逆向工程与精确设计

通过对轿车摇窗机扇形齿轮的设计，说明逆向工程与精确计算相结合，同时也介绍了扇形齿轮的冲压工艺、模具及数控线切割加工方法。通过测量扇形齿轮实样可以直接得到齿顶圆直径、齿根圆直径和公法线长度。测量轿车摇窗机总成可以得到齿轮传动中心距，结合供货方提供的啮合电动机小齿轮精确参数，有渐开线直齿圆柱齿轮模数、齿数、变位系数和压力角，推算出扇形齿轮的其他齿轮参数；扇形齿轮复杂形状的其他尺寸数据均由常规逆向工程方法测量确定，说明精确计算与常规逆向工程相结合能够获得更高的制造精度。

Reverse engineering and precision computing

We usually pay attention to the work on computer and ignore the precision computing in the reverse engineeringThis paper uses an example making a sector gear of window moving machine of an automobile to show the importance of the precision computing in the reverse engineeringThe parameters of the sector gear are gotThe sector gear measure method and the process, the stamping technology,die and mould, NC WEDM working are introducedThe outside diameter and root diameter of the gear are measured directly from the partThe centre distance between the gear pair are measured from the assemblyThere are other parameters of the matched small gear from the providerThe other parameters of the gear part of the sector gear can be computed according to the known conditionsThe other dimensions of the sector gear can be obtained from the normal reverse engineeringIt makes reverse engineering more accurate to combine with the precision computing