| 摘要 |
PURPOSE:To maintain a high screw cutting process accuracy, to reduce abrasion of a tool, and to shorten process time by determining the depth of each notch not more than an allowable cutting amount and at a value as close as this. CONSTITUTION:The depth of a first assigned notch d1 is defined as its cutting amount S1, defining the depth of notch dN when the screw cutting process is performed corresponding to the bottom of the screw at the (N)th time and its cutting amount as SN. Based on a constant a1 and b1, or a2 and b2 determined from Sp as allowable cutting amount that is described as Sp=a1d+b1, or Sp=a2 d2+b2, as well as based on the expression and on the assigned depth of notch d1, etc., from d2 at the second time to dN-1 at the (N-1)th time are determined in turn, so as to perform screw cutting process cycle. If the cutting amount S1 and the cutting amount SN are not more than the allowable cutting amount Sp and is as close as the value, from the second time on, the cutting amount S at the (N-1)th time is not more than the allowable cutting amount Sp, and is as close as the value. |
