JP3264015B2 - Inclined joint welding method - 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 welding a tilted joint.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a curved plate 1 such as a container is provided with a short tubular nozzle or the like, and this nozzle is used as a pipe 2 to be welded. There is a case where a welding method called a so-called inclined joint 5 is used in which the connecting pipe 4 is butt-welded from the outer peripheral side or the inner peripheral side on the inclined surface 3 substantially along the inclination.

[0003] The inclined joint 5 is formed by welding the pipe 2 to be welded and the connecting pipe 4 at an inclined surface 3 cut at an angle other than 90 ° with respect to the axis thereof. As shown in FIG. 4 (A), a tongue-shaped tip 6 is formed on the connecting pipe 4 at a position of 0 ° in the direction, and a U-shape facing the tongue-shaped tip 6 is formed on the welded pipe 2. A tongue-shaped tip 6 is formed on the pipe 2 to be welded as shown in FIG.
Is formed with a U-shaped bottom portion 7 facing the tongue-shaped tip portion 6. The 90 ° and 270 ° positions are shown in FIG.
As shown in FIG.

In the case of welding from, for example, the inner peripheral side having the above-described shape, conventionally, as shown in FIG. 5, along the inner periphery of the inclined joint 5, it is perpendicular to the axis of the welded pipe 2 and the connecting pipe 4. A groove 8 having the same groove cut angle α between the pipe 2 to be welded and the connecting pipe 4 at all positions with respect to the flat surface is formed.
The connection pipe 4 is attached to the pipe 2 to be welded 2 by overlay welding 9 as shown in FIG.

[0005]

However, in the conventional method of forming the groove 8 having the same groove cutting angle α at all the positions and overlay welding 9 the inclined joint 5, the tongue-like tip is used. Since the strength of the portion 6 is much smaller than that of the U-shaped bottom portion 7, the tongue-like tip portion 6 has a middle portion as shown by an arrow due to shrinkage at the time of solidification of the weld overlay 9 as shown in FIG. A deformation S that enters the side occurs, and the deformed S causes the misalignment L between the pipe 2 to be welded and the connecting pipe 4. Therefore, when the equipment passes through the pipes 2 to be welded and the connecting pipe 4, the equipment can pass. The welded pipe 2 and the connecting pipe 4 may be lost due to the deformation.
In this case, there is a problem that the inside of the pipe to be welded 2 and the connecting pipe 4 need to be cut.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has been made in order to minimize the deformation and the misalignment between a pipe to be welded and a connecting pipe when welding the tilted joint. The aim is to provide a method.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method of welding a tilted joint, in which a connecting pipe is butt-welded to a pipe to be welded on an inclined surface obtained by cutting a circular pipe at an angle other than 90 ° with respect to an axis of a shaft. The pipe to be welded is attached to the inclined joint between the pipe to be welded and the connection pipe.
The groove cut angle of the tongue-shaped tip formed on both the connecting pipe and the tongue is small, the groove cut angle of the U-shaped bottom facing the tongue-shaped tip is large, and the groove cut of the other part After forming a continuous groove so that the angle is the same between the pipe to be welded and the connecting pipe, the inclined joint is characterized in that the groove is overlaid and the connecting pipe is attached to the pipe to be welded. Welding method.

[0008]

According to the present invention, the groove cut angle formed at the tongue-shaped tip of the pipe to be welded and the connecting pipe is reduced, and the groove cut angle formed at the U-shaped bottom opposed to the tongue-shaped tip is reduced. The groove is formed so as to be continuous so that the groove cut-in angle of the other part is the same between the pipe to be welded and the connecting pipe, and the weld is welded to the groove. By increasing the strength of the tip and reducing the strength of the U-shaped bottom, the difference in strength between the tongue-shaped tip and the U-shaped bottom is reduced, thereby suppressing deformation.

[0009]

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

FIGS. 1 and 2 show an embodiment of the present invention. The same components as those shown in FIGS. 3 to 6 are denoted by the same reference numerals, and detailed description is omitted.

