Method and apparatus for manufacturing a rock bit leg

摘要

A method of manufacturing a rock bit leg from a rough bit leg forging is disclosed whereby multiple machining operations are performed by a six-axis CNC machining center. Three dimensional datum surfaces are initially formed on a rough leg forging. The rough leg forging is then mounted in a holding fixture. The fixture, including the leg forging, is secured to the six-axis CNC machining center. A three dimensional datum reference from the leg forging is set into the NC function of the six-axis machining center. The rough leg forging includes a pair of extended flanges coincident with the 120 DEG leg surfaces. The leg flanges mount to complimentary surfaces formed on the leg holding fixture, thus securing the leg within the fixture without interference of any of the machining processes. The CNC machining center performs a majority of the material removal operations to prepare the leg for subsequent assembly through manipulation of the six interactive axes of the CNC machining center. The machining center positions the rough forging of the rock bit leg in any and all attitudes necessary to accomplish each of the separate material removal operations thereby maintaining extremely close tolerances since the leg forging remains indexed to and secured within the fixture throughout all of the machining processes.