Piston Baffle Ring Structure for Limiting Oil-Triggered Abnormal Combustion
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Solution Overview
Problem
Internal combustion engines face limitations in increasing power density due to abnormal combustion caused by oil droplets igniting in the cylinder, particularly in gaseous fuel engines, which can lead to early combustion, multiple ignition locations, and reduced fuel burning capacity.
Innovation Solution
A piston design featuring an oil-blocking baffle ring, pressure balancing passages, and a shielding wall to prevent oil droplets from entering the combustion chamber, with the baffle ring being non-loaded and positioned between the uppermost and second land to block upward oil migration, and the shielding wall assisting in preventing oil intrusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If more gaseous fuel is delivered into the engine cylinder to increase power density, then the power output increases, but abnormal combustion occurs due to oil droplet ignition
Solution Approach 1:
The patent extracts and removes the harmful element (oil droplets) from the combustion chamber environment by implementing a baffle ring structure that prevents oil from entering the combustion zone, thereby eliminating the cause of abnormal combustion while allowing increased fuel delivery
Solution Approach 2:
The baffle ring acts as an intermediary barrier between the oil supply system and the combustion chamber, blocking oil droplets while permitting the combustion process to proceed normally with increased fuel delivery
2Object-affected harmful factors
If a baffle ring is added to block oil droplets, then abnormal combustion is prevented, but device complexity increases
Solution Approach 1:
The baffle ring is merged with the existing piston structure by integrating it into the piston crown's ring groove system, combining the oil-blocking function with the existing piston architecture rather than adding a separate component
Solution Approach 2:
The baffle ring structure serves multiple functions: it blocks oil droplets from entering the combustion chamber, maintains piston ring sealing, and integrates with the existing piston crown structure, thereby reducing overall device complexity despite adding oil-protection capability
Data Source
AI summary
A piston in a piston and cylinder liner assembly for an internal combustion engine includes a piston crown, and a plurality of piston rings seated within a plurality of ring grooves in a crown outer surface. The plurality of piston rings includes a baffle ring seated within an uppermost ring groove. A plurality of pressure balancing passages extend through the piston crown each from a first opening formed in an uppermost land to a second opening formed in a second land. The baffle ring may be a non-loaded ring structured to prevent oil droplets from entering a cylinder and causing abnormal combustion. In an embodiment, a shielding wall projects axially from an annular rim of the piston to prevent entry of oil not deflected by the baffle ring.