Connector Partition Wall Convex Portion Stress Distribution

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Solution Overview

Problem

Existing connectors with synthetic resin housings and glass fiber reinforcement experience stress concentration and cracking issues due to temperature changes, particularly at the interface between terminals and partition walls.

Innovation Solution

A connector design featuring an elongate convex portion on the partition wall with through holes for terminal insertion, where the glass fiber reinforcement is oriented parallel to the resin flow direction during molding, reducing stress concentration and the risk of cracks by distributing thermal expansion and contraction forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If terminals are press-fitted into through holes in a flat partition wall, then liquid-tight connection is achieved, but tensile stress concentrates at the through hole peripheries causing cracks under temperature changes

Engineering Contradiction:
Improveliquid-tight connectionVSAvoidstress resistance at terminal interface
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The partition wall surface is made non-uniform by adding convex portions at specific locations where terminals are press-fitted. This local modification creates stress-dispersing structures only where needed, rather than changing the entire partition wall design. The convex portions provide localized stress distribution while maintaining the overall flat surface for liquid-tight sealing.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Convex portions with curved surfaces are added to the partition wall instead of maintaining a completely flat surface. The curved geometry of the convex portions helps distribute tensile stress more evenly around the through holes, preventing stress concentration at sharp corners and reducing crack formation under thermal cycling.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Strength

If glass fiber is mixed in resin for housing formation, then mechanical strength is improved, but stress concentration and cracking still occur at terminal press-fitting locations

Engineering Contradiction:
Improvehousing mechanical strengthVSAvoidcrack resistance at terminal interface
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

While glass fiber is mixed throughout the resin for overall strength, the convex portions are strategically placed at terminal press-fitting locations to provide localized stress management. This combines the bulk reinforcement effect of glass fiber with local geometric modifications to address stress concentration at critical points.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The partition wall uses a composite structure combining resin matrix with embedded glass fiber for baseline strength, plus additional convex geometric features made from the same composite material. This multi-level composite approach provides both bulk reinforcement and localized stress distribution capabilities.

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 design reduces tensile stress at the terminal interface, minimizing the risk of cracks and improving durability during temperature fluctuations.

Implementation Method 1

the stress increases or decreases with temperature changes, which may cause a crack at the positions where the stress is concentrated

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

the glass fiber piece is oriented in substantially parallel with the flow direction of the resin, reducing stress concentration and the risk of cracks

Methodology Applied
Scientific EffectStress relaxation: Stress Relaxation

Data Source

PatentEP3573188B1connector
Publication Date: 2022.11.16 YAZAKI CORP
  • EP3573188B1 patent drawingFigure 1~2
  • EP3573188B1 patent drawingFigure 3~4
  • EP3573188B1 patent drawingFigure 5A~5B

AI summary

A connector (100) includes an outer tube (10), an inner (20) tube formed to be continuous from the outer tube (10), and a partition wall (30) configured to isolate the outer tube (10) and the inner tube (20). The partition wall (30) has an elongate convex portion (2), the convex portion (2) is formed on a surface of the partition wall (30) in a side of the outer tube (10), and the convex portion (2) has a through hole (4) penetrating the partition wall (30) which is formed in the convex portion (2) and a terminal (9) is press-fitted into the through hole (4).