NUMERICAL CONTROLLER EQUIPPED WITH AUTOMATIC TOOL REPLACEMENT DEVICE

PURPOSE:To perform safe tool replacement while avoiding the interference between a tool, and a pot and a main shaft and to shorten the time of the tool replacement by controlling simultaneous operation while detecting the current positions of two servo motors which drive the numerical control automatic tool replacement device. CONSTITUTION:A simultaneous operation start position detecting means 8 detects a swivel start position where the interference between the tool, and pot and main shaft can be avoided even if a tool replacement arm begins to swivel halfway in tool extraction and an insertion start position where the interference between the tool, and pot and main shaft can be avoided even if the tool begins to be inserted during the swivel of the tool replacement arm. Thus, the accurate simultaneous operation start positions are detected by detecting the current positions of the swivel shaft and insertion/extraction shaft of the tool replacement arm, so simultaneous operation can be performed while operation in the inserting/extracting direction is corrected by the movement in the inserting/extracting direction by the swivel operation.