JPH0318064Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention relates to a seam welding device suitable for application to, for example, can manufacturing equipment.

``Prior Art'' Conventionally, there has been known a can manufacturing apparatus that manufactures a can by overlapping two opposing sides of a rectangular metal plate to form a cylindrical shape, and then seam welding the overlapped parts. However, the seam welding apparatus applied to this type of can manufacturing apparatus had a configuration as shown in FIG.

In this figure, 1 is a copper wire, 2 and 3 are disc-shaped electrode rollers, and 4 is a wire support roller.The electrode rollers 2 and 3 are each supported by a support mechanism, and by these support mechanisms. A force is applied in the direction of pressing each other, and the rotational force of a motor (not shown) is transmitted through the copper wires 1, 1, respectively, so that they are rotated. 5
is the can body to be welded, and a metal plate bent into a cylindrical shape is fed from the left side of the drawing by a feeding mechanism (not shown), and as shown in Figure 3, the metal plate is bent into a cylindrical shape to form a belt-like shape. A portion S to be welded is guided between electrode rollers 2 and 3. As a result, the part S to be welded of the can body 5 to be welded is
It is designed to be sandwiched and pressurized by electrode rollers 2 and 3 via the electrode rollers 2 and 3. Further, reference numeral 6 shown in FIG. 2 denotes a welding start end (hereinafter referred to as the start end) Sa and a welding end end (hereinafter referred to as the start end) of the welded part S.
This is a proximity switch that detects Sb (abbreviated as termination section) (see FIG. 3), and a detection signal from this proximity switch 6 is supplied to a control circuit 7. On the other hand, 8 is a welding power supply circuit that supplies a welding current between the electrode rollers 2 and 3, and outputs a welding current according to a command value supplied from the control circuit 7. 9 is the starting end Sa and the ending end Sb of the welded part S
a first setting device for setting the welding current Iw necessary when welding the steady-state part Sc (see Fig. 3) excluding
Reference numeral 10 denotes a second setting device for setting the welding current Imin required when welding the starting end Sa and the ending end Sb of the welded part S. The control circuit 7 outputs the welding current Iw or Imin at the value set by the first setting device 9 or the second setting device 10 to the welding power source circuit 8 based on the detection signal of the proximity switch 6. Instruct. In this case, the starting end of the welded part S
Welding current Imin when welding Sa and end part Sb
must be lower than the welding current Iw when welding the steady section Sc. This applies, for example, to the starting end of the welded part S, as shown in FIG.
When Sa reaches the position Δl before the line L connecting each axis of the electrode rollers 2 and 3, the starting end Sa is already in contact with the electrode rollers 2 and 3 via the copper wires 1 and 1, and welding This is due to the fact that current flows and, in addition, the direction of transfer of resistance heat generated at the bonding surface is limited to the direction of the stationary part Sc. The same can be said of the terminal end portion Sb of the welded portion S. Therefore,
In order to equalize the welding conditions for each part of the starting end Sa, the ending end Sb, and the steady part Sc, the welding current Iw>Imin must be satisfied. Based on the detection signal from the proximity switch 6, the control circuit 7 controls the welding current supplied between the electrode rollers 2 and 3 from the welding power supply circuit 8, as shown in FIG. First, before the start end Sa of the welded part S of the can body 5 to be welded reaches the line L connecting the axes of the electrode rollers 2 and 3, it is set by the second setting device 10. The welding current Imin is supplied between the electrode rollers 2 and 3, and then the starting end Sa reaches the line L,
When this is detected by proximity switch 6
During the period from T ₁ to T ₃ , the welding current Iw set by the first setting device 9 is supplied, and the steady portion Sc is welded. Next, after the time _T3 when the steady portion Sc passes on the line L and the rear end portion Sb passes on the line L and this is detected by the proximity switch 6, the welding current Imin increases again. Supplied.

"Problems to be Solved by the Invention" By the way, the welding current can be adjusted depending on various factors such as the material of the can body 5 to be welded, the pressure applied by the electrode rollers 2 and 3, and the welding speed (feed speed of the can body 5 to be welded). This must be done every time welding conditions are changed. In this case, in the conventional seam welding apparatus described above, the welding current Iw is adjusted by actually welding the can body 5 to be welded, and then the welding current Iw is adjusted by actually welding the can body 5 in the same manner. I had to make some adjustments to Imin. Therefore, there is a problem in that it takes time and effort to adjust the welding current as various welding conditions are changed, and this adjustment work is complicated.

This invention was made in view of the above-mentioned circumstances, and aims to provide a seam welding device that allows easy adjustment of welding current in accordance with changes in welding conditions.

"Means for Solving the Problem" This invention involves rotating each of the electrode rollers while sandwiching and pressurizing a band-shaped part to be welded where two sides of a metal plate overlap, and creating a gap between each of the electrode rollers. In a seam welding device that performs seam welding by supplying welding current to
Welding current supply means for supplying a welding current corresponding to a set voltage, detection means for detecting the relative position of the welded part with respect to the pair of electrode rollers, and a stationary part of the welded part other than both ends are welded. a first setting means for setting a welding current necessary for welding both ends of the welded part; a second setting means for setting a welding current necessary for welding both ends of the welded part; and control means for supplying a set voltage outputted from the first setting means or the second setting means to the welding current supply means, the first setting means having a constant voltage as a reference. Outputs the set first set voltage, and outputs the second set voltage.
The setting means is set based on the first set voltage outputted from the first setting means, and outputs a second set voltage that changes in conjunction with the first set voltage. .

