Proximity Sensor Shield Extension for Clamp-Side Voltage Resistance

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Solution Overview

Problem

In proximity sensors equipped with an electrostatic shield, the sealing of the resin inside the housing can lead to bubble formation, which degrades the voltage resistance due to uncovered substrate portions on the clamp side.

Innovation Solution

A proximity sensor design that includes a shield with an extension portion covering at least a part of the circuit inside the clamp, preventing bubble-induced voltage resistance degradation, even when the inner diameter of the clamp is smaller than the housing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If an electrostatic shield is added to cover the coil and substrate, then electromagnetic wave interference is prevented, but the device complexity increases

Engineering Contradiction:
Improveelectromagnetic wave interferenceVSAvoidstructure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The shield serves multiple functions simultaneously: it acts as an electrostatic shield to block electromagnetic waves, provides structural support within the housing, and extends to cover circuits in the clamp region. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity while maintaining electromagnetic interference protection.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The shield is integrated with the housing structure and the clamp assembly, merging multiple protective functions into a single component. This integration reduces the number of separate parts and assembly steps, limiting the increase in device complexity while providing comprehensive electromagnetic shielding.

Inventive Principle:
Principle #5Merging (Combining)

2Strength

If the clamp inner diameter is made smaller than the housing inner diameter, then the clamp provides better structural support, but the shield extension to cover circuits becomes more difficult

Engineering Contradiction:
Improvestructural supportVSAvoidshield installation
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The shield has different dimensional characteristics in different regions: the main body portion matches the housing inner diameter for optimal electromagnetic shielding, while the clamp portion is designed with reduced dimensions to fit through the smaller clamp opening. This local quality variation allows the shield to provide structural support where needed while facilitating manufacturing and installation.

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 shield's extension portion effectively suppresses voltage resistance degradation by covering the circuit within the clamp, ensuring reliable operation despite resin bubbles.

Implementation Method 1

it is necessary to arrange an electrostatic shield in order to make the coil and the circuit not be affected by the electromagnetic wave from the outside

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Data Source

PatentEP3955274B1Proximity sensor
Publication Date: 2024.08.21 OMRON CORP
  • EP3955274B1 patent drawingFigure 1
  • EP3955274B1 patent drawingFigure 2
  • EP3955274B1 patent drawingFigure 3

AI summary

Provided is a proximity sensor that can limit degradation in voltage resistance. A proximity sensor 1 comprises: a housing 10; a coil unit that is accommodated in one end of the housing 10; a clamp 20 that is connected to the other end of the housing 10; a substrate 30 that has a circuit mounted thereon, such circuit being electrically connected to the coil unit; a shield 45 that covers a portion of the substrate 30 which is located on the housing 10 side; and a resin which is provided inside the housing 10 and the clamp 20, and which covers at least a portion of the substrate 30. The shield 45 extends to the inside of the clamp 20, and has an extension section 452 that covers at least a portion of the circuit that is located inside the clamp 20.