Developing an automated tool monitoring system is anything but an easy task. Even small changes, such as a different batch of the material to be machined or a different type of machine, usually influence the tool life. CERATIZIT has already developed the CERAsmart ToolScope process monitoring system for users with well-established processes and large component quantities, which documents the progression over time as well as the forces and currents of the tools.

However, as soon as the process changes, this running-in procedure has to be repeated. Users who mainly produce small quantities often find this solution too cumbersome.

Serious damage must be avoided

The pressure to automate manufacturing processes is growing due to the ever-increasing demands on quality and cost efficiency, as well as other factors such as labour shortages. However, even if current generations of machine tools are already prepared for the automated guidance of cutting tools along predefined paths and this part of production runs automatically, the supervision of an operator is still essential for a safe and productive process flow.

After all, some scenarios cannot be predicted and many questions cannot be answered in advance: When does the performance of the tools used deteriorate to a critical degree? When will the cutting edges even break off? Or when will the tool break completely? If damage to the tool goes unnoticed, the consequences can not only be a significant reduction in productivity, but also a lack of surface quality and even serious damage due to excessive forces and bending moments on the tool and the drilling spindle or collisions between the spindle and the workpiece.

Information exchange between user and machine tool

In order to reduce the need to run in tools to predict tool life in the future and to relieve the machine operator, universally applicable models and methods were to be developed as part of the ‘SmartDrilling’ project. To this end, drilling processes that are particularly common in machining were analysed. The prerequisite for this is a significant further development in the exchange of information between the user and the machine tool with the aim of developing a ‘Tool Condition Monitoring System’ that indicates the damage status of drilling tools while they are still in use.

This is based on sensor signals recorded by the machine tool, which are segmented using specially developed software-based data processing technology so that the analysis can concentrate exclusively on the signals relevant to the tool condition.

Manual intervention, machine loading and maintenance are optimised

The developed data analysis algorithm constantly provides information on the current status of the tool damage, which is constantly updated on a display during the drilling process.

A loud audible alarm sounds even before the drilling tool reaches a critical damage state. This means that a single user can operate several machine tools reliably and optimise the time required for manual intervention, machine loading and maintenance.

Economic and environmental benefits

The project managers at the Materials Centre Leoben (MCL) and CERATIZIT admit that there is still a long way to go before a saleable product is ready. But thanks to the many insights gained over the past three years, they have already achieved a milestone in terms of increasing the efficiency of metal-cutting component production with the tool condition monitoring system realised in SmartDrilling.

Against this backdrop, they predict that the cost benefits for manufacturing companies generated by using the Tool Condition Monitoring System will make a decisive contribution to the competitiveness of local industrial companies. In addition to the expected economic benefits, major environmental savings can also be expected as a result of drills being reground in good time and workpiece scrap being avoided.