Patent ID: 6711817
Filing Date: 2004-03-30
Classification: B21J,B21K,Y10T

Abstract:
A method of producing hypoid ring gears for differentials, comprising the steps ofupset-forging a round bar blank heated to a predetermined temperature to form a first disk-like intermediate article, die-forging said first intermediate article to form a second intermediate article in the form of a bottom-closed annular body which is smaller in inner and outer diameters and larger in axial thickness than the end product, punching out the bottom of said second intermediate article to form a third intermediate article in the form of a bottom-opened annular body which is smaller in inner and outer diameters and larger in axial thickness than the end product, shot-blasting said third intermediate article to remove the scale and reheating it to a predetermined temperature and ring-rolling it to form a fourth intermediate article in the form of a crude product which is somewhat smaller in inner and outer diameters and somewhat larger in axial thickness than the end product, orbitally forging said fourth intermediate article to form a fifth intermediate article having hypoid teeth formed therein, and normalizing and shot-blasting said fifth intermediate article to effect normalization and scale removal and then punching out any inner burr which is formed on said fifth intermediate article during tooth forming operation based on orbital forging and then cold-coining it, thereby forming the end product.