Claims
- 1. A pulse welding apparatus comprising:
- a pulse current waveform control circuit for outputting a group of pulse currents including a plurality of pulse currents having one of more than one pulse width, more than one pulse peak value and more than one pulse interval, a smoothed current waveform of the group of pulse currents becoming a maximum peak value during a pulse group duration at a predetermined time after a beginning of outputting the group of pulse currents, said group of pulse currents being periodically repeated to form a train of said group of pulse currents;
- a timing unit for setting, based on welding conditions, the predetermined time occurring at any time after the beginning of outputting the group of pulse currents during the pulse group duration;
- a smooth current waveform generator for generating a signal representing the smoothed current waveform of the group of pulse currents, wherein said pulse current waveform control circuit generates said plurality of pulse currents based on said signal; and
- a pulse arc current waveform generator for generating a pulse arc current waveform by superimposing a continuous base current onto the train of said pulse group currents.
- 2. A pulse welding apparatus according to claim 1, wherein said pulse current waveform control circuit comprises:
- a pulse group period setting device for setting a pulse group period in accordance with a wire-supplying speed;
- a pulse group duration setting device for setting a pulse group duration;
- a pulse group waveform setting device for setting a pulse group waveform;
- a pulse width setting device for setting a pulse width of each pulse forming said pulse group waveform;
- a pulse period setting device for setting a pulse period of said each pulse;
- a pulse shaper for outputting pulse group currents shaped by set signals from each of said devices;
- a base current outputting device for outputting a base current to which the train of pulse group currents is superposed; and
- an adder for superposing the train of said pulse group currents to said base current.
- 3. A pulse welding apparatus according to claim 2, wherein said pulse group waveform setting device comprises:
- a flip flop which receives said pulse group period signal and pulse group duration signal to produce a signal during the pulse group duration;
- a variable resistor for setting a separation timing of a molten droplet from beginning of outputting the pulse group till the pulse peak value is reached;
- a timer which operates in accordance with a setting of said flip flop;
- an OP amplifier for amplifying the output of said flip flop;
- a resistor and a capacitor which form a charging circuit when an output of said OP amplifier rises;
- a resistor which forms a discharge circuit together with said capacitor when the output of said OP amplifier falls;
- a first transistor for controlling said timer to turn ON;
- a charging circuit transistor for selecting time constants of said charging and discharging circuits;
- a discharge circuit transistor;
- an inverting buffer which controls said flip flop to turn and said discharge transistor to turn ON; and
- an inverting circuit which inverts the output of said OP amplifier to output a hill-shaped envelope signal of the pulse group current.
- 4. A pulse welding apparatus according to any one of claims 2 or 3, wherein said pulse group period setting device is adapted to set the pulse duration of said group of pulse currents in accordance with said wire-supplying speed.
- 5. A pulse welding apparatus according to claim 4, wherein pulse intervals of said group of pulse currents are controlled to vary according to the pulse group period set in accordance with said wire-supplying speed.
- 6. A pulse welding apparatus according to claim 3, wherein pulse intervals of said group of pulse currents are controlled by the pulse group period setting device to vary according to the pulse group period set in accordance with said wire-supplying speed.
- 7. A pulse welding apparatus according to claim 2, wherein pulse intervals of said group of pulse currents are controlled by the pulse group period setting device to vary according to the pulse group period set in accordance with said wire-supplying speed.
- 8. A pulse welding apparatus comprising:
- a pulse current waveform control circuit for outputting a group of pulse currents including a plurality of pulse currents having more than one pulse peak value, a smoothed current waveform of the group of pulse currents becoming a maximum peak value during a pulse group duration at a predetermined time, said group of pulse currents being periodically repeated to form a train of said group of pulse currents;
- a timing unit for setting, based on welding conditions, the predetermined time occurring at any time after the beginning of outputting the group of pulse currents during the pulse group duration; and
- a pulse arc current waveform generator for generating a pulse arc current waveform by superimposing a continuous base current onto the train of said pulse group currents.
- 9. A pulse welding apparatus comprising:
- a pulse current waveform control circuit for outputting a group of pulse currents including a plurality of pulse currents having more than one pulse width, a smoothed current waveform of the group of pulse currents becoming a maximum peak value during a pulse group duration at a predetermined time after a beginning of outputting the group of pulse currents, said group of pulse currents being periodically repeated to form a train of said group of pulse currents;
- a timing unit for setting, based on welding conditions, the predetermined time occurring at any time after the beginning of outputting the group of pulse currents during the pulse group duration;
- a smoothed current waveform generator for generating a signal representing the smoothed current waveform of the group of pulse currents, wherein said pulse current waveform control circuit generates said plurality of pulse currents based on said signal; and
- a pulse arc current waveform generator for generating a pulse arc current waveform which is formed by superimposing a continuous base current onto the train of said pulse group currents.
- 10. A pulse welding apparatus comprising:
- a pulse current waveform control circuit for outputting a group of pulse currents including a plurality of pulse currents being spaced by more than one pulse interval, a smoothed current waveform of the group of pulse currents becoming a maximum peak value during a pulse group duration at a predetermined time after a beginning of outputting the group of pulse currents, said group of pulse currents being periodically repeated to form a train of said group of pulse currents;
- a timing unit for setting, based on welding conditions, the predetermined time occurring at any time after the beginning of outputting the group of pulse currents during the pulse group duration;
- a smoothed current waveform generator for generating a signal representing the smoothed current waveform of the group of pulse currents, wherein said pulse current waveform control circuit generates said plurality of pulse currents based on said signal; and
- a pulse arc current waveform generator for generating a pulse arc current waveform by superimposing a continuous base current onto the train of said pulse group currents.
Priority Claims (8)
Number |
Date |
Country |
Kind |
1-45935 |
Feb 1989 |
JPX |
|
1-56960 |
Mar 1989 |
JPX |
|
1-102765 |
Apr 1989 |
JPX |
|
1-102766 |
Apr 1989 |
JPX |
|
1-102767 |
Apr 1989 |
JPX |
|
1-102768 |
Apr 1989 |
JPX |
|
1-102769 |
Apr 1989 |
JPX |
|
1-156414 |
Jun 1989 |
JPX |
|
Parent Case Info
This is a Continuation of application Ser. No. 07/601,717 filed Nov. 19, 1990, abandoned.
US Referenced Citations (6)
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EPX |
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Nov 1989 |
EPX |
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May 1990 |
EPX |
58-176074 |
Oct 1983 |
JPX |
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SUX |
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Sep 1969 |
GBX |
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Non-Patent Literature Citations (1)
Entry |
Ueguri et al, "Study of Metal Transfer in Pulsed GMA Welding", Welding Journal, Aug. 1985, pp. 242 et seq. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
601717 |
Nov 1990 |
|