Angled Sensor Coil for Thin Object Detection

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Solution Overview

Problem

Existing contactless sensors lack sufficient sensitivity for detecting thin objects, particularly in applications like turbocharger blades, where the orientation and alignment of the sensor coil significantly impact detection accuracy and inductance variation.

Innovation Solution

A contactless inductive sensor with a coil axis arranged at an angle between 30° and 85°, preferably between 65° and 75°, relative to the sensor pin's longitudinal axis, enhancing inductance variation and sensitivity, and featuring a compact design with a cylindrical shape and partial cylindrical rim for protection during mounting, potentially using two mirror-inverted sensor coils for increased sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the sensor coil is arranged with its axis parallel to the normal of the test object surface, then the sensor can detect objects moving parallel to the coil axis, but the sensitivity for detecting thin objects is insufficient

Engineering Contradiction:
Improvedetection sensitivityVSAvoidcoil arrangement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the orientation parameter of the coil axis from being parallel to the surface normal to forming an angle between 30° and 85° with the surface normal. This parameter change optimizes the magnetic field interaction with thin objects, significantly improving detection sensitivity while maintaining a relatively simple single-coil structure.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If multiple sensor coils are arranged in different positions and orientations, then detection coverage is improved, but the device complexity and alignment requirements increase

Engineering Contradiction:
Improvedetection coverageVSAvoidnumber of coils
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Instead of using multiple coils to achieve comprehensive detection coverage, the patent inverts the approach by optimizing a single coil's orientation angle to 30°-85° relative to the surface normal. This single optimized coil can effectively detect objects moving in various directions, reducing device complexity while maintaining versatility.

Inventive Principle:
Principle #13The other way round (Inversion)

3Measurement precision

If the coil axis is oriented at a steep angle to the surface normal, then inductance variation increases for thin objects, but the alignment precision requirements during mounting increase

Engineering Contradiction:
Improveinductance variationVSAvoidalignment precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent selects an optimal angle range of 30°-85° (preferably 65°-75°) that balances inductance variation enhancement with manageable alignment requirements. This parameter optimization ensures sufficient detection sensitivity while keeping mounting alignment within achievable manufacturing tolerances.

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

The sensor achieves improved sensitivity and inductance variation for detecting thin objects, enabling precise position and speed measurement of rotating blades, even in high-temperature environments and high-frequency applications, with enhanced durability and alignment precision.

Implementation Method 1

A contactless inductive sensor with a coil axis arranged at an angle between 30° and 85°, preferably between 65° and 75°, relative to the sensor pin's longitudinal axis, enhancing inductance variation and sensitivity

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

A contactless eddy current sensor, particularly for detecting essentially flat test objects, comprising at least one sensor coil, eddy currents being able to be induced in the test object

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Data Source

PatentEP3062067B1Contactless sensor
Publication Date: 2021.01.06 TYCO ELECTRONICS BELGIUM EC
  • EP3062067B1 patent drawingFigure 1
  • EP3062067B1 patent drawingFigure 2
  • EP3062067B1 patent drawingFigure 3~4

AI summary

The invention refers to a contactless sensor for detecting an object, comprising: at least one sensor coil that is embodied to induce eddy currents in the object, wherein the sensor coil is arranged at a front end of the sensor, wherein the sensor coil defines a coil axis, wherein the sensor coil is arranged in that way that the coil axis is arranged in an angle between 30° and 85° with respect to a longitudinal axis of the sensor.