Design and analysis of a prototypical sensory Z-slide for machine tools

摘要

Due to the advancements in high speed and high performance cutting, further improvements of machine component design and process monitoring are necessary. For this purpose, new machine components with process monitoring capabilities have to be developed. In this paper, a new spindle carrying Z-slide for a 5-axis machining center with integrated sensing capabilities for process monitoring is presented. First, the overall system design is described. The sensing capabilities to enable process monitoring are realized by application of a micro-strain gauges network on to the structure of the slide. The optimal sensor positions are computed by application of a special sensor placement algorithm. The prototype of the slide has been built up to investigate the system behavior. The electronic system of the prototype to realize the signal amplification and the communication via an industrial bus are presented. Furthermore, the results of the system analysis of the prototype are described. Because the sensor amplitudes, which can be monitored by strain gauges on stiff structures, are generally small, a method to increase these amplitudes by use of the notch effect and new micro-strain sensors is discussed. With this method, the signal amplitudes can be increased significantly, without degrading the stiffness noticeably. At the end of the paper a method to manufacture notches in the prototype by a milling process is presented. The surface roughness of plan notch ground, measured with a laserprofilometer, shows roughness values lower than 3 μm.