Positioning tool for machining lockrand groove of gear shaft

A positioning tool for machining an edge locking groove of a gear shaft comprises a fixing body and a positioning body, the fixing body comprises a fixing base and a positioning plate, two hinge plates are fixed to the fixing base, the positioning plate is hinged between the two hinge plates, the positioning body comprises a sleeve with the two through ends, a screw hole is formed in the sleeve wall of the sleeve, and the screw hole is in threaded fit with a bolt. A fin plate is fixed in the radial direction of the sleeve, positioning grooves are formed in the outer end of the fin plate, the two positioning grooves are symmetrical along the axis of the sleeve, and when the positioning plate is located in the positioning grooves, the two side faces of the positioning plate are in surface contact with the two groove walls of the positioning grooves. Compared with the prior art, the positioning tool has the advantages that the two symmetrical positioning grooves of the positioning tool are utilized, workpiece po