Steering Column Energy Absorption Strip Plastic Deformation
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Solution Overview
Problem
Existing collapsible steering column assemblies, particularly internal collapsing systems, face challenges in achieving reduced weight, fewer components, a longer collapse stroke, and adaptability for different vehicle performance specifications while maintaining minimal hardware substitution and effective energy absorption during secondary impacts.
Innovation Solution
A steering column assembly with a housing, a displaceable inner tube, and a telescoping actuator, utilizing a unique energy absorption strip that plastically deforms to absorb impact energy, allowing for adjustable and tunable energy absorption characteristics, and integrating a telescoping motor subassembly that remains fixed during impacts, enabling a longer collapse stroke within a compact packaging envelope.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional energy absorption mechanisms relying on friction are used, then energy absorption during impact is achieved, but the collapse stroke is limited and the system requires more components and hardware substitution
Solution Approach 1:
The patent replaces traditional friction-based energy absorption mechanisms with a plastic deformation mechanism. The energy absorption strip undergoes permanent plastic deformation during collapse, converting impact energy into deformation work rather than relying on friction between components. This substitution enables a longer collapse stroke of 70mm or more while maintaining effective energy absorption.
Solution Approach 2:
The patent changes the fundamental parameter of energy absorption from friction-based to plastic deformation-based. By selecting materials and geometries that facilitate plastic deformation (such as the curved portion and elongated body of the energy absorption strip), the system achieves extended collapse stroke while absorbing impact energy through permanent material deformation rather than friction.
2Length of moving object
If more components and hardware substitution are used to achieve longer collapse stroke, then energy absorption performance improves, but device complexity and weight increase
Solution Approach 1:
The patent merges multiple functions into the energy absorption strip itself. The strip's curved portion and elongated body are designed to simultaneously provide structural support during normal operation and undergo plastic deformation during impact. This integration eliminates the need for separate energy absorption components, reducing overall device complexity while achieving 70mm or more collapse stroke.
Solution Approach 2:
The energy absorption strip serves multiple functions: it provides structural support during normal steering column operation and acts as the primary energy absorption mechanism during impact. The telescoping actuator also remains fixed during impact while enabling normal telescoping adjustments. This multi-functionality reduces the number of dedicated components needed for each function separately.
3Device complexity
If the telescoping actuator remains fixed during impact, then the collapse mechanism simplifies and weight reduces, but the ability to provide both telescoping adjustment and energy absorption simultaneously is challenged
Solution Approach 1:
The patent segments the steering column system into distinct functional zones: the telescoping actuator and its mounting structure remain fixed during impact, while the energy absorption strip and column tube are designed to collapse. This segmentation allows the fixed actuator to maintain telescoping adjustment capability while the separate collapse mechanism handles impact energy absorption, resolving the conflict between simplification and versatility.
Solution Approach 2:
The system transitions from a static configuration to a dynamic one during impact. During normal operation, the actuator provides telescoping adjustment. During impact, the energy absorption strip undergoes plastic deformation while the actuator remains fixed. This dynamic behavior allows the same components to serve different functions under different conditions, maintaining both telescoping capability and energy absorption.
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 achieves a significant collapse stroke of 70 mm or more, reduces weight and component count, and allows for tunability across various vehicles, providing effective energy absorption during secondary impacts without relying primarily on friction, thus enhancing safety and adaptability.
Implementation Method 1
an energy absorption strip adapted to be carried within a steering column assembly and absorb energy by plastic deformation during translation of a column tube during an impact exceeding a threshold load
Data Source
Figure 1~2
Figure 3~4
AI summary
An energy absorption strip (40) having a generally elongated body portion (46), a first end (42) and a curved portion (44) between the first end (42) and the generally elongated body (46) portion that forms and angle between the first end (42) and the generally elongated body portion (46). The energy absorption strip (40) is adapted to be carried within a steering column assembly (10) and absorb energy by plastic deformation during translation of a column tube (20) during an impact exceeding a threshold load. A steering column assembly (10) including the energy absorption strip (40) is also contemplated.