Lighting the Way (turning night into day) - The Story of Your Headlamps

  

The Institution of Electrical Engineers (IEE), Oxfordshire branch, organised a visit to Hella Manufacturing in Banbury on 12th May 2004.  This provided a fascinating insight into an aspect of the automotive supply chain that is often overlooked; lighting.

  

The history of Hella and the Banbury site was introduced by Nigel Gunter.  Hella have been in the "luminaires" business since 1899 when they made coach lamps (with a candle as a light source).  Their first automotive luminaire was an acetylene lamp in 1908, since then they been supplying lamps for the automotive industry that have been state-of-the-art for their day.  Their most recent clusters include halogen, Xenon, LED, light tubes and a plethora of lens and reflector arrangements. The emphasis lately from the Automotive OEMs' has been more on styling than performance and there is often a ongoing "discussion" between the vehicle stylists and lighting designers on the best way forward.  The manufacturing processes have similarly advanced, from machining metal reflectors and glass lens, to moulded reflectors and plastic lenses to today's' popularity of optic free lens, free-form moulded reflectors, light tubes and motorised lens-reflector combinations for beam forming.

   

The front lighting activities of the company were expanded upon by Kristof Muylle who explained the differences between traditional halogen and new Xenon high intensity discharge (HID) light sources, as well as Hellas' developments for Adaptive Front lighting Systems (AFS).  The AFS includes bi-functional (main beam and dipped beam) halogen and Xenon light sources, free-form reflector construction, self-leveling lamp housings and adjustable beam pattern arrangements.  The AFS features a common lamp carrier system allowing upgrades to be provided for various models in a vehicle range, without redesigning the cluster or lamp fixings.  The most recent advances of beam patterning and dynamic and static "light bending" systems are potentially significant safety advances for the automotive luminaire, however, homologation lags behind current developments and these are yet to be fully approved for European or North American markets.  The front lighting presentation concluded with a look at the possible future uses of LED's and new front cluster arrangements for daylight running lamps (DRL).

   

Signal and Rear Cluster Lighting (RCL) systems were presented by Robin Best.  The most recent advances for RCL include light-tube and LED arrangements for Central High Mounted Stop Lamps (CHMSL) and some rear lighting functions.  The most radical development is the use of intelligent control electronics to adjust rear signaling in response to either driving conditions (e.g. harsh braking) or weather conditions such as bright sunlight or heavy rain and misty atmosphere.  The Adaptive Signal System (ASIGNIS) is the Hella rear lighting equivalent of their AFS.  The use of signature lighting and styling was discussed and some of the most recent configurations of utilising lighting to make a statement on vehicle brand were shown.

   

After the presentations a tour of the manufacturing facility at Banbury was provided, this gave an insight into the moulding and production processes involved in producing a modern lamp cluster.  It was clear from the start that the production process requires a massive investment in machine tools and that the production of lighting for the automobile has moved on massively behind the scenes to keep pace with developments in the automotive industry in general.  Headlamps are primarily manufactured in thermoset materials and RCL in standard thermoplastics.  All require a significant amount of surface treatment and coatings, even before the aluminised reflective layers are added and finally the lens or clear cover is sealed onto the cluster assembly.  This often overlooked area of the automobile has made, and is continuing to make, significant technological advances in an area that we all too often simply take for granted. An enlightening event for all who attended.

 

Martin O'Hara

13th May 2004


The author would like to thank the Oxfordshire branch of the IEE for organising the visit, Nigel Gunter, Kristof Muylle and Robin Best of Hella for their time during the visit and Hella Manufacturing for hosting the visit and providing the pictures used to illustrate this review.  


www.AutoEMC.net 2004                                                           TOP OF PAGE                                                                 HOME