Antipodal Bar Magnet Sensor for Extended Linear Range

Solution Overview

Problem

Magnetic position sensors face limitations in measurement range and accuracy, particularly when using permanent magnets, and struggle to detect linear movements effectively, leading to increased installation space and weight, as well as restricted design flexibility.

Innovation Solution

The use of bar magnets with recesses and a housing designed with congruent recesses allows for expanded measurement range and improved accuracy by defining the distance between opposite poles, enabling non-contact operation and precise alignment, with the option of the housing being attached to the object or forming part of it, and incorporating features like threaded holes and projections for secure attachment and guidance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the magnetic sensor is designed to be sufficiently large to remain within the effective range despite object movement, then the measurement range is improved, but the installation space and weight increase

Engineering Contradiction:

Improvemeasurement rangeVSAvoidinstallation space

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The magnetic sensor is divided into multiple segments (first magnetic sensor, second magnetic sensor, etc.) arranged in series. Each sensor detects a portion of the total movement range, allowing the system to achieve a large overall measurement range while keeping individual sensor units compact and minimizing installation space requirements.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If the magnetic sensor is designed to be sufficiently large to remain within the effective range despite object movement, then the measurement range is improved, but the weight increases

Engineering Contradiction:

Improvemeasurement rangeVSAvoidweight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The magnetic sensor is divided into multiple segments (first magnetic sensor, second magnetic sensor, etc.) arranged in series. Each sensor detects a portion of the total movement range, allowing the system to achieve a large overall measurement range while keeping individual sensor units compact and minimizing installation space requirements.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If a magnetic sensor is used to detect linear movements, then the measurement capability is improved, but the measuring accuracy is limited

Engineering Contradiction:

Improvemeasurement capabilityVSAvoidmeasuring accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The magnetic sensor is divided into multiple segments (first magnetic sensor, second magnetic sensor, etc.) arranged in series. Each sensor detects a portion of the total movement range, allowing the system to achieve a large overall measurement range while keeping individual sensor units compact and minimizing installation space requirements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces mechanical contact-based measurement systems with a magnetic field-based detection system. The magnetic sensor detects changes in magnetic flux caused by object movement without physical contact, eliminating mechanical wear and improving measurement accuracy while maintaining versatility for linear movement detection.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 configuration enhances the measurement range and accuracy of magnetic position sensors, reduces installation space, and allows for flexible design, while ensuring correct positioning and secure attachment, thereby improving the overall performance and usability of the sensor system.

Implementation Method 1

at least two bar magnets (2) arranged with opposite poles to one another in a housing (3)... The opposing-pole arrangement of the bar magnets (either south poles or north poles to each other) allows the measuring range of the magnetic position sensor to be extended

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

positioned or suspended by the repulsive forces of magnetic poles (N, S) of the same name

Methodology Applied

Scientific EffectMagnetic repulsion: Ion Repulsion/Attraction

Data Source

PatentEP2778622B1Magnetic position sensor with two antipodal rod magnets

Publication Date: 2024.08.28 HIRSCHMANN AUTOMOTIVE GMBH

Figure 1~2
Figure 3

AI summary

The locator has a magnetic sensor attached with a magnet transmitter (1) for acquisition of a movement of the magnet transmitter, where the magnet transmitter comprises two bar magnets (2), which are arranged with counter-poles in a housing (3). The bar magnets are provided with a first recess, and the housing is formed with a second recess (5), where depths of the first and second recesses are different and/or same from each other. The housing is formed with a threaded bore (4) and provided with a projection (6), where the housing is formed from a plastic overmolding coat.