JPH0426776Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pipe joint for joining relatively thin pipe materials such as stainless steel pipes for general piping.

[Prior Art] Conventionally, as a pipe joint for joining pipe materials such as stainless steel pipes, a chevron-shaped protrusion is formed on the outer periphery of the end of a stainless steel pipe, as described in Japanese Utility Model Application Publication No. 107390/1983. A connection mechanism is known in which the gasket, which is inserted into the joint and then tightened with a cap nut, is fitted into a notch at the end of the joint and is brought into close contact with the chevron-shaped protrusion for sealing. However, in order to form the above-mentioned chevron-shaped projections on stainless steel pipes, a tube expansion tool made of rubber is used on site, but in order to do so, a large force must be applied to the rubber of the tube expansion tool. First, it has the disadvantage of poor workability, and the disadvantage is that tightening using the slope of the chevron-shaped protrusion of the stainless steel pipe has a small slip-out prevention force.

[Problems to be solved by the invention] The present invention solves the problems seen in conventional pipe joints, and not only makes the joining work easy, but also has an extremely excellent sealing effect and a large force to prevent pipe material from coming out. It was completed for the purpose of a pipe joint.

[Means for Solving the Problems] The pipe joint according to the present invention has an insertion opening of the pipe joint body which is inserted into the end of the pipe material to be joined through a stepped portion and has a uniform diameter expanded part. an internal vertical end surface of a cap nut, the end of which is formed into a tapered surface that expands toward the pipe joint, and has a small diameter portion at its end that is screwed into the external thread of the pipe joint body and engaged with the stepped portion of the expanded tube portion; and the pipe joint. The present invention is characterized in that an annular packing is interposed between the tapered surface of the main body and seals the outer circumferential surface of the expanded pipe portion by pressure generated by tightening the cap nut.

[Embodiments] Next, the present invention will be described in detail with reference to illustrated embodiments.

In the first embodiment shown in FIGS. 1 and 2,
Reference numeral 1 refers to a relatively thin pipe material to be joined, such as a stainless steel pipe for general piping.
is assumed to have been formed. Reference numeral 2 denotes a pipe joint main body, and the pipe joint main body 2 has a diameter of about 45 mm extending outwardly from the end surface of the insertion port into which the expanded tube portion 5 of the pipe material 1 having a uniform diameter is inserted.
A tapered surface 9 is formed which widens at an angle of .degree. Reference numeral 3 denotes a cap nut having a small diameter portion 11 at its end that is screwed into the external thread 8 of the pipe joint body 2 and engaged with the stepped portion 10 of the expanded tube portion 5, and the internal vertical end face of the cap nut 3 is 12 and the tapered surface 9 of the pipe joint body 2 is interposed an annular packing 4 which seals the outer circumferential surface of the expanded pipe portion 5 by pressure generated by tightening the cap nut 3. The pipe joint main body 2 has a short cylindrical part 7 protruding from both sides of an intermediate nut-shaped part 6 into which the expanded tube part 5 of the pipe material 1 with a uniform diameter is inserted, and the outer periphery of the short cylindrical part 7 is A male thread 8 for screwing the cap nut 3 is formed in the holder.

3 and 4 show a second embodiment, which is different from the first embodiment in that the angle of the tapered surface 9 is made slightly smaller and the annular packing 4 is wedge-shaped in cross section. It's just different.

With this structure, the expanded pipe portion 5 of uniform diameter formed at the end of the pipe material 1 to be joined is inserted into the short cylindrical portion 7 which is the insertion opening of the pipe joint body 2,
The internal vertical end surface 12 of the cap nut 3 screwed in advance to the external thread 8 formed on the outer periphery of the short cylindrical portion 7 and the outwardly expanding tapered surface formed on the end surface of the short cylindrical portion 7 of the pipe joint body 2. If the cap nut 8 is tightened with the annular packing 4 interposed between the cap nut 8 and the cap nut 8, the annular packing 4 will press against the outer peripheral surface of the expanded tube portion 5 of the tube material 1. Second
It is to be sealed as shown in the figure. and,
In this case, the annular packing 4 interposed between the internal vertical end surface 12 of the cap nut 3 and the outwardly expanding tapered surface 9 of the end surface of the pipe joint main body 2 rotates into the tapered surface 9 as the cap nut 3 is tightened. At the same time, the small diameter portion 11 at the end of the cap nut 3 is pushed smoothly toward the bottom of the tube, and the sealing effect against the expanded tube portion 5 is excellent. 10, the pipe joint body 2 is firmly fixed to the pipe material 1, and as a result, the force for preventing the pipe material 1 from coming off can be greatly improved compared to conventional ones. It can also be used in piping systems subject to large internal pressures.
However, the expanded tube portion 5 of uniform diameter formed at the end of the tube material 1 through the stepped portion 10 is processed on-site using a tube expansion tool, but in this case, unlike conventional methods, a part of the tube material is The expanded pipe portion 5 can be formed with two-thirds of the force required when forming a mold protrusion.

[Effects of the invention] As is clear from the explanation of the above embodiments, the invention has the following advantages:
It has a large ability to prevent pipe material from slipping out, provides an excellent sealing effect, and has extremely great practical value as it eliminates the problems of conventional pipe fittings of this type. It is something.

[Brief explanation of the drawing]

1 and 2 are partially cutaway side views showing a first embodiment of the present invention, FIG. 1 showing the state before tightening, and FIG. 2 showing the state after tightening. Third
4 are partially cutaway side views similarly showing the second embodiment. DESCRIPTION OF SYMBOLS 1... Pipe material, 2... Pipe joint body, 3... Cap nut, 4... Annular packing, 5... Tube expansion part, 8...
Male thread, 9...Tapered surface, 10...Stepped portion, 11...
...Small diameter part, 12...Internal vertical end surface.

Claims (1)

[Scope of utility model registration request] The end surface of the insertion opening of the pipe joint body 2 into which the expanded tube portion 5 of uniform diameter formed through the stepped portion 10 is inserted into the end of the pipe material 1 to be joined is formed into a tapered surface 9 that expands outward, An internal vertical end surface 12 of a cap nut 3 having a small diameter portion 11 at its end that is screwed into the male thread 8 of the pipe joint body 2 and engaged with the stepped portion 10 of the tube expansion portion 5 and a taper of the pipe joint body 2. A pipe joint characterized in that an annular gasket 4 is interposed between the surface 9 and the annular gasket 4 for sealing the outer circumferential surface of the expanded tube portion 5 by pressure generated by tightening the cap nut 3.