Part outer circle clamping device

The invention discloses a part outer circle clamping device, and relates to the technical field of tool fixture manufacturing. The part outer circle clamping device comprises a base, a middle supporting column is arranged over the base, two L-shaped clamping arms are oppositely arranged on the two sides of the middle supporting column, the inner ends of the L-shaped clamping arms are hinged to first pin shafts installed in sliding grooves of the middle supporting column in a penetrating mode, and the bent portions of the L-shaped clamping arms are hinged to the base through second pin shafts;and the portion, located under the middle supporting column, of the base is provided with a limiting hole, and a spring connected with the middle supporting column in a pressing mode is installed in the limiting hole. Compared with the prior art, when the part outer circle clamping device is used, a part is put on the middle supporting column, the middle supporting column moves downwards under theaction of the gravity to