Progettazione di maschere di supporto per la produzione di convogli metropolitani = Design of support jigs for the production of subway trains

In recent years, underground systems have become an essential part of modern urban infrastructure due to the growth of the population and size of cities and the increasing demand for efficient, sustainable and reliable transportation solutions. The advantages related to the use of subways are numerous, and the most important are the ability to alleviate traffic congestion, the enhancement to job opportunities and services connecting the city center with the neighborhoods and the possibility to have an easy transportation access that leads to a more inclusive system. The aim of the work is the design and realization of support jigs to produce parts of subway cars that will enter service on the Washington DC subway in 2027. The components for which the jigs were made are: the side walls, the door frame, the flat end, the cabin and the power converters. Support jigs allow for increased productivity, high accuracy, and repeatability of operations, as well as optimization of the workflow cycle by reducing the risk of error, as they allow for milling, welding, and assembly on the same stationary workpiece. Starting from the 3D model of the assemblies and the drawings of the components, the jigs have been realized using software, such as Solidworks and Autocad, and following the rules of the norms for jigs production for railways applications. In addition, a static analysis of the supporting components, such as braces and frames, was carried out to ensure that they would not fail due to the weight they bear. Subsequently, the designs of the components were developed and the work cycle of each individual part was defined. For future studies, it could be considered to change some parts of the jigs based on the client’s requests during the process to adapt the work to new requirements or to improve the production cycle.