Abstract: An NC apparatus 1 replaces a required machining shape of a workpiece 5 with a predetermined canned machining cycle depending on a specification of machining conditions including a machining start point, a machining end point, and the size of an end mill E to be used. Calculation of an estimated value of cutting force exerted on the end mill E fed along the assumed tool path during the replaced canned machining cycle is repeated until a predetermined comparison and evaluation result is obtained in comparison with a predetermined appropriate value. Accordingly, the tool path of the end mill E together with the feed rate in each portion of the tool path is determined. This permits generation of an NC program which is used in a NC machine equipped with an end mill serve as a cutting tool, and which optimizes the tool path of the end mill together with the feed rate in each portion of the tool path such as to achieve high machining efficiency and accuracy.

Abstract: A maximum undeformed chip thickness, a cutting arc length or an engage angle, and an active angle for each tooth of the end mill are calculated when a ball end mill is used in machining, or the maximum undeformed chip thickness, the cutting arc length or the engage angle, and an axial depth of cut for each tooth of the end mill are calculated when a straight end mill is used in machining. Then, the estimated value of the cutting force Fxy or Fxyz in each portion of the tool path is calculated on the basis of a response surface whose explanation variables are composed of the above-mentioned calculated values, whereby the feed rate contained in an equation for the maximum undeformed chip thickness tm is determined to maintain the obtained estimated value of the cutting force Fxy or Fxyz at an appropriate value.

Abstract: An NC apparatus 1 replaces a required machining shape of a workpiece 5 with a predetermined canned machining cycle depending on a specification of machining conditions including a machining start point, a machining end point, and the size of an end mill E to be used. Calculation of an estimated value of cutting force exerted on the end mill E fed along the assumed tool path during the replaced canned machining cycle is repeated until a predetermined comparison and evaluation result is obtained in comparison with a predetermined appropriate value. Accordingly, the tool path of the end mill E together with the feed rate in each portion of the tool path is determined. This permits generation of an NC program which is used in a NC machine equipped with an end mill serve as a cutting tool, and which optimizes the tool path of the end mill together with the feed rate in each portion of the tool path such as to achieve high machining efficiency and accuracy.

Abstract: A maximum undeformed chip thickness, a cutting arc length or an engage angle, and an active angle for each tooth of the end mill are calculated when a ball end mill is used in machining, or the maximum undeformed chip thickness, the cutting arc length or the engage angle, and an axial depth of cut for each tooth of the end mill are calculated when a straight end mill is used in machining. Then, the estimated value of the cutting force Fxy or Fxyz in each portion of the tool path is calculated on the basis of a response surface whose explanation variables are composed of the above-mentioned calculated values, whereby the feed rate contained in an equation for the maximum undeformed chip thickness tm is determined to maintain the obtained estimated value of the cutting force Fxy or Fxyz at an appropriate value.