Shear cutting: inline measurement of wear and cut quality

During shear cutting of sheet metal materials, inline monitoring of the tool as well as of the cut surface parameters and component quality is currently not possible. Based on the Seebeck effect this invention enables dynamic monitoring of the manufacturing process for the first time. In addition to being used in new stamping dies, the system can also be integrated into existing dies. This avoids rejected parts and extends maintenance intervals.

The design conditions in shear cutting tools make the implementation of sensors very difficult. The reasons are the limited space as well as the high surface pressure. Lubricants and contaminants increase the problem. Sudden tool damage and changes in the cutting edge geometry can only be detected in retrospect. This often leads to a large number of rejected parts. Maintenance intervals are defined based on experience before the actual wear limit. This directly reduces process profitability.

The solution was to create a sensor that can be used despite the conditions in the shearing tool without impacting its performance. Based on the thermoelectric Seebeck effect, which leads to the generation of voltage in vasrious sheet metal processings, it is possible to use the tool itself as a sensor. This allows instantaneous detection of stochastically occurring tool damage, as well as determination of the wear condition of the active elements independent of the wear mechanism that is occurring. The system enables the exact cuttingsurface shape determination inline at any stroke rate and for any tool.

• Can be used independently of material and tool type
• Instantaneous monitoring of process and cut surface characteristics
• Maintains optimal tool performance
• Easy retrofitting

TRL 7: System prototype demonstrated in operational environment