Steering Column Shear Pin and Friction Support Mechanism
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Solution Overview
Problem
In steering column systems where the column is attached to the vehicle body through a capsule, the column tends to fall during erroneous operations due to decreased separation load settings, making it difficult to perform steering operations effectively.
Innovation Solution
A steering device with a cylindrical inner column, an outer column, a telescopic friction plate, and a shear pin that allows the inner column to move forward while maintaining support, preventing the column from falling by releasing the shear pin's connection and relying on friction forces, and a rotation stopper to regulate the inner column bracket's rotation during collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the separation load setting is decreased to protect light-weight operators from secondary collision, then operator protection is improved, but the steering column easily falls due to erroneous operation
Solution Approach 1:
The steering column system is segmented into multiple support mechanisms: the shear pin connection that can detach during excessive load, and the friction-based support between inner and outer columns that prevents falling. This segmentation allows the system to provide operator protection through controlled detachment while maintaining stability through alternative support paths.
Solution Approach 2:
The friction plate and friction force are prepared in advance as a backup support mechanism. When the shear pin detaches during erroneous operation, the pre-existing friction between the inner column and outer column immediately prevents the steering column from falling, providing beforehand cushioning against instability.
2Reliability
If the shear pin connection is released to allow inner column movement during collision, then impact absorption is improved, but the inner column bracket may rotate and contact the inner column causing disturbance
Solution Approach 1:
The friction plate acts as an intermediary between the inner column bracket and the inner column. When the inner column bracket rotates after shear pin detachment, the friction plate controls this rotation through friction, preventing direct contact and disturbance between the bracket and inner column, thus maintaining movement stability during impact 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 effectively suppresses the steering column's fall during erroneous operations and maintains impact absorption capability by ensuring continuous support and regulating the inner column's movement, even with reduced separation load settings.
Implementation Method 1
since a shearing force is applied to the shear pin, the shear pin is cut when the load exceeds an allowable shearing force of the shear pin
Implementation Method 2
the inner column is supported in the axial direction by a friction force generated between the inner column and the outer column
Implementation Method 3
the rotation stopper contacts the telescopic friction plate when the telescopic friction plate rotates about the rod in the event of a secondary collision
Data Source
Figure 1
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Figure 4
AI summary
A steering device includes: an inner column having a first hole opened therein; an outer column having a slit; an outer column bracket clamping the outer column along with a telescopic friction plate; a rod supporting the telescopic friction plate; an inner column bracket supported by the telescopic friction plate and having a second hole opened therein; a shear pin separably connecting the inner column and the inner column bracket to each other at a position across the first hole and the second hole; and a rotation stopper provided at a rear side in relation to the rod and contacting the telescopic friction plate when the telescopic friction plate rotates about the rod in the event of a secondary collision.