Method of electrical resistance roll seam welding with only one electrode wire, machine for performing the process and use of the process

US4572937A · kind A · utility

Assignee

• SOUDRONIC AG · CH

Inventors

• Paul Opprecht · Bergdietikon, CH
• Wolfgang Weil · Heitersheim, DE

Key dates

• Filing date: Sep 18, 1984
• Grant date: Feb 25, 1986
• Expiry date: Sep 18, 2004

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B23K11/309
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

A welding machine with wire electrodes is used to electrically resistance roll seam weld tin plate. Only one electrode wire running over both of the electrode carrying rolls is used. To prevent the formation of a loop in the wire stretch between the electrode carrying rolls a hard wire is required which is produced by a prior rolling of a soft round wire. With this rolling there results however a non-uniform hardness distribution over the wire cross section with areas of high and areas of low material hardness so that the average strength increase over the entire wire cross section of the electrode wire remains below the increase in strength which could theoretically be reached if no portion of the wire cross section remained outside of the area of high material strength. A closer approach to this theoretical increase in strength is achieved instead of rolling, by cold forming in several steps, in which cold forming the round wire is in a first forming stage cold formed to smaller diameter by drawing and thereafter in a second forming stage is cold formed by flat rolling. This brings advantages to the welding process as well as substantial savings in wire.