Convexity grinding apparatus

The utility model relates to a convexity grinding device which is characterized in that one side of a bottom plate is vertically fixed with a vertical positioning plate, the upper and the lower parts of which are respectively provided with a pair of vertical strip holes, wherein, a screw is respectively arranged in each vertical strip hole, and the vertical strip holes are connected with corresponding threaded holes at the side face of a grinding head seat by threads. The upper end of the vertical positioning plate is fixed with a bearing seat through a fastener, and a lead screw is arranged in a shaft hole of the bearing seat; the part of the lead screw positioned below the bearing seat is connected with the threaded holes at the upper part of the grinding head seat by threads, the part of the lead screw positioned above the bearing seat is fixedly connected with a percentage channel core sheathed on the bearing seat through a pin key; the percentage channel core is connected with a graduated ring surrounded out of the percentage channel core through a spring sheet. The upper end of the lead screw is provided with a hand wheel which is connected with the lead screw through the pin key. In addition, the grinding head seat is provided with a grinding wheel, the grinding wheel is fixed with one end of an indicating needle at one end through which an electric main shaft penetrates, and the free end of the indicating needle is corresponding to a graduated plate arranged at the side face of the vertical positioning plate. The utility model has the advantages of high productive efficiency and constant convex meter.