Spark Plug Ground Electrode Protrusion Angles Suppress Re-discharge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional spark plugs experience frequent re-discharge, leading to fluctuating spark position and reduced ignitability, causing wear on electrodes and inefficiencies in air-fuel mixture combustion.
Innovation Solution
The spark plug design features a ground electrode with a ground protrusion part and a center electrode with a center protrusion part, both having angled surfaces that maintain the discharge spark at specific angles, preventing movement towards the base material and reducing re-discharge by ensuring the electric field intensity around these angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional spark plug electrodes are used with base materials and noble metal chips, then the spark discharge gap is formed, but re-discharge frequently occurs causing spark position fluctuation and reduced ignitability
Solution Approach 1:
The electrode is divided into a base material portion and a protrusion portion with angled surfaces. The protrusion portion segments the discharge surface to create specific angular geometry that prevents re-discharge, while the base material provides structural support. This segmentation resolves the contradiction by maintaining reliable ignition through controlled spark positioning.
Solution Approach 2:
The protrusion portion introduces asymmetric angular surfaces (acute angles or right angles) to the otherwise symmetric electrode structure. This asymmetry creates a preferred discharge path that stabilizes spark position and prevents re-discharge, improving ignitability while eliminating the harmful re-discharge effect.
2Ease of manufacture
If the electrode structure is simplified, then manufacturing is easier, but spark discharge control and prevention of re-discharge become difficult
Solution Approach 1:
Instead of complicating the entire electrode structure, only the local discharge surface is given specific angular quality. The protrusion portion with acute or right angles is applied locally to the center or ground electrode, maintaining simple base material construction while achieving precise discharge control through localized geometric modification.
3Device complexity
If the discharge spark position is allowed to fluctuate, then the electrode structure is simpler, but ignitability is reduced and electrode wear increases
Solution Approach 1:
The protrusion portion with specific angular surfaces is pre-formed on the electrode before operation. This preliminary geometric configuration actively guides the discharge spark to a stable position, preventing fluctuation before it can occur. The acute or right angles are预先 designed to control electron emission and ionization paths, ensuring reliable ignition without complex additional structures.
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 effectively suppresses re-discharge, improving ignitability by maintaining the discharge spark position and reducing wear on electrodes, resulting in more efficient combustion and better engine performance.
Implementation Method 1
ensuring the electric field intensity around these angles
Data Source
AI summary
A center electrode is held in insulating glass, in which a tip end portion of the center electrode protrudes. A ground electrode has a connection part connected to a housing. The ground electrode forms a spark discharge gap between the center electrode and the ground electrode. The ground electrode has a ground base material that includes the connection part and a ground protrusion part that protrudes from the ground base material toward the center electrode and forms the spark discharge gap between the center electrode and the ground electrode. An angle between a ground discharge surface of the ground protrusion part and a side surface of the ground protrusion part is a right angle or an acute angle. At least a portion of the side surface of the ground protrusion part and at least a portion of a side surface of the ground base material are flush with each other.