Vehicle Fuel Cap Axial Grooves Static Discharge

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional vehicle fuel caps face issues with static discharge effectiveness, dust invasion, and aesthetic appearance, due to inaccurate gap dimensions and long slits that compromise functionality and appearance.

Innovation Solution

A vehicle fuel cap design featuring a conductive lid with a projection form and longitudinal grooves on the inner peripheral face, which narrows the gap between the lid and filler neck, prevents dust invasion, and improves dimensional accuracy, while also forming depressions to adjust air pressure within the fuel tank.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a long slit is formed in the lid to prevent surface sink during injection molding, then manufacturing reliability is improved, but the appearance quality deteriorates and dust can invade into the fuel cap

Engineering Contradiction:

Improveinjection molding reliabilityVSAvoidappearance quality

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The single long slit is segmented into multiple short slits arranged in a circular pattern around the discharge projection. This segmentation maintains the total venting area needed for injection molding while significantly improving appearance by eliminating long visible gaps and preventing dust invasion through the distributed, smaller openings

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The slit configuration transitions from a single linear dimension (long slit) to a two-dimensional circular arrangement (multiple slits around the discharge projection). This dimensional change allows the slits to be positioned in a pattern that is less visually prominent while maintaining functional effectiveness

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If the gap between the discharge projection and filler neck is reduced to improve static discharge effectiveness, then static discharge performance is improved, but manufacturing precision requirements increase and dust invasion risk increases

Engineering Contradiction:

Improvestatic discharge effectivenessVSAvoidgap dimension accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The discharge projection is designed with a specific geometry where the discharge tip is positioned close to the filler neck for effective static discharge, while the base of the projection is integrated with the lid structure. The multiple slits are positioned at the base area, creating local functional zones that separate the discharge function from the venting function, allowing independent optimization of each

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The discharge projection acts as an intermediary element between the lid interior and the filler neck. It provides a controlled discharge point that maintains a precise, small gap for static discharge while the multiple slits provide an alternative path for air venting that does not require the same level of gap precision

Inventive Principle:

Principle #24Intermediary (Mediator)

3Volume of moving object

If the lid outer diameter is reduced to improve compactness, then space efficiency is improved, but the gap between lid and filler neck becomes smaller increasing dust invasion risk

Engineering Contradiction:

Improvelid outer diameterVSAvoiddust invasion

Core Design Contradiction:

Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The air venting function is segmented from the main gap between lid and filler neck by introducing multiple discrete slits around the discharge projection. This segmentation allows the lid to be positioned closer to the filler neck for compactness while dust prevention is handled by the controlled slit openings rather than relying on a larger peripheral gap

Inventive Principle:

Principle #1Segmentation

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 design effectively discharges static charges, prevents dust entry, maintains a good appearance, and ensures accurate gap dimensions, thereby eliminating discomfort from static and preventing spark discharge, while allowing for proper air pressure adjustment.

Implementation Method 1

the conventional vehicle fuel cap 100 earths the static charge in the human body from the lid 200 to the filler neck 300 and through a bracket (not shown) to a vehicle body side

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

discharge static charged in the lid to the filler neck

Methodology Applied

Scientific EffectElectrostatic discharge: Electrostatic Discharge

Data Source

PatentUS7543715B2Vehicle fuel cap with axial longitudinal grooves in casing body

Publication Date: 2009.06.09 HONDA MOTOR CO LTD

AI summary

A vehicle fuel cap comprises a casing body for opening/closing a filler opening of a filler neck communicating with a fuel tank; and a lid that is equipped at an upper portion of the casing body and is formed of a conductive material, and the vehicle fuel cap forms a discharge portion in the lid for discharging static charge in the lid to the filler neck, wherein the discharge portion comprises a projection form provided on an inner peripheral face of the lid opposite to an outer peripheral edge of the filler opening, and on the inner peripheral face a longitudinal groove is formed at both sides of the discharge portion and along an axial direction of the casing body.