DEVICE AND METHOD FOR DETECTING AN APPROACH OF A TOOL TO A WORKPIECE

A device for determining an approach of a tool to a workpiece in a machine tool with internal cooling supply includes a measuring arrangement, having a measuring graduation arranged in a rotationally fixed manner on a shaft and at least one position sensor arranged in a fixed manner relative to the shaft, and a data processor. The position sensor is adapted to scan the measuring graduation and to generate position values therefrom that indicate a position of the shaft. The position values are fed to the data processor, which, by evaluating a progression of the position values when the tool approaches the workpiece, determines that the tool is located in an approach area relative to the workpiece, and signals, by an approach signal, when the tool reaches an approach position relative to the workpiece, in which the tool is close to the workpiece without touching it.