Corona Igniter Forward Assembly Design

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The reverse-assembly method of corona igniters, which requires the insulator to be inserted into the shell from the combustion chamber, leads to operational and manufacturing compromises such as difficulty in retaining the insulator without putting it in tension, and limits the ability to achieve optimal electrical performance.

Innovation Solution

A corona igniter design where the conductive inner diameter is less than the insulator outer diameter adjacent the insulator nose region, allowing for forward-assembly and maintaining exceptional electrical performance while avoiding the issues associated with reverse-assembled igniters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the insulator outer diameter is increased to improve electrical performance, then the insulator cannot be assembled into the shell using conventional forward-assembly methods

Engineering Contradiction:
Improveelectrical performanceVSAvoidassembly method
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent inverts the conventional assembly sequence by performing reverse-assembly, where the insulator is inserted into the shell from the combustion chamber end rather than from the opposite end. This allows the insulator outer diameter to be larger than the shell inner diameter at the assembly end, enabling optimal electrical performance while maintaining manufacturability through the inverted assembly approach

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

The forward-assembly method enables the corona igniter to achieve exceptional electrical performance without the tension-related issues of reverse-assembled designs, ensuring reliable operation and improved assembly processes.

Implementation Method 1

a central electrode formed of an electrically conductive material for receiving a high radio frequency voltage and emitting an radio frequency electric field

Methodology Applied
Scientific EffectRadio frequency electric field emission: Electromagnetic Induction

Implementation Method 2

The electric field causes a portion of a mixture of fuel and air in the combustion chamber to ionize and begin dielectric breakdown

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 3

facilitating combustion of the fuel-air mixture... corona discharge occurs, also referred to as a non-thermal plasma

Methodology Applied
Scientific EffectCorona discharge: Corona Discharge

Data Source

PatentEP3379665B1Corona ignition device with improved electrical performance
Publication Date: 2020.12.09 FEDERAL MOGUL IGNITION LLC
  • EP3379665B1 patent drawingFigure 1
  • EP3379665B1 patent drawingFigure 1A
  • EP3379665B1 patent drawingFigure 2

AI summary

A corona igniter (20) comprises a central electrode (22) surrounded by an insulator (26), which is surrounded by a conductive component. The conductive component includes a shell (34) and an intermediate part (36) both formed of an electrically conductive material. The intermediate part (36) is disposed between said insulator outer surface and said shell inner surface and between said insulator upper end and said insulator lower shoulder.