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An improvement in a short circuiting arc welding apparatus comprising a single D.C. power supply causing a welding current to pass through a welding wire extending from a holder and between said wire and workpiece at a molten metal pool on the workpiece, wherein the current flows in response to an a

An improvement in a short circuiting arc welding apparatus comprising a single D.C. power supply causing a welding current to pass through a welding wire extending from a holder and between said wire and workpiece at a molten metal pool on the workpiece, wherein the current flows in response to an arc voltage and the welding wire is subjected to a succession of welding cycles. Each of the welding cycles includes an arcing condition during which said wire is spaced from the pool and the energy applied to said wire exceeds a given value raising the temperature at the end of the wire to a molten temperature to form a molten metal ball on the end of the wire and a short circuit condition during which the molten metal ball on the end of the wire first contacts said molten metal pool and then transfers from the wire to the workpiece by a necking action breaking the molten metal ball from the wire to initiate an arc in a subsequent welding cycle. The welding cycles have a generally fixed frequency of repetition. The improvement comprises providing the power supply with a chopper circuit for applying a succession of input current pulses across the wire and workpiece at a pulse frequency substantially greater than the generally fixed frequency of repetition of the welding cycles and a pulse width changing circuit for adjusting current flow between the wire and the workpiece many times during each of the welding cycles.

대표청구항 ▼

In a short circuiting arc welding apparatus comprising a single D.C. power supply means for causing a welding current to pass through a welding wire extending from a holder and between said wire and a workpiece at a molten metal pool on said workpiece, said current flowing in response to an arc volt

In a short circuiting arc welding apparatus comprising a single D.C. power supply means for causing a welding current to pass through a welding wire extending from a holder and between said wire and a workpiece at a molten metal pool on said workpiece, said current flowing in response to an arc voltage, wire feeding means for feeding said wire from said holder toward said workpiece whereby said welding wire is subjected to a succession of welding cycles, each of said welding cycles including an arcing condition during which said wire is spaced from said pool and the energy applied to said wire exceeds a given value raising the temperature at the end of said wire to a molten temperature to form a molten metal ball on the end of said wire and a short circuit condition during which said molten metal ball on the end of said wire first contacts said molten metal pool and then transfers from said wire to said workpiece by a necking action breaking said molten metal ball from said wire to initiate an arc in a subsequent welding cycle, wherein said welding cycles have a generally fixed frequency of repetition, the improvement comprising: said power supply includes means for applying a succession of input current pulses across said wire and workpiece at a pulse frequency substantially greater than said generally fixed frequency of repetition and pulse width changing means for adjusting current flow between said wire and said workpiece many times during each of said welding cycles, including a switch means for directing said put pulses across said wire and said workpiece, a high impedance branch circuit in parallel with said switch means and means for opening said switch means during said short circuit condition immediately before said molten metal ball is broken to initiate said arc.