JPH11300479A - Controller for inverter type seam welding machine and welding method by the machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to weld synchronously with the shape of a base material and a welding speed by making it possible to speed up the welding speed, making the control of energizing time and cooling time an arbitrary time unit, for instance, ms (millisecond) unit, moreover making no unwelded part occur, further making it possible to arbitrarily change energizing interval and welding current. SOLUTION: A welding current being made to flow through the base material, is converted into a trapezoidal wave alternate current type. The cooling time after energizing is set to, for instance, a 1 ms unit. A conventional thyristor type is shown by a drawing (a). For the cooling time after energizing, at least 20 ms (when the welding current is 50 Hz) of one cycle, is necessary. By setting the control of the cooling time to the ms unit, the speeding-up of the welding speed is possible without occurring unwelded parts. Also, by controlling the value of the welding current, and by controlling an energizing time at the same time, the improvement of weldability and the speeding-up are possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an inverter type seam welding machine in which a welding current is trapezoidal wave AC type and a welding method in the inverter type seam welding machine.

[0002]

2. Description of the Related Art As is well known, a seam welding machine has a pair of rotating electrode plates connected to a secondary conductor of a welding transformer, and transfers the base material to the pair of electrode plates while moving the base material at a predetermined speed. The base material is welded by repeatedly applying pressure, energizing and releasing.

FIG. 8 is an electric circuit diagram of a conventional seam welding machine, and shows a thyristor type circuit. A pair of thyristors 52 and 53 connected in reverse parallel are interposed between the primary side of the welding transformer 51 and the power supply.
A pair of electrode plates 54, 5 connected to the secondary side conductor 1
In step 5, the base material 56 is welded. As shown in FIGS. 8 and 9, this thyristor-type welding current is repeated in a substantially sinusoidal manner toward the positive electrode side and the negative electrode side every half cycle according to the power supply frequency (50 Hz / 60 Hz), and is applied to the base material 56. Flows.

[0004] The waveform of the thyristor-type welding current is as shown in FIG. 9. In the case of actual welding to a base material, FIG.
As shown by 0, one cycle is energized, the next one cycle is a cooling period, and the next one cycle is energized, and this is repeated to weld the base metal. Further, as shown in FIG. 11, there are cases where two cycles are energized, the next two cycles are set as a cooling period, and this is repeated to weld the base metal.

[0005]

The conventional thyristor-type welding method in the seam welding machine can control only one cycle unit according to the power supply frequency, and cannot control the output time regardless of the power supply frequency. there were. In other words, the cooling period is one of the power supply frequency (50 Hz / 60 Hz).
Only one cycle can be taken, and one cycle is 20 ms when the power supply frequency is 50 Hz. Therefore, the cooling period after energization requires at least 20 ms,
When the welding speed is increased, there is a problem that welding is lost.

In the conventional control method, a preset energizing time and a cooling time are alternately repeated, or only the energizing time is controlled, and the control of the welding current is controlled only at a predetermined value. there were. In other words, the control time can be controlled only in units of one cycle according to the power supply frequency,
Further, the welding current could only be changed by a fixed value by an external signal.

[0007] The present invention has been made in view of the above points, and the control of the energizing time and the cooling time can be performed in arbitrary time units.
For example, the welding speed can be increased in units of ms (milliseconds), and welding can be prevented from occurring. In addition, the interval between welding currents and welding current can be arbitrarily changed, and the shape of the base material and welding speed can be adjusted. It is an object of the present invention to provide a control device for an inverter-type seam welding machine and a welding method for the inverter-type seam welding machine, which enable welding synchronized with the above.

[0008]

Therefore, in the control device for an inverter type seam welding machine according to the first aspect of the present invention, a pair of rotary electrode plates 4 and 5 for pressurizing and energizing the base material 6 and the rotating electrode plates 4 and 5 are provided. A welding transformer 11 for passing a welding current to the base material 6 by the electrode plates 4 and 5; an inverter circuit 10 for driving the welding transformer 11; and an inverter control device for oscillating the switching elements of the inverter circuit 10 at a predetermined frequency. 7. An inverter-type seam welding machine comprising a base material 6 and a trapezoidal-wave alternating current flowing through the base material 6, wherein a cooling time after energizing the base material 6 can be set in arbitrary time units. It is characterized by comprising control means 20, 30.

With this configuration, the conventional 1
Although the cooling time could only be controlled on a cycle-by-cycle basis, by controlling the cooling time on a per-ms basis, for example, it is possible to increase the welding speed without causing welding omissions.

