| 摘要 |
PURPOSE:To certainly detect abnormality of a cutting tool by discriminating each condition of idling before cutting, cutting, and steady cutting by using electric current which flows to a motor for main shaft in order to discriminate wear of the tool and in case of discriminating wear. CONSTITUTION:Penetrating bore machining is done by a drill 102 equipped on a main shaft 103 to a work 101. A detecting part 111 detects that rotation N of the main shaft 103 has become larger than a settled value n of the rotation of a motor 104. An electric current detecting part 107 detects the current of an armature in DC motor 104. Various calculations are done by using these detecting signals, wear discriminating signals are output from a discriminating part 123. Bits of memory area in the tool number corresponding to a memory means M-1 go from 0 to 1 by these discriminating signals. |
