Riveted Steering Column Assembly Tolerance Compensation
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Solution Overview
Problem
Existing height-adjustable safety steering column arrangements face challenges in achieving high rigidity and natural frequency while compensating for assembly tolerances between the bracket fixed to the vehicle and the casing tube, requiring a solution that is simple, inexpensive, and reliable.
Innovation Solution
A height-adjustable safety steering column arrangement is achieved through a riveted connection between the outer jacket tube and the console, using diametrically positioned rivets that form an axis of rotation coinciding with the universal joint axis, with chamfers and countersinks to accommodate assembly tolerances and reduce play, and optionally incorporating a plastic bushing to reduce friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the jacket tube is pivotably mounted on the console using a rotary axis with traditional connection methods, then height adjustability is achieved, but assembly tolerances cause play and reduce connection stiffness
Solution Approach 1:
A positioning device with an elongated hole serves as an intermediary element between the jacket tube and console. The expandable clamping element acts as a mediator that transfers and distributes clamping force across the joint, compensating for tolerance variations while maintaining connection stiffness. This intermediary mechanism enables both height adjustability and rigid connection without requiring precise pre-positioning.
Solution Approach 2:
The connection system transitions from a static rigid joint to a dynamic adjustable connection. The pivotable mounting allows the jacket tube to rotate relative to the console for height adjustment, while the expandable clamping element dynamically adapts to tolerance variations during assembly. This dynamic system maintains connection stiffness across different assembly conditions while preserving adjustability.
2Reliability
If traditional connection methods are used to achieve a stiff connection, then connection stiffness is improved, but manufacturing complexity increases due to low tolerance requirements and post-processing
Solution Approach 1:
The positioning device changes the tolerance parameters from tight to loose by introducing compensating mechanisms. The elongated hole and expandable clamping element allow the system to accommodate larger assembly tolerances while maintaining connection stiffness. This parameter change eliminates the need for precision machining and post-processing, reducing manufacturing complexity.
Solution Approach 2:
The positioning device extracts the tolerance compensation function from the manufacturing process itself and places it in a separate assembly-time mechanism. Instead of requiring tight manufacturing tolerances, the elongated hole and expandable clamping element provide tolerance compensation during assembly, separating manufacturing simplicity from connection stiffness requirements.
3Strength
If the axis of rotation is connected firmly to achieve high rigidity, then natural frequency is improved, but adjustment smoothness deteriorates
Solution Approach 1:
The connection system is segmented into two functional zones: a firm connection zone with the expandable clamping element that provides high rigidity and natural frequency, and a smooth rotation zone within the elongated hole that enables comfortable adjustment. This segmentation allows the same joint to provide both high stiffness during normal operation and smooth adjustability during height changes.
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 provides a steering column with high rigidity and natural frequency, improved safety, and simple, cost-effective assembly by compensating for axial and radial play, ensuring a secure and smooth adjustment mechanism.
Implementation Method 1
The rivet connection, in particular, enables positive axial and radial play compensation so that a steering column with high rigidity and natural frequency is obtained
Implementation Method 2
at least one plastic bushing is provided in the passage opening formed jointly by the passage opening in the jacket tube side and the passage opening in the console side
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a height-adjustable safety steering column assembly, comprising a console (2) which is installed securely on the vehicle and in which an outer jacket tube (1) is pivotably mounted, said outer jacket tube comprising a steering spindle (3) having a universal joint and further comprising an inner jacket tube, which surrounds a telescoping steering wheel-side section of the steering spindle (3). The pivotable connection of the outer jacket tube (1) with the console (2) installed securely on the vehicle is implemented by means of two riveted joints, wherein the two riveted joints are provided diametrically on a circumference of the jacket tube (1) and form an axis of rotation (D-D) corresponding to the universal joint axis of the steering spindle (3) in that, for each of the connections formed by two rivets (4), the console (2) installed securely on the vehicle has a passage (5) which leads into a passage (6) of the outer jacket tube (1), wherein in each case a rivet closing head (4') is seated on the jacket tube side.