PRECISION FORGING METHOD OF HELICAL GEAR FOR CAR TRANSMISSIONS

摘要

The present invention relates to a precision forging method of a helical gear for an automobile transmission, the technical problem to be solved is to manufacture a helical gear in a non-rotating precision forging method that does not involve machining, mold manufacturing is simple and has a high durability automobile transmission To provide a precision forging method for helical gears. To this end, the precision forging method of the helical gear for an automobile transmission according to the present invention includes a hot upsetting step of seating a cylindrical billet on a lower mold and pressing the upper surface of the billet with an upper mold to form a preformed billet. Hot closed forging step of seating the preformed billet on the die and rotationally pressing the upper surface of the preformed billet to the upper die to form a preformed helical gear, and punching the lower surface of the preformed helical gear Hot tooth shape forging step of forming a spiral helical tooth on the outer circumferential surface of the preformed helical gear by rotating without pressure and rotating the lower surface of the preformed helical gear on which the helical tooth is formed to the punch part without heating. And a cold sizing step of pressurizing to form the helical gear. It shall be.