Spark Plug Intermediate Electrode Segmentation
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Solution Overview
Problem
Existing spark plugs either require structural modifications to the engine or electrical system, generate low plasma volume, or suffer from high breakdown voltage leading to insulation wear and calamine deposition, which affects combustion efficiency.
Innovation Solution
A spark plug design featuring an intermediate electrode on a ceramic insulator between the central and ground electrodes, with mini electrodes of specific shapes and arrangements to generate two simultaneous discharges, maintaining breakdown voltage comparable to conventional systems and preventing calamine deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If a double spark plug with intermediate electrode in shape of star washer is used to generate two simultaneous discharges, then plasma volume is increased, but breakdown voltage becomes high causing insulation wear and calamine deposition
Solution Approach 1:
The intermediate electrode is segmented into multiple projection portions (at least two) that are distributed around its circumference. Each projection portion creates a separate discharge path, allowing the plasma volume to be increased through multiple localized discharges rather than a single large discharge, thereby reducing the voltage stress on insulation while maintaining high plasma volume
Solution Approach 2:
The intermediate electrode features localized projection portions with specific geometries (sharp edges or points) at predetermined positions around its circumference. These local structural variations create concentrated electric fields at specific locations, enabling controlled discharge initiation points that optimize plasma generation while managing breakdown voltage requirements
2Volume of stationary object
If a double spark plug with intermediate electrode in shape of star washer is used to generate two simultaneous discharges, then plasma volume is increased, but calamine deposition occurs on electrodes
Solution Approach 1:
The intermediate electrode is divided into multiple projection portions that create separate, distributed discharge zones. This segmentation prevents calamine deposition by dispersing the combustion energy across multiple locations rather than concentrating it at a single point, reducing localized overheating and material degradation
Solution Approach 2:
The projection portions on the intermediate electrode act as intermediary structures between the central electrode and ground electrode. These intermediaries create controlled discharge paths that initiate combustion more uniformly, preventing the excessive localized heating that leads to calamine formation on the electrode surfaces
3Productivity
If multiple secondary electrodes are bent towards the main electrode to create multiple discharges, then combustion initiation is improved, but plasma volume remains low
Solution Approach 1:
The intermediate electrode extends radially outward from the central electrode axis, creating discharge paths that utilize the radial dimension of the combustion chamber. This dimensional approach allows multiple discharge zones to be distributed around the chamber perimeter, increasing the overall plasma volume while maintaining effective combustion initiation across the air-fuel mixture
4Volume of stationary object
If radio frequency power supply is used to generate plasma with single central electrode, then plasma generation is achieved, but electrical system complexity increases
Solution Approach 1:
The spark plug system utilizes the existing conventional ignition power supply and electrical infrastructure already present in the engine. The intermediate electrode with its projection portions is designed to work with standard high-voltage ignition systems, allowing the system to generate the necessary plasma volume through clever electrode geometry rather than requiring complex additional electrical equipment
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 achieves high-quality combustion initiation with a high plasma volume, similar electrical energy consumption, and reduced wear, without requiring engine or electrical system modifications, while preventing calamine deposition and maintaining efficient ignition.
Implementation Method 1
generates two simultaneous electric discharges providing, through the cumulated length of said two discharges, a high quality initiation of combustion of the air-fuel mixture
Implementation Method 2
generation of high volume of plasma generated by two simultaneous electrical discharges
Data Source
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AI summary
The present invention refers to a spark plug with double electrical discharge comprising: a central electrode (3) having a discharge surface (3a), a ground electrode (4) having a discharge surface (4a), an insulator (2) located concentrically on a longitudinal central axis (y) of the spark plug, between electrodes (3) and (4) on whose exterior circumference there is a groove accommodating an intermediate electrode (1) having two opposing superior (1.3) and inferior (1.4) discharge surfaces, wherein the electrode (1) has a shape of a flat washer with a central hole and protrusions (8) allowing the placement on the electrode (1) of at least two superior mini electrodes (5) on the surface (1.3) of the electrode (1), of at least two inferior mini electrodes (6) on surface (1.4) of electrode (1), at a distance between these mini electrodes (5, 6), on the surface (4a) of electrode (4) are placed at least two ground mini electrodes (7), at a distance from the mini electrodes (5, 6), and the total number of mini electrodes (5, 6, 7) is at least 6 and at most 54, while the number of mini electrodes (6) equals the number of mini electrodes (7), such that a simultaneous ignition of an electrical discharge between electrode (3) and electrode (1) and of an electrical discharge between electrode (1) and electrode (4) upon initiation of combustion is generated.