The IO-Link as a Standard for Grippers

The range of gripping systems from the German manufacturer Zimmer has been widening lately. The hybrid series, which combines pneumatic and electric technology, is now joined by the electric gripper with an integrated monitoring system and by the gripper thought for human-robot collaboration, meeting the latest standards in terms of safety. All this models are compliant with the IO-Link technology.

by Cesare Pizzorno

The latest exhibitions, such as Automatica, highlighted the features of some top-notch models from the broad Zimmer range. These models are increasingly compliant with the requirements of Industry 4.0. In particular, the GEH6000IL electric gripper series is extremely compact, however ensuring quite a long stroke as well as the possibility to adjust force (from 70 N to 1900 N, according to the size), jaws positioning and gripping speed. The gripper is equipped with a brushless, DC motor, which is virtually unaffected by wear and thus offers excellent operating safety. The integrated monitoring system for the gripping fingers/jaws positions makes external sensors unnecessary, while the integrated gear wheel and worm gear keep the gripping force in case of power failure. The GEH6000IL gripper is also equipped with the IO-Link standard, thus using a single cable. The IO-Link technology allows users to carry out services that belong to the idea of digitized production, such as advanced diagnostics or preventive maintenance. The IO-Link makes it possible to set the parameters on a gripper and then applying them on other grippers, without restarting the set-up. Furthermore, in case of a sudden power failure, the parameters remain set and there’s no need for a new programming.

Fully collaborative gripper
Human-robot collaboration (HRC) is another key concept for the digital factory. Thinking right about the interaction with operators, Zimmer released the HRC gripper series, featuring the characteristics of the GEH6000IL series and of course ready to be integrated on collaborative robots. In terms of design, the gripper has a white case with rounded shape at their sides and no sharp edges. The colour of a LED strip indicates the gripper status (blue = stand-by; yellow = moving jaws; green = piece gripping; red = error). Zimmer’s gripper for HRC meets the current safety requirements, summarized in the technical specification of the ISO/TS15066 standard on HRC. Talking about safety, the integrated Safety Torque Off (STO) function is activated in case of unwanted interaction with the operator’s hands. A gripper finger is then unlocked, thus avoiding possible injuries. Just like the GEH6000IL electric gripper series, the GEH6060IL series rely on the IO-Link technology.

The benefits of hybrid technology: a balance between pneumatics and electronics
The Zimmer’s portfolio also includes GPP5000IL hybrid gripper series – quite an optimal compromise between pneumatic and electric technology -, equipped with an integrated solenoid valve that allows a 50% faster response time compared to the grippers featuring an external solenoid valve. The gripper, which can be set using the IO-Link technology, has also a sensor that ensures an adjustable reading on the entire stroke and a part detection accuracy up to 0.05 mm, as well as the possibility of setting up to 32 positions. Being fitted to the IO-Link technology, preventive maintenance operations can be carried out. As for mechanics, the hybrid gripper has similar features compared to the 5000 pneumatic gripper series, such as the DLC (Diamond-Like Carbon) coating with anti-corrosion effect that minimizes friction, the IP64 protection standard and the possibility to achieve up to 30 million cycles without maintenance in ordinary environmental conditions.