JP2629931B2 - Pipe welding equipment to header - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe welding apparatus for a header, which is particularly effective for MIG welding between a header and a pipe, such as attaching a stub tube to a header of a boiler. is there.

[Prior Art] When a stub tube is erected on an outer peripheral surface having a curved surface such as a boiler header and attached by MIG welding, to obtain a good bead, the torch angle is changed depending on a groove shape. There must be.

That is, as shown in FIG. 5, a pipe 1 is formed into a base material 2 having a curved surface.
In order to secure a welding margin, a wide-angle groove 3 is generally required when the pipe 1 is erected on the outer periphery of the pipe 1 and, as shown in FIG. When welding to 4, usually, the groove 3 is formed at an acute angle because it is easy to secure a welding margin. Therefore, in order to weld a stub tube, which is a tube, to the tubular header wall, as shown in FIG. 7, the width of the header 5 is wide (wide angle) and the width of the header 5 is axial. A groove 3 having an elliptical external appearance that is narrow (a sharp angle) is required. Here, in order to obtain a good bead, it is generally considered better to arrange the torch 6 at an angle that divides the angle of the groove 3 into two. In the wide (wide angle) portion 7 and the narrow (acute angle) portion 8, the torch angle must be changed as shown in FIGS.

[Problems to be Solved by the Invention] However, since a large number of stub tubes are attached to the header 5 of the boiler in a dense state, if the torch 6 is inclined to increase the angle of the torch 6, the inclined torch 6 will be It cannot be turned because it interferes with other stub tubes. Therefore, automation of this type of welded joint is difficult,
It was a very difficult and inefficient operation, relying exclusively on manual welding.

Conventionally, as a means for welding a narrow portion, a method in which a nozzle tip at the tip of the torch has a curvature to perform welding while avoiding interference with other pipes has been considered. It is not possible to cope with the case where the angle of 3 changes, and even if it is used, a good bead cannot be obtained.

The present invention has been made in view of the above-described circumstances, and has a nozzle tip having a curvature and a torch provided with a rotation mechanism, which can cope with a change in the angle of a groove, and a header that can be used even in a narrow portion. It is an object of the present invention to provide a pipe welding apparatus of the type described above, which makes it possible to automate a welding operation, to reduce the operation, and to reduce the cost.

Means for Solving the Problems According to the present invention, a torch is attached to a rotating part which is fitted to a pipe to be attached and is supported so as to be rotatable in the circumferential direction around the pipe, and the rotating part is rotated. In the pipe welding apparatus to a header, which automatically turns the outer periphery of the pipe to the torch to perform welding by forming the torch, a nozzle tip of the torch is formed to be bent at a required curvature, and the nozzle tip is further attached to the torch. The torch is provided with a rotating mechanism that rotates around the axis of the torch.

[Operation] Therefore, when the torch is turned along the outer periphery of the pipe to automatically perform welding, when the nozzle tip is turned by the turning mechanism so as to bend inward in the turning radial direction of the torch. The angle of entry of the nozzle tip into the welded portion can be increased, and when the nozzle tip is rotated by the rotating mechanism so as to bend in the turning direction of the torch, the nozzle tip enters the welded portion. Angle can be reduced.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

1 and 2 show an embodiment of the present invention. As shown, a bent nozzle tip 9 having a required curvature is attached to a torch tip 10, and the torch tip 10 is attached to the torch. The main body 11 is rotatably fixed to the main body 11 with its axis as a rotation axis. Further, a gear 12 is provided on an outer peripheral portion of the torch tip portion 10 so as to be fitted integrally with the outer peripheral portion, and a gear 13 meshed with the gear 12 is provided.
Is mounted on the torch main body 11, and the above-described gears 12 and 13 and the stepping motor 14 constitute a rotating mechanism 15.

Further, a torch 16 comprising the torch tip 10 having the above-mentioned turning mechanism 15 and the torch main body 11 is inserted into a turning portion 18 of a torch turning device 17 shown in FIG.
Is held so that it is inclined inward. The rotating part 18 is
The stub tube 19 has a C-shaped shape having a notch 21 leading to an opening 20 at the center thereof, and is provided on the outer periphery of the rotating portion 18 and has a cutout substantially equivalent to the rotating portion 18. It is supported rotatably clockwise and counterclockwise by a rotating portion support portion 22 having a notch 21 '.

Further, the torch turning device 10 is provided with a stepping motor 23 capable of driving the turning portion 18 to turn clockwise and counterclockwise alternately via a gear mechanism (not shown).

Here, the stepping motors 14 and 23 are control devices.
25, the torch 16 and the rotating part 18 of the torch turning device 10 are controlled by a command from the control device 25,
The torch 16 operates synchronously, and the turning angle of the torch tip 10 and the nozzle tip 9 can be set according to the turning angle of the torch 16. In addition, nozzle tip 9
Is curved at a required curvature, and its tip is located substantially on the axial extension of the torch 16.

The torch 16 in the figure is connected to an electrode wire 24 by a feeding device (not shown) such as a push type, a pull type, or a push-pull type.
It goes without saying that a welding rod is fed to the tip of the nozzle tip 9 so that welding can be performed.