In the control apparatus for an inverter type seam welding machine according to a second aspect of the present invention, the cooling time after the energization is in milliseconds. Thus, by controlling the cooling time in units of ms, it is possible to increase the welding speed without causing welding omission.

The control device for the inverter type seam welding machine according to the third aspect is characterized in that the control device is provided with second control means 20 and 30 capable of arbitrarily setting a welding current.
This makes it possible to improve the weldability and increase the speed.

A control device for an inverter type seam welding machine according to a fourth aspect of the present invention is characterized in that the control device includes third control means 20 and 30 capable of arbitrarily setting the energizing time.

According to a fifth aspect of the present invention, there is provided a control device for an inverter type seam welding machine, wherein a value of an energizing time, a cooling time, and a welding current can be variably set during welding. This makes it possible to input arbitrary welding conditions during welding, and by switching the energization time, cooling time, and timing of the welding current, it is possible to select conditions suitable for the welding speed anywhere in the straight section and corner section. Become.

In the control device for an inverter type seam welding machine according to the present invention, the energization time, the cooling time, and the welding current can be arbitrarily changed by an external signal. With such a configuration, the power supply interval and the welding current can be arbitrarily varied regardless of a preset program value, and welding can be performed in synchronization with the shape of the workpiece and the welding speed.

In a welding method for an inverter type seam welding machine according to a seventh aspect of the present invention, a pair of rotary electrode plates 4 and 5 for pressing and energizing the base material 6 and the base material 6 are formed by the rotary electrode plates 4 and 5. A welding transformer 11 for flowing a welding current, an inverter circuit 10 for driving the welding transformer 11, and an inverter control device 7 for oscillating a switching element of the inverter circuit 10 at a predetermined frequency are provided. An inverter-type seam welding machine in which a wave-current welding current is supplied, wherein a cooling time after energizing the base material 6 is performed in arbitrary time units to weld the base material 6. Features.

Thus, the cooling time can be controlled only in units of one cycle in the past, but by controlling the cooling time in units of ms, for example, it is possible to increase the welding speed without causing welding omission. be able to.

In a welding method for an inverter-type seam welding machine according to the present invention, the cooling time after the energization is in milliseconds. Thus, by controlling the cooling time in units of ms, it is possible to increase the welding speed without causing welding omission.

According to a ninth aspect of the present invention, a welding method for an inverter type seam welding machine is characterized in that the welding current is switched alternately between high and low.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. In the cooling time of one cycle unit, a phenomenon that a welding omission occurs when the welding speed is increased is observed. However, in order to solve the problem, the present invention controls the time in the inverter type seam welding machine to an arbitrary time unit, for example, The use of milliseconds makes it possible to increase the welding speed and to prevent welding omission. In addition, two types of control of the welding time and the welding current are prepared, and the current is alternately applied to improve the weldability and increase the speed.

Further, the seam welding is usually performed by using a programmed energizing time, a cooling time, and a welding current.
By inputting 0V), the current interval and the welding current can be arbitrarily varied regardless of the program value, and welding in synchronization with the shape of the workpiece and the welding speed is enabled.

FIG. 1 shows a block diagram of an inverter type seam welding machine.
Are provided with rotatable disk-shaped rotating electrode plates 4 and 5, respectively. The pair of electrode plates 4 and 5 make 2
The base materials 6 are welded by applying pressure and current.

The inverter control device 7 controls the output of a welding time, a welding current, a pressurizing signal, a rotation signal for rotating the electrode plates 4, 5 and the like for seam welding the base material 6. In addition, an inverter circuit 1 as a main circuit
0 is IGBT (InsulatedGate Bipolar Transistor)
) And a semiconductor switching element such as a transistor, and is configured as a full bridge circuit (see FIG. 7). Then, the inverter control device 7 controls on / off of the switching element of the inverter circuit 10 at a predetermined frequency, and the output current of the inverter circuit 10 is converted by the welding transformer 11 into a trapezoidal wave AC type welding current.

The electrode driving device 1 includes the electrode plates 4 and 5
The rotation is controlled by a signal from the control device 12. Further, the electrode plates 4 and 5 rotate while passing a welding current. Control device 1
The pressurizing mechanism 13 is driven by a signal from 2, and the pressurizing mechanism 13 presses and opens the electrode plates 4 and 5. Further, the control device 12 is a device that controls the pressure, drive, rotation speed, and the like of the electrode plates 4 and 5 by a signal of the inverter control device 7. The program box 14 is a device for writing data necessary for the material, thickness and the like of the base material 6 in the inverter control device 7.

