Abstract: In recent years, with the rapid development of China's automobile industry, which gradually becomes the mainstay industry in machinery manufacturing industry, the numerical control technology in the automotive industry plays a pivotal role, especially in the machining of key parts in the field of heavy trucks. For products with simple shape/structure, for convenience and speed, the numerical control machining programs are usually completed by manual programming. Taking the engine support of a heavy truck as an example, this paper studied the machining content of drilling four bottom holes and milling 3° surface. Through an analysis of product processing technology, two processing technology schemes were formulated. According to the process scheme, the two manual programming methods of scheme A and scheme B were compared and analyzed by FANUC numerical control system programming. After the field practice for many times, we concluded that by applying G68 rotating instructions, scheme B can simplify the programming difficulty, improve programming efficiency, reduce the error rate of programming and provide a new idea and method for the subsequent products of the same type.

Key words: FANUC numerical control system; G68 rotating instructions; Manual programming; Heavy truck engine support; Numerical control machining

摘要： 近年来，随着我国汽车工业的快速发展，并逐渐成为机械制造行业中的支柱性产业， 而数控技术在汽车行业起到了举足轻重的作用，尤其是体现在重卡领域关键零部件的机械加 工中。对于形状/结构简单的产品来说，为方便、快捷，数控加工程序通常采用手工编程来完 成。文章以某重卡发动机支架为例，针对钻四个底孔和铣 3°面的加工内容进行了研究。通 过对产品加工工艺进行分析，制定了两种加工工艺方案，依据工艺方案，通过 FANUC 数控 系统编程，对方案 A 和方案 B 两种手工编程方法进行了对比分析，经现场多次实践，并得出 结论，方案 B 通过应用 G68 旋转指令，简化了编程难度，提升了编程效率，降低了编程出错 率，为后续同类型产品提供了一个新思路、新方法。

关键词: FANUC 数控系统；G68 旋转指令；手工编程；重卡发动机支架；数控加工