Diseño de un jig adaptable para optimizar la precisión estructural y mejorar la ergonomía operativa durante el ensamble de roll bars en la empresa Muebles León

Abstract

This project focuses on the design of an adaptable jig intended to improve structural accuracy and operational ergonomics during the assembly of metallic roll bars at the company Muebles León, located in Ambato, Ecuador. The initiative arises from a production process that, despite complying with the dimensional standards required by AMBACAR, presents technical and ergonomic limitations due to the use of a completely fixed template. These restrictions lead to misalignments, physically demanding maneuvers, and prolonged operational times. The research was carried out using a quasi-experimental approach complemented by principles of Design Thinking, which enabled a clear understanding of the process before and after the intervention. Technical–ergonomic observations, structured interviews, and photographic field documentation were applied. The pretest revealed assembly cycles between 48 and 50 minutes, along with a very high ergonomic risk level according to the REBA method, associated with inclined postures, manual lifting, and the absence of mechanisms that allow controlled rotation or inclination of the structure. In response, an adaptable jig was designed, incorporating a dual mobility axis, an independent inclination system, and calibrated clamping mechanisms, while preserving the original template approved for automotive use. The implementation of the prototype under real workshop conditions reduced operational time to 35 minutes, improved dimensional stability, and decreased the physical strain experienced by the operator during welding tasks. The results show that industrial design, applied from a user-centered perspective and validated through a quasi-experimental process, can generate direct improvements in efficiency, safety, and assembly quality within metalworking environments.