Multipoint Ignition Engine Central and Peripheral Spark Gaps
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Solution Overview
Problem
In spark ignition engines, flames propagating from peripheral spark gaps to the center often interfere, reducing combustion speed and leading to inefficient fuel use and increased exhaust emissions.
Innovation Solution
Simultaneous ignition of both central and peripheral spark gaps ensures rapid combustion, allowing for ignition timing closer to top dead center, reducing fuel loss and improving engine output and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If multiple peripheral spark gaps are used for ignition, then flame extinction on peripheral portion is suppressed and combustion speed is improved, but flames interfere with each other during propagation, reducing combustion efficiency
Solution Approach 1:
The combustion chamber is divided into multiple ignition zones by positioning spark gaps at specific locations: the center of the combustion chamber and multiple peripheral positions around the cylinder opening. This segmentation allows independent flame propagation from each spark gap without interference, as each spark gap serves as a separate ignition source for its respective zone.
Solution Approach 2:
Different regions of the combustion chamber are assigned different ignition characteristics. The central spark gap ignites the core region, while peripheral spark gaps ignite the boundary regions near the cylinder opening. This local differentiation ensures that each region receives appropriate ignition treatment, preventing flame extinction at the periphery while avoiding flame interference in the center.
2Stability of the object's composition
If ignition is performed from the center, then flame propagation is simple and uniform, but flame is cooled by wall surface and may be extinguished on peripheral portion
Solution Approach 1:
The single central ignition source is segmented into multiple ignition sources: one central spark gap and multiple peripheral spark gaps. This segmentation extends the effective ignition coverage from only the center to include both the center and peripheral regions, ensuring complete combustion throughout the combustion chamber.
Solution Approach 2:
Instead of igniting only from the center and letting the flame propagate outward (conventional approach), the invention ignites from multiple peripheral points and allows flames to propagate inward toward the center. This inverted approach ensures that the peripheral regions, which are prone to flame extinction due to wall cooling, receive direct ignition attention.
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 approach enables complete combustion of the air-fuel mixture, reducing unburned gas discharge, lowering HC and CO emissions, and enhancing fuel efficiency while maintaining stable engine operation.
Implementation Method 1
an air-fuel mixture in a combustion chamber is ignited by a spark plug
Implementation Method 2
the air-fuel mixture can be burned rapidly
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A multipoint ignition engine (1) includes a central electrode pair (9), disposed in the center of a combustion chamber (2), for forming a central spark gap (10), and a plurality of peripheral electrode pairs (12) held in a head gasket (15), which has an opening portion having a substantially identical diameter to an opening portion of a cylinder (5) in a position corresponding to the opening portion of the cylinder (5), for forming a plurality of peripheral spark gaps (13) around the inner periphery of the opening portion in the cylinder (5). An air-fuel mixture in the combustion chamber (2), which is obtained by mixing together fuel and air evenly to the stoichiometric air-fuel ratio or a richer/leaner air-fuel ratio than the stoichiometric air-fuel ratio, is ignited using both the central spark gap (10) and the plurality of peripheral spark gaps (13).