Steering Column Blocking Device Using Magnetorheological Fluid

Solution Overview

Problem

Conventional adjustable steering columns are bulky and heavy due to the need for a locking device that requires additional space and mass to control the energy absorption and adjustment mechanisms.

Innovation Solution

An adjustable steering column with a blocking device featuring a threaded rod and spindle nut in a roller bearing surrounded by magnetorheological fluid, controlled by an electromagnet to adjust viscosity and enable space-saving and lightweight adjustment and energy absorption, eliminating the need for additional locking mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional locking device is used to control the energy absorption device, then the steering column can be adjusted and locked, but the installation space and mass of the steering column increase

Engineering Contradiction:

Improveadjustment controlVSAvoidsteering column mass

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The locking device and energy absorption device are merged into a single integrated unit. The piston-cylinder unit serves dual functions: as a locking mechanism that can hold the steering column at adjustable positions and as an energy absorption device that dampens crash forces. This eliminates the need for separate locking mechanisms, reducing overall mass and installation space while maintaining both adjustment control and safety functions

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The piston-cylinder unit filled with magnetorheological fluid performs multiple functions simultaneously: it acts as a locking device to maintain adjustable positions, an energy absorption device for crash protection, and a controllable damping mechanism. By making this single component universal, the patent eliminates the need for additional dedicated locking mechanisms, thereby reducing mass and space requirements

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a locking device is added to control the energy absorption device, then the steering column adjustment can be controlled, but the device complexity increases

Engineering Contradiction:

Improveadjustment controlVSAvoidsteering column structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The locking device and energy absorption device are merged into a single integrated unit. The piston-cylinder unit serves dual functions: as a locking mechanism that can hold the steering column at adjustable positions and as an energy absorption device that dampens crash forces. This eliminates the need for separate locking mechanisms, reducing overall mass and installation space while maintaining both adjustment control and safety functions

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The piston-cylinder unit filled with magnetorheological fluid performs multiple functions simultaneously: it acts as a locking device to maintain adjustable positions, an energy absorption device for crash protection, and a controllable damping mechanism. By making this single component universal, the patent eliminates the need for additional dedicated locking mechanisms, thereby reducing mass and space requirements

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 allows for compact, lightweight adjustment and energy absorption, enabling precise control over the steering column's position and torque, enhancing safety and comfort while reducing installation space and mass.

Implementation Method 1

The viscosity of the magnetorheological fluid can be controlled by means of the electromagnet, which in turn can be used to adjust the through-torque of the roller bearing, so that the adjustment of the steering column can be blocked (fixed position) or released (release position).

Methodology Applied

Scientific EffectMagnetorheological fluid viscosity control: Magnetorheological Fluid

Implementation Method 2

The magnetorheological fluid can include ferromagnetic particles that become tense due to the influence of a magnetic field that is provided by the electromagnet, so that the viscosity of the magnetorheological fluid can be adjusted.

Methodology Applied

Scientific EffectElectromagnet magnetic field generation: Electromagnet

Data Source

PatentEP3645371B1Adjustable steering column having at least one mrf actuator

Publication Date: 2021.03.31 THYSSENKRUPP PRESTA AG

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AI summary

The invention relates to a steering column (1) for a motor vehicle, comprising a steering shaft (2) which is surrounded by a casing tube (4) and is connected to a steering wheel, and a guide clamp (5) in which the casing tube (4) is guided displaceably along the longitudinal axis of the steering shaft (2). The guide clamp (5) is mounted pivotably about a pivot axis (100) in a holding part (6) which can be connected to a chassis of the motor vehicle, and the position of the casing tube (4) is adjustable relative to the holding part (6). A blocking device (22, 122) is arranged between the casing tube (4) and the holding part (6), the blocking device (22, 122) having a threaded rod (12, 112) which meshes with a shaft nut (13, 113), and the shaft nut (13, 113) being mounted in a rolling bearing (23). The rolling elements (24) of the rolling bearing (23) are at least partially surrounded by a magnetorheological fluid (25), and the blocking device (22, 122) comprises an electromagnet (26).