The best of two worlds combined for modern multi-material designs 28 November 2018

The automotive industry cannot do without modern lightweight concepts. Not only do they considerably improve vehicle dynamics, but they also help to reduce emissions. Lightweight construction therefore continues to be a key technology for future cars. It is also important for e-mobility because the green innovation capacity counts on the know-how in battery and lightweight technology. While chasing an ever greater reach, lightweight construction is particularly essential to further promote electromobility.

However, efficient lightweight construction also sets high standards for multi-material concepts thus requiring innovative fastening technology, such as the established RIVSET self-pierce riveting technology from Böllhoff Group. This technology enables the joining of different materials in a single production step without pre-punching.

There are the reliable multi-material designs with aluminium (die-cast, extruded profile, sheet metal), multiple-layer joints, applications with adhesive as intermediate layer and deep-drawing steels with a tensile strength of up to 500MPa. Now, high strength steels with a tensile strength of up to 1,600MPa have been added, which are suitable for series production. In this context of lightweight construction and the use of related materials, the self-pierce riveting technology with semi-tubular rivets had to be further developed beyond the known technology limits.

High strength results
A great number of fastener varieties result from the many possibilities of use. RIVSET self-pierce rivets can vary in geometry, hardness, surface, head shape, shank length and diameter. The application defines the rivet type.

As a fastening technology expert, Böllhoff develops fasteners according to the material trends. Due to continuous development, Böllhoff can offer the RIVSET HDX for solutions to join materials with tensile strengths of up to 1,600MPa and a sheet thickness of 1.7mm in the top layer in series.

To that end, the fastener geometry has been optimised and the rivet hardness adapted. However, today’s body designs are not only characterised by an innovative use of materials.

Maximum life and minimum maintenance
Böllhoff has broken new ground with the innovative assembly system Automation EH. For this assembly system, the focus is on functionality, flexibility and design. Plus a long life, maximum availability and minimum maintenance, this is the foundation for effective production.

The intelligent machine variants such as the modular and comprehensive range allows high flexibility from prototyping to large-scale production. The fast and high performance control provides open software interfaces for robot communication, as well as for provision of data via OPC UA.

The main requirements for such systems are a 100% electrical installation on robots (no hose coupling), the compensation of punches (for high strength steel applications with tensile strengths up to 1,600MPa) and short process times – for some applications <1.5 seconds. These systems are hard to outperform, since a TPM-concept is also provided.

Further technical key highlights include the new die changer, the new magazine feed, as well as the new RIVSET feeder with simple feeding technology. The new die changer is suited for up to 8 dies, with die changing taking less than six seconds. The optional automatic 100% die recognition improves production reliability.

Böllhoff states that nothing compares to the new magazine feed. Rivet sequences of the same rivet diameter and up to eight different rivet lengths are processed. Partial loading and buffers are available. A die change takes less than four seconds and is executed during non-productive cycle times.

Plug & play
For modern production systems, production planning and control are also of great importance for defining and optimising manufacturing processes. Such requirements have also given new impulse to Böllhoff as an expert in self-pierce riveting technology. In cooperation with its customers, it elaborates new concepts, such as a software-based workflow to plan and handle the procurement of process devices. Transparent and project specific data and information are thus guaranteed. Another example is an intelligent delivery concept based on the modular design of Böllhoff components. Time critical machine components are separated from non time critical components. Those are two concepts that are very useful contributions to a flexible and equally efficient production and procurement planning.

Innovative industries need innovative partners
Böllhoff also offers a service package including a specialised maintenance team for optimum maintenance of the process machines. The team provides significant support for smooth and trouble-free production.

“Böllhoff fasteners and joining tools for self-pierce riveting come from a single source, which are ideal conditions to continue to stand out as a solution specialist for innovative industries in the future.”

 

Claire Aldridge Deputy Editor t: +44 (0) 1727 814 450

Having joined the magazine in 2012, Claire developed her knowledge of the industry through the numerous company visits, exhibitions and conferences she attended both in the UK and abroad.

Responsible for social media and the online platforms, Claire prides herself on keeping readers well informed and up to date with the latest industry news.