Further, a current control command circuit 15 for arbitrarily changing the magnitude of the welding current is provided, and an analog signal of, for example, a voltage of 0 to 10 V is input to the current control command circuit 15 to supply the welding current. Is variable. For example, the welding current is made variable by taking in a signal proportional to the rotation of the electrode plates 4 and 5 from the tachogenerator. Further, the energization signal command circuit
Controls the interval of energization to the base material 6, and specifically, enables a cooling period after energization to be set in ms (millisecond) units. For example, it is composed of a pulse generator.

The power source of the seam welding machine is shown in FIG.
In the above, three-phase 200 V / 400 V is used, but single-phase 200 V / 400 V may be used.

Next, the configuration of the inverter control device 7 will be described with reference to FIG. Reference numeral 20 denotes a microcomputer. The microcomputer 20 has a control program for a seam welding machine incorporated therein, and performs overall control. The crystal oscillating unit 21 outputs a frequency suitable for the microcomputer 20, and the prescaler 22 divides the frequency from the crystal oscillating unit 21 into an appropriate frequency. The first counter 24 counts up at the output of the prescaler 22, and returns to 0 when the value becomes equal to the value of the first counter register 23. The first
Of the first counter 24
Is set, and the frequency (about 3 kHz) of the PWM circuit 27 is determined. The frequency of the PWM circuit 27 can be arbitrarily set according to the set value of the first counter register 23.

The first coincidence detecting circuit 25 compares the contents of the first counter 24 and the contents of the first counter register 23, and clears the first counter 24 when the contents become equal. Further, the first flip-flop 26 outputs an inverted signal to the PWM circuit 27 every time an output from the first coincidence detection circuit 25 is output.
The M signal is synchronized (PWM synchronization signal).

The second counter 31 has a prescaler 2
The counter is incremented by the output of 2, and returns to 0 when the value becomes equal to the value of the second counter register 30. The second counter register 30 sets an upper limit value of the second counter 31 and determines an output frequency (50 Hz / 60 Hz) of the welding current. In addition, although it is an inverter type seam welding machine,
The frequency of the welding current corresponds to the power supply frequency so that the cycle of the commercial power supply can be managed. Also, the second
The counter register 30 is also used for cycle time management of non-energization time such as initial pressurization time, cooling time, and holding time. When controlling the cooling time in milliseconds, the first counter register 30 is set to a value at which this output frequency becomes 0.5 ms.

The second coincidence detecting circuit 32 compares the contents of the second counter 31 and the contents of the second counter register 30 and clears the second counter 31 when the contents become equal. When the contents of the second counter 31 and the contents of the second counter register 30 match, the microcomputer 20 is interrupted by the second match detection circuit 32 to manage the energized time and the non-energized time. I have. The second flip-flop 33 outputs an inverted signal for each output of the second coincidence detection circuit 32, and synchronizes the output frequency of the welding current with the inverted signal (output synchronization signal).

The PWM circuit 27 generates a PWM waveform from a current reference value from the microcomputer 20, a current feedback value from the current transformer CT, and a PWM synchronization signal from the first flip-flop 26. The D / A converter 35 converts a current reference from the microcomputer 20 into an analog voltage.
The / D converter 36 converts a current feedback value from the current transformer CT into a digital signal.
The A / D converter 36 controls the effective value of the current.

The gate drive circuit 34 has a PWM
A drive signal for the IGBT of the inverter circuit 10 is generated by a signal, an output synchronization signal, and a gate control signal from the microcomputer 20. Current transformer CT
Detects a primary current of the welding transformer 11, and the welding transformer 11 uses a step-down transformer to obtain a welding current.

FIG. 7 shows an inverter circuit 10 of the inverter type seam welding machine. An AC power supply is rectified by a rectifier 40, smoothed by a capacitor 41, and supplied to a switching element. As shown in the drawing, the welding current waveform is a trapezoidal wave AC type, and a current is applied to the base material 6 via the electrode plates 4 and 5 on the positive electrode side and the negative electrode side at predetermined time intervals. FIG. 3A shows the waveform of the welding current in the case of continuous energization.

Next, control of the energization time will be described.
The PWM frequency in the PWM circuit 27 is usually about 3 k
Hz. The value of the first counter register 23 is set when the power of the inverter control device 7 is turned on so that the frequency becomes this frequency. As for the output frequency of the welding current, the value of the second counter register 30 is reset for each of the energization control and the non-energization control.

