End face positioning mechanism of valve rod end face grinding machine

The invention relates to the field of grinding machines, and particularly discloses an end face positioning mechanism of a valve rod end face grinding machine, which comprises a base, a positioning column, a front air cylinder, a grinding disc, a fixing plate arranged on one side of the grinding disc, a V-shaped block arranged in front of the fixing plate, a pressing device arranged on one side of the V-shaped block, and an air cylinder fixing seat arranged in front of the V-shaped block, the V-shaped block is movably connected with the base in the direction parallel to the disc face of the grinding disc, and the pressing device is movably connected with the V-shaped block. The positioning column is fixedly connected with the fixing plate; the front air cylinder comprises a cylinder body and a push rod, the cylinder body is fixedly connected with the air cylinder fixing base, and the push rod, the disc end face of the valve on the V-shaped block, the rod end face of the valve and the positioning column are se