Design and Development of Fixture for I- Stiffener Welding

Abstract

In the stiffener ring manufacturing process, welding is the primary process by which two parts of the ring (flange and web) are joined. GMAW (Gas Metal Arc Welding) and SAW (Submerged Arc Welding) are widely used processes. Welding is carried out mostly in a down hand position (1G Position) being a highly economical method for fabrication, defect proof, and easy process compared to other processes. Welding fixtures play an important role in the whole process of manufacturing to avoid distortions, enhance quality, and productivity and reduce the cost of products directly and indirectly. The present work discusses the design of welding fixtures for stiffener ring welding. In Stiffener, ring welding, different parts (web and flange) are welded using the double torch GMAW welding process. The 3-2-1 locating principle has been used to simulate real-time situations. Flanges are fabricated by rolling into a cylindrical shell for smaller diameter or fabricated in circular segments for larger diameter and welded together by using long seam welding. The web is fabricated using a water jet cutting from a single plate. It is required to modify and upgrade the existing setup of long seam welding to increase productivity and maximize shop floor utilization. Long Seam welding setup is designed for stiffener ring’s diameter ranges from 3000 mm to 6000 mm and flange thickness ranges from 30mm to 60mm and web’s dimensions remain constant. For new development, it is required to provide conceptual design considering various parameters like type of welding, weld positions, manual/robotic welding, and space utilization to fulfill the requirement of the end-user. In web to flange setup arrangement, it is required to design a universal clamp than can accommodate stiffeners of different range of dimensions. Clamps positions are designed universally so that clamps can be placed in different locations to accommodate different diameters of the ring in the same fixture. In Stiffener ring final welding station concept welding can be done by mounting the ring (after setup) to chuck and placing two KUKA robots in double torch configuration to weld simultaneously.