Cam type self-locking four-jaw chuck

The utility model discloses a cam type self-locking four-jaw chuck, which relates to the technical field of four-jaw chucks and comprises a synchronous clamping disc, an upper axial adjusting disc and a lower axial adjusting disc, a cross-shaped groove is arranged on the upper surface of the synchronous clamping disc, sliding strips are arranged on the inner side walls of the cross-shaped groove, a clamping jaw is arranged between the two sliding strips, sliding grooves are arranged on the two side walls of the clamping jaw, and the upper axial adjusting disc and the lower axial adjusting disc are arranged in the sliding grooves. A left hexagonal head is arranged at the left end of the coupling rod, a right hexagonal head is arranged at the right end of the coupling rod, an inner hexagonal hole is formed in the right side wall of the right hexagonal head, soft magnetic skin is arranged on the periphery of the left end of the coupling rod, and an NS hollow magnet is arranged at the right end of the coupling ro