Intelligent hybrid material slide component for machine tools

In mid-scale and large five axis overhead gantry type milling machines, the vertical z-slide (ram) often constitutes one of the most sensitive and critical components regarding stiffness, structural vibrations and thermal influences. During machining, the z-slide is loaded by (quasi-) static process and drive forces, transient acceleration forces, periodic excitations by the tool engagement, as well as by thermal effects resulting from altering ambient conditions, heated chips, cooling lubricant and power losses in drives, guides and bearings. Deflections, thermal deformations and vibrations of the z-slide lead to geometric machining errors and inacceptable surface location errors at the workpieces. Furthermore, instable cutting conditions and regenerative chatter limit applicable material removal rates and, thus, productivity. In this work, a newly developed hybrid material structure for an exemplary z-slide, involving metal parts and mineral cast, is introduced. Structural optimization methods as well as process simulation techniques were applied in order to derive the final design solution. The integration of active cooling circuits for thermal stabilization is investigated and the use of fibre optical strain sensors is analysed with respect to a state monitoring of the machine tool component.