JPS5713122A - Quench hardening method for tooth surface - Google Patents

Abstract

PURPOSE:To make uniform hardening of teeth long in a tooth trace direction proximate to each other possible through simple operation by scanning a laser beam which is diffused after it is focused at a focus by a lens along tooth profiles at a constant speed. CONSTITUTION:After the parallel beams from a laser generator 10 are focused at a focus F by a convex lens 13, the beam is projected by an angle theta0 of diffusion onto teeth 2 of small addendum of an index plate W such as curbic coupling. The bottom end diameter (d) of this diffused beam B is made equal to the distance between the centers of bottom lands 2a, 2a by the vertical movement of the lens 13. The angle theta0 is approximately equal to an angle theta1 of intersection of both tooth side faces 2b, 2b and the positions of the teeth 2 are so determined that the outside edge at the bottom end of the beam B projects the central points P, P of the bottom 2a. If set values are programed in a control device 17, and a hardening device M is turned on, a stage table 14 moves to a reference position, and the device 10 goes on, thereby scanning the teeth 2 along the tooth profiles (tooth trace direction) while moving the table 14 in a radial direction at a constant speed.