A pulse welding apparatus such as a pulse arc welding apparatus or a short-circuiting arc welding apparatus utilizing pulse discharge, wherein there is provided a pulse current waveform control circuit which feeds a desired pulse arc current to the arc welding power source that supplies pulse arc current to the welding load unit, the circuit being so designed as to effect optimum welding without adjusting or changing the circuit components. Even under various welding conditions or environments, furthermore, it is allowed to prevent defective welding during the arc welding caused by the magnetic blow phenomenon and to prevent defective welding such as undercut or sputtering caused by disturbances in the welding torch. The pulse current waveform control circuit is realized as a microcomputerized digital circuit, and the pulse arc current is controlled by the control operation of a program, in order to realize a desired current control by changing the program but without changing the circuit. By utilizing the memory, furthermore, the optimum welding current waveform parameter or a desired arc length signal is learned during the first welding, and the arc length feedback control or the current waveform control is effected during the second welding using a program prepared with the thus learned welding current waveform parameter or the desired arc length signal as a reference. Thus, the molten mass is prevented from being erroneously removed by the magnetic blow phenomenon, and a change in the arc length is suppressed that is caused by disturbance in the welding torch, contributing to improving the welding quality under various welding environments.

Pulse welding apparatus

A contact tip suitable for electric arc welding has a consumable electrode. The contact tip has a body which defines a bore through which the electrode is able to pass to enable electric current from a welding power supply to be transferred from the body to the electrode. The body, in part of the length of the bore between an inlet end and an outlet end, has at least one region (herein referred to as a primary contact region) at which the body is adapted to enable primary electrical contact with the electrode, and along a remainder part of the length of the bore, the body is adapted such that any secondary contact between the body and the electrode along the remainder part does not substantially short circuit the primary electrical contact in the primary contact region of the bore.

Consumable electrode arc welding

PROBLEM TO BE SOLVED: To solve the problem that a workability is poor and a control cables are likely to cause disconnection because bundled and integrated control wires must be moved together with a wire feeding equipment which is separated from a welding power supply, when transported. SOLUTION: The consumable electrode type arc welding equipment is a type in which an output control power supply PS for a standby welding period is provided in a welding power supply WER2, a control power supply SP incorporating a feeding device which inputs a control voltage from a power cable is provided in a wire feeding device WSR2, a spectrum expansion communication part which transmits and receives a control signal by a spectrum diffusion communication method between the wire feeding device WSR2 and the welding power supply WER2 via a power cable. The control voltage, which the control power supply SP incorporating a feeding device inputs, is supplied from the output control power supply PS for a standby welding period during a welding standby period, supplied from an arc voltage during a welding period, and supplied from a no-load voltage of the welding power supply WER2 during a period of a no-load voltage output. COPYRIGHT: (C)2003,JPO

Consumable electrode type arc welding equipment

In an electric arc welder for creating an arc welding process between a consumable electrode advancing through a contact tip and a workpiece, the welder including a power supply to create an arc current and arc voltage and having a first lead connected to the contact tip and a second lead connected to the workpiece, the improvement comprising dividing the contact tip into an upper tip section and a lower tip section with an insulator electrically isolating the sections, a first switch selectively shiftable to a conductive state connecting one of the power supply leads to said upper tip section, a second switch selectively shiftable to a conductive state connecting the one lead to the lower tip section and a switch operating network creating a first switch signal to shift the first switch to its conductive state and/or a second switch signal to shift the second switch to its conductive state to control the effective CTWD of the arc welding process.

Arc welder and torch for same

PROBLEM TO BE SOLVED: To provide a gas shielded arc welding method where the generation of spatters can be suppressed even in high speed welding without depending on welding speed, further, the uniformization of the shape of toes is satisfactory, a wide and flat bead shape can be obtained, and cracking resistance, blow hole resistance or the like are excellent as well. SOLUTION: In the gas shielded arc welding method where pulse welding is performed using a solid wire, the solid wire comprises S, Si, Mn, C and P each by prescribed quantity, and the balance Fe with inevitable impurities, and in which pulse peak current (Ip) in a pulse P of pulse welding is ≥350 A, a pulse peak period (Tp) is 0.5 to 2.0 msec, and further, as a shielding gas, a gaseous mixture composed of, by volume, 75 to 98% Ar, and the balance one or more selected from CO 2 and O 2 is used. COPYRIGHT: (C)2008,JPO&INPIT

Gas-shielded arc welding method

PURPOSE: To reduce spatters at the arc regenerating time by passing the second base current during the short circuit term of the body to be welded and wire, then by cutting the second base current and by returning to a pulse current or the first current. CONSTITUTION: A integrating circuit 141, comparators 151, 152 and signal reversing element 161, analog switching element 193 are arranged in the equipment circuits. The welding voltage detected by a voltage detector is inputted into the comparator 151 and the arc maintaining voltage Vc is inputted into the comparator 151 from an arc maintaining voltage setting part 22 as well. When a short circuit is caused between the wire and the body to be welded during the welding, the welding voltage v is reduced and becomes a short circuit voltage. In this case, the second base current IB 2 having higher value than that of the first base current IB 1 is passed by comparing the welding voltage v and arc holding voltage Vc. At the short circuit releasing time, the second base current IB 2 is cut and returned to the original. With this method, the spatter at the arc regenerating time is reduced. COPYRIGHT: (C)1986,JPO&Japio

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Papers

Arc welding equipment