First, the sequence at the time of energization is as follows. The second counter 31 is stopped and its contents are set to zero. Next, a value at which the output frequency is obtained is set in the second counter register 30. For example, if the output frequency of the welding current is 50 Hz, the second flip-flop 33 is inverted at a conduction time of 10 ms, and a value that interrupts the microcomputer 20 is calculated and set. Note that this 10 ms is a half value of one cycle (20 ms in the case of 50 Hz). Next, the second flip-flop 33 is forcibly turned on. This is because current always starts flowing in the same phase. Next, the microcomputer 20 outputs a gate-on signal to the gate drive circuit 34 to activate the second counter 31.

As a result, the microcomputer 20 is interrupted every 10 ms thereafter, and the microcomputer 20 switches the second flip-flop 33 every time an interrupt is received.
Is checked, and if it is off, the energization cycle is managed by decrementing the energization count by one. Second flip-flop 33
When the count of energization becomes 0, half a cycle of energization still remains. During this time, microcomputer 2
0 completes the preparation of the next energized or non-energized data. Next, when an interrupt occurs, the energization is completely finished. The microcomputer 20 outputs a gate-off signal to the gate drive circuit 34.

When this energization cycle is set, that is, when energization of the positive electrode side and the negative electrode side is one cycle (one cycle), 1
The number of cycles, such as two cycles, is set by the energization signal command circuit 16.

The sequence of time management of the output frequency with no power supply (cooling) is as follows. First, the second counter 31 is stopped and its contents are set to zero. Next, a value at which the output frequency of the welding current is obtained is set in the second counter register 30. For example, if the frequency of the welding current is 50 Hz, the second flip-flop 3
3 is inverted, and a value that interrupts the microcomputer 20 is calculated and set. Then, the second flip-flop 33 is forcibly turned on, and the second counter 3
Start 1

As a result, the microcomputer 20 is interrupted every 10 ms thereafter, and the microcomputer 20 switches the second flip-flop 33 every time an interrupt is received.
Is checked, and if it is off, the non-energizing cycle is managed by decrementing the non-energizing count by one. When the de-energization count reaches 0, de-energization still remains for half a cycle. During this time, the microcomputer 20 completes the preparation of the next energized or non-energized data. Next, when an interruption occurs in the microcomputer 20, the non-energization is completely finished.

In the above example, energization and non-energization (cooling) are controlled in a cycle unit (20 ms unit when the welding current is 50 Hz). For example, one cycle of energization and one cycle of non-energization are performed. Alternatively, the energization signal command circuit 16 can arbitrarily set the energization to two cycles and the non-energization to two cycles.
Further, it is possible to set such that two cycles of energization and one cycle of non-energization are performed. In this way, the energization interval can be arbitrarily varied. Further, as shown in FIG. 4, the strength of the welding current may be varied to perform welding. The second counter register 3 is provided for each of the energization control and the non-energization control.
Since the set value of 0 is reset, an arbitrary energizing time and a non-energizing time can be set.

In the current control command circuit 15, for example, a voltage of 0 to 10V can be output, and an analog voltage signal from the current control command circuit 15 is input to the microcomputer 20. D /
The magnitude of the welding current is varied by a signal from the A conversion unit 35. That is, the microcomputer 20 sets (increases or decreases) the welding current at the time of the next energization based on the signal received from the current control command circuit 15, and sets the value of the welding current that is currently energized to “10”. , The welding current is set to “12” at the next energization after the non-energization.
Alternatively, it can be arbitrarily changed to “8”.

Also, by taking in a signal proportional to the rotation of the electrode plates 4 and 5 from a tacho generator (not shown), the welding current is changed according to the rotation speed of the electrode plates 4 and 5, that is, the welding speed of the base material 6. Can be varied. That is, when the welding speed is high, the welding current is increased, and when the welding speed is low, the welding current is reduced. Accordingly, appropriate welding can be performed even when the welding speed is high, as well as when the welding speed is low, and it is possible to prevent poor welding.

FIG. 3 (a) shows the waveform of the welding current in the case of continuous energization, and FIG. 3 (b) shows the waveform of the welding current in the continuous energization where the welding current is increased or decreased. Also, FIG.
The waveform of the welding current is shown in the case where the application of the large welding current is repeated for two cycles, the non-energization (cooling) is performed for one cycle, the small welding current is applied for two cycles, and the non-application is performed for one cycle. .

