JPS626792A - Method for welding pipe crossing part - Google Patents

Abstract

PURPOSE:To simplify a grove shape and to realize automatic welding by performing a beveling so as to form the end part of a branch pipe in convex conical surface and by performing a beveling to form a concave conical surface corresponding to the convex conical surface thereof on a main pipe as well. CONSTITUTION:A beveling is performed so that the lower end part of a branch pipe 2 becomes in the convex conical surface 5 centering around the shaft center of the branch pipe 2. The apex angle theta2 of the concave conical surface 6 is made larger than the apex angle theta1 of the convex conical surface 5 with beveling so as to make the concave conical surface 6 centering around the shaft center of the branch pipe 2 to be joined so that the lower end part can be fitted on the main pipe 1 side as well. The narrow groove is then formed by the convex conical surface 5 and concave conical surface 6. With performing said welding, the locus of the welding becomes circular and secondary curve to simplify the work.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a method of welding pipe intersections.

[Prior art] Conventionally, in pipe joints such as boiler nozzles, Fig. 2 a and b
, the main pipe 1 and the branch pipes 2 are separated by the method shown in Fig. 3a and b.
Welding was carried out with

That is, in the method shown in FIGS. 2a and 2b, the lower end surface of the branch pipe 2 is beveled, the branch pipe 2 is mounted on the main pipe 1, and welded from the outside.

Next, in the method shown in FIGS. 3a and 3b, the lower end of the branch pipe 2 is formed into a convex pseudo-tapered shape 3, and the main pipe 1 side is also formed with the same bevel over the entire circumference with respect to the pseudo-tapered shape 3. In order to obtain the desired condition, a concave depression 4 is cut out, and the main pipe 7 is welded overlay in this groove shape.
and branch pipe 2 are being welded.

[Problems to be Solved by the Invention] However, in the conventional method shown in FIGS. 2a and 2b, since the outer surface of the main pipe 1 is a curved surface, the groove shape and the groove cross section are also different. Therefore, the weld line also becomes three-dimensional, and the amount of deposited metal varies at each location.

For this reason, it is difficult to apply automatic welding, and manual welding has been performed.

In addition, in the conventional method shown in FIGS. 3a and 3b, the groove shape is constant over the entire circumference, but the welding line is still three-dimensional and automation is difficult. Furthermore, the pseudo-taber shape 3 of the branch pipe 2, Hollow 4
The curved surface is also complicated, making it difficult to process.

In view of the above circumstances, the present invention aims to simplify the groove shape, facilitate groove processing, and realize automatic welding. Conical surface part 5 [Means for solving the problem] The present invention provides a concave cone that corresponds to the convex conical curved surface on the main pipe while processing the above-mentioned σ light between the branches so that the end of the branch pipe becomes a convex conical curved surface. The bamboo pipe and branch pipe are welded together on the main plane by cutting a bevel to form a flat surface.
L tc If [effect]
When the pipe 1 has a shape with an opening length of 1 formed by the convex conical curved surface and the concave conical curved surface, the welding line is a quadratic curved surface, and the movement of the welding tor (Fig. simplification to be heard, including
Main pipe 1C [Example]
! 2. Detailed description of the present invention below with reference to the drawings.
The lower end of the V-branch pipe 2 is beveled so that it forms a convex conical surface 5 centered on the axis of the branch pipe. In addition, the branch pipe 2 to be joined is made so that the lower end part fits into the stiff side of the main pipe 1"1z.
12 M The groove is machined to form a concave conical curved surface 6 centered on the I axis. The convex welding efficiency and the concave conical curved surface 6 form a narrow gap).

), the machining operation is a single process, and the 12 convex conical curved surfaces 5 and concave conical curved surfaces 6 perpendicular to the axis of the branch pipe 2 are cut r, and all of the shapes become perfect circles. However, since there is only one main cylinder, the generatrix direction of the concave conical curved surface 6 varies depending on the location. For example, as shown in , the length 11 is the longest when cut along both axes of the main pipe 1 and the branch pipe 2, and the shortest when cut along a plane perpendicular to one axis.

When welding is performed with a groove shape like this, the weld becomes a perfect circle and a quadratic curve, simplifying the work. Therefore, at least the above-mentioned area can be welded in exactly the same way, and the area 1 can also be over-welded, so there is no practical problem at all.

The groove shape formed is a narrow groove, and the groove shape is improved.

[Effects of the Invention] As described above, according to the present invention, the welding line becomes a quadratic curve, making it possible to automate the welding line, and also facilitating beveling, thereby improving the efficiency of setup work.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the present invention, and Figs. 2 and 3 are explanatory diagrams of a conventional example. The cross section b is a cross section cut along a plane perpendicular to the axis of the main pipe. 1 is a main pipe, 2 is a branch pipe, 3 is a tapered shape, 4 is a depression, 5 is a convex conical curved surface, and 6 is a concave conical curved surface. Patent application Hitoshi Kawajima Harima Heavy Industries Co., Ltd. Figure 2 (a) (b) Figure 3

Claims (1)

[Claims] 1) The main pipe and the branch pipe are welded by bevelling the end of the branch pipe to form a convex conical curved surface, and by bevelling the main pipe to form a concave conical surface corresponding to the convex conical curved surface. Method of welding pipe intersections.