Manipulation of wheel wear in cylindrical grinding with active systems

• Applicants: Professor Dr.-Ing. Berend Denkena; Professor Dr.-Ing. Tobias Johannes Ortmaier
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: from 2011 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 174838673

As final and quality-determining process, grinding takes place in the process chain for manufacturing a heat-treated steel parts. Vibrations occurring in the process can reduce workpiece surface quality and reduce process capability significantly. The dynamic compliancy of the machine tool and the process dynamics results in self-excited vibrations and limit the productivity. This occurs especially in cylindrical grinding processes with conventional grains like corundum. Vibrations result in unequal wear on the grinding wheel at high frequencies and thus, a wavy surface structure of the grinding wheel. The prognosis and preventing of this self-exited vibration due to the regenerative effect on the grinding wheel surface is a major challenge and can only safely be avoided by reduced productivity or frequent dressing cycles. This regenerative effect develops slowly. It influences the workpiece quality only after prolonged progress. Therefore, the early detection in the finishing process is vibrations of great interest. In order to predict the progress of the regenerative effect, an exact knowledge about the influence of grinding wheel wear on the stability behavior is required. At the Institute of Production Engineering and Machine Tools (IFW), this effect is analyzed model-based. The phase detection and classification of local waviness is essential for its suppression. Therefore, the wave tool wear is identified. Due to the transmission behavior of the machine structure in the relevant frequency range, the suitability of sensors has to be examined in detail. With the overall aim to avoid frequent dressing cycles, active compensation of wheel-sided waviness is being studied and used for varying processes. Therefore, the Institute for Mechatronic Systems (imes) develops an electromagnetic actuator. This actuator is used for disturbing of the regenerative effect. By a suitable identification to its effect on the process, the process can be is stabilized. Thus, the grinding process can be made more productive.

• DFG Programme: Research Grants