Automatic replacing device for grinding wheel of numerical control tool grinding machine

The utility model discloses an automatic replacing device for a grinding wheel of a numerical control tool grinding machine. The device mainly comprises a moving part, a rotating part and a cooling part, the moving part comprises a main shaft, the main shaft is provided with a guide rail, a ram and an oil cylinder, and the oil cylinder controls the ram to slide along the slide rail; the rotating part comprises a rotary table, a bench clamp mounting seat and a grinding wheel unit; n cooling connecting holes are uniformly formed in the bench clamp mounting seat, N normally-closed hydraulic bench clamps are uniformly distributed and fixed on the bench clamp mounting seat, one of the N grinding wheel groups is mounted on the main shaft, a grinding wheel rod is tensioned by a pull claw in the main shaft, and the grinding wheel rods of the other grinding wheel groups are respectively clamped by clamping claws on the normally-closed hydraulic bench clamps corresponding to the grinding wheel groups; the number of the