Monitoring pilger forming operation by sensing periodic lateral displacement of workpiece

摘要

A production measuring system is provided for early identification of dimensional or operational problems in a pilger forming device. The forming device has a mandrel for supporting a tubular workpiece to be elongated and thinned, at least two opposed dies bearing against the workpiece, and a mechanical drive for rolling the dies over the workpiece under pressure while periodically rotating and advancing the workpiece along the mandrel. Sensors are directed at the workpiece and produce signals reflecting displacement of the workpiece in rotation, axial displacement and transverse displacement. The signals can be compared to nominal standards and/or graphed and displayed, for visualizing operational conditions. The sensors can be disposed axially before or after the dies, or both. Preferably, idler rollers coupled to rotary variable differential transformers encode axial and rotational displacement after the dies (on the formed workpiece), and a pair of non-contacting proximity sensors disposed at right angles encode transverse displacement of the workpiece before the dies.