Automotive Lamp Grommet With Retractable Legs for Sheet Metal Sealing

Solution Overview

Problem

Existing grommets for car lamps often damage car body sheet metal due to high-strength support legs, leading to a failure in sealing between the grommet and the car body sheet metal.

Innovation Solution

A grommet design featuring support legs that can extend and retract, with elastic filling portions to fill gaps between the support legs and windows, allowing for secure mounting without excessive pressure on the sheet metal, and a sealing edge to ensure waterproofing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If high-strength support legs are used to ensure structural strength, then the support legs can provide adequate mechanical strength, but they will damage the car body sheet metal when passing through

Engineering Contradiction:

Improvesupport leg strengthVSAvoiddamage to car body sheet metal

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The support legs are designed with elastic material properties, allowing them to change their mechanical characteristics dynamically. During installation, they can be compressed to reduce cross-sectional area for easy passage through the sheet metal hole, then recover their original shape to provide sufficient support strength, thus resolving the contradiction between installation ease and structural strength

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The support legs transition from a static rigid structure to a dynamic elastic structure that can adapt its state. They are designed to be deformable during installation and then maintain a stable supporting state, enabling them to pass through the sheet metal without damage while still providing the necessary mechanical strength for mounting

Inventive Principle:

Principle #15Dynamics

2Stability of the object's composition

If rigid support legs are used to maintain structural stability, then the grommet can provide stable mounting, but sealing between the grommet and car body sheet metal fails

Engineering Contradiction:

Improvegrommet mounting stabilityVSAvoidsealing performance

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The support legs are designed with elastic material properties, allowing them to change their mechanical characteristics dynamically. During installation, they can be compressed to reduce cross-sectional area for easy passage through the sheet metal hole, then recover their original shape to provide sufficient support strength, thus resolving the contradiction between installation ease and structural strength

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The support legs transition from a static rigid structure to a dynamic elastic structure that can adapt its state. They are designed to be deformable during installation and then maintain a stable supporting state, enabling them to pass through the sheet metal without damage while still providing the necessary mechanical strength for mounting

Inventive Principle:

Principle #15Dynamics

3Strength

If the support legs extend outward to provide mounting support, then the grommet can be securely mounted, but gaps are created between the support legs and windows allowing fluid flow

Engineering Contradiction:

Improvemounting support capabilityVSAvoidfluid flow through gaps

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

Elastic filling portions are introduced as intermediary elements between the support legs and the windows. These filling portions adapt to the gaps created by the extended support legs, effectively sealing the spaces without interfering with the mounting function, thus resolving the contradiction between mounting support and fluid sealing

Inventive Principle:

Principle #24Intermediary (Mediator)

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 grommet achieves a good sealing performance by preventing the expansion of the hole in the car body sheet metal, filling gaps to prevent fluid flow, and ensuring a tight seal with the sheet metal and car lamp, thus providing effective waterproofing.

Implementation Method 1

The pair of filling portions are elastic such that the pair of support legs have extending position and retracting position

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

The pair of support legs are configured such that the pair of support legs have extending position and retracting position, and the pair may move between the extending position and the retracting position

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 3

the grommet further comprises a cap, wherein the cap is provided around the neck ring, is connected to the neck ring and is provided with a sealing edge at a free end thereof

Methodology Applied

Scientific EffectSealing:

Data Source

PatentUS11878625B2Grommet

Publication Date: 2024.01.23 ILLINOIS TOOL WORKS INC

AI summary

A grommet that comprises a main body, a cavity, an outer wall, a pair of windows, a pair of support legs and a neck ring. The main body extends along an axis of the grommet. The cavity is recessed downward from an upper surface of the main body along the axis. A first channel is formed between a first outer wall portion and a first side face of the main body, and a second channel is formed between a second outer wall portion and a second side face of the main body. The pair of windows are respectively provided in the first outer wall portion and the second outer wall portion and are respectively in communication with the first channel and the second channel. The pair of support legs are respectively connected to lower edges of the pair of windows through bottoms thereof.