JPH09141449A - Seam welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the quantity of wear generated locally at the tip of a rotary electrode ring by providing an extremely small angle at the relative position between the travel line for rotary electrode rings and the welding seam of a lap joint part. SOLUTION: The travel line for rotary electrode rings E1 and E2 is provided with the extremely small angle to the welding seam of the lap joint part. The couple of rotary electrode rings E1 and E2 while made vertically open are inserted into the welding start end of the lap joint part (A). The couple of rotary electrode rings E1 and E2 are pressed against the start point (B). Pressed surfaces and of the electrode surfaces of the tips of the electrode rings move in order to the left along the width of the electrode surfaces (C) and (D). In the figure, (E) shows the movement positions of the pressed surfaces 8a) and (a) at the positions where the couple of rotary electrode rings E1 and E2 reach welding end terminals. The electrode travel line is given the extremely small angle and the pressed surfaces and which come into contact with metal plate end parts of the electrode surfaces move along the width of the electrode surfaces, so that the deformation of the electrode surfaces due to a welding bead formed between the electrode rings is dispersed uniformly along the electrode surface width of the electrode ring tips.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seam welding method used for jointing two metal plates.

[0002]

2. Description of the Related Art Conventionally, when a plate joint formed by slightly overlapping two metal plate materials (workpieces) is sandwiched between a pair of rotating electrode wheels and seam welded, as shown in FIG. A seam welding machine body 40 having a pair of rotary electrode wheels E1 and a rotary electrode wheel E2, a so-called clamp device 41 for positioning and holding two plate materials S1 and S2, and a clamp jig device 42 having a clamp device 41. It is composed of.

In this case, the jig device is movable with respect to the fixed welding machine main body, and the clamp jig moving type in which seam welding is performed while the clamp jig device 42 moves on the work side, and conversely the work side. Clamp for positioning and holding
There are two methods of moving the electrode, in which the jig device 42 is a fixed type and welding is performed while the welding machine 40 side is moving. In both of these, the traveling lines of the rotary electrode wheels E1 and E2 are always advanced at the advancing angle which coincides with the welding line L.

Generally, in this seam welding, as described above, the positional relationship between the electrode wheel and the end of the metal plate of the lap joint is always fixed as shown in FIG. As a result, the flat pressing surface (a) of the electrode wheel tip gradually wears and deforms locally as shown in FIG.

When the electrode wheel is used in such a deformed state, one side of the electrode surface comes into contact with the other plate as shown in FIG.

In order to avoid this phenomenon, therefore, as shown in FIG. 8, the electrode which makes the wear amount uniform by moving the tip end surface of the rotating electrode wheel by a fixed amount in the left-right direction (electrode surface width direction) for each welding. Measures have been taken by installing a shift device.

On the other hand, after the welding work is performed at regular intervals, before the deformation adversely affects the welding quality, the electrode tip is cut or polished and shaped by the cutting device until it reaches the initial flat state. Came.

[0008]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is that in the seam welding that has been used for plate joints so far, the relative position between the electrode running line and the metal plate end of the welding line is fixed. Therefore, the deformation of the electrode wheel must be frequently corrected by dressing, and the method of shifting the electrode wheel complicates the structure. It is rational to reduce the consumption of the electrode wheel and simplify the welding equipment. It was difficult to promote.

In addition, recently, a so-called tailored blank material is manufactured by using the scrap material of the scraping for the purpose of reuse, or by butt-welding and integrating metal plates having different plate thickness and materials according to the functional use. In the field, the mash seam welding, which is considered to be more advantageous in terms of manufacturing cost than the conventional laser welding and electron beam welding, has been put into practical use, and the seam welding method with less wear of the rotary electrode wheel has been improved. Has been attracting attention.

[0010]

Therefore, the present invention has been developed in view of the above trends, and has the following technical means. That is, a lap joint formed by stacking metal plates is sandwiched by rotating electrode wheels, and the rotating electrode wheels are rotationally driven while the necessary pressing force and welding current are applied to the joint portions to perform seam welding. In the method, an angle is provided at a relative position between a welding line of the joint portion and a traveling line of the rotating electrode wheel, and a surface of the rotating electrode wheel that comes into contact with an end of the metal plate has a welding start point to a welding end point. It is characterized in that the electrode surface width (W) is changed during the welding process.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the method of the present invention in which a pair of rotating electrode wheels E1 and E2 are attached to a lap joint portion of a plate material.
FIG. 3 is a plan view showing an outline of an electrode moving type in which a traveling line is provided with a relative angle. FIG. 2 is a plan view showing the outline of the electrode moving type in which the welding line of the lap joint portion of the plate material is angled with respect to the straight running line of the rotating electrode wheel for easy understanding.

As is well known, the rotary electrode wheels E1 and E2 used for seam welding are made of a copper alloy in a disk shape.
The disk-shaped electrode wheel has a flat tread surface as an electrode surface on the tip circumference. When plate joining is performed by seam welding using this rotating electrode wheel, the two plate members S1 and S2 are firmly clamped and held by the clamp device with their ends facing each other with a slight overlap margin. While driving the distance between the welding start end and the welding end end of the clamped butted portion with a pair of rotating electrode wheels E1 and E2,
During that time, the welding pressure and welding current necessary for welding are applied to proceed.

In the case of mash seam welding, the basic structure is the same as that of the above seam welding. However, in the case of this mash seam welding, literally a large pressure force is applied between the electrodes to smooth the overlap margin. Proceed with seam welding.

