Metallic Elastic Bush Energy Absorbing Steering Column
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing energy absorbing steering columns face challenges in separately setting and maintaining the load for starting and during axial movement, with materials like synthetic resin being prone to rigidity deterioration due to temperature and time changes, leading to low space efficiency and impracticality.
Innovation Solution
An energy absorbing steering column design featuring a first cylindrical member with a press-fit portion and a second cylindrical member with a supporting portion, utilizing a metallic elastic bush to apply radial elastic force, allowing axial movement only when a predetermined load is applied, thus enabling separate setting of loads for starting and during movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a spacer made of synthetic resin material is utilized, then the relative inclination of both columns caused by deformation of the protruding portions can be small, but the load for starting a movement is easily affected by change with time and temperature change, leading to deterioration in rigidity
Solution Approach 1:
The patent changes the material parameter from synthetic resin to metallic material for the spacer, which fundamentally alters the thermal and temporal stability characteristics. The metallic spacer maintains consistent mechanical properties across temperature variations and time, eliminating the rigidity deterioration issue while preserving the small relative inclination benefit.
Solution Approach 2:
The patent employs a composite structure where a metallic elastic bush is integrated with the metallic spacer. This composite arrangement combines the dimensional stability of metal with elastic deformation capabilities, allowing the spacer to maintain rigidity while providing controlled load characteristics that are resistant to temperature and time changes.
2Stability of the object's composition
If a spacer made of synthetic resin material is utilized, then the relative inclination of both columns caused by deformation of the protruding portions can be small, but deterioration in rigidity with time or heat is of great concern
Solution Approach 1:
The patent fundamentally changes the material parameter from synthetic resin to metallic material for the spacer. This parameter change eliminates the time-dependent and temperature-dependent rigidity deterioration while maintaining the small relative inclination characteristic, as metallic materials exhibit superior dimensional stability under varying conditions.
Solution Approach 2:
The patent creates a composite structure integrating a metallic elastic bush with the metallic spacer. This composite design preserves the rigidity and dimensional stability of metal while incorporating elastic properties that allow controlled deformation, thereby maintaining both small relative inclination and high rigidity resistance to time and heat.
3Force
If a cone-shaped configuration member is provided with a material weakening portion, then the load for starting a movement can be determined, but it is difficult to separately set the load for starting the movement and the load during the movement, and the dimension in axial direction becomes large
Solution Approach 1:
The patent segments the load control function into two distinct components: the metallic spacer determines the load for starting movement through its interference fit design, while the metallic elastic bush with spring portions determines the load during movement through elastic deformation. This segmentation allows independent adjustment of each load parameter without increasing axial dimension.
Solution Approach 2:
The patent changes the structural parameters by replacing the cone-shaped configuration with a cylindrical metallic spacer and elastic bush assembly. The spacer's outer diameter and interference fit parameters control the starting load, while the elastic bush's spring portion geometry controls the movement load, enabling separate parameter optimization without increasing overall axial dimension.
4Stability of the object's composition
If a metallic elastic bush is provided between the first press-fit portion and the first supporting portion, then the axial movement can be restricted by applying elastic force, but the structure becomes more complex
Solution Approach 1:
The metallic elastic bush serves multiple functions simultaneously: it provides axial movement restriction through elastic force, determines the load during movement through spring deformation, and works in conjunction with the metallic spacer to maintain radial positioning. This multi-functionality reduces the need for separate components, thereby limiting the increase in structural complexity while achieving superior axial movement 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
This design allows for easy and appropriate setting of the load for starting axial movement, maintaining stability and efficiency while preventing looseness, and ensures energy absorption by allowing axial movement when a predetermined load is exceeded, ensuring effective energy absorption properties.
Implementation Method 1
a metallic elastic bush provided between the first press-fit portion and the first supporting portion for applying elastic force in a radial direction for biasing the first press-fit portion and the first supporting portion in the radial direction
Data Source
AI summary
An energy absorbing steering column includes a first cylindrical member for rotatably supporting a steering shaft of a vehicle, the first cylindrical member including a first press-fit portion formed on an outer surface thereof, a second cylindrical member for normally supporting the first cylindrical member at a predetermined position, the second cylindrical member including a first supporting portion formed on an inner surface thereof, and a metallic elastic bush provided between the first press-fit portion and the first supporting portion for applying elastic force in a radial direction to restrict an axial movement of the first cylindrical member relative to the second cylindrical member. The metallic elastic bush allows the axial movement of the first cylindrical member relative to the second cylindrical member when a load applied to the steering shaft is equal to or larger than a predetermined value.