JPH0146757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a joint for connecting two pipes in a T-shape, in which the end of the other pipe connected to the side of one pipe is fixed to the side of said one pipe. The purpose of this invention is to provide a method for manufacturing a T-shaped pipe joint that can be screwed to such a joint, and to improve the efficiency of piping work at the site.

For example, as shown in FIG. 1, when connecting branch pipes 2, 2 to the side of a main pipe 1 in a T-shape, a second As shown in the figure, there is a through hole 3 on the side of the main pipe 1.
A joint 6 consisting of a curved collar part 4 and a short pipe part 5, which are shaped to match the side surface of the main pipe 1 as shown in FIG. The branch pipe 2 is welded to the side surface of the pipe 1, and then the end of the branch pipe 2 is butt welded to the short pipe portion 5 of the joint 6 for connection.

By the way, regarding the joint 6 used in this manner, there is a desire to be able to connect the branch pipe 2 to the joint 1 with screws. That is, the short pipe part 5 of the joint 6 is made slightly larger in diameter than the branch pipe 2, and a female thread (for example, a tapered thread) is carved on the inner peripheral surface of the short pipe part 5, and a male thread is provided on the outer peripheral surface of the end of the short pipe part 5. If the carved end of the branch pipe 2 is screwed in to connect the joint 6 and the branch pipe 2,
Troublesome welding work for connecting the branch pipes 2 can be reduced.

However, simply increasing the diameter of the short pipe portion 5 of the joint 6 as shown in Fig. 3 and carving a female thread on its inner circumferential surface renders it useless as a threaded joint, as described below. . That is, the female thread on the inner circumferential surface of the short pipe section is carved in the factory when the joint is manufactured, and then this joint is welded to the side of the main pipe 1 at the construction site, but the heat and heat generated by this welding work are Due to the thinning phenomenon that occurs with welding, the short pipe section 5 of the joint is deformed into an oval shape, etc., and when the end of the branch pipe is screwed into the short pipe section and both pipes are connected, a gap is created at the connection section. occurs, and the fluid flowing inside the pipe leaks.

The method for manufacturing a T-shaped pipe joint of the present invention eliminates the above-mentioned disadvantages.

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

4-6 show a T-shaped pipe fitting 7 manufactured according to the invention. The joint 7 has an outer surface (convex side surface) of a curved collar portion 4 that is curved to match the cylindrical outer surface of the main pipe 1 (FIGS. 1 to 3) to be welded.
A short tube section 5 having a female thread 8 such as a tapered screw on the inner circumferential surface is formed integrally with the curved collar section 4, and a metal ring body 9 is fitted on the outer circumferential surface of the short tube section 5. I'm wearing it. The ring body 9 has an inner diameter slightly smaller than the outer diameter of the short pipe part 5 and is strongly press-fitted into the short pipe part 5, so that the outer circumferential surface of the short pipe part 5 is stronger than the inner circumferential surface of the ring body 9. In the compressed state, the short tube portion 5 and the ring body 9 are firmly connected.

Since the T-shaped pipe joint manufactured by the method of the present invention is constructed as described above, the joint 7 is connected to the main pipe 1.
Even when the outer periphery of the curved flange 4 of the joint 7 and the outer periphery of the main pipe 1 are welded to connect to No leakage occurs from the threaded part.
That is, the short pipe part 5 has a cylindrical outer surface and is strongly tightened by the ring body 9 having a slightly smaller diameter than the short pipe part, so that it is not easily deformed, so that thermal distortion when sequentially welding the curved collar part 4 to the main pipe 1 is reduced. Even if the short pipe part 8 is reached through the collar part 4, the ring body 9 suppresses the deformation and prevents the deformation. Therefore, there is no distortion of the short pipe portion 5 during welding, or even if there is, it is extremely small. For this reason, the branch pipe 2 is attached to, for example, a tapered female thread carved on the inner circumferential surface of the short pipe portion 5.
By screwing in the corresponding male threads cut into the outer peripheral surface of the end (FIG. 1), the branch pipe 2 and the joint 7 are tightly connected, and no leakage occurs from the joint.

