Mitsubishi Denki Kabushiki Kaisha

Nippon Steel Corporation

Akiyoshi Uomori

Toshihiko Baba

Takao Kawanami

Akimichi Takeda

Junji Miyata

Hiromi Tajiri

Yoshimasa Komatsu

Satoshi Hanai

Tadayasu Tsuchitani

A method and apparatus for flash welding are disclosed wherein a first predetermined voltage is applied between a pair of workpieces to be welded to generate flashes therebetween, and a second predetermined voltage lower than the first predetermined voltage is then applied between the workpieces to maintain fine flashes when the temperature of weld surfaces of the workpieces has reached a predetermined temperature. The workpieces are upset when the total number of flashes has reached a predetermined value. The pressure welding is maintained with an upsetting pressure sufficient to upset the workpieces and slightly higher than a pressure at which the workpieces are deformed near their recrystallization temperature until the temperature of weld surfaces has decreased to lower than the recrystallization temperature. The applied voltage and the upsetting pressure are controlled in accordance with the weld progress.

Method and apparatus for flash welding

A flash welding machine for butt welding the trailing edge of a preceding metal strip to the leading edge of a following metal strip in a rolling mill or the like. A preceding carriage and a following carriage are provided, movably mounted on a common set of rails. Each carriage is provided with electrodes capable of clamping respective ones of the preceding strip and the following strip when the two strips are in abutment with on another. Welding cylinders are provided for selectively joining the two carriers when the two strips are in abutment and the welding operation is to be performed, and then releasing the carriers from one another.

Flash welding machine

In a flash welding apparatus, different length guides and driving devices thereof are formed on lower parts of an inlet side electrode table and an outlet side electrode table and the electrode tables and a compact rotary shear unit are arranged in the direction perpendicular to a strip line when both of the electrode tables are approached and one of the guides is commonly used as a guide for shifting a flash trimmer lower unit and a guide is formed on one of the upper electrode frames of the electrode tables so as to shift a flash trimmer upper unit and the rotary shear unit of the inlet side electrode table and the rotary shear unit of the outlet side electrode table and a pair of the upper and lower trimmer units are aligned in the plan view.

Flash welding apparatus

In a flash welder, instead of using a flexible conductor, the electrical connection to the moveable electrode table is made by a connecting conductor which is slidably connected both to the moveable electrode table and the secondary of the welding transformer. The connecting conductor is mounted on the moveable electrode table in such a manner that, during non-welding periods, it may be retracted within the moveable table, disconnecting it from the transformer and thereby clearing the space between the electrode tables for other workpiece machining operations.

Conductor connector in flash welding apparatus

A welding apparatus comprises a pair of suspension type electrode press devices for clamping an upper electrode and a lower electrode in perpendicular relation to workpieces for synchronizing them, whereby a clamping force is treated as the inner force of the pushing mechanism and the apparatus can be miniaturized. The surfaces of the workpieces can be uniformly clamped by the upper and lower electrodes whereby the consumptions of the upper and lower electrodes are substantially the same and the calibration of the positions of the upper and lower electrodes for consumption is not required. The welding apparatus is especially effective for continuous rolling in single or plural lines of a rolling apparatus for rolling hot steel billets, etc. and welding them.

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Amagasaki, Japan

Akiyoshi Uomori