Magnetic Torque Sensor with Substrate Cutout for Reduced Gap

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Solution Overview

Problem

Conventional contactless torque sensors face detection errors due to magnetic detector tilting and require additional components for support, leading to increased complexity and potential magnetic flux leaks, which affect detection accuracy.

Innovation Solution

A magnetic detection device with a first and second magnetic collector, a substrate with cutout portions, and surface-mounted magnetic sensors, where the collectors collect magnetic flux and the sensors are positioned between them, reducing the magnetic circuit gap and eliminating the need for additional support components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the magnetic detector is mounted orthogonal to the substrate surface, then the detection accuracy may be improved, but the magnetic detector may tilt causing detection errors

Engineering Contradiction:

Improvedetection accuracyVSAvoiddetection stability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The magnetic detector is merged with the substrate through surface mounting, where the detector is positioned on the substrate surface with its detection surface facing a magnetic collector. This integration eliminates the need for separate support structures that could cause tilting, while maintaining detection accuracy through direct positioning on the substrate.

Inventive Principle:

Principle #5Merging (Combining)

2Manufacturing precision

If another member is separately provided to support the magnetic detector on the substrate, then the magnetic detector positioning is improved, but the number of components increases

Engineering Contradiction:

Improvemagnetic detector positioningVSAvoidnumber of components

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The magnetic detector is directly mounted on the substrate surface without requiring separate support members. The substrate itself serves as the mounting structure, integrating the support function into the existing component and reducing the total number of parts while maintaining positioning accuracy.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The substrate is given multiple functions: it serves as both the structural base and the mounting platform for the magnetic detector. This multi-functionality eliminates the need for dedicated support components, simplifying the overall device structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If the magnetic sensor is surface mounted on the substrate, then the number of components is reduced, but the magnetic circuit gap increases causing magnetic flux leaks

Engineering Contradiction:

Improvenumber of componentsVSAvoiddetection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

A cutout portion is created in the substrate at the position where the magnetic detector is mounted. This removes the substrate material that would otherwise create a magnetic circuit gap, allowing the magnetic collector to be positioned closer to the detector and reducing magnetic flux leaks while maintaining the simplified surface mounting structure.

Inventive Principle:

Principle #2Taking out (Extraction)

4Adaptability or versatility

If the magnetic sensor surface area is increased, then integrated circuits can be provided, but the detection area may be compromised

Engineering Contradiction:

Improveintegrated circuit capabilityVSAvoiddetection area

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The magnetic detector is positioned to utilize the space above the substrate surface, with the cutout portion allowing the magnetic collector to approach from below. This three-dimensional arrangement enables the detector to maintain its detection area while accommodating additional circuitry on the substrate surface plane.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 detection accuracy by minimizing magnetic flux leaks and reducing the number of components, allowing for integrated calculation circuits and improved surface area utilization of the magnetic sensors.

Implementation Method 1

The magnetic detection element detects a magnetic field formed by the first collector portion and the second collector portion

Methodology Applied

Scientific EffectMagnetic field detection: Magnetic Field

Implementation Method 2

The first magnetic collector and the second magnetic collector collect magnetic flux from the magnetic yoke at the first collector portion and the second collector portion

Methodology Applied

Scientific EffectMagnetic flux collection: Magnetism

Data Source

PatentUS9689763B2Magnetic detection device and torque sensor including the same

Publication Date: 2017.06.27 DENSO CORP

AI summary

A cutout portion is formed in a substrate of a magnetic detection device, the cutout portion opening at an outer edge of the substrate. Magnetic detection elements of a magnetic sensor detects magnetic field formed by first and second collector portions. A mold section encapsulates the magnetic detection elements. The magnetic sensor is surface mounted such that a portion of the mold section overlaps with the cutout portion. The first collector portion faces a front surface of the magnetic sensor. A portion of the second collector portion is positioned in the cutout portion to face a rear surface of the magnetic sensor. Accordingly, compared to a case where a cutout portion is not provided, a magnetic circuit gap between the first and second collector portions is reduced.