JPS62282776A - Terminal part welding method for body to be welded - Google Patents

Abstract

PURPOSE:To prevent the burn through at welding start and completion end parts and improve the quality of the weld zone by transferring the arc for working to the arc induction fitting arranged at the butt welding end of the body to be welded or the vicinity. CONSTITUTION:The arc induction fitting 2, 3 consisting of such a metal as a brass or copper and having the arc induction parts 2b, 3b located higher than the butt parts 2a, 3a of the body 1, 1' to be welded are arranged at the start end X and terminal end Y of the butt part Z of the body 1, 1' to be welded. In case of a arc torch 5 being set to the start end X of the butt part Z, the arc 4 can be formed between the arc torch 5 and arc induction fitting 2b, so the excess heat input into the butt part start point X can be prevented. It is similar at the finishing point as well. In this way, the quality of the weld zone can be improved.

Description

[Detailed Description of the Invention] 6. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a bath welding method for butt welding of plate-shaped objects to be welded, and particularly to a bath welding method suitable for butt welding steel plates together using an arc. .

[Conventional example]

Generally, when thin steel plates are butted against each other and bath welded using an arc such as a plasma arc, if arc bath welding is applied across both ends, the melt will fall from the welding start end and the welding end end, creating a hole. It has been known. The main reason for this is said to be that heat is most difficult to dissipate at both ends of the steel plate because the steel plate is welded while being held down by the presser fittings from both sides.

Therefore, conventionally, as shown in Fig. 6, a thin steel plate 1.1'
Start welding at a point X' that is more than a few fins inward from one starting end Alternatively, as shown in Fig. 4, one tab and 1B, 1'A and 1'B are provided at the welded end of each steel plate 1.1', and one tab and 1'B are provided. There is a method of starting arc welding from the starting end of tab 1'A and ending welding at the terminal end of tabs 1B and 1'H.

[Problem that the invention seeks to solve]

In the case of the former mentioned above, the welding of the butt weld does not cause holes due to dripping, but there is a major drawback in that both ends of the butt surface of the steel plate are not welded more than a few millimeters.
If the positions of , Y' are not determined accurately and welding is carried out, the unwelded part will be longer than necessary (7tJ), and conversely, the weld will have the disadvantage of dripping and creating holes etc. In the latter case, the tab portion must be cut after welding is completed, which not only complicates the work, but also wastes steel plate material and increases the cost.

[Means for solving problems]

When the nozzle of an arc torch that generates a processing arc passes directly above the butt welding end of the workpiece, an arc inducing metal fitting is disposed in contact with or near the butt welding end of the workpiece. It is characterized in that the processing arc is formed at.

[For production]

According to such a welding method, it is possible to adjust the arc induction fitting to the butt weld ends, that is, the butt weld start end and the butt weld end, or both, and to adjust the arc induction to the height of the bath contact surface. By increasing the height of the metal fitting t'141E, the processing arc formed in the arc-inducing metal fitting can be moved to the welding point slightly inside the butt welding start end of the workpiece, or the butt welding end of the workpiece can be As the welding progresses to the bath contact point somewhat inside the welding point, the processing arc can be transferred from that welding point to the arc-inducing metal fitting, and the welding result of the butt weld end can be greatly improved.

〔Example〕

An embodiment of the arc welding method according to the present invention will be explained with reference to FIGS. 1(A) and 1(B).

Arc-inducing metal fittings 2.6 made of metal such as copper or brass are provided at the starting end X and the ending end Y of the abutting portion of the workpiece 1.1', such as a steel plate, respectively. Arc induction fittings 2.6
are the parts 2a and 3a that are pressed in the direction of the arrows to the starting end X and end Y of the abutting part of the welded workpiece 1゜1', respectively, the arc-inducing parts 2b and 3b that are placed higher than these, and the 0 arc-inducing metal fittings 2 that exceed them. Each of the parts 2a and 3a of .6 is grown to a thickness less than or equal to the thickness of the workpiece 1.1', and has the role of absorbing a portion of the heat at the end of the workpiece during bath welding, and 1.1' serves to maintain the distances X,'! between the start end X and end Y of the abutting part and the respective arc attracting parts 2b and 3b at a predetermined constant value, and the parts 2a and 3a are not necessarily necessary. .The arc-inducing parts 2b and 3b always have a part substantially higher than the level of the welding surface, and their height relative to the thickness of the workpiece 1.1' is approximately at the distance x, y from the starting end X and the ending end Y. and each arc-inducing portion 2
When the heights of a and 3a are exactly equal, the distance X is slightly larger than y due to the difference in heating of the welded part depending on the direction of welding progress.

