Spark Plug Asymmetric Tip Surface Directing Discharge
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Solution Overview
Problem
Existing spark plugs face challenges in improving ignitability, particularly during lean combustion, as the discharge generated can be inhibited by proximity with the combustion chamber walls, leading to reduced fuel efficiency and limited combustion limits.
Innovation Solution
A spark plug design featuring a tubular housing, insulator, and central electrode with a ground electrode, where the tip surface is inclined to direct the air stream away from the combustion chamber walls, preventing discharge and flame cooling losses and promoting flame growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the discharge is generated close to the combustion chamber walls, then the ignitability is improved, but the discharge and flame are cooled by the walls leading to reduced fuel efficiency
Solution Approach 1:
The tip surface is designed with an asymmetric inclination relative to the axial direction, creating a specific direction that is not symmetric. This asymmetric geometry directs the discharge and initial flame away from the combustion chamber walls, preventing cooling losses while maintaining ignitability.
Solution Approach 2:
The invention introduces a specific direction that is orthogonal to the axial direction by inclining the tip surface. This dimensional change allows the discharge to be directed in a direction that avoids the cooling effect of the combustion chamber walls, resolving the contradiction between maintaining ignitability and reducing cooling losses.
2Productivity
If the discharge is directed toward the combustion chamber walls, then the flame growth is promoted, but the discharge is stretched and cooled reducing combustion efficiency
Solution Approach 1:
The asymmetric inclination of the tip surface creates a specific direction that optimizes flame growth while avoiding wall contact. The asymmetric geometry ensures the flame grows effectively without being stretched and cooled by the combustion chamber walls.
Solution Approach 2:
By creating a specific direction orthogonal to the axial direction through tip surface inclination, the invention enables flame growth in an optimized direction that promotes combustion efficiency while preventing energy loss through wall cooling.
3Device complexity
If the tip surface is made flat and perpendicular to the axial direction, then the structure is simple, but the discharge direction cannot be controlled to avoid cooling losses
Solution Approach 1:
The tip surface is designed with an asymmetric inclination rather than being flat and perpendicular to the axial direction. This asymmetric geometry provides discharge direction control to prevent cooling losses while maintaining relatively simple structural complexity.
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 inclined tip surface directs the discharge and initial flame away from the combustion chamber walls, enhancing ignitability and fuel efficiency by reducing cooling losses and improving combustion limits.
Implementation Method 1
the tip surface having a tip inclined surface that is inclined toward the tip end of the spark plug from the front end to the rear end of the tip surface
Implementation Method 2
A discharge generated by the spark plug ignites the fuel-air mixture in the combustion chamber
Data Source
AI summary
A spark plug has a specific direction orthogonal to an axial direction of a spark plug; the specific direction has opposing front directional side and rear directional side; the housing has a tip surface having a front end in the front side of the specific direction and a rear end in the rear side, the tip surface has a tip inclined surface inclined toward the tip end of the spark plug from the front end to the rear end of the tip surface. The tip inclined surface has a rear end in the specific direction, the insulator having a front end of the specific direction, the rear end is located to be closer to the tip end of the spark plug than the front end of the tip surface is, and to be more rearward than the front end of the insulator in the rear side of the specific direction.