Pic. 5.8. The mechanism for changing the tilt and height of the steering column
The mechanism for changing the tilt and height consists of the following parts and assemblies: a lever, a locking device, a bracket, eccentric locks and an aluminum case.
To change the height, a splined connection of the steering column with the main shaft was used.
The use of an aluminum housing allows you to increase the efficiency of fixing the steering column.
fixation zone (eccentric locks) offset to the center of the steering column to smooth the shape of the lower part, which in a collision can hit the driver's feet.
Steering column fixed
When fixing the mechanism for changing the height and tilt of the steering column by moving the lever to position B, the eccentric locks wedged the housing relative to the bracket. Thanks to this, the steering column is securely fixed in the angular and axial directions.
Steering column not fixed
When loosening the mechanism for changing the height and tilt of the steering column by moving the lever to position A, the eccentric locks allow the body to move relative to the bracket. Due to this, the fixation of the steering column is weakened and its inclination and height can be changed.
Safety design
Impact energy is absorbed as a result of deformation of the limit plate (damper).
The following structural elements participate in the absorption of impact energy: a restrictive plate, a bracket, clamps, the main and intermediate shafts moving relative to each other.
The intermediate shaft is installed in the main shaft with interference, due to which the impact energy is absorbed in the process of mutual movement of the shafts.
The safety collapsing on impact bracket used in previous models has been replaced with a reinforced one to reinforce the instrument panel.
The aluminum housing holds the steering column housing in place. When the steering column housing is displaced as a result of a collision, the impact energy is absorbed by the friction force.
Primary consequences of the collision
Pic. 5.9. Primary consequences of the collision
When the steering mechanism is displaced as a result of an impact (primary consequences) the intermediate shaft enters the main shaft, due to which the steering column penetrates into the cabin for a shorter length.
Secondary consequences of the collision
Pic. 5.10. Secondary consequences of the collision
Impact energy transmitted to the steering wheel in a collision (secondary impact), is absorbed by the steering wheel and the driver's airbag. In addition, the impact energy is absorbed by the frictional force that occurs when the steering column housing moves when the height changes. At this point, the restrictive plate deforms and also absorbs the impact energy. Such a scheme of successive absorption of impact energy makes it possible to minimize the secondary consequences of a collision.
Electric steering column lock
On previous models, the driver had to insert the key into the ignition to unlock the steering column. New models are equipped with an engine start button, so the steering column is unlocked by the electric motor at the command of the electronic control unit of the steering column lock mechanism. To lock the steering column, turn off the engine and remove the key from the ignition.