Numerical control drilling restart control system

An NC machining restart control system responsive to a machining interruption of a machine tool at an interrupt position, said system comprising:

• positioning means for moving the machine tool and detecting a current position of the machine tool;
• program means for storing a numerical control machining program divided into blocks where each block performs a machining task;
• data means for storing modal information for a current block currently being performed and for storing block restart data indicating a restart position in dependence upon the current position and the block currently being performed, the restart position being the beginning of the current block when a machining interruption occurs prior to completion of the machining operation, corresponding to the current block and the beginning of a successive block when the interruption occurs after completion of the machining corresponding to the current block;
• control means, operatively connected to said positioning means, said program means and said data means, for controlling said positioning means to machine with the machine tool in dependence upon the numerical control machining program, for storing, into said data means, at the beginning of the execution of a current block, the modal information for the current block, for storing into said data means block restart data including the restart position block, which is the beginning of the successive block, when a block is completed and for automatically restarting machining responsive to the machining interruption at the restart position in dependence upon the block restart data.

An NC machining restart control method, comprising the steps of:

• storing modal data and start position data for a current machining block of a numerical control program during machining based on the current machining block;
• storing block restart data when a block is completed;
• and
• restarting machining automatically at a restart position in dependence upon the modal data, the start position data and the block restart data when machining is interrupted, where the restart position is the beginning of the current machining block when machining is interrupted prior to completion of the current block, and a beginning of a successive block when machining is interrupted after machining of the current block is completed.