Pre-Chamber Spark Plug Thermal Management via Filling Medium

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Solution Overview

Problem

Spark plugs with prechambers experience reduced service life due to high temperatures affecting the center electrode and insulator, leading to increased wear and decreased dielectric strength.

Innovation Solution

A heat dissipation zone is created by introducing a filling medium between the insulator and the housing, enhancing heat transfer and reducing thermal stress, with the option to adjust the fill level and materials like silicone, copper, and silver for improved conductivity and insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the center electrode and insulator are exposed to high temperatures during combustion, then the spark plug can function at high power, but the service life is reduced due to increased wear and decreased dielectric strength

Engineering Contradiction:
Improvecombustion powerVSAvoidservice life
Core Design Contradiction:
PowerVSDuration of action of stationary object

Solution Approach 1:

A filling medium is introduced as an intermediary substance between the insulator and the housing. This filling medium facilitates heat transfer from the hot insulator to the cooler housing, acting as a thermal mediator that protects the insulator from excessive temperature while maintaining the high-power combustion function

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The thermal parameters of the insulator-housing system are changed by introducing the filling medium with specific thermal conductivity properties. This modifies the heat flow path and temperature distribution, reducing the thermal stress on the insulator and center electrode to extend service life while maintaining combustion performance

Inventive Principle:
Principle #35Parameter changes

2Duration of action of stationary object

If a filling medium is introduced between the insulator and housing to improve heat dissipation, then service life is extended, but device complexity increases

Engineering Contradiction:
Improveservice lifeVSAvoidmanufacturing complexity
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The filling medium can be introduced in various forms including porous materials that allow for easy filling during manufacturing. The porous structure enables the material to be injected or packed into the annular space between the insulator and housing without requiring complex assembly steps

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The filling medium's physical parameters (viscosity, hardness, thermal conductivity) can be adjusted to optimize both heat dissipation performance and ease of manufacturing. By selecting materials with appropriate parameter ranges, the filling process becomes simpler while maintaining effective thermal management

Inventive Principle:
Principle #35Parameter changes

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 solution extends the service life of spark plugs by effectively dissipating heat, maintaining dielectric strength, and providing improved sealing and electrical insulation, while allowing for a simpler and cost-effective manufacturing process.

Implementation Method 1

a heat dissipation zone is created by introducing a filling medium between an insulator and a housing that at least partially surrounds the insulator

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The filling medium can advantageously contain silicone... This allows for the use of a conventional design, making the spark plug simple and cost-effective to manufacture, while the heat dissipation zone created by the filling medium ensures sufficient heat dissipation

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Data Source

PatentEP4175081A1Spark plug and method for producing a spark plug
Publication Date: 2023.05.03 DKT VERW
  • EP4175081A1 patent drawingFigure 1
  • EP4175081A1 patent drawingFigure 2
  • EP4175081A1 patent drawingFigure 3

AI summary

A spark plug, in particular a pre-chamber spark plug, comprising a housing (2), an insulator (1) and a central electrode (8), wherein the housing (2) at least partially surrounds the insulator (1) and wherein the central electrode (8) can be supplied with electrical voltage via a supply line running at least partially in the insulator (1) and wherein a heat dissipation zone (14) is realized by a filling medium (13) arranged between the insulator (1) and the housing (2), characterized in that the housing (2) has an opening (12) for introducing the filling medium (13).