Toyota Jidosha Kabushiki Kaisha

Hitachi Seiko, Ltd.

Hitoshi Matsui

Satoshi Shionoya

Hiroshi Suzuki

Fumiaki Kawahata

Tsuneo Shinada

Tsuneo Mita

Taiji Hattori

A pulsed arc welding apparatus includes a short circuit detecting circuit for detecting a time during which a short circuit is being produced by melting a consumable electrode across a consumable electrode and a base metal, a comparison circuit for comparing an integrated value or a mean value of short circuit generating time detected by the short circuit detecting circuit with an optional set value, and a control circuit for controlling either one of the supply time of the pulse current and the base current supply time in accordance with the result of comparison by this comparison circuit, thereby to control the arc length.

Pulsed arc welding method and apparatus

An arc welding torch which can generate an electric arc in a predetermined position even when large rotational torque acts on welding wire. A passage of the arc welding torch has a plurality of curves which are taken first in one direction and then in another direction along the passage, and the curvature radius and curve angle of each of the curves are designed so that minimum torque T1 which is necessary for the welding wire to turn in the guide passage is greater than torque T2 which causes torsional yielding of the welding wire. Owing to the curvature radius and curve angle of each of the curves and elasticity of the welding wire which comes in contact with each of the curves, the welding wire is inhibited from turning in the guide passage. Therefore, a fore end of the welding wire occupies the same position with respect to the current feed chip, and an electric arc can be generated in a desired position.

Arc welding torch

A pulsed arc welding apparatus includes a consumable electrode wire which is fed toward a workpiece at a wire feeding rate, a power supply for supplying a welding current to the wire to produce a droplet at the end of the wire by the heat of arc, a pulse form setting part for setting a pulse form of the welding current supplied by the power supply, based on a peak current and a pulse duration, an optimum pulse determining part for determining a peak current and a pulse duration for each of pulses of the welding current based on an average current and for supplying the peak current and the pulse duration to the pulse form setting part so that each respective peak current and each respective pulse duration of the welding current supplied to the wire have a minimum value needed to transfer a droplet from the wire to the workpiece for each pulse at a rate synchronous with the wire feeding rate, and an average current setting part for setting the average current based on the wire feeding rate and for supplying the average current to the optimum pulse determining part.

Apparatus for welding with a current waveform controlled by sensing arc

Pulsed arc welding apparatus having a consumable electrode wire

A contact tip for arc welding includes a feed surface constructed of conductive material which has a negative thermoelectromotive force with respect to pure platinum at temperatures above 0.degree. C. When welding current flows from the contact tip to a welding wire, an endothermic reaction occurs at the feed surface to lower the temperature of the feed surface and to improve the thermal durability of the contact tip.

Contact tip for arc welding

In this method for removing spatter deposits accumulated upon the inner surface of the end portion of a tubular arc welding torch nozzle, an end portion of a welding rod being fed for arc welding through an end portion of this nozzle with a space being left between this welding rod and the inner surface of the end portion of the nozzle, an electrical current is supplied through an electromagnetic coil positioned longitudinally proximate to the end portion of the nozzle. This electrical current typically generates an electromagnetic force upon the spatter deposits in the general direction parallel to the central axis of the nozzle, thus removing such spatter deposits from the inner surface of the end portion of the nozzle. The electrical current through the electromagnetic coil may further be provided from a condenser, in which case it will be quickly varying, and yet further the electromagnetic force may be advantageously concentrated by a sheath of ferromagnetic material fitted around the electromagnetic coil. A device is also disclosed for implementing this method.

Method and device for electromagnetic removal of spatter on nozzle of

A welding structure for a disc wheel installed on a vehicle. The disc wheel comprises a rim and a disc, the disc having an outer peripheral portion fixed to an inner surface of the rim by welding. The edge surface of the outer peripheral portion of the disc is inclined with respect to the rim, and when assembled contains the end portion of the weld.

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Toyota, Japan

Hitoshi Matsui