Steering Column Leaf Spring Clearance Mechanism

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Solution Overview

Problem

Existing steering column designs face complexity and increased component count in achieving desired clearance between the casing tube and carrier body, leading to potential rattling noises and cumbersome assembly processes.

Innovation Solution

A leaf spring is used to press against the casing tube at two spaced points in the circumferential direction, allowing for simple construction and assembly by directly or indirectly contacting a cylindrical jacket-shaped section, with optional interposition of bearing bodies and a lubricant film for reduced friction and ease of assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a sleeve that more or less completely surrounds the casing tube is arranged between the casing tube and the carrier body to eliminate play, then rattling noises are avoided, but the assembly of the components becomes relatively complex

Engineering Contradiction:
Improverattling noisesVSAvoidassembly complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The leaf spring is divided into multiple segments or leaves that are stacked together, allowing the single component to provide comprehensive support at multiple locations around the casing tube while eliminating play and rattling noises. The segmented structure achieves complete circumferential coverage without requiring multiple separate support components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The leaf spring serves multiple functions simultaneously: it supports the casing tube against the carrier body, eliminates play in all directions, prevents rattling noises, and provides a simple assembly structure. This single multi-functional component replaces what would otherwise require multiple separate elements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Length of stationary object

If a leaf spring is arranged in the longitudinal direction and presses against the casing tube via blocks arranged in the transverse direction, then clearance is achieved, but the construction becomes more complex with additional blocks

Engineering Contradiction:
ImproveclearanceVSAvoidconstruction complexity
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The blocks that would normally be required to transmit the pressing force from the leaf spring to the casing tube are eliminated. The leaf spring is designed with extended ends that directly contact and press against the casing tube, extracting the intermediate block components and simplifying the overall construction.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of having the leaf spring press against blocks which then press against the casing tube, the design inverts this sequence by having the leaf spring ends directly press against the casing tube. This reversal eliminates the intermediate blocking elements and reduces construction complexity.

Inventive Principle:
Principle #13The other way round (Inversion)

3Length of stationary object

If the casing tube is pressed by means of a leaf spring with the interposition of a bearing body over the entire surface, then clearance is achieved, but the assembly requires a receiving part welded to the casing tube increasing complexity

Engineering Contradiction:
ImproveclearanceVSAvoidassembly complexity
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The receiving part that would need to be welded to the casing tube is completely removed from the design. The leaf spring with its extended ends directly engages with the casing tube outer surface, eliminating the need for any intermediate receiving structures and their associated welding operations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The casing tube itself serves as the mounting surface for the leaf spring through its outer surface, eliminating the need for separate receiving parts. The design utilizes the existing structure of the casing tube rather than requiring additional components to be attached to it.

Inventive Principle:
Principle #25Self-service

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 solution provides effective clearance between the casing tube and carrier body, reducing rattling noises and simplifying assembly while eliminating the need for complex locking mechanisms, allowing for precise longitudinal adjustment via a motorized drive.

Implementation Method 1

a leaf spring (7) which presses in a transverse direction (8) orthogonal to the longitudinal direction (5) of the steering spindle (3) against a cylindrical jacket-shaped section (9) of the casing tube (2)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

with the interposition of at least one bearing body (17)

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP2855237B1Steering column for a motor vehicle
Publication Date: 2016.11.09 THYSSENKRUPP AG
  • EP2855237B1 patent drawingFigure 1~2
  • EP2855237B1 patent drawingFigure 3
  • EP2855237B1 patent drawingFigure 4~6

AI summary

The invention relates to a steering column (1) for a motor vehicle having a casing tube (2) for rotatable mounting of a steering shaft (3) and having a carrier body which engages around the casing tube (2) at least in some areas, wherein the casing tube (2) is mounted so as to be movable in the carrier body (4) at least in a longitudinal direction (5) of the steering shaft (3), wherein the steering column (1) has at least one leaf spring (7) which presses in a transverse direction (8) orthogonally to the longitudinal direction (5) of the steering shaft (3) against a section (9) of the casing tube (2) in the form of a cylindrical casing, wherein the leaf spring (7) has at least two contact surfaces which are distanced from one another in the circumferential direction (10) of the casing tube (2) and which press against the casing tube (2) directly or having at least one bearing body (17) interposed, wherein exclusively the side of the leaf spring (7) which faces the casing tube (2) presses against the casing tube (2), both when the leaf spring presses directly and also when the leave spring presses while the bearing body (17) is interposed.