Magnetic Sensor Switch Structure for Explosion-Proof Devices

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Solution Overview

Problem

Conventional switch structures for explosion-proof devices require large magnets and increased distances between magnetic switches due to thick non-magnetic container walls, limiting the thickness of the container and the proximity of magnetic switches.

Innovation Solution

A switch structure where the magnetic field from a magnet acts on a magnetic sensor through a first magnetic body at the container wall, allowing efficient magnetic field transmission even with thick container walls, reducing the need for large magnets and minimizing the distance between adjacent switches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thick non-magnetic container wall is used for explosion-proof performance, then the explosion-proof performance is improved, but the magnetic field transmission efficiency deteriorates requiring larger magnets

Engineering Contradiction:
Improveexplosion-proof performanceVSAvoidmagnet size
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

A magnetic body is introduced as an intermediary component at the container wall to facilitate magnetic field transmission. The magnetic body serves as a mediator between the magnet outside and the magnetic sensor inside, enabling efficient magnetic coupling through the non-magnetic container wall without requiring an increase in magnet size.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a thick non-magnetic container wall is used, then the explosion-proof performance is improved, but the distance between adjacent magnetic switches must be increased to prevent magnetic field interference

Engineering Contradiction:
Improveexplosion-proof performanceVSAvoiddistance between magnetic switches
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The magnetic body acts as a localized intermediary that confines and directs the magnetic field through the container wall. This mediation effect reduces magnetic field spread into surrounding areas, allowing magnetic switches to be positioned closer together without experiencing interference, thus reducing the required distance between adjacent switches.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The magnetic body provides localized magnetic field concentration at the container wall interface. By concentrating the magnetic field where it is needed (through the wall to the sensor) rather than allowing it to spread broadly, the local quality of the magnetic field is improved, enabling closer spacing of magnetic switches.

Inventive Principle:
Principle #3Local quality

3Reliability

If a thick non-magnetic container wall is used, then the explosion-proof performance is improved, but the magnetic field must travel a longer distance resulting in weaker field strength at the sensor

Engineering Contradiction:
Improveexplosion-proof performanceVSAvoidmagnetic field strength
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The magnetic body serves as a magnetic flux conduit that efficiently guides the magnetic field from the magnet through the non-magnetic container wall to the magnetic sensor. This intermediary structure maintains magnetic field strength despite the increased travel distance through the thick wall, as the magnetic body provides a low-reluctance path for the magnetic flux.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables efficient magnetic field transmission and independent ON/OFF control of magnetic switches without the need for large magnets, even with thick container walls, while maintaining the explosion-proof performance.

Implementation Method 1

a magnetic body 4 provided at a container wall 1a (non-magnetic body) arranged between a magnet 3 and a magnetic sensor 2. The magnetic field from the magnet 3 acts on the magnetic sensor 2 through the magnetic body 4

Methodology Applied
Scientific EffectMagnetic field transmission: Magnetic Field

Data Source

PatentEP3065155B1Switch structure and explosion-proof device
Publication Date: 2021.01.06 AZBIL CORP
  • EP3065155B1 patent drawingFigure 1
  • EP3065155B1 patent drawingFigure 2~3
  • EP3065155B1 patent drawingFigure 4

AI summary

Magnetic bodies (4-1 to 4-4) are provided, in correspondence with magnetic sensors (2-1 to 2-4), at a container wall (non-magnetic body) (1 a) between the magnetic sensors (2-1 to 2-4) and magnets (3-1 to 3-4). In this switch structure, the magnetic fields from the outside magnets (3) act on the magnetic sensors (2) through the magnetic bodies (4) provided at the container wall (1 a).