At the ZIMM screw jack manufacturer, KUKA robots automate a flexible production of 30 different workpiece types – from the blank to the finished component.
The Austrian company ZIMM produces premium quality screw jacks – and upgrades also its own production environment. The company has recently commissioned a fully automated, modular production cell – implemented by Vischer & Bolli, equipped with two KUKA robots. The cell relieves the employees, increases productivity and makes the company competitive.
Whether in the theatre stage, to bridge height differences in industrial conveyor systems or to drive dish aerials – the screw jacks from the Austrian premium manufacturer ZIMM usually do their job without being noticed. The production of gearboxes at the company’s headquarters in Lustenau, Vorarlberg, is a real eye-catcher, however: a five-axis milling machine from the manufacturer GROB ensures that the raw material – aluminium and cast cubes of different sizes – results in usable and high-precision components. What is special: The machine tool is part of a modular production cell in which loading and unloading of the workpieces and their subsequent post-processing is fully automated – by means of two KUKA robots.
Workpiece automation increases productivity and efficiency
Until recently, the path to the finished component was a bit more arduous: “In case of pure pallet handling, workpieces have usually been manually clamped onto pallets,” Marcel Haltiner, Head of Automation at Vischer & Bolli GmbH explains. “For one thing, it was time-consuming and for another, it was also expensive. 50 machine pallets, for example, easily cost EUR 200,000 or more, with each pallet additionally requiring a clamping device. Moreover, it always had to be manually clamped and unclamped.”
To make production more efficient and at the same time more productive, the company Vischer & Bolli developed an automation solution in close cooperation with ZIMM.A modular robot cell, equipped with one KR QUANTEC and one KR AGILUS by KUKA, takes over fully automatically the tasks that previously had to be carried out by hand: material feed of the five-axis milling machine, automated post-processing of the workpieces and output of the finished gear components.
Economical production possible from batch size one
The employees of ZIMM literally hand the raw material on a silver platter: instead of manually loading machine pallets as before, the employees now load so-called trays within a lift system. The four-meter-high tower uses the space upwards in the production hall to store raw material and machined products. Clamping devices and, if necessary, tools are stored in the lift system as well. In larger halls, even lift systems up to 18 meters high can be integrated.
Then work of the connected robot cell begins. One KR QUANTEC robot of KR 240 R2900 Ultra type first removes the trays loaded with blanks from the lift system and places them on a front table. The robot then automatically positions four blanks in a device and inserts them into the milling machine. “The machine can produce around 30 different components from aluminium and cast iron in batch sizes between one and 200“, Marcel Haltiner explains and adds: „By loading the device outside the machine, we avoid unnecessary downtime. As the robot only loads and unloads the loaded devices, we can make the entire process even more efficient.”
While the milling machine is processing the four workpieces, KR QUANTEC is loading an additional device. After the components are processed on both sides, the turning process is also automated and the robot places them on the post-processing station in the cell. They are deburred and cleaned by a KR AGILUS of KR 10 R900-2 type there. The host computer of the robot cell takes over the entire logistics. “The next step in automation ensures that all measuring parameters are checked in the further process step. Tolerance deviations can then be transmitted and automatically corrected via a feedback loop to the milling machine,” Marcel Haltiner says.
Unmanned shifts increase competitiveness
Once a component has gone through all the steps, the KUKA robot sorts it back into its place on the tray, which is then parked in the lift system. The employees only need to remove the finished products on the other side. The robot cell means for ZIMM an enormous further development of the production processes. “Among other things, automation allows us to produce in unmanned shifts at night and at weekends, which increases our productivity and competitiveness,” Hardy Ponudic, Production Manager at ZIMM says.
The robots in the cell now do what previously had to be done manually, requiring a lot of personnel and time. “We are upgrading our workplaces because employees are now being trained to become robot operators.” Due to the shortage of skilled workers, it is becoming increasingly difficult also for ZIMM to find qualified employees. The automation enables employees who have previously mainly loaded the milling machine magazine to be used in other areas where they can concentrate on value-adding activities. “Our solution runs largely without further action and relieves the employees of less demanding tasks such as clamping and unclamping the workpieces,” Marcel Haltiner says. In addition, the robot cell enables flexible working: for example, messages can be sent to a smartphone via the integration of a mobile communication solution. The alarmed employee can then decide whether intervention is necessary.
Central host computer system, unlimited possibilities
All processes within the cell are controlled by a host computer, which can also be integrated into the ERP system. For example, he takes over the job management and the coordination of the workpieces, controls the peripheral devices and provides information about ongoing and upcoming processes. Due to the modular structure of the cells, Haltiner can see almost unlimited possibilities for use: “Mechanical and mould making, medical technology, automotive sector – in principle, we offer a possibility of entry into automation for all machining companies.” Marcel Haltiner is namely confident that the future of machine tool manufacturing is automated. Above all, when it comes to handling parts, he can see hardly any other option in terms of economy and feasibility in the future. ZIMM has recognised this trend: talks on the production of another robot cell are already underway.
(Source: KUKA AG)