"Function" When the first setting means is adjusted, the output of the second setting means increases or decreases proportionally. Once the means is adjusted, subsequent adjustment of the welding current accompanying changes in welding conditions can be made by simply adjusting the first setting means.

"Embodiments" Hereinafter, embodiments of this invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of this invention, and parts corresponding to those in FIG. 2 are designated by the same reference numerals and their explanations will be omitted.

In this figure, numeral 9 is a first setting device for setting the welding current Iw, and is composed of a variable resistor. A first fixed terminal 9a connected to one end of a resistor inside the first setting device 9 is connected to a constant voltage +V, and a second fixed terminal 9b connected to the other end of the resistor is grounded. There is. Further, the sliding terminal 9c connected to the slider inside the first setting device 9 is connected to the input terminal of the buffer amplifier _A1 in the control circuit 7.

On the other hand, 10 is a second setting device for setting the welding current Imin, and like the first setting device 9, it is constituted by a variable resistor. The first fixed terminal 10a of this second setting device 10 is a buffer amplifier.
connected to the output end of A ₁ , its second fixed terminal 10
b is grounded. Further, the sliding terminal 10c of the second setting device 10 is connected to a buffer amplifier in the control circuit 7.
Connected to the input end of _A2 . Note that the buffer amplifiers A ₁ and A ₂ are connected to the first setter 9 and the second setter 9.
The setting device 10 is provided so that its output is not affected by variations in load impedance.

In the above configuration, when the first setter 9 is adjusted, a voltage divided according to the position of the slider based on a constant voltage +V is output as the first set voltage V ₁ . . In addition, the second setting device 1
0 adjustment, the voltage divided according to the position of the slider based on the first setting voltage V ₁ output from the first setting device 9 becomes the second setting voltage V ₂ is output as Thereby, when the first setting device 9 is adjusted, the setting voltage V ₂ outputted from the second setting device 10 increases or decreases proportionally. In this case, the set voltage V ₂ is a value obtained by multiplying the set voltage V ₁ by an arbitrary multiplication factor between 0 and 1.0. Therefore, once the welding conditions are appropriate,
Once the setting device 9 and the second setting device 10 are adjusted, the welding current can be adjusted only by adjusting the first setting device 9 in accordance with subsequent changes in welding conditions.

"Effect of the invention" As explained above, according to this invention, the first setting means for setting the welding current necessary when welding the steady part of the welded part is set with a constant voltage as a reference. output the first set voltage, and
A second setting means for setting the welding current necessary when welding both ends of the welded part is set based on the first setting voltage output from the first setting means, and this first setting means is set based on the first setting voltage output from the first setting means. Since it outputs a second set voltage that changes in conjunction with the set voltage of
Once the first setting means and the second setting means are adjusted to provide appropriate welding conditions according to the material to be welded, if the welding conditions such as the welding speed are changed thereafter, the first setting means By simply adjusting the setting means, the second setting voltage also changes in conjunction with the setting means.
It is only necessary to adjust the setting means, and therefore, the effect that the welding current can be easily adjusted in accordance with a change in the welding conditions can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of this invention, FIG. 2 is a block diagram showing the configuration of a seam welding device applied to a conventional can manufacturing device, and FIG.
The figure is a perspective view for explaining the positional relationship between the electrode roller and the can body to be welded in the same seam welding device.
Figures A and B are diagrams for explaining the operation of the seam welding apparatus at the time of starting welding, and FIG. 5 is a diagram for explaining the operation of the seam welding apparatus. 2, 3... Electrode roller, 5... Can body to be welded, 6
... Proximity switch (detection means), 7 ... Control circuit (control means), 8 ... Welding power supply circuit (welding current supply means), 9 ... First setting device (first setting means),
10...Second setting device (second setting means), V ₁ ...
...First set voltage, V ₂ ...Second set voltage, S
...Welded part, Sa...Welding start end, Sb...Steady part, Sc...Welding end.

Claims (1)

[Claims for Utility Model Registration] A band-shaped part to be welded where two sides of a metal plate overlap are sandwiched between a pair of electrode rollers and each electrode roller is rotated while applying pressure, and a welding current is supplied between each of the electrode rollers. A seam welding apparatus that performs seam welding by means of a welding current supply means for supplying a welding current corresponding to a set voltage between the pair of electrode rollers, and detecting a relative position of the welded part with respect to the pair of electrode rollers. a detection means; a first setting means for setting a welding current necessary when welding a steady portion of the welded part excluding both ends; and a welding current necessary when welding both ends of the welded part. a second setting means for setting, and a control for supplying a set voltage output from the first setting means or the second setting means to the welding current supply means based on the detection result of the detection means. means, the first setting means outputs a first set voltage set with reference to a constant voltage, and the second setting means outputs a first set voltage set with reference to a constant voltage, and the second setting means outputs a first set voltage set with reference to a constant voltage.
A seam welding device characterized by outputting a second set voltage that is set based on a set voltage of and that changes in conjunction with the first set voltage.