Rotatable Annular Core Isolation Valve for Spark-Ignition Engines
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Solution Overview
Problem
Spark-ignition piston engines experience engine pre-fire events due to hot points on spark plug electrodes, and existing valve designs fail to provide precise control over fuel, oxidant, and exhaust gas flow, limiting engine efficiency and reliability, especially with multiple spark plugs.
Innovation Solution
A valve design featuring a rotatable annular core with annulus sector penetrations that synchronizes with corresponding penetration pairs in the shell and cover plate, creating N-fold azimuthal symmetry, allowing precise control over ignition pathways, fuel, oxidant, and exhaust flow passages, and isolating spark plugs from the cylinder's internal volume except during electrical activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spark plugs are continuously exposed to the cylinder's internal volume, then ignition is always available, but engine pre-fire events occur due to hot points on the spark plug electrodes
Solution Approach 1:
The spark plug is extracted from continuous exposure to the cylinder's internal volume. The valve design removes the spark plug from the hot cylinder environment during non-ignition phases, eliminating the harmful hot points that cause pre-fire events while maintaining ignition capability when needed.
Solution Approach 2:
The spark plug exposure is made dynamic rather than static. The valve controls the spark plug's exposure to the cylinder volume, transitioning between isolated and exposed states based on ignition requirements. This dynamic control prevents pre-fire events while ensuring reliable ignition when activated.
2Device complexity
If conventional valve designs are used, then the structure is simple, but precise control over fuel, oxidant, and exhaust gas flow is not achieved
Solution Approach 1:
The valve is segmented into multiple functional components: a shell with first and second ports, a rotatable core with corresponding ports, and a cover plate with third and fourth ports. This segmentation allows precise independent control of fuel, oxidant, and exhaust flow passages through the rotational positioning of the core relative to the shell and cover plate.
Solution Approach 2:
The valve employs dynamic control through the rotatable core that can be positioned at different angular orientations. This dynamic positioning precisely controls the alignment between ports in the shell, core, and cover plate, enabling accurate timing and control of fuel injection, oxidant supply, and exhaust removal operations.
3Reliability
If multiple spark plugs are used per cylinder, then combustion reliability improves, but the complexity of controlling ignition pathways increases
Solution Approach 1:
The valve design provides multi-functionality by accommodating multiple spark plugs through a single rotational mechanism. The core with multiple ignition pathways can be rotated to simultaneously or sequentially expose multiple spark plugs to the cylinder volume, providing reliable combustion initiation while maintaining a relatively simple control structure.
Data Source
AI summary
A valve comprising a stationary shell and a rotatable annular core is designed for installation on the block deck of a spark-ignition piston engine, with there being one valve installed on the engine's block for every cylinder in the block. Rotation of the annular core cyclically opens and closes the ignition pathway(s) extending between the internal volume of the valve's associated cylinder and the spark plug(s) initiating combustion within the cylinder, with the pathway(s) only being open during time intervals wherein the spark plug(s) are electrically activated as part of the engine's normal operating cycle. Control of the open-closed status of the ignition pathway(s) eliminates engine pre-fire events caused by hot points on the spark plug(s). The valve also provides improved technology for directing and regulating the flow of fuel, oxidant, and exhaust gases as they are transferred into and out of the valve's associated cylinder.