图1所示是我所研制生产的一种管壳底盘的零件图,其特点如下:1.结构较复杂、尺寸小、料薄,属非圆形零件。2.尺寸公差和形位公差要求较高。一、工艺分析鉴于零件的特点,原来我们将其分为两体加工,然后焊接在一起,这样加工的零件由于工序多、定位精度差、零件本身经焊接后存在内应力,致使成品零件精度低、光洁度差,废品率高达15～20%,且加工周期长,成本高。 Figure 1 shows a part of the shell and tube chassis that I developed and produced. The features are as follows: 1. The structure is complex, the size is small, and the material is thin, which is a non-circular part. 2. Dimensional tolerances and geometric tolerances are high. First, the process analysis In view of the characteristics of the parts, the original we will be divided into two body processing, and then welded together, so that the processing of parts due to many processes, poor positioning accuracy, the part itself after welding there is internal stress, resulting in low accuracy of finished parts , Poor finish, rejection rate as high as 15 ~ 20%, and the processing cycle is long, the cost is high.