AUMAT Maschinenbau GmbH is a Solingen, Germany-based manufacturer of broaching and special machines. When the Iseo company — a lock system manufacturer — needed a suitable solution for the machining and testing of its newly developed lock cores, they came to AUMAT.
After several months of development, AUMAT automated this process with a machining center developed especially for this customer. The approximately 20 square meter plant in Solingen consists of 10 variable stations in which the lock core is drilled, reamed, deburred, filled with pins, and pressed. A conveyor belt and a six-axis robot from Kawasaki Robotics are used to transport the cores.
The challenges for the AUMAT developers were significant. The customer set the cycle time of the process at 11 seconds. Due to the variety of products, the machine had to be designed with extreme adaptability, making it far more complex. As the space available at the customer’s location was also limited, a considerably compact design was required.
The heart of the facility is the testing and measuring station for the lock cores with the Kawaski robot. During the initial stages of the project, the AUMAT development team was still thinking about solving the complex testing process employing a clamping device for the process-safe holding of the lock cores and micro-probes for tolerance evaluation. However, research led to a new idea and possibility which could simplify the process: A special gripper could perform the two test steps as an all-in-one solution. This would not only provide a more compact solution but also fewer sources of interference.
AUMAT contacted the Zimmer Group, a company that develops handling solutions and gripping systems for various industries. The Zimmer Group suggested its GPP5000IL hybrid gripper. This gripper has a pneumatic drive combined with modern IO-Link technology. Valve technology, sensor technology, status display, pressure, and temperature monitoring are integrated into the gripper. Since there is no longer a fixed hose connection between the valve and piston that needs to be filled or emptied for each cycle, the grippers have a short reaction time and are faster than other pneumatic grippers. In addition, it has a part detection in the range of ±0.05 mm with a freely teachable tolerance range. As a result, not only is process monitoring possible, but also the identification of workpieces based on their diameter. In this process, different diameters are assigned to different workpiece numbers, which are then relayed to the control system via IO-Link. This process was a decisive factor for the developers at AUMAT because the lock cores were to be checked for dimensional accuracy (diameter, position, and length) at the test station.
Due to a large number of different types of lock cores, it was helpful that 32 workpiece data records could be programmed into the GPP5000IL gripper. An unlimited number of recipes could now be stored in the PLC, which can be continuously called up by the gripper if required. The grippers are universally applicable, protected against corrosion, and offer high gripping forces at large gripper finger lengths. Even in the standard version, they have IP64 sealing so that these grippers can also be used under challenging ambient conditions. Their high replacement accuracy enables rapid replacement without any considerable interruption in production.
The robust hard-coated guides, with a low friction coefficient, extreme hardness, and excellent emergency running properties, ensure that the grippers can handle 30 million cycles without maintenance while enduring adverse working conditions without difficulty.
At the inspection station, the lock cores fed from the belt into boxes are fed by the robot into the GPP5000IL hybrid gripper and checked for the correct diameter. The core is then aligned for further processing and, using spring-loaded metal pins, which are scanned by laser light sensors, it is checked whether the holes are present and in the correct position. The workpiece is then measured by a distance measuring system and inspected for the presence of a coupling bore. With this detailed inspection, the lock core is released for further production or is noted as NOK (not in order) and sorted out.
The automated solution will increase Iseo’s profitability, ensure process reliability in the machining and testing of lock systems, and frees employees from monotonous work. This increases both the company’s profitability and the health of the employees.
Filed Under: Fluid Power World Magazine Articles