Ignition System Electrode Geometry and Energy Optimization
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Solution Overview
Problem
Modern internal combustion engines, such as lean burn and direct injection engines, require enhanced ignition performance to improve fuel efficiency and reduce emissions, but existing ignition systems struggle to effectively utilize energy for efficient spark discharge and durability.
Innovation Solution
The ignition system is designed with a power supply outputting 100 mJ or greater per spark discharge, and specific geometric configurations between the center and ground electrodes, including protrusions, to ensure efficient spark spread and minimize electrode wear, characterized by area ratios and gap sizes that optimize energy application and electrode alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If higher ignition performance is needed for lean burn and direct injection engines, then energy output from power supply is increased to 100 mJ or greater, but this increases energy consumption and may reduce durability
Solution Approach 1:
The patent applies parameter changes by optimizing the electric energy output from the power supply to a specific range (100 mJ or greater per spark discharge) and configuring the electrode geometry (facing area ratio S1/S2 between 0.01 to 0.8, gap distance of 0.5 to 2.0 mm). These parameter optimizations enable sufficient ignition performance for lean burn engines while controlling energy consumption through efficient energy utilization in the spark discharge gap.
Solution Approach 2:
The patent applies local quality by creating a specific geometric configuration at the spark discharge gap location, where the facing area S1 of the ground electrode relative to the center electrode is optimized (S1/S2 ratio between 0.01 to 0.8). This local optimization ensures concentrated energy delivery where needed for reliable ignition while minimizing overall energy consumption and preventing excessive wear at critical locations.
2Reliability
If electric energy output is increased to 100 mJ or greater for better ignition performance, then spark discharge effectiveness is improved, but electrode wear increases reducing durability
Solution Approach 1:
The patent resolves this contradiction through parameter changes by optimizing both the energy output (100 mJ or greater) and the geometric parameters (facing area ratio S1/S2 between 0.01 to 0.8, gap distance of 0.5 to 2.0 mm). This balanced configuration ensures that sufficient energy is delivered for reliable ignition while the optimized geometry distributes the thermal and mechanical stress, preventing excessive local wear and extending electrode durability.
Solution Approach 2:
The patent applies local quality by optimizing the specific geometry at the spark discharge gap, where the facing area S1 is configured to be between 0.01 to 0.8 times the center electrode area S2. This local geometric optimization ensures that energy is effectively concentrated for ignition while preventing excessive energy concentration that would cause rapid electrode wear, thus balancing ignition performance with durability.
3Duration of action of stationary object
If facing area between electrodes is increased to reduce local wear, then durability is improved, but spark discharge efficiency decreases reducing ignition performance
Solution Approach 1:
The patent applies parameter changes by optimizing the facing area ratio S1/S2 to a specific range (0.01 to 0.8) rather than maximizing it. This optimized parameter range balances two competing requirements: sufficient facing area to distribute wear and improve durability, while maintaining adequate spark discharge efficiency for reliable ignition. The gap distance is also optimized to 0.5 to 2.0 mm to ensure efficient energy transfer.
Solution Approach 2:
The patent applies local quality by creating an optimized geometric configuration at the spark discharge gap where the facing area S1 is specifically dimensioned relative to the center electrode area S2. This local optimization ensures that the electrode geometry provides sufficient wear distribution area while maintaining the electric field intensity needed for efficient spark discharge, thus balancing durability with ignition performance.
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 configuration achieves excellent ignition performance by ensuring efficient spark spread into the combustion chamber and significantly improves durability by reducing local wear on electrodes, maintaining performance even in lean burn conditions.
Implementation Method 1
When electric energy is supplied from the power supply to the spark discharge gap, spark discharge is produced, whereby the fuel-air mixture or the like is ignited
Data Source
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Figure 3~4
AI summary
An ignition system (101) includes an ignition plug (1) having a spark discharge gap (33) formed between a center electrode (5) and a ground electrode (27), and a power supply (51) for supplying electric energy to the spark discharge gap (33). Spark discharge is produced when electric energy is supplied from the power supply (51) to the spark discharge gap (33). The electric energy output from the power supply (51) for producing spark discharge of one unit is set to 100 mJ or greater. S1 ≥ [{-30(mm-1)×G1+60}/100]×S2 and G1 < 2.0 are satisfied wherein G1 represents the size (mm) of the spark discharge gap (33), and S1 and S2 represent areas (mm2) defined such that when the center electrode (5) and the ground electrode (27) are projected on a plane VS orthogonal to the axis CL1, a region obtained by removing, from a projection region (5P) of the center electrode (5), a region where the projection region (5P) overlaps with a projection region (27P) of the ground electrode (27) has the area S1, and the projection region (5P) of the center electrode (5) has the area S2.