Special seam welding technique for continuous electric resistance welding of silver strips and copper strips

Abstract

The invention discloses a special seam welding technique for continuous electric resistance welding of silver strips and copper strips, which comprises following steps of: a, flatting whole rolls of the copper strips and aligning the copper strips to joint with the silver strips; b, towing the copper strips and sliver strips to pass through a clearance between a first electrode wheel and a second electrode wheel of the seam welding machine, wherein the first electrode wheel is a molybdenum electrode wheel or a tungsten electrode wheel, and the second electrode wheel is an alloy copper electrode wheel; c, clamping the copper strips and the sliver strips by using the first electrode wheel and the second electrode wheel to make the first electrode wheel contact with the silver strips and the second electrode wheel contact with the copper strips; d, towing the silver strips and copper strips to move continuously and introducing welding current for electric resistance welding between the first electrode wheel and the second electrode wheel. The contact surfaces of the copper strips and the silver strips can be fused at the same time by using the technique of the invention so as to form favorable molten area for welding. Then the seam welding between copper strips and sliver strips can be implemented. Welding parts of the copper strips and the silver strips are firm, stable and non-deforming, thereby the welding quality is ensured, soldering flux is ensured, and the welding effect is improved.

Description

technical field [0001] The invention relates to a seam welding process, in particular to a seam welding process specially used for continuous welding of silver strips and copper strips. Background technique [0002] In high-power and high-current conductive switches and low-voltage electrical switches, in order to avoid accidents caused by sparks, the switch contacts are usually made of silver materials with low resistivity; due to the high price of silver, silver has good plasticity and ductility. Well, it is easy to deform without returning to its original shape. The conductive sheet at the switch contact should not be made of silver sheet as a whole. Usually, copper sheet with silver contact part at the contact is used as the contact conductive part of this type of conductive switch. [0003] In the welding of silver and copper, silver solder is usually added between silver and copper for welding. The price of silver solder is very high, resulting in high cost of silver a...

AI Technical Summary

Problems solved by technology

[0003] The welding of silver and copper is usually done by adding silver solder between silver and copper. The price of silver solder is very high, resulting in high cost of silver and copper welding process.

The usual method can also be to use silver solder as the medium or other methods than seam welding to weld the finished silver point and the punched copper plate joint. This method provides materials and other welding processes. The welding process is cumbersome and the production efficiency is low. Unable to adapt to large-scale mass production, resulting in high production costs

[0004] The existing equipment uses chromium-zirconium copper as the electrode material of the electrode wheel when welding nickel strips and copper strips, but chromium-zirconium copper is easy to stick to silver, and it is impossible to achieve seam welding of silver strips and copper strips

The traditional DC current supply uses three-phase rectification, and the welding time is calculated in cycles and 20ms. It cannot achieve a stable and instantaneous high-density current, and it will not be able to ensure continuous and stable welding of the silver strip and the copper strip.

[0005] Therefore, it is generally believed that the silver strip and the copper strip cannot be welded by seam welding without adding a medium

[0006] In addition, there is another way to use copper tape to open the groove, and the silver tape is pressed into the groove by rolling, and the physical connection is achieved by plastic deformation. This connection is not completely fused, its stability is not good, and the contact resistance also big

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