Steering Column Separation Mechanism for Secondary Collision Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing steering devices face challenges in preventing the steering column from dropping due to erroneous operations, especially when the setting value of the separation load is decreased to protect lightweight operators from secondary collisions.
Innovation Solution
A steering device with a cylindrical inner column and outer column, where the inner column is inserted into the outer column during a secondary collision, and a second tightening mechanism biases a lock member to prevent the steering column from dropping, even with reduced friction force, allowing for a lower separation load setting value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the separation load setting value is decreased to protect lightweight operators from secondary collisions, then the protection effect is improved, but the steering column easily drops due to erroneous operations
Solution Approach 1:
The steering column is divided into inner column and outer column that can separate from each other. The inner column is detachably fixed to the outer column via a separation mechanism, allowing the inner column to move independently during secondary collisions while maintaining stability during normal operation.
Solution Approach 2:
A lock member is introduced as an intermediary component between the inner and outer columns. The lock member can be biased to engage with the outer column to prevent dropping, while still allowing separation when the separation load is exceeded during secondary collisions.
2Object-affected harmful factors
If the friction force between inner column and outer column is reduced to allow lower separation load, then the separation mechanism works better for lightweight operators, but the steering column becomes unstable during normal operation
Solution Approach 1:
The lock member acts as a mediator that provides additional stabilization force through biasing. This compensates for the reduced friction force between the inner and outer columns, maintaining stability during normal operation while allowing separation during collisions.
Solution Approach 2:
The system changes the stabilization mechanism from relying solely on friction force to using a biased lock member. This parameter change allows the friction force to be reduced for better separation performance while maintaining overall stability through the active biasing force.
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 prevents the steering column from dropping during erroneous operations and reduces the impact of secondary collisions on lightweight operators by maintaining stability and adjusting the separation load setting value.
Implementation Method 1
a second tightening mechanism biasing a lock member to the pressed portion in a tilt direction
Implementation Method 2
when an excessive load is applied to a steering column attached to a vehicle body through a capsule so that the steering column is pressed toward the front side of the vehicle body
Implementation Method 3
a friction force between the inner column and the outer column; the setting value of a separation load in which the steering column moves toward the front side of the vehicle body is decreased
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A steering device includes a cylindrical inner column that rotatably supports an input shaft connected to a steering wheel, an outer column that is a cylindrical member into which at least a part of the inner column is inserted and includes a slit formed by notching one insertion side end of the inner column, a column bracket that is fixed to a vehicle body side member and tightens the outer column by a pressing bracket squeezing the outer column, a pressed portion that is provided in the outer periphery of the inner column, a first tightening mechanism that tightens the outer column in response to the rotation of a manipulation lever, a second tightening mechanism that biases a lock member to the pressed portion in the tilt direction in response to the rotation of the manipulation lever, and a separation mechanism that causes the inner column to be separable by changing the relative position with respect to the pressing bracket in a state where the first tightening mechanism tightens the outer column and the second tightening mechanism biases the lock member to the pressed portion in the tilt direction.