TOOTH CUTTING METHOD

PURPOSE:To enhance the total cutting efficiency of a tooth cutting process by a gear shaper or a hobbing machine, by increasing the radial feed speed when the cycle number of stroking is small, and by gradually decreasing the radial feed speed as the cycle number is increased. CONSTITUTION:A cutting chip area Area(N)at N-th stroke can be approximated by the following formula: Arear(N)=c(a+Fr(N)).Fr(N)).fr(N) where fr is feed speed during the radial feed speed is constant, Cr is cutting amount, a is distance from the cross point between prolonging lines of both sides of a trapezoidal shape ABCD having a height Cr, by which a tool blade is approximated when the cutting amount is set to be equal to the height Cr, c is a constant, fr(N) is a radiaL feed speed at N-th stroke and Fr(N) is cumulative radial feed speed. Meanwhile, the cutting chip area becomes maximum just before a dowel cutting position when the feed speed is constant, and is approximated by the following formula: Amax=c(a+Cr).fr Accordingly, at an arbitrary stroke N, fr=(a+Cr).fr/(a+Fr(N)) allows the Area to be equal to the Amax.