Next, a method for manufacturing the T-shaped pipe joint of the present invention will be explained.

First, a circular thick metal plate is pressed to form a hat-shaped element body 10 having a flange 10b around the opening of a bottomed cylindrical part 10a, as shown in FIG.

Next, this element body 10 is further pressed to curve the flange 10b into a shape that matches the outer surface of the main pipe 1 to form the curved flange 4 as shown in FIG. The ring element 11 is strongly pressed onto the press. This annular body element 11 has an annular standing wall 11b formed around a disk-shaped flat plate part 11a, and the inner diameter of the standing wall 11b is slightly smaller than the outer diameter of the bottomed cylindrical part 10a of the element body 10 (each member Although it differs depending on the material and size of the parts 10 and 11, if both are made of iron and the outer diameter of the cylindrical part 10a is about 5 cm, the diameter of about 0.5 m/m is sufficient.). In addition,
If the press machine has sufficient capacity, the step of bending the flange portion 10b may be performed at the same time as forming the bottomed cylindrical portion 10a.
The process of press-fitting the curved collar part 1 and the process of press-molding the curved collar part 4 may be performed separately, but if they are performed at the same time, the number of processes can be reduced and it will be more efficient.

Next, as shown in FIG. 9, the bottom of the cylindrical portion 10a of the element body 10 and the flat plate portion 11a of the ring body element 11 are opened by appropriate means such as punching with a press or cutting. As shown in Figure 10, ring element 1
Cut the top of 1. Alternatively, from the state shown in FIG. 8, the head of the element body 10 and the upper part of the ring body element 11 are simultaneously cut off as shown by the chain line a in the same figure, and immediately the short tube portion 5 is cut off as shown in FIG. A ring body 9 may be fitted onto the outer periphery of the ring body.

As shown in FIG.
Once fitted, a female thread is carved on the inner peripheral surface of the short pipe portion 5 to form a joint 7 as shown in FIGS. 4 to 6.
is completed. This internal thread may be carved in the state shown in FIG. 9.

According to the method for manufacturing a T-shaped pipe joint of the present invention as described above, the ring body 9 can be firmly fitted to the outer peripheral surface of the short pipe portion 5 of the element body 10 press-molded from a thick metal plate, In addition, since all of this can be done by cold working, deformation of the short tube portion 5 and the female thread 8 is almost eliminated, and the manufacturing work can be carried out more efficiently and with less trouble than in the case of shrink fitting.

[Brief explanation of drawings]

Figure 1 is a side view of the main pipe with branch pipes, Figure 2 is a side view of the main pipe with a through hole, and Figure 3 is a conventional T.
A side view of a main pipe showing a situation in which a branch pipe is welded by a pipe joint, FIGS. 4 to 6 show a T-shape pipe joint manufactured according to the present invention, FIG. 6 is a sectional view taken along line BB, and FIGS.
It is a sectional view similar to the figure. 1...Main pipe, 2...Branch pipe, 3...Through hole, 4...
Curved collar part, 5... Short pipe part, 6, 7... Joint, 8
... Female thread, 9 ... Ring body, 10 ... Element body, 10a
...Bottomed cylindrical part, 10b...flange part, 11...ring element, 11a...flat plate part, 11b...standing wall.

Claims (1)

[Claims] 1 Press-molding a circular metal flat plate to make the element body 10 having a flange 10b around the opening of the bottomed cylindrical part 10a, and on top of the bottomed cylindrical part 10a, around the circular flat plate part 11a. A cylindrical portion 10a with a cylindrical shape and a bottom.
Ring element 11 forming a standing wall 11b with a slightly smaller diameter
During the above process, the flange 10b of the element body is formed into a curved surface that matches the cylindrical outer surface of the main tube 1, and then the ring body element 11 and the bottomed cylindrical part 1 are
A ring body 9 is strongly fitted to the outer periphery of the pipe, except for the upper part with 0a, and a short pipe part 5 is formed with an open end.
A method for manufacturing a T-shaped pipe joint, characterized in that a female thread 8 is then carved on the inner circumferential surface of the short pipe portion 5.