Steering Column Energy Absorption with Mirror-Symmetric Bending Elements
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Solution Overview
Problem
Existing steering column energy absorption devices face issues with frictional forces disrupting even force distribution during crashes, requiring special coatings and increasing manufacturing complexity and cost, while also being prone to deformation impairment.
Innovation Solution
The implementation of mirror-symmetrically arranged bending elements, which support each other to prevent sliding friction and allow for controlled deformation, reducing the need for additional support structures and coatings, and enabling a simpler, more compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single bending element is used in the energy absorption device, then the structure is simpler, but sliding friction occurs during deformation which disrupts force distribution and requires additional coatings
Solution Approach 1:
The patent applies asymmetry by using two bending elements with different designs: a first bending element with a U-shaped cross-section and a second bending element with an I-shaped cross-section. This asymmetric configuration between the two elements creates complementary deformation behaviors that eliminate sliding friction while maintaining uniform force distribution during energy absorption
Solution Approach 2:
The energy absorption device is segmented into two distinct bending elements instead of using a single element. Each element has its own specific cross-sectional shape and deformation characteristics, allowing them to work together to eliminate the sliding friction problem while distributing forces uniformly
2Reliability
If friction-reducing coatings are applied to the bending element, then sliding friction is reduced, but manufacturing effort and cost increase
Solution Approach 1:
The patent converts the potential harmful effect of friction into a beneficial design feature by using asymmetric bending elements whose complementary deformation patterns naturally eliminate sliding friction. This eliminates the need for friction-reducing coatings and their associated manufacturing complexity and costs
3Manufacturing precision
If additional support structures are added to prevent lateral deflection, then deformation control is improved, but device complexity increases
Solution Approach 1:
The two bending elements serve each other through their asymmetric designs. The first U-shaped element and the second I-shaped element provide mutual lateral support during deformation, with each element's geometry contributing to preventing the other's lateral deflection. This self-supporting mechanism eliminates the need for additional external support structures
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution ensures reliable energy absorption with reduced manufacturing effort and eliminates sliding friction, providing a consistent force profile and improved safety during crashes without the need for friction-reducing coatings.
Implementation Method 1
an energy absorption device is coupled between the outer casing and the support unit, which converts the introduced kinetic energy into plastic deformation of an energy absorption element
Implementation Method 2
The amount of energy absorbed by the bent cross-section of the material of the bending element can be defined relatively accurately
Data Source
Figure 1~3
Figure 4~7
Figure 8~10
AI summary
The present invention relates to a steering column (1) for a motor vehicle, comprising a supporting unit (3) which can be connected to the body of the vehicle, and a casing unit (21), in which a steering spindle (22) is mounted such that it can be rotated about its longitudinal axis (23) and which is received in the supporting unit (3) such that it can be displaced in the longitudinal direction (L) parallel to the longitudinal axis (23), wherein an energy absorption device (5, 7, 73) is attached between the supporting unit (3) and the casing unit (21), which energy absorption device (5, 7, 73) comprises at least one first bending element (51, 71, 721) with an elongate entry limb (511) arranged parallel to the longitudinal direction, the free end (512) of said limb being connected to a first one of the two elements, the supporting unit (3) or to the casing unit (21), and the other end of said limb transitioning into a bend (513) which is adjoined by a fixed limb (514) connected to the other one of the two elements, the supporting unit (3) or to the casing unit (21). In order to make simplified production and reliable function possible in the event of a crash, the invention proposes that a second bending element (52, 72, 722) is of mirror-symmetrical configuration with respect to a first bending element (51, 71, 721) and is arranged in a mirror-symmetrically adjacent manner with respect to the first bending element (51, 71, 721).