Machine tool positioning system - determines position of groove on workpiece, giving voltage corresp. to circumference, and angular position of tool spindle, and uses phase difference between two sets of signals to position motors

摘要

The system positions a tooth-cutting or groove-making tool (21) automatically relative to a workpiece (10) with a previously made indentation or groove (12). The tool is mounted on a spindle (14) running across, or oblique to, the workpiece spindle (3). The tool spindle can be adjusted in the direction of its axis (15) or across it by positioning motors. The angular position of the indentation or groove is determined by an analogue sensor (28), giving a voltage corresp. to the circumference of the piece. The voltage is scanned and digitised into discrete voltage values as measuring signals, while the angular position of the tool spindle is determined by a second analogue sensor (35) in a similar way, giving reference signals. The phase difference between the two sets of signals is found, providing a control signal for the positioning motors. ADVANTAGE - Improvement in accuracy and speed.