Automatic clamping and centring mechanism of gear ring part with specific tooth number

The utility model relates to an automatic clamping and centring mechanism of a gear ring part with a specific tooth number. The problem that at present, no proper automatic centring clamp is used for clamping the part of this kind is solved. The automatic clamping and centring mechanism comprises a clamp, a four-jaw chuck, two-jaw locating jaws, compressing mechanisms and single-jaw locating jaws, a centring disc is arranged at the bottom of the clamp, supporting blocks with the supporting and locating function are arranged on the upper surface of the clamp, the four-jaw chuck and the clamp are concentric and are arranged on the clamp, the two-jaw locating jaws and the single-jaw locating jaws all comprise handle portions and head portions bent vertically and upwards, telescopic locating jaws are arranged on the head portions, the handle portions of the locating jaws of two kinds are connected with cross U-shaped grooves of four movable jaws of the four-jaw chuck, the two two-jaw locating jaws are opposite to each other, the two single-jaw locating jaws are opposite to each other, and the compressing mechanisms are arranged on the supporting blocks. The mechanism achieves accurate machining and locating and convenient clamping, and completely adapts to machining and producing of workpieces of this kind.