Steering Wheel Vibration Exciter Using Magnetic Attraction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vibration exciters for motor vehicle steering wheels are difficult to assemble and manufacture due to the need for precise assembly of small air gaps, leading to increased costs and complexity.

Innovation Solution

A vibration exciter with a movable actuator using a ferromagnetic attraction concept, where an electromagnet and ferromagnetic pull-on elements generate a non-linear magnetic attraction force, allowing for inexpensive production and reduced installation space, utilizing alternating current to create oscillations without noise and without requiring tight tolerances between moving parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If small air gaps are maintained between moving parts for proper functioning, then the vibration exciter can function properly, but precise assembly is required which increases manufacturing complexity and cost

Engineering Contradiction:
Improveproper functioningVSAvoidprecise assembly
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The vibration exciter is divided into separate modules: a housing module containing the electromagnet and a pendulum module containing the mass and attraction elements. This segmentation allows each module to be assembled and tested independently, then combined without requiring precise alignment between all components, thereby reducing manufacturing precision requirements while maintaining proper functioning.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A non-magnetic intermediary element (such as a plastic or composite component) is introduced between the electromagnet and the pendulum assembly. This intermediary acts as a spacer and positioning element that maintains the necessary air gaps without requiring precise metal-to-metal alignment, thus reducing assembly complexity while ensuring proper magnetic circuit function.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If traditional electromagnetic vibration exciters are used, then vibrations can be generated, but the assembly complexity and manufacturing cost increase due to tight tolerance requirements

Engineering Contradiction:
Improvevibrations for warningVSAvoidassembly complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The invention uses a pendulum-based dynamic system where the mass is suspended on elastic elements rather than being rigidly mounted. This dynamic mounting allows the pendulum to oscillate freely in response to magnetic forces from the electromagnet, generating effective vibrations without requiring precise positioning or tight tolerances in the mounting structure, thereby reducing assembly complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the operational parameters by using a ferromagnetic attraction concept with non-linear magnetic attraction. This allows the system to generate sufficient vibration forces with larger, more tolerant air gaps compared to traditional linear electromagnetic actuators, reducing the need for tight tolerances and simplifying assembly while maintaining effective vibration generation for driver warnings.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If tight tolerances are maintained between moving parts, then proper function is achieved, but production cost increases

Engineering Contradiction:
Improveproper functionVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By segmenting the device into independently assembled modules with standardized interfaces, the invention allows for easier manufacturing and quality control. Each module can be produced with standard tolerances and then assembled without requiring costly tight tolerance machining across the entire assembly, thereby reducing production cost while maintaining proper function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention employs simple, easily manufactured components such as stamped metal attraction elements and standard elastic elements rather than precision-machined parts. These simpler components can be produced more cheaply with less stringent tolerances, reducing overall production cost while maintaining sufficient functional performance for the warning application.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 enables a cost-effective and compact vibration exciter that effectively generates perceivable vibrations for driver warnings, with a natural frequency range of 10-100 Hz, particularly 40-60 Hz, which is sensitive to human perception, without disturbing noise or assembly challenges.

Implementation Method 1

a magnetic attraction force can be generated between the actuator and the tightening elements

Methodology Applied
Scientific EffectFerromagnetic attraction: Ferromagnetism

Implementation Method 2

the actuator having an electromagnet

Methodology Applied
Scientific EffectElectromagnetism: Electromagnet

Implementation Method 3

the actuator moves back and forth against the force of spring elements acting against one another

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 4

The actuator is advantageously supplied with alternating current, which in particular has a frequency of 50 Hz, so that a magnetic attraction force is generated alternately

Methodology Applied
Scientific EffectAlternating magnetic field: Alternating Magnetic Field

Data Source

PatentEP3217035B1Vibration generator
Publication Date: 2019.10.30 VIBRACOUSTIC GMBH
  • EP3217035B1 patent drawingFigure 1
  • EP3217035B1 patent drawingFigure 2

AI summary

The present invention relates to a vibration exciter (10) for a motor vehicle steering wheel comprising a housing (12) and an actuator (14) which is movably arranged within the housing (12) to generate vibrations, wherein the actuator (14) has an electromagnet (24), wherein two attracting elements (64a, 64b) made of a ferromagnetic material are axially spaced apart from the actuator (14), wherein a magnetic attraction force can be generated between the actuator (14) and the attracting elements (64a, 64b) such that the actuator (14) moves back and forth, and wherein the actuator (14) moves back and forth against the force of mutually acting spring elements (60a, 60b).