Next, the sequence for time management in an arbitrary time, for example, in milliseconds (ms) without power supply is as follows. First, the second counter 31 is stopped and its contents are set to zero. Then, when the unit of the cooling time is 1 ms, a value that gives 0.5 ms of the half cycle is set in the second counter register 30 and the second counter 31 is started. As a result, the microcomputer 20 is interrupted every 0.5 ms thereafter. The microcomputer 20 manages the de-energization cycle by decrementing the de-energization count by one every time an interrupt is received. When the count of the non-energization becomes 0, the non-energization still remains for 0.5 ms. During this time, the microcomputer 20 is energized next,
Alternatively, the preparation of the non-energized data is completed. Next, when an interruption occurs in the microcomputer 20, the non-energization is completely finished.

In this case, energization can be performed at an arbitrary cycle, and non-energization (cooling) can be arbitrarily set in units of 1 ms. One cycle of energization in this case is 20 ms when the output frequency of the welding current is 50 Hz. Therefore, the energization can be set to an arbitrary cycle, and the non-energization time can be set arbitrarily in units of 1 ms. Thereby, the non-energization time can be arbitrarily set each time according to the welding speed. For example, if the magnitude of the welding current is constant,
If the welding speed is low, set the non-energizing time longer, and if the welding speed is high, set the non-energizing time short, thereby improving weldability and speeding up without causing welding omission. it can.

Also, by combining the ability to arbitrarily set the magnitude of the welding current and the ability to arbitrarily set the non-energization time each time, welding can be reliably performed in accordance with the welding speed. It is possible to improve the weldability and increase the speed without causing welding omission.

FIG. 5 is a diagram showing non-energized time management of the conventional thyristor type and the inverter type of the present invention.
(A) is a conventional thyristor type, and the time of non-energization is 1
Only a cycle unit, that is, a 20 ms unit, which is one cycle when the frequency of the commercial power supply is 50 Hz, can be managed.
However, in the case of the present invention, as shown in FIG. 5B, the non-energization time can be set in units of 1 ms. Therefore, as shown in FIG. 6, the welding speed is greatly improved as compared with the conventional case. I was able to.

FIG. 6 shows a conventional example in the case where the welding speed is from 1 m to 60 m per minute (at the time of alternating current).
And the present invention (in the case of an inverter). FIG. 6 shows a case where the non-energization (cooling) time is 1 cycle (20 ms) in the case of the conventional example, and 1 ms in the case of the present invention. For example, when the welding speed is 1 m / min, the moving distance of the base material 6 during the non-energization time is 0.333 mm in the case of the conventional example, but is 0.016 mm in the case of the present invention. In the case of the present invention, the welding speed when the moving distance of the base material 6 is 0.333 mm when the power is not supplied is 20 m / min. That is, if the moving distance of the base material 6 is the same at the time of non-energization, the conventional example is 1 m / min, and the present invention is 20 m / m.
Therefore, the welding speed of the present invention is theoretically 20 times higher. Of course, the value of the welding current is appropriately set according to the welding speed.

In addition to controlling not only the cooling time in ms units but also the energizing time, the second counter register 30 is set for energizing control and non-energizing control. The value of the current can be set for each of the energization control and the non-energization control, so that the weldability can be improved and the speed can be increased without causing welding omission. In particular, the switching of welding conditions cannot be performed during welding in the past, and the apparatus is temporarily stopped, the selection is switched from a plurality of preset conditions, and the apparatus is restarted after the switching of the welding conditions. I was letting it.

However, according to the present invention, switching can be made possible by inputting a signal of an arbitrary condition (energization time, non-energization time, welding current) during welding. And, not only the switching of the welding current, but also the timing of the energizing time and the non-energizing time can be switched at the same time.
It is possible to select a condition at a welding speed anywhere in the corner.

In the above embodiment, the energizing time,
The case where the cooling time is controlled in the unit of ms has been described, but the cooling time is not limited to the unit of ms. For example, the control may be performed in ms units including a decimal point or in μs units. That is, these control times can be arbitrarily set by setting a desired value in the second counter register 30.

In the seam welding machine of the present invention, the energizing time, the non-energizing time, and the welding current can be independently controlled, and can be controlled in combination with each other.

[0052]

According to the present invention, conventionally, in many cases, when the welding speed is increased in the cooling time of one cycle unit, welding omissions often occur. However, by applying an inverter type welding machine,
By controlling the time such as the energizing time and the cooling time in arbitrary time units, for example, in ms units, it is possible to improve the welding speed without causing welding omission. Further, by using two types of control of the welding time and the welding current, it was possible to improve the weldability and increase the speed.

