FEATURE FASTENINGS & ADHESIVES
MECHANICAL FASTENING
DEVELOPMENTS I
n the majority of engineering applications there are only two methods
which can be employed to join engineered components together – mechanical and chemical. Despite the ‘maturity’ of mechanical fastening, however, just as much development continues to be poured into advances in the technology as it does into any other aspect of engineering, in both the design and production environments. Yet whilst the engineering community gasps (justifiably) at developments in some manufacturing sectors, fastening often remains low on the excitement list – despite some massive advantages being brought to the table through innovative joining technologies and products. Many of the more interesting
developments have occurred as a direct result of advances in materials technology. Take, for instance, the continuing drive towards lightweight vehicles which are not only more energy efficient (irrespective of their power source) but also need to be recycled more efficiently when they reach the end of their service lives.
HIGH STRENGTH JOINING As major automotive OEMs have migrated to new, lightweight, materials – including plastics, composites and aluminium – to get the desired balance of performance, economy and end-of-life recycling ability, so the methods and processes necessary to design and manufacture with them have had to change. The emergence of Self Pierce Riveting
(SPR) is a good example of this. In the ‘old’ days, metals were drilled and a rivet placed into the hole. Today, on more and more applications, the ‘drill and rivet’ process has been replaced with just ‘rivet’ as a new generation of SPR products and processes are employed. Take Böllhoff’s RIVSET self pierce
riveting, which is proven for use in aluminium, composites and a variety of material mixes. Not only does this deliver low cost, high strength and repeatably
12 NOVEMBER 2018 | DESIGN SOLUTIONS
Despite being a ‘mature’ technology, many interesting developments are still taking place in the world of mechanical fastenings, as Clive Brown, Böllhoff Fastenings, explains
mirrors onto the fairings. The product can also be seen fixing the rear light clusters onto the back panels of top-of- the-range Burstner motorhomes. Other significant developments in
mechanical fastening include RIVTAC, an ultra-high speed impact joining system; and QUICKLOC, a range of light weight quarter turn plastic fasteners. FAST- TURN, meanwhile, is made from metal and offers a step up in strength for ‘ease of repeated access’ quarter turn fasteners. The FLEXITOL range is an innovative
accurate joints of high integrity, but it can be applied using an array of tools to suit all volumes of production, from low to high. By inserting the rivet directly into the host material using the special RIVSET tooling and self-pierce rivets, production is speeded up, assembly energy is saved, weight is reduced and a
cleaner, quieter, working environment is
obtained. An added advantage is that RIVSET is a ‘blind’ fastener so only needs access from a single side.
DEVELOPMENTS Interesting developments have also been taking place in other areas of mechanical fastening and fixing where practicality and ease of access have joined lightweighting and speed of initial assembly as primary considerations. An example of this can be seen in Böllhoff’s SNAPLOC range. With so many everyday products
needing to be either occasionally or frequently disassembled, the demands of designers seeking the best of all worlds are being met through innovation. In this case, using a basic ‘ball and socket’ principle, Böllhoff engineers invented a mechanical fixing system that is robust, light in weight, and can be used to affix sometimes bulky items securely to the required mounting points. Many models of BMW touring motorcycles use the SNAPLOC system to mount rear view
Böllhoff Fastenings
www.boellhoff.com/gb-en
Mechanical fasteners are especially useful for applications where frequent access is required throughout the lifetime of a product. Here, FAST-TURN fasteners are used to secure an access panel on a heavy goods vehicle
tolerance-compensating mechanical fastener. This has provided real freedom in both design and production engineering where a degree of misalignment is expected but where a reliable, durable and assured fastening nevertheless remains essential. This is being used in a wide range of applications, including the manufacture of utility vehicles, in drive units for washing machines, in vehicle cab liners and in machine housings. Mechanical fastening has always been
at the centre of practical, functional, safe and cost-efficient engineering design and manufacture. As can be seen from the examples set here by just a single manufacturer, the future advantages of mechanical fastening and fixing remains assured.
Even mature products have benefited from ongoing development. For example, Helicoil Plus threaded inserts have drastically reduced installation time by eradicating the need to pre-wind the inserts prior to insertion
/ DESIGNSOLUTIONS
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44
