Turning clamp for heavy fork parts

A heavy fork part turning clamp comprises a chuck, the chuck comprises a fixed seat, a pull rod, a rear pull assembly and two movable rods, the right ends of the two movable rods are connected with first pressing devices respectively, each first pressing device comprises a hinge seat, a hinge plate, a pressing plate, a pressing head and a positioning ring seat, the movable rods are hinged to one end of the pressing plate, and the other end of the pressing plate is hinged to the positioning ring seat. The hinge seat is detachably connected to the side face of the fixed seat below the movable rod, the hinge seat is hinged to one end of the hinge plate, the other end of the hinge plate is hinged to the other end of the pressing plate, and the positioning ring seat is detachably connected to the side face of the fixed seat below the hinge seat; according to the turning clamp for the heavy fork parts, a workpiece is positioned through the arc-shaped positioning groove of the positioning ring seat, the pull rod dri