A groove 10 formed in the inclined joint 5 between the pipe 2 to be welded and the connecting pipe 4 is attached to the tongue-shaped tip 6 of the pipe 2 to be welded and the connecting pipe 4 (see FIGS. 2A and 2C). (The positions of 0 ° and 180 ° shown), the groove cutting angle α ₁ formed at the U-shaped bottom 7 opposed to the tongue-shaped tip 6 is increased, while the groove cutting angle α ₂ formed at the U-shaped bottom 7 is large. Portion (90 shown in FIG. 2B)
At the 込 み and 270 ° positions).
The connection pipe 4 is formed so as to be equal and smoothly continuous.

The connecting pipe 4 is attached to the pipe 2 to be welded by overlay welding the groove thus formed as shown in FIG.

As described above, the groove cut angle α ₁ formed at the tongue-shaped tip 6 of the pipe 2 to be welded and the connecting pipe 4 is small, and the U-shaped bottom 7 is opposed to the tongue-shaped tip 6. When the groove 10 is formed so that the groove cut angle α ₂ formed in the groove ₁₀ is large and the groove cut angle α of the other part is made continuous between the welded pipe 2 and the connection pipe 4, the tongue-shaped tip is formed. Since the strength of the portion 6 is increased and the strength of the U-shaped bottom 7 is reduced, the difference in strength between the tongue-shaped tip 6 and the U-shaped bottom 7 is reduced, so that deformation during overlay welding is reduced. Be able to be held down. Therefore, the misalignment between the pipe 2 to be welded and the connecting pipe 4 is reduced due to the reduction in the deformation.

The present invention is not limited to the above embodiment, but may be applied to a case in which a groove is formed on the outer side of the inclined joint between the pipe to be welded and the connecting pipe, and the outer groove is welded from the outside. It goes without saying that various changes can be made without departing from the spirit and scope of the present invention.

[0015]

According to the method for welding a tilted joint of the present invention,
The groove formed in the inclined joint of the pipe to be welded and the connection pipe is formed at the tongue-shaped tip with a small groove cut angle, and the groove formed at the U-shaped bottom opposed to the tongue-shaped tip. Since the angle is large and the shape is continuous so that the groove cut angle of the other part is equal in the pipe to be welded and the connecting pipe,
The strength of the tongue-shaped tip can be increased, the strength of the U-shaped bottom can be reduced, and the difference in strength between the tongue-shaped tip and the U-shaped bottom can be reduced. It is possible to obtain an excellent effect that generation is reduced, and at the same time, misalignment between the welded pipe and the connection pipe is also reduced.

[Brief description of the drawings]

FIG. 1 is a cutaway side view showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a groove cutting angle at each position of a groove formed in the inclined joint portion of FIG. 1;

FIG. 3 is a side view showing an example of a tilt joint.

FIG. 4 is a side view showing the shape of each of the inclined joint portions in FIG. 3 at each position.

FIG. 5 is a cut-away side view showing an example of a groove formed in a conventional inclined joint portion.

FIG. 6 is a cut-away side view showing a deformed state when the groove of FIG. 5 is overlay-welded.

[Description of Signs] 2 Pipe to be welded 3 Inclined surface 4 Connection pipe 5 Inclined joint 6 Tongue-shaped tip 7 U-shaped bottom 10 Groove

Claims (1)

(57) [Claims] 1. A method for welding a connection pipe to a pipe to be welded by butt-welding a connection pipe to a pipe to be welded on an inclined surface obtained by cutting a circular pipe at an angle other than 90 ° with respect to an axis of an axis. Formed on both the pipe to be welded and the connecting pipe at the inclined joint
The tongue-shaped tip has a small bevel cut angle, the U-shaped bottom facing the tongue-shaped tip has a large bevel cut angle, and the other portions have a bevel cut angle of the welded pipe and the connecting pipe. And forming a continuous groove so as to be the same as in step (a), and then welding the groove by welding to attach a connecting pipe to a pipe to be welded.