Rivets join two workpieces together permanently - quickly and easily. In contrast to screwing or welding, this proven joining method does not require a thread to be cut and there is no risk of material distortion. In series production, rivets punch through or form the sheets themselves in a single work step. A system that can apply and absorb the necessary pressing forces is important for a precise result.

With the combination of suitable press systems and press drives, Tox Pressotechnik from Weingraten offers users an optimal and economical solution for joining sheet metal. The customer has the option of choosing the perfect press system from the modular system. They can also choose between pneumohydraulic and electromechanical drives. Tox Pressotechnik has extensive expertise in form-fit joining technologies such as clinching, riveting and press-fitting and can therefore provide users with comprehensive advice.

This performance package also convinced a Slovakian automotive supplier and its equipment supplier. They were looking for a system for riveting clutch components that would meet the requirements of large-scale production. In addition to the high throughput rate, precision was also important. The solution from Weingarten consists of a sturdy C-frame press with an interchangeable tool system and a four-station rotary indexing table - all mounted on a base plate. Four workpiece holders feed the press with the clutch components to be riveted.

High demands on precision

During this assembly process, several rivets are set simultaneously in a single operation. A correspondingly high, precisely adjustable and, above all, reproducible pressing force is therefore just as necessary as a stable frame. The engineers at Tox Pressotechnik opted for a TOX C-frame press from the PC 100 series, which has a solid, welded base body with minimal deflection and a ram designed as a four-column guide that ensures the functionality of the tool system and its process reliability even under one-sided loads.

To meet the high pressing force requirements for setting the multiple rivet joints, the engineers opted for the Tox-ElectricDrive type EPMK 1000 electromechanical servo drive, which has a very high power density in a short, compact design and generates pressing forces of up to 1,000 kN. It offers a stroke of up to 300 millimeters and a positioning speed of up to 90 mm/s. This enables dynamic process sequences and high cycle rates for riveting.

Safe operation with cooling

The Tox-ElectricDrive is equipped with an additional external water cooling system to cope with the high loads in continuous operation and multi-shift large-scale production. For safe operation, it is equipped with a quick stop and safety brake. The scope of delivery also includes the servo controller with ToxsoftWare, which is used to parameterize and control the drive.

Tox Pressotechnik supplied the main components, i.e. the press, drive and control system, assembled ready for connection to the supplier of the production system. The supplier was responsible for the design of the entire system, the integration of the press and the four-station rotary indexing table as well as the production and installation of the tool system for multiple riveting. He also manufactured the workpiece holders and finally assembled the individual system components. The precisely working basic system with drive, controller, software and the practical user interface serves the customer as an exact and reliable basis on which he was able to build his complete solution in a time and cost-saving manner.