Steering Column Energy Absorbing Coil Strip
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Solution Overview
Problem
Existing collapsible steering column assemblies face challenges in controlled energy absorption during crashes, particularly with packaging issues arising from traditional energy-absorbing devices like deformable straps, which can provide inconsistent resistance and increase complexity.
Innovation Solution
The implementation of an elongate energy-absorbing strip with a coiled central portion and projecting end portions, secured to the support bracket and the vehicle, which unwinds to control the collapse of the steering column assembly, providing a low initial resistance that increases significantly as the coil unravels, allowing for controlled energy absorption and reduced packaging complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a deformable strap is used as an energy absorbing device, then energy absorption effectiveness is improved, but packaging space requirements increase and device complexity increases
Solution Approach 1:
The energy absorbing device utilizes the existing hollow capsule structure as a container, nesting the energy absorbing element within the capsule's internal volume. This eliminates the need for separate packaging space while maintaining the energy absorption function.
Solution Approach 2:
The capsule structure serves dual purposes: it acts as both the frangible connection element for controlled collapse initiation and as the housing for the energy absorbing device. This multi-functionality reduces overall device complexity and space requirements.
2Loss of energy
If a deformable strap is used as an energy absorbing device, then energy absorption effectiveness is improved, but device complexity increases
Solution Approach 1:
The capsule structure serves dual purposes: it acts as both the frangible connection element for controlled collapse initiation and as the housing for the energy absorbing device. This multi-functionality reduces overall device complexity and space requirements.
Solution Approach 2:
The frangible capsule and energy absorbing device are combined into a single integrated assembly. The capsule's structural elements are reused to contain and support the energy absorbing mechanism, reducing the total number of separate components.
3Loss of energy
If the energy absorbing device provides high resistance force, then energy absorption effectiveness is improved, but reach adjustment difficulty increases
Solution Approach 1:
The device transitions from a high-resistance state during normal operation (when the clamp prevents movement) to a low-resistance state during collapse (when the capsule breaks and the energy absorbing device activates). This dynamic behavior allows both easy adjustment and effective energy absorption.
Solution Approach 2:
The clamp mechanism is designed to maintain the steering column in a fixed position during normal use, preventing any movement that would engage the energy absorbing device. This preliminary constraint ensures that adjustment forces do not activate the high-resistance energy absorption mechanism.
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 enables a controlled and efficient collapse of the steering column assembly during crashes, providing a consistent and high resistance force to absorb energy, while minimizing packaging issues and maintaining ease of adjustment for reach and rake.
Implementation Method 1
the forces on the U bracket are sufficiently high to cause it to break away from the capsules thus permitting the U bracket to move relative to the vehicle or second support bracket
Implementation Method 2
the two end portions of the strip are pulled away from one another causing the coil of the strip to at least partially become unwound thereby controlling the collapse of the steering column assembly
Implementation Method 3
the energy absorbing device... deforms so as to absorb energy and thereby at least partially control the collapse of the steering column assembly
Data Source
Figure 1~8
Figure 2~3
Figure 4~5
AI summary
A steering column assembly (1) comprises a shroud (2) which supports a steering column shaft (7),a support bracket assembly (17) comprising at least a first support bracket (10) which is arranged to be fixed to the shroud (2) through a releasable clamp assembly (9) and to be fixed to a fixed part of the vehicle through at least one frangible capsule,and at least one energy absorbing device (15) that acts between the first support bracket (10) and a fixed portion of the vehicle or the capsule (16) and which in the event of a collapse of the steering column assembly (1) that causes the capsule (16) to break deforms so as to absorb energy and thereby at least partially control the collapse of the steering column assembly (1), the energy absorbing device (15) comprising an elongate strip having two opposed ends and a central portion that is wound into a coil, the two free ends of the strip projecting away from the coil, a first end being secured to the first support bracket part and a second end being secured to the fixed part of the vehicle or the capsule (16), whereby in the event of a collapse of the steering column assembly (1) following breaking of the capsule (16) the two ends of the strip are pulled away from one another causing the coiled portion of the strip to at least partially become unwound.