August 11, 2011 in Saabology
WARNING: Long post!!!
I never thought that I would say that active structures makes sense, as I still don’t think that an active bonnet makes a big difference if a car collides with a young child, but in this case I will make an exception.
Autoliv in cooperation with Saab is developing an expandable A-pillar, so reports the Automotive Engineering International magazine in its printed version. The full article can also be found here.
A expandable A-pillar is just a pillar that expands to its full size only if needed, but remains thin for almost its complete life.
Why is this development so interesting?
There is a cynical adage in the motor industry that driver visibility is essential because “people like to see what they are going to hit.”
Or in other words, a thin A-pillar, like in the classic 900, increases the front visibility by a big amount, but it is too fragile to get best notes on the different crash test (EuroNCAP, NHTSA,…). The solution, a thin pillar that gets thick when needed.
Despite huge advances in primary and secondary visibility, there continues to be constraints on further improvement caused by the often conflicting requirements of vehicle design and structural integrity, including the thickness of the A-pillar—a vital aspect of crashworthiness. But now, Autoliv has come up with a potential solution: an expandable pillar.
I’ve heard sometimes that people like this impression of sitting in a tank when they sit or drive a new 9-5, it gives them a certain safety feeling. On the other side when I drive fast on a curvy road, there are too many moments (left curves) were the whole road in front of me is covered by the A-pillar of my OG9-5, impeding me to see any incoming cars, thus making an enjoyable ride too risky, and although my car is capable of more I end driving like an old man.
One solution to solve that could be to use very thick high strength steel for the A-pillar, but this would increase the weight and move the centre of gravity up and to the front, and both things are not good.
Ten years ago Volvo presented the Volvo SCC or Safety Concept Car.
It was a proposition to solve this problem, but the final car, the C30, never had this kind of A-pillar.
So Autoliv is now working with Saab for a modern solution using its experience in airbag design and manufacture.
Autoliv is working on the expandable A-pillar solution with Saab. It allows the pillar to be slimmed down to only 23 mm (0.9 in), about three times thinner than a typical pillar, while providing required crash energy-absorbing capability. And it could give a car the sort of chic visual effect that the 1955 Citroën DS 19 achieved with its slimline, set-back A-pillar design.
I think it is enough if it gives the chick visual effect of a Saab 99 or 900.
Autoliv and Saab have presented the results of this research in September 2010 at the ICRASH 2010 (International Crashworthiness Conference) and more recently on June 2011 at the ESV 2011 (Technical Conference on the Enhanced Safety of Vehicles). And looking at the pictures it seems like it is quite production ready.
And how does it work?
The pillar uses high-grade but not high-strength steel. The structure is folded and welded airtight, with a gas generator at one end. In the event of a serious crash, the generator is activated and the steel unfolds and expands, the added cross-section giving the required added strength.
So what is this post all about?
First of all, we are talking here on a very interesting engineering solution to a problem that no car manufacturer has been able to solve. So even if Saab didn’t have anything to do with this, I think it is worth talking about.
Secondly to add some flesh to sentences that we have heard many times in the last months like: Saab can’t go down now, there is too much going on. And there is not only a lot going on, but a lot of interesting and very innovative things.
Thirdly because of a sentence Victor Muller said back in 2010, II might quote him wrong, but the meaning was much like this: Many suppliers may want to work with Saab, because Saab with its small production figures makes it more attractive to test new technologies. For Autolive a Saab car using this technology is a proof of concept, and with that they can go to VW, GM or whoever and sell it out of the shelves.
And last but not least. Autoliv is Autoliv AB a Swedish company, Saab is also a Swedish company, and this shows the engineering potential that exist in Sweden. Sweden should be proud of people and companies like those. To throw this away would be a sin.
I want to congratulate Dr. Bengt Piepkorn from Autoliv Research and Mr. Jesper Lundström from Saab Automobile, and all other people involved in this project for this, imo, great achievement in the automotive industry.
And thank you to A-RO 95 for the hint!!!