Effective production monitoring thanks to strain sensors by Kistler

Winterthur, August 2018 – Piezoelectric strain sensors from Kistler safeguard machines against overload and help to achieve precise monitoring of the strain on tools in production sectors such as punching, forming and joining technology. Simple installation and wide measuring ranges make these sensors ideal for retrofitting on existing plants.

With advances in digitization as we move towards Industry 4.0, sensors are gaining more and more ground in industrial manufacturing. They are now conquering sectors where the processes are mainly mechanical: examples include punching and press-fit technology as well as forming and joining processes. Strain sensors broaden the options for process monitoring: they can either be mounted directly on the machine or integrated into tools as measuring pins. 

Early warning system ensures effective protection for machines

Piezoelectric (PE) surface strain sensors by Kistler can deliver high-resolution measurements of the strain in a structure. It is transmitted to the measuring element via static friction as a shear force. Measurements feature long-term stability (with no creep), and these rugged sensors are protected against overloading (degree of protection: IP67); they are also resistant to interference from disturbance variables such as temperature influences. Kistler's compact sensors are mounted directly on the machine with just one screw. If irregular force peaks occur, they are registered immediately with no risk of damage to the sensors. In case of overload, they 'skid' on the surface until the strain is relieved. It makes no difference whether the forces occurring are very small or very large – thanks to their high natural frequency and wide measuring range, these sensors can cope with both. Piezoelectric surface strain sensors from Kistler act as an early warning system, delivering effective machine protection that helps to reduce costly downtime.

Tool monitoring made easy

To obtain valuable process data on individual assembly steps, strain sensors can be integrated directly into the tool as measuring pins. Measuring pins are mainly used where conditions are not suitable for a measurement on the surface, or if the installation space is very limited. Thanks to this option, customers benefit from effective monitoring and optimization for applications in punching and forming technology, among others. Kistler's highly sensitive measuring pins detect the smallest deformations of the material, even under highly dynamic and quasi-static loads. Integration in the tool requires a cylindrical bore hole in which the measuring pin is preloaded with axial or radial alignment. Extension and deflection can be measured either longitudinally or transversely to the sensor. 

Digital signal evaluation simplifies the measurement chain

Kistler added the 5074A charge amplifier to its portfolio at the start of this year. This amplifier digitizes PE signals and – for the first time ever – users can integrate any desired piezoelectric sensors into the control environment. Thus, customers now have the opportunity to connect PE strain sensors with the machine control via Industrial Ethernet. There is no longer any need for the detour via an analog evaluation system, and networking with higher-level systems is simplified.