Model development for consideration of process, machine and tool influences in the wear calculation and prognosis for cutting tools

 

The aim of the project in cooperation with pro Micron GmbH is the development of models which enable the monitoring of milling processes.

The project partner pro Micron produces and distributes the sensory tool holder "SPIKE", which measures the bending moments of the tool holder and transmits them via radio to a transmission unit. This data is to be used for process monitoring of the milling process. The role of WZL in the project is to develop models on the basis of which this monitoring can take place.

The primary monitoring objective is the free surface wear of the tool. This is to be measured by the expected increase of the cutting force and thus of the bending moments. For this purpose, a wear model is first developed, which establishes the relationship between the free surface wear and the resulting increase of the bending moments.

Since the tool load depends not only on the wear but also strongly on the process and engagement conditions of the tool, a second model is required which identifies the engagement conditions from the process signals of the bending moments. So-called pole figures are used for this purpose, which plot the bending moments in two orthogonal directions in a Cartesian coordinate system. This results in characteristic patterns which are directly dependent on the conditions of engagement. By certain evaluations of the patterns it is possible to deduce the conditions of engagement.