Apparatus and method for measuring a workpiece on machine tool

摘要

A workpiece measuring apparatus (20) includes a programmable controller (25) which acquires positional data (C1) of a measuring head (8). At the same time that the programmable controller (25) acquires the positional data (C1), a pulse output unit (24) outputs timing pulses (P). The measuring head (8) measures a workpiece (9) on a machine tool (1) according to a measurement command (f) which is output positively earlier than the timing of predetermined time intervals (”T) by a time difference (n) which is preset by a predictive system (29). As a result, a first time (T1) at which the programmable controller (25) acquires the positional data (C1) of the measuring head (8) and a second time (T2) at which the measuring head (8) measures the workpiece in response to the measurement command (f) synchronize. The workpiece measuring apparatus (20) is capable of measuring the workpiece highly accurately in a three-dimensional space according to a minimum required amount of measured data (B1) without the need for modifying an existing NC apparatus combined with the machine tool.