Clamp for polishing of circular arc surface of special-shaped part of automobile engine

The invention relates to the field of quick clamping of inner cavities of parts, in particular to a clamp for polishing of the circular arc surface of a special-shaped part of an automobile engine. By means of the clamp, the part can be clamped stably and the polishing quality is ensured. The clamp comprises a tool bottom board, sliding rails are installed on the tool bottom board, and a sliding platform is installed on the sliding rails. A rotary bottom board is installed on the sliding platform through a rotary shaft and provided with a front support. A positioning module and an outward-expanding clamping mechanism are installed on the front support. The outward-expanding clamping mechanism comprises an upper shear board and a lower shear board, and the upper shear board and the lower shear board can be combined with each other or separated from each other. Clamping heads are arranged on the outer side of the front end of the upper shear board and the outer side of the front end of the lower shear board cor