JPS5828030B2 - Automatic arc welding device for pipe and tube sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic arc welding device for circumferentially welding a tube sheet and the end of a tube passing through the same by covering the tube sheet with an inert gas.

FIG. 1 is a diagram showing the configuration of a conventional automatic arc welding device of this type. In the figure, 1 is a tube plate, 2 is a tube that passes through the tube plate 1, and 3 is an end portion that is rotatably fitted into the tube 2. 4 is a torch support device that rotates together with the centering hardware 3 and supports the welding torch 5; 6 is a wire reel that rotates together with the welding torch 6; 7 is a welding wire 8 fed from the wire reel 6; a tubular wire guide that guides the
9 is a welding head housing that rotatably supports the welding head 10 that rotates together with the welding torch 5; 11 is an eye bolt that hangs the welding head housing 10;

With the above structure, circumferential welding is performed while spraying inert gas from the welding torch 5 to the welded part between the tube 2 and the tube sheet 1. However, when welding materials such as carbon steel and low alloy steel, Therefore, even with such conventional equipment, welding can be performed smoothly.

However, if the material is titanium, stainless steel, or Inconel, which easily oxidizes, gas shielding only the welded part may cause defects in the welded part, so it is not necessary to gas shield the weld bead, which is in a high temperature state immediately after welding. It became necessary.

This invention was made in view of the above points, and provides an automatic arc welding device for pipes and tube sheets that can gas-shield even the weld bead in a high temperature state by only partially changing the centering fittings. be.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

The figures all show centering fittings according to the present invention.
Since everything other than the centering fitting 12 is the same as that shown in FIG. 1, illustration thereof is omitted.

In FIGS. 2 to 4, reference numeral 13 denotes a shielded chamber provided in the centering fitting 12, which is provided so that the end of the outer periphery abuts against the tube plate 1, and a part of the outer periphery is connected to the welding torch 7. The tip is cut large enough to be inserted.

13a is an abutment portion that abuts against the tube plate 1, and 13b is a cutout portion on the outer periphery.

By using the centering metal fitting 13 configured as described above, the open end 13a of the shielding chamber 13 of the centering metal fitting 12 constantly abuts against the tube sheet 1 during welding, so that the centering metal fitting 12 is supplied from the welding torch 7. The inert gas fills the shielding chamber 13 and shields the welded portion, and also shields the weld bead in a high temperature state to prevent oxidation.

In addition, since it is easy to maintain a constant distance between the electrode of the welding torch 5 and the tube sheet 1, the distance between the electrode of the welding torch 5 and the tube sheet 1 can be easily maintained, regardless of the protrusion length of the tube sheet 1 of the tube 2, and regardless of whether the tube 2 is melted or not. , the arc length can be kept constant.

As described above, according to the present invention, circumferential automatic arc welding is possible for materials such as titanium, which are easily oxidized, and there is almost no need to adjust the welding torch depending on the protrusion length of the pipe from the tube sheet. This can improve work efficiency.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing the configuration of a conventional device, Figures 2 to 4
The drawings show an embodiment of the centering fitting according to the present invention, in which FIG. 2 is a front view, FIG. 3 is a side view, and FIG. 4 is a longitudinal sectional view. In the figures, the same reference numerals indicate the same or Buddhist monk parts, and 1
is a tube plate, 2 is a pipe, 5 is a welding torch, 12 is a centering fitting,
13 is a shielding chamber, and 13b is a notch of the shielding chamber.

Claims (1)

[Scope of Claims] 1. An automatic arc welding device for circumferentially welding a tube sheet and a tube passing through it by covering it with an inert gas. A centering metal fitting whose end part is rotatably fitted into the tube and rotates together with the welding torch is provided, and the centering metal fitting has a part of its outer periphery cut out and a shield whose open part abuts against the tube sheet. An automatic arc welding device for welding a tube and a tube plate, wherein a chamber is provided, and the welding torch is guided by a cutout on the outer periphery of the shielded chamber.