我厂加工的薄壁缸套零件(见图1 所示),“精车外圆及切两端面”工序安排在C7620车床上加工,由于工艺要求定心精度较高,为此我们设计了外胀式自动定心夹具。1.夹具的结构外胀式自动定心夹具的结构见图2,它是由夹具体13、圆锥体9、锥瓣7 等组成,夹具体上的定位健10是防止圆锥体9转动,定位套6是防止锥瓣7作轴向移动。定位套安装在夹具体上,并用螺钉4定位。密封圈5是为了防止铁屑由锥瓣7端面进入定位套影响锥 I plant processed thin-walled cylinder liner parts (see Figure 1), “fine car cylindrical and cut both ends” process arranged in the C7620 lathe processing, due to the high centering accuracy of the process requirements, for which we designed the outside Expansion of self-centering fixture. 1. Structure of the fixture The structure of the self-centering fixture of the expansion type is shown in Fig. 2, which is composed of the clamp body 13, the cone 9 and the cone valve 7. The fixture 10 on the clamp body is to prevent the cone 9 from rotating and positioning The sleeve 6 prevents the cone 7 from moving axially. Positioning sleeve installed in the fixture body, and positioning with screws 4. Seal 5 is to prevent iron filings from the end face of the cone valve 7 into the positioning sleeve impact cone