Connector Shield Shell Corrosion Prevention via Interposed Member

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Solution Overview

Problem

Conventional connectors face durability issues due to potential differences in ionization tendencies between metal materials used in the shield shell and the case, leading to increased risk of galvanic corrosion.

Innovation Solution

Incorporating an interposed member made of conductive rubber material between the shield shell and the case, which eliminates potential differences and prevents corrosion, while also allowing for electrical connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the shield shell and case are made from metal materials with different ionization tendencies, then the electrical conductivity and noise prevention performance are improved, but the durability deteriorates due to galvanic corrosion

Engineering Contradiction:
ImprovedurabilityVSAvoidgalvanic corrosion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a resin material as an intermediary layer between the shield shell and the case. This resin layer physically separates the two metal components with different ionization tendencies, preventing direct contact and thus eliminating the galvanic corrosion pathway while allowing both metals to maintain their respective functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent divides the contact interface between the shield shell and case into separate functional layers: the shield shell, the resin intermediate layer, and the case. This segmentation isolates the dissimilar metals from direct contact, preventing electrochemical reactions while maintaining structural integrity and electrical grounding functionality.

Inventive Principle:
Principle #1Segmentation

2Strength

If the shield shell is fixed to the case using metal fixtures, then the mechanical strength and electrical connection are improved, but the durability deteriorates due to increased galvanic corrosion risk

Engineering Contradiction:
Improvemechanical strengthVSAvoiddurability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The resin material serves as an intermediary that replaces metal fixtures in the fastening mechanism. The resin anchors the shield shell to the case without creating metal-to-metal contact, thereby maintaining mechanical strength while eliminating the galvanic corrosion pathway that would be created by metal fasteners.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a composite fastening system where the resin material combines mechanical anchoring capability with electrical insulation and corrosion resistance. This composite approach allows the shield shell to be securely fixed to the case while preventing the electrochemical reactions that would occur with pure metal fixtures.

Inventive Principle:
Principle #40Composite materials

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 use of a conductive rubber interposed member enhances the durability of both the connector and the counterpart device by preventing corrosion and maintaining electrical connectivity, even when the shield shell and case are made from metals with different ionization tendencies.

Implementation Method 1

when metals in contact with each other have different ionization tendencies from each other, a larger potential difference resulting from the difference in ionization tendency may increase a possibility of reducing durability depending on their usage environment

Methodology Applied
Scientific EffectGalvanic corrosion prevention:

Implementation Method 2

the interposed member is formed from a conductive rubber material

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3790119B1connector
Publication Date: 2022.12.07 YAZAKI CORP
  • EP3790119B1 patent drawingFigure 1
  • EP3790119B1 patent drawingFigure 2
  • EP3790119B1 patent drawingFigure 3

AI summary

A connector (1) includes: a terminal metal fitting (10) that is connected to an electric wire (We) and is configured to be inserted into a connector insertion hole (501a) of a metal case (501) of a counterpart device (500) from an opening (501a1); a housing (20) includes a connector insertion part (23) configured to be inserted into the connector insertion hole (501a) from the opening (501a1) together with the terminal metal fitting (10); a liquid seal member (62) that is configured to seal a gap between the housing and a rim of the opening (501a1) in the case (501); a shield shell (30) that includes a cylindrical accommodation body (31) accommodating the housing (20) therein, an annular flange (32) configured to be opposed to an annular surface (501b1) around the rim of the opening (501a1) in the case (501), and a fixed part (33) configured to be fixed to the case (501); and an annular interposed member (40) that is configured to be interposed between the flange (32) and the annular surface (501b1) to be sandwiched therebetween.