Waterproof Lock Structure for Electric Connection Box

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Solution Overview

Problem

Existing lock structures for electric connection boxes fail to effectively prevent liquid ingress, particularly between the engaged body and engaging body, which can lead to performance deterioration and durability issues due to water entry.

Innovation Solution

A lock structure with orthogonal first and second engaged walls, a connection wall, and a third engaging wall, featuring liquid-proof protrusions and guide protrusions to block and redirect liquid entry, ensuring the lock structure can prevent liquid from entering the housing even when gaps form between the connection wall and locker.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lock structure with engaged body and engaging body is used to hold fitting members, then the fitting members can be securely locked, but gaps between the engaged body and engaging body allow liquid to enter the housing

Engineering Contradiction:

Improvelocking reliabilityVSAvoidliquid ingress

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The lock structure is divided into multiple functional walls: first and second engaged walls for locking, a connection wall connecting the engaged walls, and a third engaging wall with a locker. This segmentation creates multiple barriers against liquid while maintaining locking functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces orthogonal dimensions to the locking mechanism by adding first and second engaged walls disposed at intervals in a direction orthogonal to the insertion/removal direction. This creates a three-dimensional barrier structure that blocks liquid from multiple directions.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If the lock structure components are positioned close together for compact design, then the housing size is reduced, but liquid can more easily penetrate through gaps between components

Engineering Contradiction:

Improvehousing volumeVSAvoidliquid penetration

Core Design Contradiction:

Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent uses protrusions and curved surfaces (such as the engaged protrusion and liquid-proof protrusion) to create overlapping barriers that block liquid paths while maintaining compact dimensions. The curved geometry allows efficient space utilization.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The lock structure components are nested within each other, with the engaged body inserted into the engaging body, and protrusions extending into accommodation spaces. This nesting creates multiple blocking surfaces within a compact volume.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS11329465B2Water-proof lock structure, electric connection box, and apparatus

Publication Date: 2022.05.10 YAZAKI CORP

AI summary

A lock structure includes: an engaged body; and an engaging body capable of inserting and removing the engaged body along insertion and removal directions opposite to each other. An engaged body includes first and second engaged walls disposed opposite to each other at an interval, a connection wall which connects end portions on the insertion direction side thereof, and an engaged protrusion protruding from an outer wall surface of the second engaged wall. An engaging body has first and second engaging walls in which a space between the respective inner wall surfaces is defined as an accommodation space of the engaged body, an engaging protrusion protruding from the inner wall surface of the second engaging wall and capable of locking the engaged protrusion on the removal direction side, and a third engaging wall disposed between the first and second engaging walls.