Shielded Spark Plug Extender for Remote Coil Mounting
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Solution Overview
Problem
Existing shielded ignition configurations for engines face issues with high cost and limited configurations of shielded spark plugs, increased vibration and temperature exposure for ignition coils mounted on the valve cover, and corrosion due to trapped combustion gases, which reduce the performance and lifespan of the ignition system.
Innovation Solution
A shielded ignition configuration using a non-shielded spark plug with a spark plug extender that allows remote mounting of ignition coils, featuring a flange and retainer system for secure engagement with the valve cover, and a seal to prevent gas ingress and egress, enabling the use of conventional spark plugs while mitigating corrosion and vibration exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If shielded spark plugs are used in shielded ignition configurations, then hazardous area requirements are met and electrical noise is prevented, but cost increases and configuration options are limited
Solution Approach 1:
The ignition system is divided into separate components: a standard spark plug, a shielded spark plug adapter, and a shielded secondary lead. This segmentation allows each component to be optimized independently, enabling the use of inexpensive standard spark plugs while achieving shielded ignition functionality through the adapter and lead assembly.
Solution Approach 2:
A shielded spark plug adapter is introduced as an intermediary component between the standard spark plug and the shielded secondary lead. This adapter provides the shielding function and electrical connection without requiring modification to the standard spark plug, thus maintaining compatibility and reducing cost.
2Ease of operation
If ignition coils are mounted to the valve cover, then space is utilized efficiently, but temperature and vibration exposure increases reducing coil lifespan
Solution Approach 1:
The ignition coil is extracted from the valve cover mounting location and relocated to a remote position. The shielded secondary lead serves as the connecting element, allowing the coil to be positioned away from high temperature and vibration environments while maintaining electrical connection to the spark plug.
3Ease of manufacture
If conventional spark plugs are used with remote coil mounting, then cost is reduced and coil exposure is minimized, but combustion gases may cause corrosion
Solution Approach 1:
A shielded secondary lead with flexible shielding serves as a barrier between combustion gases and the electrical components. The shielding structure prevents combustion gases from reaching and corroding the spark plug and connection points while allowing the system to use conventional spark plugs.
Data Source
AI summary
A shielded ignition configuration is provided comprising a non-shield spark plug having an electrode, a spark plug extender having first end configured to mount to the spark plug such that a conductor of the extender makes electrical contact with the spark plug electrode, a second end having a cup configured for connection to a secondary lead such that the conductor makes electrical contact with the secondary lead, and a flange, and at least one retainer configured to engage the flange and cause a lower surface of the flange to engage an upper surface of a valve cover.