JPS59137190A - Welding method of piping - Google Patents

Abstract

PURPOSE:To connect easily and securely piping by using a short tube which is expanded at one end and is cut square at the other end, and connecting the other end of the piping which is chamfered at one end to the ther piping by nonfiller welding via an insert ring. CONSTITUTION:A short tube 1 is worked and formed with an expanded part 2 at one end and is cut square in the axial direction of a piping 7 at the other end to a suitable length. Said part 2 and the chamfered 4 side of a piping 3 are disposed in tight contact with each other. On the other hand, the other end of the adapter is cut to conform to the space l2 between the pipings 3 and 7 to be connected by allowing for the width of an insert ring 5 and the piping 7 is disposed in tight contact with said end of the short tube. The part 2 and the ring 5 are penetrated by nonfiller welding, thereby connecting the pipings 3, 7. The ring 5 is made larger in the outside diameter than the outside diameter of the piping 7 and is made equal or smaller in the inside diameter to or than the inside diameter in the wall thickness of the piping 7. A thick walled part 6 is formed at the center of the inside surface and said part 6 is so formed as to be positioned on the outside diameter of the piping 7.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a method for welding pipes.

[Technical background of the invention and its problems]

Conventionally, the butt method, sleeve (short pipe), and socket method have been used to weld pipes.

However, the butt method requires a jig for groove alignment and groove alignment, which is a process before pipe beveling and welding, and for this reason, the dimensional accuracy and installation errors of the pipe must be strictly controlled. There wasn't.

In addition, the sleeve and socket method requires no beveling of the piping, and the eccentricity, dimensional accuracy, and installation errors of the piping can be absorbed within the sleeve or socket, but the strength of the joint is weaker than that of butt joints.

Furthermore, automatic welding using the sleeve or socket method currently requires the use of a welding rod, resulting in an increase in welding costs.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to absorb the shortcomings of conventional pipe welding methods, such as pipe manufacturing accuracy for pipe groove alignment, installation errors, etc., and to use a non-filler butt It is an object of the present invention to provide a pipe welding method for pipes that can obtain a strength equivalent to that of laminated welding.

[Summary of the invention]

In order to achieve the above object, the method of welding pipes according to the present invention involves arranging a short pipe and an insert ring closely in series between pipes having the same or almost the same diameter, and welding the short pipe with a welding torch. The tube expansion part and insert ring part at one end of the pipe are melt-fitted to connect the pipes.

In addition, as for the configuration of the short pipe, one end of the short pipe has the same or almost the same outer diameter and inner diameter as the pipe to be connected, and the other end is welded at any time to determine the pipe length on site.
The rounded parts are chamfered so that they can be cut as desired, and are made of aluminum, stainless steel, iron, etc.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1(a) and 1(b) are a plan view and a sectional view of a factory-manufactured short pipe 1 used in the method of the present invention.

That is, a short pipe 1 is shown in which an enlarged pipe portion 2 is formed by expanding the two halves of a short pipe 1 having substantially the same outer and inner diameters as the pipes to be connected.

The length 11 of this short pipe 1 is manufactured at a factory to be longer than the interval between pipes to be connected at the site, and before welding at the site, except for the part necessary for the dimensions to be welded, the expanded part of the short pipe 1 is 20
Cut the other side.

Figure 2 shows the pipe 3 to be welded on-site and the short pipe 1 shown in Figure 1.The end face of the pipe 3 to be connected is chamfered 4, and the end face of the short pipe 1 to be connected is chamfered. 2 shows a state in which the expanded tube portion 2 has been processed.

FIGS. 3(a) and 3(b) show plan views of the insert ring 5, which is placed in close contact with the short pipe 1 between the pipes to be welded together.

That is, the insert ring 5 may have an outer diameter larger than the outer diameter of the pipe T shown in FIG. 4 to be welded, and an inner diameter equal to or smaller than the inner wall thickness of the pipe 7. A thick portion 6 is formed at the center of the inner surface.

FIG. 4 is a layout diagram showing the configuration of the pipe welding method according to the present invention.

