut ring-shaped material is expanded, and finally. A method for forming a steel pipe connecting engagement end forming material, wherein an outer circumference is cut to form a large-diameter step on the other surface.