PURPOSE: To perform the work by calculating the data required for the threading only form the inputted lead of screw, by storing the specific fomula for calculating the first time cutting amount and the height of the screw thread from the lead of the screw.
CONSTITUTION: When performing the threading work by a neumeric control lathe, the first formula for calculating the screw thread B from the lead of screw A and the second formula for calculating the first time cutting amount are stored into a memory 2. Prior to the working, the lead of the screw is inputted to calculate the screw thread B and the first time cutting amount in an arithmetic unit 1 to obtain the required data. In case of JIS screw, the screw thread = screw lead A×0.6495 is obtained from the first formula while the first time cutting amount = lead A×α+β is obtained from the second formula. Here α=0.05, β=0.02.
HASHIMOTO HIDEO
TSUNODA TOMOHIKO
