Collapsible Steering Column Tolerance Ring for Jam-Free Impact Collapse
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Solution Overview
Problem
Conventional collapsible steering column assemblies experience jamming and scratching due to slip between the tolerance ring and the inner jacket, which deteriorates energy absorption performance during impact.
Innovation Solution
A collapsible steering column assembly design featuring a tolerance ring with friction protrusions on its inner surface and a blocking portion, allowing it to move together with the inner jacket during collapse, preventing slip and enhancing energy absorption by ensuring synchronized movement with the outer jacket.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tolerance ring is press-fitted between the inner jacket and outer jacket with friction protrusions, then the steering column can be collapsed during impact, but jamming and scratching occur on the outer surface of the inner jacket due to slip between the tolerance ring and inner jacket
Solution Approach 1:
A lubricant layer is introduced as an intermediary substance between the tolerance ring and the inner jacket. This lubricant layer prevents direct contact and friction between the friction protrusions on the tolerance ring and the inner jacket surface, thereby eliminating jamming and scratching while maintaining the collapse function for energy absorption during impact
2Loss of energy
If the tolerance ring is press-fitted between the inner jacket and outer jacket, then the structure can absorb impact energy, but slip occurs between the tolerance ring and inner jacket causing deterioration of energy absorption performance
Solution Approach 1:
The friction characteristics between the tolerance ring and inner jacket are modified by changing the surface condition through the introduction of a lubricant layer. This parameter change reduces friction and prevents slip, ensuring that the tolerance ring and inner jacket move together synchronously during collapse, thereby maximizing energy absorption performance
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 effectively prevents jamming and scratching, thereby enhancing the energy absorption performance of the steering column by ensuring the tolerance ring and inner jacket move in sync, improving the column's ability to absorb impact energy.
Implementation Method 1
a tolerance ring (50) which is interposed between the outer jacket and the inner jacket, the tolerance ring (50) being configured so as to make the inner jacket and the outer jacket move together to realize a telescopic motion
Data Source
AI summary
A collapsible steering column assembly includes: a mounting bracket having a pair of arms and is configured to be fixed to a vehicle body; a supporting housing which is disposed between the pair of arms to be tiltable about the mounting bracket; a steering column which passes through the supporting housing so as to be able to undergo a tilt motion together with the supporting housing; and a locking device which is configured to be in a locking state or an unlocking state to selectively allow a telescopic motion and a tilt motion of the steering column by selectively applying clamping force to the pair of arms. The steering column comprises an outer jacket, an inner jacket which is slidably inserted into the outer jacket and a tolerance ring which is interposed between the outer jacket and the inner jacket, and the tolerance ring is configured so as to make the inner jacket and the outer jacket move together to realize a telescopic motion in the unlocking state of the locking device and so as to allow the inner jacket to move into the outer jacket by impact in the locking state of the locking device. The tolerance ring is configured to move relative to the outer jacket in a longitudinal direction while the inner jacket collapses into the outer jacket.