Steering Column Preload Device Linear Guidance

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Solution Overview

Problem

Existing motor-adjustable steering columns require additional measures to secure the inner coat against twisting, increasing manufacturing and assembly effort, and often result in lower resilience, rigidity, and self-frequency.

Innovation Solution

Integration of a preload device with a pressure piece and guide device, along with shape elements that form a form closure in the circumferential direction, to provide linear guidance and prevent twisting between the inner and outer coats, thus eliminating the need for a separate turning protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If additional measures are taken to secure the inner casing against twisting, then the steering column achieves sufficient rigidity and stability, but the manufacturing and assembly effort increases

Engineering Contradiction:
Improveanti-twisting stabilityVSAvoidassembly complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The guide device is integrated into the pretensioning device, combining the anti-twisting guidance function with the existing pretensioning structure. The guide groove is formed directly in the outer casing, and the guide projection is formed directly on the inner casing, eliminating the need for separate anti-twisting components and reducing assembly complexity while maintaining stability

Inventive Principle:
Principle #5Merging (Combining)

2Stability of the object's composition

If flattened portions are used as positive-locking elements, then the steering column provides anti-twisting protection, but the load capacity, rigidity, and natural frequency are relatively low

Engineering Contradiction:
Improveanti-twisting stabilityVSAvoidload capacity
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The guide projection is formed as a radially extending web with a curved cross-section that fits into the guide groove. This web-like structure with optimized geometry provides superior load capacity and rigidity compared to flattened portions, while the curved surfaces enable smooth relative movement between the inner and outer casings

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 enables a functionally optimized steering column with reduced assembly effort, higher rigidity, and improved torsional stiffness, while maintaining smooth adjustability and preventing undesirable twisting.

Implementation Method 1

a guide groove (36) formed in one piece by plastic deformation into the inner casing (31) or the outer casing (33)

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

The guide device has form-locking elements which act in the circumferential direction, wherein the guide elements comprise a slide rail and a slide piece which is guided so as to slide therein

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4117979B1Steering column for a motor vehicle
Publication Date: 2025.05.07 THYSSENKRUPP PRESTA AG
  • EP4117979B1 patent drawingFigure 1~2
  • EP4117979B1 patent drawingFigure 3~4
  • EP4117979B1 patent drawingFigure 5~6

AI summary

The present invention relates to a motor-adjustable steering column (1) for a motor vehicle, comprising a casing unit (3), in which a steering spindle (30) can be mounted for rotation about a longitudinal axis (L) and which has an inner casing (31) arranged in an outer casing (33) so as to be telescopable relative to the outer casing (33) in the direction of the longitudinal axis (L), and a motor adjusting drive (6), which is coupled to the inner casing (31) and to the outer casing (33), wherein a preload device (7) is provided, which has a thrust piece (72) which is supported on the outer casing (33) and can be braced against the inner casing (31). In order to allow an optimized longitudinal adjustment with reduced effort, the invention proposes that the preload device (7) has a guide device which interacts with the thrust piece (72) and which serves for the linear guidance of the inner casing (31) relative to the outer casing (33) in the direction of the longitudinal axis (L).