The width of the welding line is narrower than the width (W) of the electrode surface at the tip of the electrode wheel. Considering the width of the welding line, the jig device is set at the advancing angle provided with α or β, which is the angle obtained from the welding length, so that it enters the width (W) of the electrode surface at the tip of the electrode wheel in one welding operation. Alternatively, by moving the main body of the welding machine, a pressing surface (a) that comes into contact with the end of the metal plate of the electrode surface from the welding start end to the welding end end within the allowable range of the electrode surface width (W) at the electrode tip is moved. ) Will move. That is, the relative position between the tip of the electrode wheel and the welding line, which is the above-mentioned drawback, does not always coincide and be fixed.

Further, since the rotating electrode wheel is consumed, the length of the welding line and the circumference of the electrode ring cannot be made to coincide with each other. This means that in the next welding cycle, the same as the step of the previous welding line. The tip of the electrode wheel cannot step on the trace.

That is, by providing a small angle between the welding line and the relative position of the jig device or the traveling line of the welding machine, the amount of wear on the electrode surface can be uniformly distributed in the electrode surface width (W) direction. It will be possible.

FIG. 3 is a sectional view of the electrode running line of FIG. 1A in which the pressing surface (a) of the electrode surface contacting the end of the metal plate of the lap joint during the running process of the pair of rotating electrode wheels E1 and E2. 6A and 6B are schematic diagrams showing a state in which (a) sequentially moves in the electrode surface width (W) direction from the welding start point to the welding end point.

In this case, the traveling line of the pair of rotating electrode wheels E1 and E2 is provided with a minute angle α or a minute angle β with respect to the welding line L of the lap joint, and the pair of rotating electrode wheels E1 and E2 is provided. Will advance line A or line B in FIG.

FIG. 3A shows a pair of rotating electrode wheels E1,
The rotating electrode wheel E2 is inserted into the welding start end of the lap joint with the upper and lower sides open. In (B), the pair of rotating electrode wheels E1 and E2 press the starting point. (C) and (D) The pressure surfaces (a) and (a) of the electrode surface at the tip of the electrode wheel sequentially move to the width (W) direction of the electrode surface, and thus to the left in the A line. (E) shows the moving positions of the pressure surfaces (a) and (a) at the position where the pair of rotating electrode wheels E1 and rotating electrode wheel E2 reach the welding end end.

As described above, the electrode running line is provided with a minute angle, and the pressing surface (a) contacting the metal plate end of the electrode surface,
By moving (a) in the electrode surface width (W) direction, it is possible to uniformly disperse the electrode surface deformation due to the welding beat generated between the electrode wheels in the electrode surface width (W) direction at the tip of the electrode wheel. .

[0021]

As described above, according to the seam welding method of the present invention, by providing a very small angle at the relative position between the traveling line of the rotating electrode wheel and the welding line of the lap joint, the rotation is performed. The pressure surface of the electrode wheel does not follow the previous welding line, that is, the same trace as the end of the metal plate, and the amount of wear locally generated at the electrode wheel tip can be greatly reduced. Therefore, the conventional electrode shift device is not required, and the number of times of dressing the electrode wheel can be reduced, thereby reducing the seam welding equipment cost and extending the life of the electrode wheel.

[Brief description of the drawings]

FIG. 1 is a plane view showing an outline of an electrode moving type in which a traveling line of a pair of rotating electrode wheels is provided with an angle with respect to a welding line L formed on a lap joint portion of a metal plate, which is an embodiment of the method of the present invention. It is a figure.

FIG. 2 is a plan view showing an outline of an electrode moving type in which an angle is provided to a welding line L formed on a lap joint of a plate material with respect to a straight traveling line of a rotary electrode wheel.

3] In the electrode running line of FIG. 1A, the pressing surface (a) of the electrode surface which is in contact with the metal plate end of the lap joint during the running process of the rotating electrode wheel from the welding starting point during the welding process It is the schematic which shows the transition which moves to an electrode surface width (W) direction one by one by the time of a welding end point.

FIG. 4 is an explanatory view showing the principle of conventional seam welding of a plate joint.

FIG. 5 is a cross-sectional view of the tip of the electrode wheel showing the positional relationship between the pressure surface (a) of the electrode surface of the rotary electrode wheel and the end of the metal plate of the lap joint by the conventional seam welding method for plate joints.

FIG. 6 is a cross-sectional view of the tip of the electrode wheel showing wear and deformation of the pressure surface of the electrode surface of the rotating electrode wheel by the conventional seam welding method for plate joints.

FIG. 7 is a cross-sectional view of an electrode tip in which a lap joint portion is pressed by a rotating electrode wheel that has been worn and deformed by a conventional seam welding method for plate joints.

FIG. 8 is a cross-sectional view of a tip of an electrode when a rotating electrode wheel is shifted by an electrode shift device in a conventional seam welding method for plate joints.

[Explanation of symbols]

S1 ... Metal plate E1 ... Rotating electrode wheel S2 ... Metal plate E2 ... Rotating electrode wheel L ... Welding line (end of metal plate) (B) ... Pressurized surface of electrode surface W ... Width of electrode surface

Claims (1)

[Claims] 1. A lap joint formed by stacking metal plates is sandwiched by rotating electrode wheels, and the rotating electrode wheels are rotationally driven while the necessary pressing force and welding current are applied thereto to form the joint portions. In the seam welding method, an angle is provided at a relative position between a welding line of the joint portion and a traveling line of the rotary electrode wheel, and a surface of the rotary electrode wheel that comes into contact with an end of a metal plate is welded from a welding start point to a welding end point. A seam welding method, characterized in that the electrode surface width (W) is changed during the welding process up to the point.