Safety steering column
The safety steering column prevents the steering column of an automobile from entering the passenger compartment in the event of a head-on collision. It complements other safety devices such as seat belts and airbags .
The basic concept of the safety steering column goes back to an idea by the designer Béla Barényi in 1947.
history
At the beginning of the automobile era, the vehicle's steering column was hardly a problem in collisions; Compared to today, collisions were less frequent and mostly at low speed. As the number of cars moving at higher speeds increased, security systems became more important. In the 1960s, the seat belt established itself as a restraint system, supplemented from the 1980s by the airbag. At the same time, attempts were made to reduce the risk of injury in the event of a steering column penetrating the passenger compartment.
A first approach were bowl-shaped steering wheels (from 1959 in the VW Beetle and Lloyd Arabella ), which the driver's chest hits in a collision. The hub, which is recessed in the bowl, was able to move closer to the driver without injuring him by bending the (usually three) spokes of the steering wheel. Another approach and a forerunner of the airbag were steering wheels with a padded, large-area hub, the impact absorber . However, it was not until the invention of the safety steering column that the problem of the steering column penetrating the passenger compartment was solved.
Systems
Various systems of the safety steering column have developed since the 1960s. The most important are the mesh tube, the angled steering column, the corrugated tube and the release coupling. They prevent the steering column from penetrating the passenger compartment by shortening or moving it. Nowadays, several systems are often used in combination, with the additional support of a recessed or padded steering hub.
Another form of a safety steering column was the Procon-ten system developed by Audi in the 1980s . In the event of a collision, this pulled the steering column and steering wheel back towards the dashboard using a steel cable wrapped around the engine block and tightened the seat belts. However, this system was not compatible with the emerging airbag, which is normally integrated in the steering wheel for the driver. Audi deleted the registration of the brand in 2002.
Mesh tube
With the mesh tube, part of the steering column is made of a kind of expanded metal . In the event of a collision, the steering tube is shortened by compressing the mesh. Steering columns with such a safety element had been used by the VW Beetle since 1967 and the VW 411 in 1968 .
Angled steering column
In this system, a multi-part steering column with at least two cardan joints is installed if the steering gear cannot be reached directly. This construction also serves as a safety steering column: a shift in the lower part of the steering column does not continue on the upper part of the steering column that carries the steering wheel, similar to the folding of a folding rule. Such a system was u. a. installed in the Porsche 911 (1963) as well as in the VW Beetle 1302 (1970) and 1303.
Corrugated pipe
The corrugated pipe works like the mesh pipe . It absorbs the energy used to push the steering column into the passenger compartment by deforming. It can be compressed, but it also kinks.
Release coupling
In the case of the release coupling, the steering column consists of two parts that are attached to one another but can move against one another.
literature
- Hans-Hermann Braess, Ulrich Seiffert: Vieweg manual automotive technology. 2nd edition, Friedrich Vieweg & Sohn Verlagsgesellschaft mbH, Braunschweig / Wiesbaden 2001, ISBN 3-528-13114-4
- Karl-Heinz Dietsche, Thomas Jäger, Robert Bosch GmbH: Automotive pocket book. 25th edition, Friedr. Vieweg & Sohn Verlag, Wiesbaden 2003, ISBN 3-528-23876-3