Prechamber Spark Plug with Converging Ignition Flares

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Solution Overview

Problem

Conventional spark plugs with hook electrodes are unsuitable for lean-burn operation in internal combustion engines, as the diverging ignition flares do not lead to rapid and complete combustion of fuel-air mixtures in the combustion chamber.

Innovation Solution

A spark plug design featuring a prechamber with transfer openings arranged to concentrate ignition flares parallel or convergingly, with a center electrode and ground electrode configuration that ensures ignition flares spread out in a controlled manner to enhance combustion efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional spark plugs with hook electrodes are used, then the structure is simple, but the combustion of fuel-air mixture in lean-burn operation is incomplete and slow

Engineering Contradiction:
Improvecombustion speedVSAvoidcombustion completeness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The combustion chamber is divided into a prechamber and a main chamber separated by an antechamber wall with transfer openings. Fuel ignition occurs first in the prechamber, and the ignited fuel then transfers to the main chamber through the transfer openings. This segmentation allows controlled ignition and improves combustion efficiency in lean-burn operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The transfer openings in the antechamber wall are specifically designed with particular geometries (circular, slot-shaped, or annular) and arrangements to control the direction and concentration of ignition flares. This local structural design ensures that ignition flares are concentrated rather than divergent, achieving rapid and complete combustion in the main chamber.

Inventive Principle:
Principle #3Local quality

2Duration of action of moving object

If transfer openings are arranged to produce diverging ignition flares, then the structure is conventional, but combustion time increases and electrode corrosion worsens

Engineering Contradiction:
Improvecombustion timeVSAvoidelectrode corrosion
Core Design Contradiction:
Duration of action of moving objectVSObject-generated harmful factors

Solution Approach 1:

Instead of allowing ignition flares to diverge as in conventional designs, the transfer openings are designed to concentrate and direct the ignition flares in a controlled manner. This inversion of the flare propagation pattern reduces combustion time and minimizes electrode exposure to harsh conditions, thereby reducing corrosion.

Inventive Principle:
Principle #13The other way round (Inversion)

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 design achieves rapid and complete combustion of the fuel-air mixture with shorter combustion times and reduced electrode corrosion, increasing the service life of the spark plug.

Implementation Method 1

the fuel/air mixture in the prechamber is first ignited by means of ignition sparks

Methodology Applied
Scientific EffectElectrical discharge: Electric Spark

Implementation Method 2

The ignited fuel then exits in the form of ignition flares from the transfer openings in the antechamber wall into the combustion chamber of the internal combustion engine in order to ignite the lean fuel-air mixture there

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP1984993B1Sparkplug
Publication Date: 2013.08.28 GE JENBACHER GMBH & CO OG
  • EP1984993B1 patent drawingFigure 1
  • EP1984993B1 patent drawingFigure 2
  • EP1984993B1 patent drawingFigure 3

AI summary

Sparkplug for internal combustion engine, in particular for lean operation, having an initial chamber wall (2) which surrounds an initial chamber (1), is essentially closed and has transfer openings (3, 4), with at least two transfer openings (3, 4) being designed and arranged such that fuel which is ignited in the initial chamber (1) propagates, after leaving the initial chamber (1), through the transfer openings (3, 4) in the form of ignition flares which run essentially parallel or converge towards one another.