Electromagnetic Steering Lock with Dual-Coil Position Detection

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Solution Overview

Problem

Existing steering devices with locking mechanisms for immobilization can unintentionally lock during driving, posing a safety risk due to vibrations, and require additional detection means, increasing complexity and cost.

Innovation Solution

An electromagnetic steering lock with a movable blocking element driven by two coils and a position detection system using inductance changes, eliminating the need for additional detection means and allowing for real-time monitoring of the locking state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a locking mechanism is added to the steering device for immobilization, then the steering device can be locked when parking, but the steering device may unintentionally lock during driving due to vibrations

Engineering Contradiction:
Improvelocking functionVSAvoidunintended locking during driving
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The control unit continuously monitors the position of the locking element before actual locking occurs. By detecting position changes in advance through the coils during driving, the system can prevent unintended locking by keeping the locking element in the unlocked position when vehicle motion is detected, while still allowing locking when the vehicle is stationary.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses the coils to continuously detect the position of the locking element and provides feedback to the control unit. This feedback mechanism allows the control unit to monitor the locking element's position in real-time and respond to any unintended movement caused by vibrations, ensuring the steering device remains in the desired unlocked state during driving.

Inventive Principle:
Principle #23Feedback

2Reliability

If additional detection means are added to monitor the locking element position, then unintended locking can be prevented, but the device complexity and cost increase

Engineering Contradiction:
Improveposition monitoringVSAvoiddetection means
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The coils serve dual functions: they act as both actuators to move the locking element and as sensors to detect its position. This multi-functionality eliminates the need for separate detection means, reducing device complexity and cost while maintaining reliable position monitoring to prevent unintended locking.

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

Solution Approach 2:

The locking mechanism's own components (the coils) perform the detection function that would otherwise require separate sensors. The coils detect changes in their electrical characteristics based on the position of the locking element, allowing the system to monitor its own state without external detection devices.

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

Prevents unintended locking during driving by detecting position changes through inductance, ensuring the steering device remains unlocked and allowing for cost-effective implementation without additional sensors.

Implementation Method 1

The steering lock has at least two or exactly two electromagnetic coils that are operatively connected to the blocking element, with the electromagnetic coils each being arranged and designed to move the blocking element back or forth when energized

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

The position detection device is connected to at least one of the coils and is designed to detect an inductance of the coil and to detect a position of the armature as a function of the inductance of the coil

Methodology Applied
Scientific EffectInductance: Inductor

Data Source

PatentEP2536598B1Vehicle steering device
Publication Date: 2014.03.19 ROBERT BOSCH GMBH
  • EP2536598B1 patent drawingFigure 1
  • EP2536598B1 patent drawingFigure 2
  • EP2536598B1 patent drawingFigure 3

AI summary

The invention relates to a steering device for a motor vehicle. Said steering device comprises a drive (10), especially an electromotive drive. Said drive is designed to generate torque for assisting the steering of a motor vehicle. According to the invention, the steering device comprises an electromagnetic steering lock (5,7,11,16) comprising a blocking element (11) that can be moved back and forth along a translation axis (25) or about a pivoting axis (23). The blocking element is arranged and designed in such a way as to engage in the drive (22) in a form-fitting and/or force-fitting manner, in order to block the steering. The steering lock comprises at least two, or exactly two, electromagnetic coils (5, 7) that are actively connected to the blocking element, the electromagnetic coils being respectively arranged and designed in such a way as to move the blocking element back and forth when current flows through them. The steering device also comprises a position detection device (48, 50 52, 58) designed to detect at least one position of the blocking element inside the movement interval (26), the movement interval including a blocked state and a released state of the steering device.