Grommet Rib Directs Water Flow Away from Wire Harness

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing grommets allow water to infiltrate into the protector accommodating space from the electric wire insertion opening, compromising the protection of the wire harness in vehicle door panels.

Innovation Solution

A grommet design featuring an elastic grommet body with an inner protector of higher rigidity and an outer member, where the inner protector includes a rib on its outer surface that directs water flow away from the protector accommodating chamber, preventing water infiltration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the grommet body is made of elastic material to provide flexibility and mounting adaptability, then the ease of operation and adaptability improve, but the ability to prevent water infiltration deteriorates

Engineering Contradiction:

Improvemounting adaptabilityVSAvoidwater infiltration prevention

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The grommet is divided into two distinct parts: an elastic grommet body for mounting adaptability and a rigid inner protector for water infiltration prevention. This segmentation allows each part to perform its specialized function effectively without compromise.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The grommet combines elastic material for the grommet body and rigid material for the inner protector, creating a composite structure that leverages the advantages of both material types - flexibility and sealing from the elastic portion, and water infiltration resistance from the rigid portion.

Inventive Principle:

Principle #40Composite materials

2Strength

If the inner protector is made of rigid material to provide structural support and protection, then the strength and protection capability improve, but the ease of mounting and flexibility deteriorate

Engineering Contradiction:

Improvestructural supportVSAvoidease of mounting

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

3Ease of operation

If the electric wire insertion opening is provided for wire harness access, then the ease of operation improves, but water infiltration into the protector accommodating space occurs

Engineering Contradiction:

Improvewire harness accessVSAvoidwater infiltration

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The inner protector acts as an intermediary barrier between the electric wire insertion opening and the protector accommodating space. It allows wire access while blocking water infiltration paths that would otherwise enter through the opening.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful function of the insertion opening (water infiltration) is separated from its useful function (wire access) by introducing the inner protector. The inner protector extracts the water-blocking capability from the opening structure itself.

Inventive Principle:

Principle #2Taking out (Extraction)

4Reliability

If multiple components are added to prevent water infiltration, then the water protection capability improves, but the device complexity increases

Engineering Contradiction:

Improvewater infiltration preventionVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The inner protector combines multiple functions into a single component: structural support for the wire harness, water infiltration barrier, and guide for water flow direction. This merging reduces the number of separate components needed while achieving comprehensive protection.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The inner protector serves multiple purposes simultaneously: it provides structural support, prevents water infiltration, and directs water flow away from the protector accommodating space. This multi-functionality reduces overall device complexity while maintaining high reliability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Effectively prevents water from entering the grommet body, ensuring the protection of the wire harness and enhancing the design flexibility of the vehicle's wire harness routing by keeping the grommet body dry.

Implementation Method 1

the rib projects toward an inner surface of the protector accommodating chamber of the grommet body and extends along a direction toward a lower side from an upper side with the grommet installed in a vehicle body. According to the above configuration, the rib is provided along the direction toward the lower side from the upper side on the outer surface of the protector body accommodated in the protector accommodating chamber of the grommet body, whereby water flows along the rib.

Methodology Applied

Scientific EffectWater flow direction control:

Data Source

PatentUS10994674B2Grommet

Publication Date: 2021.05.04 YAZAKI CORP

AI summary

A grommet includes a grommet body, an inner protector, and an outer member. The inner protector includes a protector body accommodated in a protector accommodating chamber of the grommet body. The protector body includes a rib on an outer surface of the protector body. The rib projects toward an inner surface of the protector accommodating chamber of the grommet body and extends along a direction toward a lower side from an upper side with the grommet installed in a vehicle body.