Design and Development of Fixtures to Reduce the Assembly Time and Rejection of MCCB

Abstract

Productivity and quality are playing key role to be a sustainable industry in the cut throat competition. It becomes further difficult to maintain productivity and quality when an industry has large number of parts in a product, large number of variants and dynamic change in product design. Productivity and quality can be enhanced with the help of fixtures in an assembly line. Further full proof design of the fixtures will help to reduce the wrong assembly and missing parts and hence leads to high acceptance and productivity. In this project an attempt has been made to enhance quality and productivity for the MCCB assembly line. All the operations involved in the assembly line was studied and riveting processes in the riveting shop, nut-plate screwing and spreader link packaging operations were identified as low productivity and poor-quality processes. Poka-Yoke philosophy was followed to develop full proof fixtures for riveting parts (Latch-links, right plate, mechanism) and nut-plate screwing. A spreader link packaging machine was also conceptualised and fabricated for packaging right spreader links in exact number. Parametric CREO software was used for 3D modelling of the fixtures and packaging machine in the conceptualization stage. Total production time could be reduced by 85 seconds and the rejections could be controlled to 2-4 percent in riveting and totally eliminated in nut-plate screwing operation.