Design and Development of Automated Filler Rod Feeding System for TIG Welding

Abstract

Tungsten Inert Gas welding is a very effective welding process widely used in many industries for joining of sheets, stainless steel pipes, automobile parts and many other manufacturing processes. This welding process has an additional advantage of protecting the weld bead with the help of shielding gas or inert gas which avoids the oxidation of the bead, making the joint wear resistant and slag free. This has increased the demand of TIG welding extensively. Generally, it is done manually by holding filler rod in one hand and the TIG torch with other. Thus, the process requires a high amount of skill and human labor. Automation of TIG welding will not only reduce human labor but also improve accuracy. The project aims to develop and design an automated filler rod feeding system for TIG welding. To fulfil this purpose, a number of mechanisms are considered namely rack-pinion mechanism, slider-crank mechanism and screw-nut mechanism. The advantages and limitations of each mechanism are weighed against each other to decide the best mechanism that can be implemented. The mechanism is then designed and fabricated so as to fulfil the objectives of the project. It has also been ensured that the product at the completion of this project is industry oriented and has commercial value. After a rigorous analysis of the different mechanisms possible, screw and nut mechanism was chosen to be fabricated. The feeding of the filler rod is coordinated with the movement of the TIG torch. The suggested mechanism is one of its first in this particular field and can prove to be a worthy replacement of the presently used wire-feeding arrangement. With proper research in this area, it can be expected that better mechanisms and arrangements will emerge or materialize