Tool and method for processing half-speed machine crankshaft

The invention relates to a tool and a method for machining a crankshaft of a medium speed machine. The machining tool is provided with a cutter for machining a load release groove, a R40 special molding cutter for machining the surface of a balance block and a plug of a crossed hole of a drill gun. The machining method comprises: firstly, according to the prior method, a crankshaft billet of the medium speed machine is subjected to primary TR forging and molding; a main journal, a turning journal, the load release groove, the output end of the load release groove and a free end flange are subjected to machining; the milling balance block ,the shape of a turning arm, and end flange drilling are evenly distributed with holes and screw holes are subjected to machining; the main journal and the turning journal are ground and are subjected to final finishing; subsequently, the load release groove is processed through the cutter for machining the load release groove from outside to inside for a few times by delamination. The R40 special molding cutter is used to machine the surface of the balance block in a vertical cutting mode. The gun drill drills and cuts a guide hole and an oil hole to a crossed hole, and a plug is adopted in the crossed hole. A phi 700 flange hole is drilled through an aiguille and is machined through a Mohs lengthening drill bush. The tool and the method for machining can ensure the quality of a product and greatly improve production efficiency.