Special fixture for processing side frames of railway vehicles

The utility model relates to a special fixture for processing side frames of railway vehicles and belongs to the technical field of tool fixtures. The special clamp includes a centering device and a positioning fixture, wherein the centering device adopts a mounting platform for side frames; three positioning pins are arranged on the centering device; bilaterally-symmetrical protruded positioning keys are arranged on the working table of a positioning device; and the positioning fixture includes a fixture bottom plate, claws, pressure plates and pressure plate screw rods, wherein two symmetrical positioning key grooves are formed at the bottom of the fixture bottom plate and used for being matched with positioning keys on the processing worktable surface to complete the integral positioning, the claws are arranged at the left and the right ends of the fixture bottom plate, screw rods on the claws are used for controlling the tightness of the claws, the pressure plates are arranged between the claws bilaterall