 Hereinafter, the operation will be described.

As shown in FIG. 7, the stub tube 19, which is a tube erected with the end thereof aligned with the groove 3 formed in the header 5 of the boiler, is provided with the rotating part 18 and the rotating part supporting part. The torch swivel device 17 is arranged so as to be positioned at the center opening 20 through the notches 21 and 21 ′ of the stepper motor 22.
The electrode wire 24 at the tip of the nozzle tip 9 is melted while the rotating part 18 is alternately rotated clockwise and counterclockwise by 180 ° or more by driving the rotating part 23 and welded in two or three layers.

At this time, as shown in FIG. 3, in a wide (wide angle) portion 7 of the groove 3 (a portion perpendicular to the axis of the header 5), the rotation angle set in the control device 25 by the driving of the stepping motor 14. The torch tip 10 is rotated so that the bending direction of the nozzle tip 9 faces the stub tube 19,
Welding is performed while turning the nozzle tip 9 into the groove 3 with the angle of penetration into the groove 3 being large, and as shown in FIG. 4 (a), the narrow portion 8 (the acute angle) of the groove 3 (the header 5). As described above, the torch tip 10 is rotated by driving the stepping motor 14 so that the bending direction of the nozzle tip 9 is directed to the turning direction of the turning portion 18 (see FIG. 2). The penetration angle of the nozzle tip 9 into the groove 3 is determined by a torch.
The welding is carried out by turning at a small angle substantially equal to the inclination angle of 16.

However, as shown in FIG. 4 (b), even in the narrow (sharp angle) portion 8 of the groove 3 shown in FIG. As shown in FIG. 3, welding is performed in a state where the angle of penetration of the nozzle tip 9 into the groove 3 is increased.

The curvature of the nozzle tip 9 is set so that when the tip is directed to the stub tube 19, the angle of entry is such that the angle of the wide (wide angle) portion 7 of the groove 3 is bisected. Is set in advance so as to be an invasion angle that bisects the angle of the narrow (acute) portion 8 of the groove 3.

Therefore, according to the above, the nozzle tip 9 is provided with a required curvature, and the torch 16 is provided with the rotating mechanism 15, so that the angle of entry of the nozzle tip 9 into the groove 3 according to the rotation of the torch 16 can be reduced. Since it can be changed to correspond to the change in the angle of the groove 3, welding of the pipe such as the stub tube 19 to the header 5 can be easily and automatically performed.

Further, since it is not necessary to incline the torch 16, it is possible to make a welded joint in a narrow portion.

Further, since the welding can always be performed while maintaining the optimum entry angle of the nozzle tip 9 with respect to the angle of the groove 3, a good bead can be obtained.

In addition, by providing the pipe welding machine for the header as described above, the welding operation of the stub tube 19 and the like to the header 5 which has conventionally relied on manual welding is automated, so that the welding operation is significantly reduced and the cost is greatly reduced. Down can be planned.

The apparatus for welding a pipe to a header according to the present invention is not limited to the above-described embodiment, and can be used for welding pipes to various headers other than the boiler header and the stub tube. It is needless to say that various methods and configurations can be adopted as long as the chip can be rotated, and various changes can be made without departing from the gist of the present invention.

[Effects of the Invention] As described above, according to the pipe welding apparatus for a header of the present invention, various excellent effects as described below can be obtained.

The angle of entry of the nozzle tip into the groove can be freely adjusted according to the change in the groove angle.

Adjusting the angle of entry of the nozzle tip does not require the torch to be tilted, thus enabling a welded joint at a narrow portion.

According to the above, the welding joint of the pipe to the header can be easily and automatically performed, so that the welding operation can be significantly reduced and the cost can be significantly reduced.

[Brief description of the drawings]

1 is an enlarged front view of a part of one embodiment of the present invention, FIG. 2 is a perspective view of one embodiment of the present invention, and FIG. 3 is a header showing a welding state of one embodiment of the present invention. 4 (a) and 4 (b) are sectional views parallel to the axis of the header showing a welding state according to one embodiment of the present invention, and FIGS. 5 and 6 show conventional examples. FIG. 7 is a front view of a groove when a stub tube is welded to a header wall. In the figure, 5 is a header, 9 is a nozzle tip, 15 is a rotating mechanism,
16 is a torch, 17 is a torch turning device, 18 is a rotating part, and 19 is a stub tube (tube).

Continued on the front page (72) Inventor Kazuo Aikawa 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside the Technical Research Institute, Ishikawajima-Harima Heavy Industries Co., Ltd. Harima Heavy Industries, Ltd.

Claims (1)

(57) [Claims] 1. A torch is attached to a rotating part which is fitted to a pipe to be mounted and is rotatably supported in a circumferential direction about the pipe, and the torch is rotated by rotating the rotating part. In a pipe welding apparatus for a header that automatically welds by rotating the outer circumference of a pipe, a nozzle tip of a torch is formed to be bent at a required curvature, and the nozzle tip is further rotated around an axis of the torch. An apparatus for welding a pipe to a header, wherein a rotating mechanism that moves is provided on the torch.