That is, between the pipes 3 and I to be connected on-site, the expanded part 2 of the short pipe 1 manufactured according to the interval 12 of each pipe 3.7 is arranged so as to be in close contact with the chamfered edge 4 side of the pipe 3. In addition, an insert ring 5 is attached so as to be in close contact between the opposite part of the short pipe 1 to the expanded pipe s2 and the pipe 7 to be welded.

Then, after installing the torch of the non-feller automatic welding machine at the top of the expanded part 2 of the short pipe 1 and the insert ring 5, an arc is generated to melt the expanded part 2 of the short pipe 1 and the insert ring 5, and the pipe 3 is melted. and 1 are connected.

〔Effect of the invention〕

As described in detail above, according to the present invention, one side of the short pipe 1 can be expanded by manufacturing at a factory, and welding conditions can be optimized.

In addition, the dimensions of the other end can be easily adjusted by simply cutting on-site.

Therefore, if the piping 3.7 comrades are all connected, the short pipe 1
By using the insert ring 5 and the insert ring 5, it is possible to absorb manufacturing dimensional accuracy of piping, installation errors, etc. compared to conventional welding methods.

In addition, the desired welding can be achieved simply by melting the expanded tube portion 2 and the insert ring 5 together using a welding machine torch.

Furthermore, since the welded portion is of a butt type, the strength of the joint can be the same as that of the base metal.

Furthermore, there is no need to align the grooves or manufacture a jig for groove alignment before welding the pipes together on-site, making it possible to easily align the pipes on-site.

In addition, since it is non-feller welding, the welding machine mechanism is 7.
Compared to error welding, it is not complicated and the size of the welding machine head can be reduced, leading to a reduction in the cost of the welding machine equipment.

Furthermore, short pipe 1 and in to be manufactured for welding? −)
The ring 5 can be manufactured not only for small-diameter piping but also for large-diameter piping according to the dimensions of the piping, and has the effect that it can be used for different types of piping such as aluminum and stainless steel piping according to the material of the piping.

[Brief explanation of drawings]

1 to 3 are for explaining each part used in the method of the present invention. The figures show piping and short pipes to be welded on site, Figures 3 (a) and (b) are a plan view and elevation view of an insert ring, and Figure 4 shows a configuration for explaining one embodiment of the present invention. FIG. 3 is a cross-sectional view partially shown in side view. 1... Short pipe 2... Expanded pipe section 3.1... Piping 4... Chamfered part 5... ...Insert ring 6...
・・・Thickness Department Agent Patent Attorney Satoshi Suyama - Figure 1 'G) (b) Figure 5 Figure 4 Procedures Amendments (Method) March 2, 1980 Commissioner of the Patent Office Hall 1, Indication of the incident, Patent Application 1982-1 @380/2,
Name of the invention Method for welding pipes 3, relationship with the case of the person making the amendment - Patent applicant: Tokyo Shibaura Electric Co., Ltd. 4, 72 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture, Agent: 101 Kanda Tamachi, Chiyoda-ku, Tokyo 2-1 Kanda Higashiyama Building Telephone 03 (254) 1039 (77)
84) Patent Attorney Sa Yama -7. Contents of the amendment Added <a> and (b) to Figure 3 as shown in the attached sheet (indicated by red mark). ``2''

Claims (3)

[Claims] (1) One end of the short pipe is expanded, the other end is cut at right angles to the piping axis direction, and using a short pipe that has not been chamfered and an insert ring, first attach it to the expanded side of the short pipe. Place the chamfered side of the pipe to be connected in close contact with each other, and place the insert ring closely between the non-chamfered side of the short pipe and the pipe part to be connected. A method for welding pipes, the method comprising: melt-fitting the expanded part of the short pipe and an insert ring by non-feller welding to connect the pipes together. (2) The insert ring has an outer diameter larger than the outer diameter of the pipe to be welded and an inner diameter equal to or smaller than the wall thickness inner diameter of the pipe. 2. The method of welding a pipe according to claim 1, wherein the position is the outer diameter position of the pipe. (3) The short pipe has almost the same diameter as the pipe to be welded and is made of aluminum, stainless steel, iron, etc., and insert an insert ring made of the same material as the pipe between the pipes with the same diameter and the same material. 2. The method of welding pipes according to claim 1, wherein the pipes are connected by melt-fitting the short pipe expanded portion and the insert ring with a welding torch in close contact with each other.