Next, an example of this welding method will be described.

For the first time, the arc torch 5 that generates the arc 4t for processing is stationary above the arc inducing metal fitting 2 or is advancing at a predetermined speed, and in any case, when it is located above the arc inducing metal fitting 2, the arc torch 5 is used for processing. Arc 4 is generated. First, the processing arc 4 is formed between the nozzle of the arc torch 5 and the arc inducing portion 2b of the arc inducing metal fitting 2. When the nozzle of the arc torch 5 advances along the welding line and reaches directly above the starting end 4. Strictly speaking, the anode point corresponding to the cathode point of the arc torch is still formed in the arc attracting portion 2b.

As the arc torch 5 further advances along the welding line and enters the distance within the starting point X, for example several times, the tip of the arc torch 5, the nozzle, becomes closer to the welding surface than the arc attracting portion 2b. , the arc 4 for subsequent processing formed between the nozzle and the arc-inducing portion 2b moves to the abutting portion of the workpiece 1.1'. Therefore, the anode point of the working arc 4 (which has a certain spread) is not formed at the starting end of the butt of the workpiece 1.1', and the relatively small amount of heat of the working arc 4 and the heat from the molten part are applied. It just happens. The amount of heat is set to 0 in the arc attracting part 2b and the distance X thereof so that it is convenient to appropriately melt the butt starting end X part.Then, as welding progresses, the arc torch 5 When the welding point is reached, the distance between the nozzle of the arc torch 5 and the arc inducing part 6b of the arc inducing fitting 6 is shorter than the distance between the nozzle of the arc torch 5 and the welding surface, so the processing arc 4 is butted. The arc transitions from a certain point inside the terminal end Y to the arc attracting portion 6b. Butt end Y
The abutting portion between the abutment and a point somewhat inward is melted and welded primarily by heat from the molten metal further inward. In these embodiments, the heat at the butting start and end of the welded objects 1 and 1' is transmitted to the arc induction fitting 2.6, but the thermal resistance between them is greater than that of a single body. Therefore, it was confirmed that if metal fittings with the same thickness as the thickness of the welded object 1.1' were butted together and placed under pressure at the starting end XX, terminal end Y, the melt would drop at the butting starting end X, terminal end Y, and the vicinity thereof. has been done.

Next, in FIG. 2, an arc-inducing metal fitting 2 that is pressed against the butt starting end X is provided with an inclined portion 2C. According to this, the thickness d of the portion 2b and the inclination angle t of the #I oblique portion 2C? By adjusting the slope part 2 to the machining arc 4
The butt starting end X can be preheated relatively favorably, so the butt starting end
And the entire vicinity can be welded in good condition. Note that the height of the portion of the arc-inducing metal fitting 2 that is pressed against the abutting starting end X is preferably approximately the same as the thickness of the objects to be welded 1, 1'.

As can be seen from the above description, in the embodiment of the present invention, a specific arc-inducing metal fitting is pressed against the butt starting end X and end end Y of the welding object with a suitable blade, and the arc torch As the entire arc torch advances, the anode point of the processing arc moves from the arc induction fitting to the bath contact near the butt start end X, or from the welding point inside the butt end Y to the arc induction fitting, and the butt end part It is something to be bathed in.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, it is possible to satisfactorily weld the butt ends of the objects to be welded together, or to sufficiently improve the welding process, and to significantly improve the quality of the welded objects. You can improve. In addition, since there are no tabs or the like as in the conventional method, it is possible to save on materials, and at the same time, the welding process can be simplified since there is no need to cut the tabs, etc., which has great effects.

[Brief explanation of drawings]

FIGS. 1 and 2 are diagrams for explaining an embodiment of the present invention, respectively, and FIGS. 6 and 4 are diagrams for fully explaining each conventional method. 1.1'... Workpiece to be welded 2.6... Arc induction fitting 4... Arc for processing 5... Arc torch Z.
...Butt part patent applicant Origin Electric Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] In a welding method in which a working arc is generated between a non-consumable electrode and the workpieces to butt weld the workpieces, the nozzle of the arc torch that generates the working arc is directly above the butt welding end of the workpiece. Welding the end portion of the workpiece, characterized in that the processing arc is formed on an arc inducing metal fitting that is placed in contact with or near the butt weld end of the workpiece. Method.