JPH0216191B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a seam welding method for welding objects to be welded that are overlapped with each other.

Generally, when lap seaming the trailing end of a leading strip and the leading end of a trailing strip in a strip processing line, the welding process involves the following steps:
For example, the apparatus shown in FIG. 1 is used.
That is, the cutting device 8, the pressure roller mechanism 5, and the rotating electrodes 41, 42 are mounted on the underframe 2, which is movable in a direction substantially perpendicular to the conveying direction of the strip 9, for example, in the Y direction.
are arranged, and with the underframe 2 positioned at the end in the _Y1 direction, each end of the leading and trailing strips is cut by the cutting device 8, and then the ends 91, 91 of each strip are cut by an appropriate mechanism. 92 is wrapped by a small amount as shown in FIG. 3a. After the pair of pressure rollers 51 and 52 are brought close to each other in this state, the underframe 2 is moved in the _Y2 direction, and as shown in FIG. 2a and FIG. Gives plastic deformation. After this step, as shown in FIG. 3c, the strips 9 are separated from each other by a small amount in the
Seam welding is performed in the state shown in FIG. 2b by moving the underframe 2 in the _Y1 direction with the It has been plastically deformed. This results in a relatively thick strip being welded. That is, the seam welding of the strip ends was performed by reciprocating the underframe once. On the other hand, since this type of strip has a wide width, it takes a long time for the underframe to move back and forth in the Y direction, resulting in a long welding operation time.

By the way, there is usually a weld at the end of the strip.
Transport of the strip to the welding equipment has been stopped. That is, during welding operations, it is necessary to stop new supply of strips to appropriate strip processing lines that are processes subsequent to the welding process.
However, in general, the strip is transported and processed at extremely high speeds, for example at 300 m/min, in post-processes after the welding process. A so-called looping device must be provided between the device and the downstream device for storing the long strip. In this way, the longer the welding work time, that is, the stop time of the strip, the larger the capacity of the looping device becomes, raising the equipment cost and increasing the equipment area. It was hoped that it would be made smaller.

An object of the present invention is to provide a seam welding method that can shorten welding work time.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

In FIG. 4, 1 is a frame, and 2 is an underframe which is movable in the Y direction while being restrained by a positioning means 3, and is moved in the Y direction by a driving means (not shown). Reference numerals 41 and 42 are a pair of rotating electrodes that can be moved toward and away from each other. For example, the upper rotating electrode 41 is supported to move in the Z direction by a suitable driving means. 51,5
2, 61, and 62 are pairs of pressure rollers disposed on both sides of the welding direction, that is, the Y direction, across the rotating electrodes 41 and 42. For example, the pressure rollers 51 and 61 are driven by drive means 53 and 63, respectively. , for example, is connected to a hydraulic cylinder and supported so as to be movable in the Z direction. The above 51 to 53 and 61 to 63 constitute the first and second pressure roller mechanisms 5 and 6. Note that the rotating electrode 4
Cables 7, 7 for supplying power to the electrodes 1, 42 are connected, for example, to the electrode support brackets 43, 44, and the pressure roller support members 64, 65 of the second pressure roller mechanism 6 are connected to the electrode support brackets 43, 42, respectively. 4
4 and is supported in a non-contact state. 8 is a cutting device for cutting the end of the strip 9.

Next, the operation will be explained. Figures 4 and 5
In the figure, with the underframe 2 located at the end in the _Y1 direction, the leading strip 91 and the trailing strip 92 are connected to each other.
The end of the is cut by the cutting device 8, and after that,
A suitable mechanism, not shown, wraps each end of the strip by a small amount, as shown in Figure 3a. After this, the rotating electrodes 41, 42 and the first
Welding is performed by moving the underframe 2 in the _Y2 direction while maintaining the pressure rollers 51, 52 and 61, 62 of the second pressure roller mechanisms 5 and 6 in a pressurized state, respectively. That is, the strip 9 is plastically deformed at the lap portion by pressure rollers 51 and 52, and this plastically deformed strip 9
The ends of are welded by rotating electrodes 41 and 42.
Further, this already welded portion is plastically deformed by pressure rollers 61 and 62 and is formed into a relatively flat surface. After the pressure rollers 61 and 62 pass the end of the strip 9 in the _Y2 direction, the welding operation is completed. That is, the movement of the underframe 2 to an appropriate position in the _Y2 direction is detected by an appropriate detector, and the strip is conveyed in the _X1 direction or the _X2 direction based on the output signal of this detector. After welding, the pressure rollers 51, 52 and 61, 62 and the rotating electrodes 41, 42 are appropriately set apart, and then the underframe 2 moves to the end position in the _Y1 direction, that is, to the retracted position. . Of course, the movement of the underframe 2 to the retracted position, that is, the movement, is carried out at the same time as the strip 9 is being conveyed, so the time for stopping the conveyance of the strip may be the time that the underframe 2 is moving in the _Y2 direction. In this way, the time required for the welding operation to stop the strip is approximately half that of the conventional method.

In addition, in the conventional welding method shown in FIGS. 1 to 3 and the welding method according to the present invention, so-called welding conditions such as the respective pressing forces of the pressure roller mechanism and rotating electrode, welding current, and welding speed are kept constant. When maintained, the thickness of the welded part obtained by the conventional welding method; t ₁ and the thickness of the welded part obtained by the welding method according to the present invention; t ₂ have the following approximate relationship.

t ₂ /t ₁ ≒1.05 to 1.09 As described above, the welded part obtained by the welding method according to the present invention is slightly bulkier than the welded part obtained by the conventional method, but the time for stopping the strip is about Since only half the amount is required, the capacity of the looping device disposed between the welding process and the subsequent process can be reduced.

As shown in FIG. 4, for example, in the second pressure roller mechanism 6, the axis of the support member 64 that supports the pressure roller 61 and the axis of the cylinder rod of the driving means 63, for example, a fluid pressure operated cylinder, are aligned. If they are connected by hinge connection so that they do not coincide, the distance between the rotating electrode 41 and the pressure roller 61 can be made as close as possible. Of course, if the driving means 53 of the first pressure roller mechanism 6 is similarly provided, the distance between the pressure roller 51 and the rotating electrode 41 can be made closer.

As described above, according to the present invention, the welding time required to stop the strip is about half that of the conventional welding process, so the capacity of the looping device installed between the welding process and the post-process can be reduced, and the welding time required for stopping the strip can be reduced. The line equipment cost can be reduced and the equipment area can be reduced.

[Brief explanation of drawings]

Figure 1 is a front view of the conventional device, Figures 2 and 3 are
1, FIG. 4 is a front view showing an apparatus for carrying out the method of the present invention, and FIG. 5 is an explanatory diagram of the operation of FIG. 4. 2... Underframe, 41, 42... Rotating electrode, 5, 6
...first and second pressure roller mechanisms, 9, 9
1,92...Strip.

Claims (1)

[Claims] 1. In a seam welding method in which a workpiece to be welded is held and welded by upper and lower rotating electrodes and upper and lower pressure roller mechanisms, the pressure roller mechanisms are disposed on the front and rear sides of the rotating electrode in the welding direction. and a seam welding method in which welding is performed by the rotating electrode while plastically deforming the workpiece by the respective pressure roller mechanisms.