Flush-Mounted Inductive Sensor Arrangement With Magnetic Field Bias

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Solution Overview

Problem

Inductive sensors installed non-flush in metal environments face limitations due to the requirement for a minimum distance from conductive materials to avoid continuous signal generation, restricting their switching distance and detection range.

Innovation Solution

A sensor arrangement where a non-flush inductive sensor is arranged substantially flush on a metallic base, with a predetermined external magnetic field applied to influence the detection range, utilizing the superposition principle to maintain or enhance the switching distance without reducing it, and to prevent unintentional triggering by metallic components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If a non-flush inductive sensor is installed in a metal environment, then the switching distance is extended, but the sensor generates a continuous signal due to proximity with conductive material

Engineering Contradiction:
Improveswitching distanceVSAvoidsignal stability
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

A magnetic field is introduced as an intermediary between the sensor and the metal environment. This magnetic field modifies the detection characteristics of the sensor, allowing it to distinguish between legitimate target objects and the surrounding conductive material, thereby preventing continuous signal generation while maintaining extended switching distance

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The magnetic field changes the operational parameters of the inductive sensor by altering its detection threshold and sensitivity characteristics. This parameter modification enables the sensor to operate reliably in proximity to conductive materials without generating false continuous signals, while preserving the extended detection range

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a flush-mounted sensor is used, then the sensor is protected from dirt and mechanical stress, but the switching distance is significantly reduced

Engineering Contradiction:
Improvesensor protectionVSAvoidswitching distance
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The magnetic field serves as a mediator that compensates for the reduced detection range inherent in flush-mounted configurations. By introducing this field, the sensor's effective switching distance is extended beyond what would normally be possible with flush mounting, while the sensor remains protected within the metal environment

Inventive Principle:
Principle #24Intermediary (Mediator)

3Length of stationary object

If a non-flush sensor is installed without magnetic field influence, then the switching distance is longer, but the detection range cannot be focused and unintentional triggering occurs

Engineering Contradiction:
Improveswitching distanceVSAvoiddetection range focus
Core Design Contradiction:
Length of stationary objectVSMeasurement precision

Solution Approach 1:

The magnetic field creates local quality variations in the detection zone, concentrating the sensor's detection capability in specific directions or areas. This spatial differentiation of detection sensitivity allows the sensor to focus on relevant targets while ignoring unrelated conductive materials, preventing unintentional triggering

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The magnetic field modifies the spatial distribution parameters of the sensor's detection range, creating an anisotropic detection pattern rather than a uniform spherical field. This parameter change enables directional focus of the detection zone, improving measurement precision while maintaining extended switching distance

Inventive Principle:
Principle #35Parameter changes

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 an almost flush installation of non-flush inductive sensors with maintained or increased switching distance, allowing for effective detection of metallic objects while minimizing unwanted triggering, and providing a compact design with focused detection areas.

Implementation Method 1

Inductive sensors operate on the principle of a change in inductance due to an interaction with an object that causes this change. Inductive sensors generate a magnetic field, and a conductive and/or ferromagnetic object changes this magnetic field.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The superposition principle describes the effect of a superposition of physical quantities, whereby magnetic fields can influence each other as a result. In general, inductive sensors and magnets generate a magnetic field in their surroundings.

Methodology Applied
Scientific EffectMagnetic field superposition: Magnetic Field

Data Source

PatentEP4383572A1Sensor arrangement for inductive sensors, vending or collecting machine and method for producing a sensor arrangement
Publication Date: 2024.06.12 SIELAFF GMBH & CO AUTOMATENBAU HERRIEDEN
  • EP4383572A1 patent drawingFigure 1
  • EP4383572A1 patent drawingFigure 2A~2B
  • EP4383572A1 patent drawingFigure 3A~3B

AI summary

The present invention relates to a sensor arrangement for inductive sensors, comprising a metallic base and at least one non-flush inductive sensor, wherein the at least one non-flush sensor is arranged substantially flush in or on the metal of the metallic base, and wherein a predetermined externally applied or applicable magnetic field is provided at the sensor. The present invention further relates to a vending or return machine and a method for manufacturing a sensor arrangement in or for a vending or return machine.