Further, the seam welding is usually performed by using the programmed energizing time, cooling time, and welding current. However, by inputting a signal from the outside, the energizing interval and the welding current can be changed regardless of the program value. It can be changed arbitrarily, and welding synchronized with the shape of the work and the welding speed can be made possible.

Also, it becomes possible to input arbitrary conditions (power supply time, cooling time, welding current) during welding.
Not only the switching of the welding current, but also the timing of the energizing time and the cooling time can be switched at the same time, so that it is possible to select the conditions suitable for the welding speed anywhere in the linear part and the corner part of the base material.

[Brief description of the drawings]

FIG. 1 is a block diagram of a seam welding machine according to an embodiment of the present invention.

FIG. 2 is a block diagram of the inverter control device according to the embodiment of the present invention.

FIG. 3A is a waveform diagram of a welding current in a case where continuous energization is performed in the embodiment of the present invention. (B) is a waveform diagram of the welding current when strong and weak continuous current is applied in the embodiment of the present invention.

FIG. 4 is a waveform diagram of a welding current in a case where strong and weak welding currents are alternately applied in the embodiment of the present invention.

FIG. 5 is a diagram for explaining non-energized time management between the conventional example and the present invention.

FIG. 6 is a diagram illustrating a movement distance of a base material when power is not supplied between a conventional example and the present invention.

FIG. 7 is a schematic circuit diagram of an inverter circuit according to an embodiment of the present invention.

FIG. 8 is a schematic circuit diagram of a conventional thyristor type welding machine.

FIG. 9 is a waveform diagram of a conventional thyristor-type welding current.

FIG. 10 is a diagram showing current and cooling of a conventional thyristor type.

FIG. 11 is a diagram showing energization and cooling of another example of the conventional thyristor type.

[Explanation of symbols]

 REFERENCE SIGNS LIST 4 rotating electrode plate 5 rotating electrode plate 6 base material 7 inverter control device 10 inverter circuit 11 welding transformer 15 current control command circuit 16 conduction signal command circuit 20 microcomputer 30 second counter register 31 second counter 32 second match Detection circuit 33 second flip-flop 34 gate drive circuit 35 D / A converter

Claims (9)

[Claims] A pair of rotary electrode plates (4) and (5) for pressurizing and energizing a base material (6), and a welding current is applied to the base material (6) by the rotary electrode plates (4) and (5). Flowing welding transformer (1
1) an inverter circuit (10) for driving the welding transformer (11); and an inverter control device (7) for controlling the oscillation of the switching element of the inverter circuit (10) at a predetermined frequency. An inverter type seam welding machine in which a trapezoidal alternating current welding current flows through (6), wherein a control means (20) capable of setting a cooling time after energizing the base material (6) in arbitrary time units. And (30) a control device for an inverter-type seam welding machine. 2. The control device for an inverter-type seam welding machine according to claim 1, wherein a cooling time after said energization is in milliseconds. 3. The control device for an inverter type seam welding machine according to claim 1, further comprising second control means (20) (30) capable of arbitrarily setting a welding current. 4. The inverter-type seam welding machine according to claim 1, further comprising third control means (20) and (30) capable of arbitrarily setting an energization time. Control device. 5. The method according to claim 1, wherein the values of the energizing time, the cooling time, and the welding current can be variably set during welding.
A control device for an inverter-type seam welding machine according to claim 4. 6. The control device for an inverter-type seam welding machine according to claim 1, wherein the energization time, the cooling time, and the welding current can be arbitrarily changed by an external signal. 7. A pair of rotary electrode plates (4) and (5) for pressurizing and energizing the base material (6), and a welding current is applied to the base material (6) by the rotary electrode plates (4) and (5). Flowing welding transformer (1
1) an inverter circuit (10) for driving the welding transformer (11); and an inverter control device (7) for controlling the oscillation of the switching element of the inverter circuit (10) at a predetermined frequency. An inverter-type seam welding machine wherein a trapezoidal alternating current welding current is applied to (6), wherein a cooling time after energizing the base material (6) is set in an arbitrary time unit to obtain a base material (6). A welding method in an inverter type seam welding machine characterized by welding. 8. The welding method for an inverter type seam welding machine according to claim 7, wherein the cooling time after the energization is in milliseconds. 9. The welding method for an inverter type seam welding machine according to claim 7, wherein the welding current is switched alternately between high and low.