Multi-Electrode Spark Plug Ignition Volume
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Solution Overview
Problem
Traditional spark plugs, including multi-electrode designs, face inefficiencies in igniting non-homogeneous fuel-air mixtures at low engine RPMs, leading to imperfect combustion, increased emissions, and reduced fuel economy, especially in 'stop and go' driving conditions.
Innovation Solution
A spark plug design featuring multiple ground electrodes that twist around a center electrode, creating a large three-dimensional spark target volume, allowing the spark to efficiently find the richest fuel-air mixture and promoting complete combustion without shielding the combustion chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional single-electrode spark plugs are used, then the structure is simple and manufacturing is easy, but combustion efficiency at low RPMs deteriorates due to inability to ignite non-homogeneous fuel-air mixtures
Solution Approach 1:
The single ground electrode is segmented into multiple ground electrodes (at least two) arranged circumferentially around the center electrode. This segmentation creates multiple spark gaps that can simultaneously ignite different regions of the combustion chamber, improving combustion efficiency in non-homogeneous fuel-air mixtures while maintaining manufacturing feasibility through standardized electrode components
Solution Approach 2:
The spark ignition transitions from a single-point (one-dimensional) spark gap to a multi-point three-dimensional spark target volume. The multiple ground electrodes are positioned at different radial distances and angular positions, creating a volumetric spark distribution that effectively ignites non-uniform fuel-air mixtures throughout the combustion chamber
2Productivity
If multiple ground electrodes are added to create large spark target volume, then combustion efficiency improves, but device complexity increases
Solution Approach 1:
The ground electrode system is segmented into multiple independent electrodes, each capable of forming a spark gap with the center electrode. This segmentation allows the spark to occur at multiple locations simultaneously, creating a larger effective spark target volume that improves combustion efficiency while keeping each individual electrode relatively simple in design
Solution Approach 2:
The multiple ground electrodes serve universal functions: each electrode can independently form a spark gap, provide a grounding path, and contribute to the overall spark target volume. This multi-functionality allows the system to achieve enhanced combustion efficiency without proportionally increasing complexity, as each electrode performs the same basic ignition function at different spatial locations
3Ease of manufacture
If conventional J-type ground electrode is used, then manufacturing is straightforward, but spark target volume is limited and combustion completeness deteriorates
Solution Approach 1:
The ground electrode geometry transitions from the conventional two-dimensional J-shape to a three-dimensional configuration where multiple electrodes are arranged circumferentially around the center electrode at different radial distances. This dimensional expansion creates a volumetric spark target that improves combustion completeness by addressing non-homogeneous fuel-air distribution throughout the combustion chamber
4Use of energy by moving object
If spark plug is designed for low RPM operation, then fuel economy improves, but emissions increase due to imperfect combustion
Solution Approach 1:
The combustion chamber is segmented into multiple ignition zones, each served by a separate spark gap between the center electrode and a ground electrode. This segmentation ensures that even when the fuel-air mixture is non-homogeneous at low RPMs, each zone can be independently and completely ignited, improving overall combustion efficiency and reducing emissions while maintaining fuel economy
Solution Approach 2:
The spark plug design changes the ignition parameter from a single spark event to multiple simultaneous spark events across different spatial locations. This parameter change ensures complete combustion of the non-homogeneous fuel-air mixture at low RPMs, simultaneously improving fuel economy and reducing emissions by eliminating unburned hydrocarbons and incomplete combustion products
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 enhances combustion efficiency at low RPMs, reduces emissions, and improves fuel economy by providing a larger, unobstructed spark target volume, resulting in faster and more complete fuel burn, lower emissions, and increased torque.
Implementation Method 1
A spark plug ignites the fuel/air mixture in a gasoline engine... the space between the center electrode 150 and the ground electrode 130 defines the 'spark gap' 135... when high voltage is supplied to the center electrode 150, spaced very near the ground electrode 130, the fuel/air mixture in the spark gap 135 becomes ionized, forming a low resistance electrical path, and the spark plug 'fires' by having a spark jump the gap between the two electrodes
Implementation Method 2
One of the plurality of ground electrodes preferably comprises a bi-metal structure configured to move radially away from the center electrode with increased temperature
Implementation Method 3
One of the plurality of ground electrodes preferably comprises a conductor having a Positive Temperature Coefficient which increases the electrical resistance with increasing temperature
Implementation Method 4
a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the engine
Data Source
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AI summary
A multi-electrode spark plug having a large spark target volume is disclosed. The spark plugs have a plurality of ground electrode rods which extend from the base of the spark plug and are twisted around center electrode to provide a plurality of substantially equidistant spark points relative to the center electrode. The spark points are formed in parallel and around the elongated axis of the spark plug. This configuration enables the spark to be created where the localized concentration of fuel to air is richer, such as that which may exist when the engine is operating with lower revolutions per minute. Test results indicate that automobiles equipped with the multi-electrode spark plugs exhibit improved fuel economy, and substantially reduced emissions and air pollution.