Magnetic Sensor Device for Welding Workpiece Detection

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Solution Overview

Problem

Existing welding systems face challenges in reliably detecting ferromagnetic workpieces, particularly in tight spaces and during galvanized wire processing, due to electromagnetic interference and welding spatter, which disrupts electrical potential monitoring.

Innovation Solution

A sensor device with at least two pole plates polarized in opposite directions enhances magnetic flux density in the detection area, making it less sensitive to electromagnetic interference and allowing the magnetic field sensor and generator to be positioned further away from the welding process, while maintaining reliable detection of ferromagnetic workpieces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrical potential monitoring is used to detect workpieces, then detection can be performed, but the system becomes sensitive to electromagnetic interference and welding spatter

Engineering Contradiction:
Improvedetection reliabilityVSAvoidelectromagnetic interference sensitivity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces electrical potential monitoring with a magnetic field-based detection system using permanent magnets and magnetic field sensors. This substitution eliminates sensitivity to electromagnetic interference from welding currents while maintaining workpiece detection capability through magnetic flux changes caused by ferromagnetic materials.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the detection parameter from electrical potential to magnetic field strength. By using permanent magnets to generate a magnetic field and measuring changes in magnetic flux density with magnetic field sensors, the system achieves robust detection that is immune to electromagnetic interference while remaining sensitive to ferromagnetic workpieces.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If magnetic field sensor and generator are placed close to detection area, then detection sensitivity is improved, but exposure to electromagnetic interference and high temperatures increases

Engineering Contradiction:
Improvedetection sensitivityVSAvoidexposure to electromagnetic interference and heat
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces permanent magnets as intermediary elements that generate a stable magnetic field in the detection area. These magnets act as a buffer, allowing the magnetic field sensor to be positioned at a distance from the welding zone while still detecting workpieces through magnetic flux changes. The permanent magnets maintain field strength without requiring the sensor to be in the immediate vicinity of the welding process.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention extends the detection range by utilizing the spatial characteristics of magnetic field lines. By positioning permanent magnets to create a distributed magnetic field, the system can detect workpieces across a larger volume without requiring the sensor to be in direct contact with the detection area, thereby reducing exposure to harmful environmental factors.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If pole plates are added to concentrate magnetic flux, then magnetic flux density in detection area increases, but device complexity increases

Engineering Contradiction:
Improvemagnetic flux densityVSAvoidsensor structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses pole plates with localized magnetic pole configurations to concentrate magnetic flux specifically in the detection area. The pole plates are designed with specific geometries (such as U-shaped or C-shaped configurations) that create regions of high magnetic flux density where workpieces are detected, while keeping the overall structure relatively simple and focused on the critical detection zone.

Inventive Principle:
Principle #3Local quality

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 robust and reliable detection of ferromagnetic workpieces with reduced maintenance costs and improved resistance to electromagnetic interference, ensuring trouble-free production.

Implementation Method 1

at least two pole plates (102a, 102b) which are polarized in opposite directions by the magnetic field generator (106) and which increase the magnetic flux density in the detection area (130)

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

the pole plates are in fact designed in the form of plates... solid bodies made of a ferromagnetic material with a high permeability

Methodology Applied
Scientific EffectFerromagnetism: Ferromagnetism

Implementation Method 3

a magnetic field sensor (107), in particular a Hall sensor, for detecting the local magnetic field

Methodology Applied
Scientific EffectMagnetic flux detection: Magnetic Field

Data Source

PatentEP3062100B1Sensor device
Publication Date: 2018.07.18 SCHLATTER IND AG
  • EP3062100B1 patent drawingFigure 1a~1b
  • EP3062100B1 patent drawingFigure 2a~2b
  • EP3062100B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a sensor device for detecting ferromagnetic workpieces in a detection zone within a welding system, particularly for detecting lattice wires. The sensor device comprises a non-magnetic housing, a magnetic field generator for producing a magnetic field, and a magnetic field sensor located within the effective zone of the magnetic field. The magnetic field sensor is configured to convert the local magnetic field into an electrical signal. The invention further relates to a sensor system for detecting ferromagnetic workpieces, a welding system with a sensor device for detecting ferromagnetic workpieces, a method for monitoring the target position of ferromagnetic workpieces within a detection zone, and the use of a sensor device or sensor system according to the invention for detecting workpieces in a ferromagnetic welding system.