Connector Lock Protrusion Chamfering to Prevent Side Wall Breakage

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Solution Overview

Problem

The existing connector designs are prone to side wall breakage due to the right-angled end corner parts of the engaging projections, which can exceed the resiliency limit and lead to deformation or breakage during the sliding process.

Innovation Solution

The connector features chamfered end corner parts of the lock protrusions in the sliding width direction, with a base dimension equal to or larger than half the mounting hole opening, and a full locking protrusion with a reduced projecting dimension to minimize sliding resistance and prevent side wall breakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the engaging projection has right-angled end corner parts, then the locking function is achieved, but the side wall is strongly pulled and may be deflected beyond resiliency limit to break

Engineering Contradiction:
Improvelocking functionVSAvoidside wall strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by chamfering only the end corner parts of the lock protrusion that contact the side wall during sliding, while maintaining the right-angled locking surfaces. This localized modification reduces stress concentration at the critical contact points without compromising the overall locking function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The chamfered corners act as a preliminary cushioning measure by providing a gradual transition surface that distributes the sliding force over a larger area before the main locking engagement. This prevents sudden stress peaks that would otherwise cause side wall deflection or breakage.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Ease of manufacture

If the lock protrusion slides on the side wall, then the locking member is mounted, but the side wall is deflected and deformed by the engaging projection

Engineering Contradiction:
Improvemounting processVSAvoidside wall shape
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The chamfered end corner parts are specifically applied to the lock protrusion to modify only the contact interface with the side wall. This localized geometric change reduces the deflection force during sliding while preserving the overall mounting functionality.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The chamfer creates an inclined surface that replaces the sharp right angle, providing a more gradual contact transition. This curved/angled interface distributes the sliding force more evenly, reducing localized deflection of the side wall during the mounting process.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 chamfered design suppresses side wall deformation and breakage by reducing the force exerted on the side walls during sliding, allowing for reliable locking without breaking the side walls, and the reduced full locking protrusion sliding resistance further prevents breakage.

Implementation Method 1

both end corner parts of the lock protrusion in the sliding width direction are chamfered... it can be suppressed that the side wall is deflected and deformed and strongly pulled by the lock protrusion and the breakage of the side wall can be prevented

Methodology Applied
Scientific EffectStress concentration reduction:

Data Source

PatentEP3324494B1connector
Publication Date: 2019.07.24 SUMITOMO WIRING SYSTEMS LTD
  • EP3324494B1 patent drawingFigure 1
  • EP3324494B1 patent drawingFigure 2
  • EP3324494B1 patent drawingFigure 3

AI summary

It is aimed to provide a connector capable of preventing the breakage of side walls (18). A housing (10) includes a mounting hole (17) into which a retainer (60) is mounted, and side walls (18) for closing the mounting hole (17) from opposite sides. The side wall (18) is provided with lock receiving portions (22). Lock protrusions (68) configured to slide while deflecting the side walls (18) in the process of inserting the retainer (60) into the mounting hole (17) and release the side walls (18) from a deflected state and enter the lock receiving portions (22) when reaching positions corresponding to the lock receiving portions (22) are provided on outer surfaces of the retainer (60). Both end corner parts of the lock protrusion (68) in a sliding width direction (Y) perpendicular to a sliding direction on the side wall (18) are chamfered.