Connector Backlash Filling Protrusion Stabilizes Locking

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Solution Overview

Problem

Existing electric connectors with fitting detection members experience reduced operation reliability due to backlash between the detection member and the connector housing, leading to potential tilting and unintended locking states, especially when the mounting wall portion is thin, causing detachment issues during disengagement.

Innovation Solution

Incorporating a backlash filling protrusion that tilts the fitting detection member using clearance-induced backlash, increasing the locking amount of the engagement protrusion with the lock portion, and reinforcing the mounting wall portion with thickening features to enhance structural strength and prevent slipping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the fitting detection member is mounted on a thin mounting wall portion, then the connector housing can be made more compact, but the connector housing is likely to bend and the fitting detection member may be pulled out during detachment

Engineering Contradiction:
Improveconnector housing sizeVSAvoidmounting wall portion strength
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The mounting wall portion is divided into two functional zones: a thin detection member mounting surface for compactness and a thickened arm portion base for strength. This segmentation allows each zone to optimize its thickness according to its specific functional requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The arm portion is designed with non-uniform thickness, being thickest at the base where it connects to the connector housing and gradually thinning toward the engagement protrusion. This local quality variation provides maximum structural strength where needed while maintaining overall compactness.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If there is clearance between the fitting detection member and connector housing, then the fitting detection member can move smoothly between positions, but backlash causes the fitting detection member to tilt and reduces locking amount

Engineering Contradiction:
Improvefitting detection member movementVSAvoidlocking amount stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The guide groove is designed with a curved path that constrains the fitting detection member's movement in both the sliding direction and the tilting direction. By adding this geometric constraint in another dimension, the design allows smooth movement while preventing harmful tilting caused by backlash.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The guide groove acts as an intermediary element between the fitting detection member and the connector housing. It mediates the interaction by providing a controlled path that accommodates necessary movement while restricting unwanted tilting motions.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the engagement protrusion is extended further to increase locking amount, then the locking reliability improves, but the arm portion becomes more prone to bending and detachment

Engineering Contradiction:
Improvelocking amountVSAvoidarm portion strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The arm portion is designed with non-uniform thickness, being thickest at the base where it connects to the connector housing and gradually thinning toward the engagement protrusion. This local quality variation provides maximum structural strength where needed while maintaining overall compactness.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The guide groove is designed in advance to constrain the arm portion's movement path, preventing excessive tilting before it can occur. This preliminary geometric constraint protects the extended engagement protrusion from bending loads during normal operation.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3809535B1connector
Publication Date: 2022.06.15 YAZAKI CORP
  • EP3809535B1 patent drawingFigure 1
  • EP3809535B1 patent drawingFigure 2
  • EP3809535B1 patent drawingFigure 3

AI summary

A connector includes a connector housing having a lock portion configured to lock a mated housing; a guide groove formed in the connector housing and guiding a fitting detection member from a temporary locking position to a final locking position; an arm portion having an engagement protrusion provided on an extended free end extending in a direction of approaching the lock portion from the fitting detection member and abutting against the lock portion at the temporary locking position; and a backlash filling protrusion that is formed on a protruding plate portion, to be engaged with the guide groove, of the fitting detection member, and is configured to tilt the fitting detection member in a direction in which a locking amount of the engagement protrusion with respect to the lock portion is increased at the temporary locking position.