Abstract: An excellent welding tip in the feed stability of a wire, in the release capacity of foreign matter, and in the stability of current control, and a process for manufacturing such a tip economically, is achieved in accordance with a sectional shape of a guide hole opened and provided to a welding tip. The sectional shape is derived by forming a wire in a passable non-circular shape. The sectional shape of the guide hole may be a polygonal or elliptic shape, or approximately so. In the case of making the sectional shape of the guide hole polygonal, it is more preferable to make it a polygon circumscribing on a circle, for example, such a polygon circumscribing on a larger circle than the outer diameter of the wire to be inserted into the guide hole by 0.02-0.20 mm in diameter. Specifically, it is preferable to arrange the sectional shape as a triangle.

Abstract: An unconsumable electrode such as tungsten is opposingly arranged with a base metal to be welded. An AC arc welding power supply is connected between the base metal and the unconsumable electrode. A filler wire such as of aluminum is fed by a wire feeder toward an arc-generated part between the base metal and the unconsumable electrode. Also included is a wire-heating power supply for producing a pulsed current. The wire heating power supply heats the filler wire by supplying thereto a pulsed current in accordance with a sync signal from the AC arc welding power supply or a detection signal of an arc current i.sub.A or an arc voltage of the AC arc power supply. The filler wire is thus heated by being supplied with a heating current i.sub.W in pulse form while the unconsumable electrode is kept negative by an AC arc formed between the unconsumable electrode and the base metal.

Abstract: A semi-automatic hot wier TIG (Tungsten Inert Gas) welding equipment comprising: a portable TIG arc torch; a portable filler wire feed torch; a hot wire switching power source for energizing the TIG arc torch, the filler wire feed torch and a base metal; a filler wire feeding device for feeding the wire to the wire feeding torch at a desired rate; a welding condition control device for controlling wire heating power so as to provide wire heating power commensurate to the wire feed rate; means for measuring the resistance value of the wire extension section between the terminal end of the wire and the terminal end of the filler wire feed torch; and means for controlling said filler wire feeding means to change the wire feed rate in response to the detected wire extension.

Abstract: A method and an apparatus for controlling the hot-wire welding process is disclosed in which the heating power for a hot-wire is automatically regulated to a proper value. The wire-heating power after fusing of a filler wire by being overheated is set to a level lower than the heating power immediately before wire fusing, and the wire-heating power is again increased gradually from the set value until the wire is fused by being overheated. By repeating this process, the molten state of the filler wire in the hot-wire TIG welding is automatically kept in optimum condition without requiring any operation of the welding operator or his intuition.

Abstract: A hot wire TIG welding apparatus has a current detector for detecting the peak period and base period of the arc current. The welding apparatus further has a controller which controls, in response to the detection signal from the current detector, the operation of the wire heating power supply such that the wire heating power is supplied only during the base period of the arc current. According to this arrangement, a hot wire switching TIG welding apparatus can be produced using commercially available power supply systems for TIG arc welders, without requiring substantial change or modification of the control circuits in the TIG arc welders.

Abstract: A hot-wire TIG welding apparatus capable of performing a stable welding regardless of change in the welding conditions. The welding apparatus comprises a hot-wire feed speed control means for controlling the speed of feed of a hot wire, and a heating power control means adapted to control the electric power for heating the hot wire. The condition of the control in either one of the control sections is changed in accordance with a change in the control condition of the other.