Piston Deflector Channels for Scavenging and Compression

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Solution Overview

Problem

Internal combustion engines face inefficiencies in scavenging and exhausting gases due to limitations in existing piston and cylinder designs, particularly in 2-cycle engines, which lead to fresh charge loss, hot spots, and knocking, hindering compression ratios and power generation.

Innovation Solution

A piston design featuring a semi-hemispherical upper dome with diametrically opposed concave channels and a downward sloped exhaust channel, optimized to guide incoming charges and promote swirl and turbulence, reducing fresh charge loss and hot spots, while allowing central placement of injectors and improved flame propagation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a deflector structure or fin is provided on the piston head to guide incoming mixture, then scavenging efficiency is improved and fresh charge loss is reduced, but the piston cannot approach the upper cylinder wall closely, limiting compression ratio

Engineering Contradiction:

Improvescavenging efficiencyVSAvoidcompression ratio

Core Design Contradiction:

ProductivityVSVolume of stationary object

Solution Approach 1:

The piston head is segmented into multiple functional zones: a central domed portion for compression and multiple concave channels (inlet channels, exhaust channel) carved into the surface. This segmentation allows each zone to perform its specific function while maintaining overall compactness, enabling the piston to achieve both effective scavenging and high compression ratio.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from traditional 2D flat piston surfaces to a 3D multi-dimensional surface topology with domed portions, concave channels, and varying depths. This dimensional transformation allows gas flow guidance to occur through three-dimensional channel structures rather than simple surface deflectors, enabling effective scavenging with reduced space requirements.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Loss of substance

If a deflector structure is used to deflect incoming charge upward, then fresh charge loss through exhaust port is reduced, but hot spots are created causing premature combustion and knocking

Engineering Contradiction:

Improvefresh charge lossVSAvoidhot spots and knocking

Core Design Contradiction:

Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

Different regions of the piston head surface are given different geometries and functions: concave inlet channels for guiding fresh charge, a central domed portion for compression, and a downward sloped exhaust channel for exhaust gas removal. This local differentiation allows each area to optimize its specific function while avoiding the creation of hot spots that cause knocking.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The piston head incorporates a domed central portion and curved concave channels instead of flat surfaces and sharp edges. These curved geometries promote smooth gas flow patterns, reduce turbulence-induced hot spots, and eliminate sharp corners where heat could concentrate, thereby preventing premature combustion and knocking.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Volume of stationary object

If flat piston heads are used to achieve higher compression ratios, then compression ratio is improved, but scavenging effectiveness is reduced compared to deflector structures

Engineering Contradiction:

Improvecompression ratioVSAvoidscavenging efficiency

Core Design Contradiction:

Volume of stationary objectVSProductivity

Solution Approach 1:

The invention merges the compression function (central domed portion) with the scavenging function (concave inlet and exhaust channels) into a single integrated piston head structure. This combination allows the piston to simultaneously achieve high compression ratio through the domed geometry while maintaining effective scavenging through the integrated channel system, eliminating the need to choose between the two functions.

Inventive Principle:

Principle #5Merging (Combining)

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

Enhances scavenging efficiency, reduces fresh charge loss, and minimizes hot spots, enabling higher compression ratios and improved power generation by directing gases effectively through the engine cylinder.

Implementation Method 1

promote swirl and turbulence in cylinder squish areas

Methodology Applied

Scientific EffectSwirl and turbulence: Turbulence

Implementation Method 2

the pumping motion of the engine pistons may scavenge the air charge into the engine cylinder from the scavenging or intake port(s) for combustion and expel the spent charge exhaust gases

Methodology Applied

Scientific EffectCompression: Compression

Data Source

PatentUS10465629B2Internal combustion engine having piston with deflector channels and complementary cylinder head

Publication Date: 2019.11.05 QUEST ENGINES LLC

AI summary

Cooperatively shaped piston and cylinder head arrangements for internal combustion engines are disclosed. The piston may have a domed head with one or more curved exhaust channels and inlet channels formed therein. The piston cylinder may have curved surfaces that are exact or close inverse or negative counterparts to the curved surfaces of all or part of the domed head, including the exhaust channels, and/or inlet channels formed on the piston.