An Ultrasound In-Process-Measuring System to Ensure a Minimum Roundness Deviation for Rings During Turning

The turning process requires a clamping of the workpiece. If the fixing of a thin-walled workpiece (i.e. a ring) is realised with a three-jaw-chuck, distortion of the outer diameter of the workpiece occurs, leading to a varying circumferential wall thickness on unclamping. This paper presents an ultrasound system for the in-process-measurement of these workpiece distortions. The measurement principle is based on the determination of phase differences between echoes of an ultrasound burst. The measured in-process values can be used to control the turning process with a fast tool servo.