Steering Column Locking Teeth Clearance for Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Collapsible steering columns experience noise and abnormal manipulation feelings due to locking teeth collisions and inefficient early-stage impact energy absorption.
Innovation Solution
A collapsible steering column assembly with a locking device featuring clearance between teeth coupling, a tilting bolt, cam members, and a biasing member, allowing selective engagement and disengagement for stable telescopic and tilt motions, and incorporating a tolerance ring for energy absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two locking teeth are engaged to fix the outer jacket and enable rotation for locking/unlocking conversion, then the locking function is improved, but collision between the two locking teeth causes noise and abnormal feeling
Solution Approach 1:
A tolerance ring is introduced as an intermediary component between the first and second locking teeth. This tolerance ring absorbs the collision impact when the locking teeth engage and disengage, preventing direct metal-to-metal contact that causes noise and abnormal feelings, while still allowing the locking function to operate effectively
2Stability of the object's composition
If two locking teeth are engaged in a state to fix the outer jacket, then the locking stability is improved, but impact energy cannot be effectively absorbed at an early stage of collapse
Solution Approach 1:
The tolerance ring is pre-positioned between the locking teeth to create a cushioning layer before impact occurs. When collapse is initiated, this pre-positioned tolerance ring immediately begins absorbing impact energy at the early stage, rather than waiting for the locking teeth to collide and transfer full impact 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
Prevents noise and abnormal feelings by minimizing locking teeth collisions and ensures stable impact absorption by distributing impact force effectively through the clearance between teeth.
Implementation Method 1
when a driver crashes into a steering wheel, an inner jacket of a steering column moves into an outer jacket by impact force so that a steering column is collapsed, and during this process impact energy is absorbed
Implementation Method 2
a cam member which is configured to be able to apply clamping force to the pair of arms in response to rotation of the tilting bolt
Data Source
AI summary
A collapsible steering column assembly includes: a mounting bracket having a pair of arms and is configured to be fixed to a vehicle body; a supporting housing which is disposed between the pair of arms to be tiltable about the mounting bracket; a steering column which passes through the supporting housing so as to be able to undergo a tilt motion together with the supporting housing; and a locking device which is configured to be in a locking state or an unlocking state to selectively allow a telescopic motion and a tilt motion of the steering column by selectively applying clamping force to the pair of arms. The steering column comprises an outer jacket and an inner jacket which is slidably inserted into the outer jacket. The inner jacket is configured to slide in the supporting housing together with the outer jacket during a telescopic motion of the steering column in the unlocking state of the locking device, and the inner jacket is configured to be able to be collapsed into the outer jacket when impact is applied to the steering column in the locking state of the locking device. The locking device is configured to selectively allow movement of the outer jacket in a direction of the telescopic motion through teeth coupling which is selectively engaged or disengaged depending on the locking state and the unlocking state. It is configured that clearance exists between two teeth of the teeth coupling such that the outer jacket is able to move by a predetermined length in a direction of the telescopic motion in the locking state.