Spark Plug Through-Hole for Electrode Gap Adjustment

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Solution Overview

Problem

Existing spark plugs face challenges in accessing and adjusting the distance between the center electrode and the ground electrode due to high temperatures and the need for electrical discharge machining, which complicates maintenance and can lead to asymmetric ignition with multiple ground electrodes.

Innovation Solution

The spark gap is made accessible along the longitudinal axis of the spark plug by creating a recess or opening in the wall surrounding the electrodes, allowing for the insertion of a spacer gauge to adjust the electrode distance, with the opening being covered by the combustion chamber housing for minimal weakening of the wall.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the wall surrounding the electrodes is made thick to protect from high temperatures, then heat protection is improved, but access to the spark gap becomes difficult

Engineering Contradiction:
Improveheat protectionVSAvoidaccess to spark gap
Core Design Contradiction:
TemperatureVSEase of operation

Solution Approach 1:

The wall is segmented by creating a through-opening that divides it into sections, allowing access to the spark gap while maintaining the overall structural integrity and heat protection of the thick wall design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A spacer gauge is introduced as an intermediary tool through the opening to adjust the electrode distance, enabling precise adjustment without requiring direct manual manipulation of the electrodes themselves

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If the electrodes are brought closer to the insulator body to ensure faster heat flow, then heat dissipation is improved, but access to the electrodes becomes more difficult

Engineering Contradiction:
Improveheat flow efficiencyVSAvoidelectrode accessibility
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The wall is divided by the through-opening to provide access pathways to the electrodes that are positioned close to the insulator body for optimal heat dissipation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Access to the electrodes is achieved by creating an opening in the radial direction of the wall, allowing adjustment from the side rather than requiring access from the end face, thus maintaining the parallel arrangement of the spark gap

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If electrical discharge machining is used to adjust electrode distance, then adjustment precision is improved, but device complexity increases

Engineering Contradiction:
Improveelectrode distance adjustmentVSAvoidmaintenance complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

A spacer gauge serves as a simple mechanical intermediary tool that provides precise adjustment of electrode distance through mechanical means, eliminating the need for complex electrical discharge machining equipment and procedures

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The adjustment mechanism allows the spark plug to be serviced using simple, self-contained tools (spacer gauge and pressing mechanism) that do not require external specialized equipment or complex procedures

Inventive Principle:
Principle #25Self-service

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

This configuration enables easier access and adjustment of the spark gap, maintaining efficient ignition while minimizing the need for increased ignition voltage and reducing the risk of asymmetric spark discharge, allowing for seamless integration with prechamber ignition systems without engine conversion.

Implementation Method 1

a wall can be provided that conducts heat well

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

the increasing distance between the center electrode and the ground electrode due to electrical discharge machining

Methodology Applied
Scientific EffectElectrical discharge machining: Electrical Discharge Machining

Data Source

PatentEP2517323B1Spark plug with a through-hole for adjustment
Publication Date: 2015.02.18 GE JENBACHER GMBH & CO OG
  • EP2517323B1 patent drawingFigure 1a
  • EP2517323B1 patent drawingFigure 1b~1d
  • EP2517323B1 patent drawingFigure 2a

AI summary

The invention relates to a spark plug (1), comprising a center electrode (2) and a ground electrode (4), wherein the center electrode (2) is arranged relative to the ground electrode (4) in such a way that the spark gap (s) extends between the ground electrode (4) and the center electrode (2), wherein the spark gap (s) is surrounded by a wall (16), wherein the wall (16) has a recess (22) or opening (20), which is designed in such a way that a feeler gauge (32) can be inserted between the center electrode (2) and the ground electrode (4).