Steering Device Hanger Bracket Friction Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing steering devices face challenges in achieving stable energy absorption during secondary collisions while minimizing size and cost.
Innovation Solution
A steering device configuration featuring an inner column, an outer column, a hanger bracket with a guide hole, and a fixing member that adjusts frictional forces to facilitate smooth energy absorption, including a first region with higher friction and a second region with lower friction for efficient load distribution during collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional energy absorption mechanism is used with a single friction region, then the structure is simple, but the energy absorption performance is unstable and requires larger size to achieve adequate absorption
Solution Approach 1:
The guide hole edge is divided into a first region with higher friction coefficient and a second region with lower friction coefficient. This local quality differentiation allows the steering device to achieve stable energy absorption performance through controlled friction variation during collapse stroke, while maintaining a compact structure without requiring additional components.
2Loss of energy
If the friction force is increased to improve energy absorption, then the energy absorption capacity increases, but the initial operating load required to activate the mechanism increases
Solution Approach 1:
The friction coefficient parameter is varied along the guide hole edge, with the first region having a higher friction coefficient for initial energy absorption and the second region having a lower friction coefficient for subsequent absorption. This parameter change allows the mechanism to achieve adequate energy absorption capacity while reducing the initial operating load required to activate the collapse stroke.
3Ease of manufacture
If the steering device structure is simplified to reduce cost, then the manufacturing cost decreases, but the energy absorption performance becomes unstable
Solution Approach 1:
The guide hole edge is divided into a first region with higher friction coefficient and a second region with lower friction coefficient. This local quality differentiation allows the steering device to achieve stable energy absorption performance through controlled friction variation during collapse stroke, while maintaining a compact structure without requiring additional components.
4Ease of manufacture
If the frictional restraining force is made uniform throughout the guide hole, then the structure is simple to manufacture, but the energy absorption performance is unstable and the device size must be increased
Solution Approach 1:
The guide hole edge is divided into a first region with higher friction coefficient and a second region with lower friction coefficient. This local quality differentiation allows the steering device to achieve stable energy absorption performance through controlled friction variation during collapse stroke, while maintaining a compact structure without requiring additional components.
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 configuration enables stable energy absorption during secondary collisions with reduced initial operating loads and improved friction resistance, maintaining the steering device's posture and enhancing energy absorption performance without increasing size or cost.
Implementation Method 1
a frictional restraining force between the seat portion and the edge portion of the guide hole in a state where the seat portion is displaced to a position opposite the second region is set to be smaller than a frictional restraining force between the seat portion and the edge portion of the guide hole at a position where the seat portion faces the first region
Implementation Method 2
the tilt pin comes out of the hole portion and moves relative to the inside of the elongated hole as the inner column moves forward during the collapse stroke. At this time, a posture of the steering column is stabilized by a guidance function of the elongated hole and the bracket comes into contact with the bulging portion, and thus the bulging portion is gradually crushed and an energy of the impact load is absorbed
Data Source
AI summary
A steering device includes an inner column, an outer column, a hanger bracket, and a fixing member. The hanger bracket has a guide hole which extends in the front-rear direction and through which the shaft portion of the fixing member passes. An edge portion of the guide hole is provided with a first region with which the seat portion of the fixing member comes into contact to fix the hanger bracket to the inner column and a second region which is disposed in front of the first region and faces the seat portion when the seat portion is displaced forward together with the inner column by a secondary collision load being input. A frictional restraining force between the seat portion and the edge portion of the guide hole in a state where the seat portion is displaced to a position opposite the second region is set to be smaller than a frictional restraining force between the seat portion and the edge portion of the guide hole at a position where the seat portion faces the first region.