Waterproof Box Double-Walled Cover Rotation Waterproofing

Solution Overview

Problem

Conventional waterproof boxes for electrical junction boxes in motor vehicles may allow water to enter due to insufficient design, particularly when water forcefully splatters onto the cover, as the inner wall length adjacent to one end is not sufficient to prevent ingress.

Innovation Solution

A waterproof box design featuring a double-walled structure for the body case and cover with a space between the outer and inner walls, along with protrusions and overlapped inner wall arrangements, to enhance waterproofing without using packing, ensuring effective water prevention during rotation and splashing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the inner wall length adjacent to one end is made shorter to prevent hitting during rotation, then the ease of operation is improved, but the waterproof property deteriorates when water forcefully splatters

Engineering Contradiction:

Improveease of mounting coverVSAvoidwaterproof property

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The peripheral wall is divided into a double-walled structure consisting of an outer wall and an inner wall. The outer wall provides the rotation path and structural support, while the inner wall provides the waterproof barrier. This segmentation allows the inner wall to be sufficiently long for waterproofing without interfering with the rotation operation, as the outer wall maintains the necessary clearance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner wall is nested within the outer wall, with both walls extending along the peripheral wall but at different radial positions. The inner wall is positioned inside the outer wall's rotation path, allowing the cover to rotate freely while the inner wall remains protected and sufficiently long to prevent water ingress.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Reliability

If the inner wall length adjacent to one end is made longer to prevent water ingress, then the waterproof property is improved, but the inner wall may hit the peripheral wall during rotation

Engineering Contradiction:

Improvewaterproof propertyVSAvoidease of mounting cover

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The peripheral wall is divided into a double-walled structure consisting of an outer wall and an inner wall. The outer wall provides the rotation path and structural support, while the inner wall provides the waterproof barrier. This segmentation allows the inner wall to be sufficiently long for waterproofing without interfering with the rotation operation, as the outer wall maintains the necessary clearance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The solution moves from a single-dimensional wall to a two-dimensional double-walled structure. By adding the outer wall dimension, the inner wall can extend further in the radial direction to improve waterproofing without compromising the rotational movement, as the outer wall absorbs the dimensional conflict.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Device complexity

If a single-walled structure is used, then the device complexity is reduced, but the waterproof property is insufficient under forceful water splashing

Engineering Contradiction:

Improvestructural complexityVSAvoidwaterproof property

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The peripheral wall is divided into a double-walled structure consisting of an outer wall and an inner wall. The outer wall provides the rotation path and structural support, while the inner wall provides the waterproof barrier. This segmentation allows the inner wall to be sufficiently long for waterproofing without interfering with the rotation operation, as the outer wall maintains the necessary clearance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The double-walled structure functions as a composite system where the outer wall and inner wall work together to provide both mechanical functionality and waterproof protection. This composite approach achieves superior waterproofing performance without proportionally increasing complexity, as both walls are integrated into a single cover component.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS8878059B2Waterproof box and electrical junction box having the same

Publication Date: 2014.11.04 YAZAKI CORP

AI summary

The waterproof box includes a body case and a cover mounted to the body case by making a hook portion at one end of the cover engaged with a projection at one end of the body case and rotatably moving the cover around the hook portion. The one end of the respective body case and the cover has a double-walled structure having an outer wall and an inner wall. With the cover mounted to the body case, the outer wall of the body case is located inside the outer wall of the cover, the inner wall of the cover is located inside the outer wall of the body case, the inner wall of the body case is located inside the inner wall of the cover, and the outer wall of the body case and the inner wall of the cover are arranged with a space between each other.