Telescopic Steering Column Shock Absorption Design
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Solution Overview
Problem
Existing shock-absorption steering devices face challenges in easily setting the level of load to be absorbed during a vehicle collision while maintaining production ease, as they often compromise on rigidity or are difficult to produce.
Innovation Solution
A shock-absorption steering device featuring a telescopic mechanism with a first tube and a second tube, where the second tube fits into the first with resin pins that break under predetermined load, and an energy-absorbing plate that deforms to absorb impact energy, allowing flexible load adjustment without reducing rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the number of notches is increased or the thickness of the wall is reduced to set the load level low, then the load absorption is improved, but the rigidity of the column tube is reduced and discomfort vibrations occur
Solution Approach 1:
The column tube is divided into multiple sections with different wall thicknesses along its axial direction. The first section has a larger wall thickness for rigidity, while the second section has a smaller wall thickness for load absorption. This segmentation allows each section to perform its specific function without compromising the overall structure.
Solution Approach 2:
Different parts of the column tube are given different local properties - the first section maintains high rigidity with larger wall thickness, while the second section provides energy absorption with reduced wall thickness. This local differentiation resolves the contradiction between overall rigidity and localized load absorption capability.
2Force
If the wall thickness is varied in the axial direction to vary the load depending on collision stroke, then the load absorption is improved, but the column tube is difficult to produce
Solution Approach 1:
The column tube is segmented into distinct sections with uniform wall thicknesses within each section. This segmentation approach is easier to manufacture than continuously varying wall thickness, as each segment can be produced using standard manufacturing processes and then assembled or formed as a complete structure.
Solution Approach 2:
The structure transitions from a static, uniform design to a dynamic, multi-section design where different segments engage at different collision strokes. The first section absorbs initial impact, and the second section engages as collision progresses, providing variable load absorption without complex continuous geometry.
3Force
If the external diameter of the second casing tube or friction resistance is varied to change the load, then the load adjustment is achieved, but the sliding load difference is difficult to minimize and production is difficult
Solution Approach 1:
Instead of varying external diameter or friction resistance, the invention changes the wall thickness parameter of the column tube sections. This parameter change achieves load adjustment while maintaining easier manufacturability, as wall thickness variations in discrete sections are more straightforward to produce than diameter variations or friction control.
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
Enables flexible adjustment of the absorbed load during a collision without compromising the steering device's rigidity, and is easier to produce by using a telescopic mechanism and energy-absorbing plate design.
Implementation Method 1
the plate is pulled into the space formed between the first tube and the second tube by a predetermined bending load on the basis of a movement of the second tube sliding within the first tube
Data Source
AI summary
A shock-absorption steering device includes a steering shaft connected to a steering wheel, a column housing for housing and supporting the steering shaft, the steering shaft and the column housing making a telescopic movement in order to absorb an impact energy, the column housing comprised of a first tube and a second tube, a first tube portion formed at the second tube fitted into the first tube, a second tube portion formed at the second tube so that a space is formed between the first tube and the second tube, a plate formed so as to extend in a longitudinal direction of the column housing, one end portion of the plate being bent and fixed to the second tube portion, the other end of the plate not being fixed; and the plate pulled into the space by a predetermined bending load according to a movement of the second tube.