Rotary Throttle Detection Module With Variable Magnetization

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Solution Overview

Problem

Existing angular position sensors for motorized vehicle handles are prone to sensitivity issues due to external magnetic fields and have limitations in axial compactness and rotation range, particularly in designs using Hall effect probes and magnets with radial magnetization.

Innovation Solution

A position detection module utilizing a magnet with a continuously variable magnetization direction and magnetic shielding to enhance insensitivity to external magnetic fields, allowing a larger rotation range of the magnetic field and integrating multiple layers of shielding for improved immunity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a Hall effect sensor with radial magnetization is used, then the sensor can detect magnetic field direction, but the sensor becomes sensitive to external disturbing magnetic fields due to absence of shielding

Engineering Contradiction:
Improvemagnetic field detection accuracyVSAvoidsensitivity to external magnetic fields
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a magnetic shield as an intermediary element between the external environment and the Hall effect sensor. This shield acts as a mediator that blocks external magnetic fields from directly affecting the sensor, while still allowing the magnetic field from the radially magnetized ring sector to reach the sensor for accurate detection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a radially magnetized ring sector is used, then the sensor can be positioned inside the magnet, but the volume of magnet used is significant and axial compactness is reduced

Engineering Contradiction:
Improvesensor positioning stabilityVSAvoidaxial compactness
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent changes the magnetization parameter from conventional radial magnetization to a specific radial magnetization pattern with optimized magnetic flux distribution. This parameter change allows the magnetic field to be concentrated more effectively in the detection region, reducing the required magnet volume while maintaining detection reliability.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the magnetic field rotation angle is limited to less than 180°, then the sensor can be simplified, but the rotation range is insufficient and external magnetic field influence is not minimized

Engineering Contradiction:
Improvesensor structure simplicityVSAvoidangular detection range
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent creates a dynamic magnetic field configuration where the magnetic field direction rotates continuously as the handle rotates. By optimizing the radial magnetization pattern, the magnetic field rotation angle exceeds 180°, providing a broader detection range and better immunity to external magnetic fields while maintaining reasonable structural complexity.

Inventive Principle:
Principle #15Dynamics

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 provides enhanced axial compactness and reduced sensitivity to external magnetic fields, enabling accurate angular position detection over a broader range than previous technologies, with the magnetic field rotation exceeding 180° and potentially three times the mechanical handle rotation, thus minimizing external interference.

Implementation Method 1

a magnetosensitive probe detecting the rotation of the magnetic field emitted by said magnet

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP3688416B1Detection module for a rotary hand operated throttle of a motorised vehicle
Publication Date: 2024.07.03 MOVING MAGNET TECH
  • EP3688416B1 patent drawingFigure 1~2c
  • EP3688416B1 patent drawingFigure 3a~4
  • EP3688416B1 patent drawingFigure 5~6

AI summary

The invention relates to a detection module for a rotary handle (2) that is intended to be attached to the tube (3) of a handlebar (1) of a vehicle next to said handle (2) and comprising a cylindrically shaped magnet, a probe for detecting the magnetic field produced by said magnet, a support for said probe, a printed circuit to which said probe is rigidly connected, a support for said magnet and a collar (4) serving as a housing for said module, said magnetically sensitive probe detecting the rotation of the magnetic field produced by said magnet and being rigidly connected to said handlebar (1), said magnet support and magnet being rigidly connected to said handle (2), said magnet support and magnet forming a cavity such that the inner radial surface of the magnet is positioned outside and facing said magnetically sensitive probe. Said magnet has a continually variable direction of magnetization such that the total rotation of the angle of the magnetic field generated by said magnet at the measurement point during the mechanical rotation of the handle (2) is greater than 180°.