Steering Column Energy Absorption Mechanism
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Solution Overview
Problem
Existing reach adjustable steering column assemblies face challenges in controlling the movement of the steering wheel during a vehicle crash, particularly in absorbing energy across various reach positions, which can lead to unpredictable forces on the driver.
Innovation Solution
A reach adjustable steering column assembly with a telescopic steering shaft, a shroud that supports the shaft, a clamp mechanism with an energy absorbing mechanism, and an anti-abuse mechanism that ensures the energy absorption mechanism is only activated during a crash, allowing for predictable control of collapse across all reach positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a deformable strap is forced around an anvil to absorb energy during collapse, then energy absorption is achieved, but the design becomes complex and must perform satisfactorily over a range of different reach positions
Solution Approach 1:
The energy absorbing mechanism is designed to function across all reach positions (reach in and reach out) without requiring separate mechanisms for each position. The deformable strap and anvil arrangement provides universal energy absorption capability regardless of the steering column's telescopic position, eliminating the need for position-specific energy absorption designs.
Solution Approach 2:
The energy absorbing mechanism is integrated into the existing clamp mechanism structure. The deformable strap is positioned to engage with the anvil as part of the normal collapse sequence, merging the energy absorption function with the existing structural components rather than adding a separate, independent energy absorption system.
2Adaptability or versatility
If the steering column assembly is made telescopic for reach adjustment, then reach adjustability is improved, but the assembly becomes more complex and requires additional locking mechanisms
Solution Approach 1:
The steering column is divided into telescopic sections (upper and lower shroud parts) that can slide relative to each other for reach adjustment. The clamp mechanism is segmented into movable locking parts that engage and disengage to control the telescopic movement, allowing smooth adjustment while maintaining structural integrity.
Solution Approach 2:
The clamp mechanism transitions between dynamic states (unclamped for adjustment, clamped for positioning) to control the telescopic movement. The locking parts move between engaged and disengaged positions, allowing the system to dynamically switch between adjustable and fixed states as needed.
3Reliability
If the energy absorbing mechanism is always active, then crash protection is improved, but the mechanism may be accidentally activated during normal adjustment operations
Solution Approach 1:
The deformable strap is positioned and configured so that it can only engage with the anvil during actual crash collapse, not during normal adjustment operations. The geometric arrangement and positioning of the strap relative to the anvil ensure that engagement only occurs when the steering column undergoes the specific telescopic movement characteristic of a crash, preventing false activation during legitimate adjustment.
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
The solution provides predictable energy absorption during a crash, reducing the forces applied to the driver and maintaining the assembly's integrity by ensuring the energy absorption mechanism functions consistently across all reach positions, while minimizing the number of components required.
Implementation Method 1
a deformable part of the energy absorbing mechanism is plastically deformed by a deforming part, thereby controlling the movement of the upper shroud part
Implementation Method 2
the bolt being connected to the first locking part through a mechanism that converts rotary movement of the bolt into reciprocal movement of the first locking part
Implementation Method 3
a rocker arm that pivots around a pivot point having a first arm that extends in one direction from the pivot point and engages the first locking part and a locking finger that extends in another direction away from the pivot point and moves up and down in opposition to the movement of the first locking part
Data Source
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AI summary
A reach adjustable steering column assembly (100) comprises a telescopic steering shaft which in use supports a steering wheel of the vehicle; a shroud (104) that supports the steering shaft comprising an upper shroud part (106) and a lower shroud part (108), the upper shroud part (106) moving telescopically relative to the lower part (108) during reach adjustment of the steering column assembly (100), a support bracket (110) that supports the shroud (104) relative to the vehicle body, and a clamp mechanism (112) that is operable between an unclamped position in which the steering column assembly (100) is adjustable for reach and a clamped position in which the reach position of the steering column assembly (100) is fixed. The clamp mechanism (112) comprises a first locking part (122) that is displaceable by an actuator assembly (114) into and out of positive engagement with a second locking part (136). An energy absorbing mechanism (144) acts between the upper shroud part (106) and the second locking part (136) and is configured so that during a crash a deformable part (146) of the energy absorbing mechanism (144) is plastically deformed by a deforming part (148), thereby controlling the movement of the upper shroud part (106), and in that one of the deformable element (146) and the deforming portion (148) of the energy absorbing mechanism (144) is secured to the upper shroud part (106), and the other is fixed relative to the second locking part (136).