TOUCH PROBE AND RELATED CHECKING METHOD WITH MINIMIZATION OF THERMAL AND ELECTRICAL NOISE

摘要

A touch probe (1; 1′; 1″; 1′″) for applications in machine tools or measuring machines includes a support frame (2) with a protective casing (3), and a movable armset (5) with a feeler (11) to touch a part to be checked (13). The probe includes a detection device (23) with a laminar piezoelectric transducer (25) made of polymeric material, such as polyvinylidene fluoride, which is connected to the support frame and fixed at a bearing and locating area (7), on which the movable armset rests in a position defined by an isostatic rest system (17). Conditioning electronics (30) connected to the support frame include processing means for processing a force signal (M) provided by the detection device, comparing it with a threshold value (S) and generating a touch signal (T). The conditioning electronics include differential charge amplifiers (3) and a processing system (55) to dynamically vary the threshold value depending on the most recent values of the force signal detected.