Clamp for welding steel piston

The utility model provides a clamp for welding a steel piston, which can quickly and accurately position a piston to be welded, and is simple in structure and convenient to operate. The clamping device comprises a clamping jaw, and is characterized by further comprising a rotating clamp, the rotary clamp comprises a rotary clamp body and a tray for placing a piston to be welded, and the tray is arranged in the center of the top end of the rotary clamp body; the clamping jaw is arranged above the tray, and the side wall, making contact with the piston to be welded, of the clamping jaw is arranged to be in a circular arc shape matched with the outer side wall of the piston. All the clamping jaws are arranged on the same horizontal plane; after the clamping jaw clamps the piston to be welded, the axis of the piston to be welded coincides with the axis of the rotary clamp body. The bottom end of the rotating clamp body is connected with a rotating motor output shaft through a rotating main shaft. 本实用新型提供一种钢活塞焊接用夹