Research on Automotive Mechanical Manufacturing Processes and Precision Machining Technology

As the automotive industry advances toward electrification, lightweight design, and intelligent features, the requirements for component machining accuracy, surface quality, and material utilization have increased significantly. Traditional rough machining processes can no longer meet the demands of modern vehicles for high-performance engines, chassis components, and lightweight aluminum parts. This paper first reviews the application characteristics and optimization strategies of casting and forging processes in the manufacture of key automotive components such as engine blocks and transmission housings, and it explains the roles and synergy of sheet metal forming and welding technologies in body panels and modular chassis production. Next, this study delves into key CNC machining technologies—multi-axis kinematic machining, high-speed cutting, and tool-parameter optimization—as well as the applications of micro-machining and surface treatment for small-feature components like electronic sensor housings and fuel-system microchannels. By combining the concepts of flexible manufacturing systems and digital workshops, and through case analysis and experimental validation, a scheme is proposed for linking casting/forging rough machining to precision CNC machining. Utilizing digital twin technology and online monitoring, the process is visualized and optimized in a closed loop. Experimental results show that, by reasonably planning tool paths, optimizing cutting parameters, and introducing automated assembly units, part dimensional accuracy can be improved to within ±0.005 mm, surface roughness reduced to Ra 0.4 μm, production cycles shortened by 15 %–20 %, and yield rates increased by 12 %. Finally, with the lightweight and high-performance requirements of new energy vehicles in mind, future directions are projected: intelligent tool-path planning, online quality inspection, and green manufacturing technologies. This work provides both theoretical guidance and practical reference for building an efficient, low-consumption, and sustainable automotive mechanical manufacturing and precision machining system.