Piston Flat Movable Surface Dynamic Clearance Volume
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Solution Overview
Problem
Internal combustion engines face inefficiencies due to residual exhaust fumes in the clearance volume, which are not effectively eliminated at the top dead centre during the exhaust stroke, affecting combustion efficiency.
Innovation Solution
A flat member connected to a flexible member, attached to the piston head via retaining members and arrow-shaped metallic members, which seals the clearance volume during the exhaust stroke while maintaining it for compression and ignition strokes, utilizing a spring-like cross-sectional geometry to manage fluid pressures and inertial forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional piston head is used with a fixed clearance volume, then the structure is simple and easy to manufacture, but exhaust fumes remain inside the clearance volume at top dead centre during the exhaust stroke, reducing combustion efficiency
Solution Approach 1:
The piston head incorporates a movable flat member (1.4) connected to a flexible member (1.3) that allows the clearance volume to dynamically change during the engine cycle. The flat member moves to different positions during compression, power, and exhaust strokes, transforming the static clearance volume into a dynamic volume that adapts to different operational phases, thereby improving combustion efficiency while managing exhaust fume evacuation.
Solution Approach 2:
The piston head is segmented into multiple functional zones: the main piston head (1.12), the movable flat member (1.4), and the flexible member (1.3) connecting them. This segmentation allows independent movement and functional specialization, where the flat member can be retained by retaining members (1.7) with arrow-shaped metallic members (1.6) when needed, while the flexible member provides the necessary compliance for volume adjustment.
2Object-generated harmful factors
If the clearance volume is eliminated at top dead centre during the exhaust stroke, then exhaust fumes are effectively removed, but the structure becomes more complex with additional components
Solution Approach 1:
The piston head design utilizes the engine's own operational dynamics to achieve exhaust fume removal. The movable flat member (1.4) and flexible member (1.3) system automatically adjusts the clearance volume based on the engine cycle phase, using the pressure differentials and motion already present in the engine operation. The retaining members (1.7) with arrow-shaped metallic members (1.6) engage and disengage automatically based on pressure forces, eliminating the need for external control mechanisms.
3Productivity
If the flat member is allowed to move freely to eliminate clearance volume, then exhaust fumes are removed, but the flat member may move higher than required and cause operational issues
Solution Approach 1:
The retaining members (1.7) with arrow-shaped metallic members (1.6) are pre-configured to engage the movable flat member (1.4) at specific positions, preventing it from moving higher than required. This preliminary constraint mechanism ensures that the flat member is stopped before it can cause operational issues, while still allowing sufficient movement to eliminate the clearance volume during the exhaust stroke. The design anticipates and prevents potential problems before they occur.
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 removes over 90% of the clearance volume at top dead centre during the exhaust stroke, maximizing combustion efficiency by ensuring gases are housed within the cylinder, and is applicable to both two-stroke and four-stroke engines.
Implementation Method 1
can be compressed downwards by fluid pressures situated over said flat member (1.4, 2.4)
Implementation Method 2
a flexible member (1.3, 2.3) which seals the volume over said flat member (1.4, 2.4) from the volume under said flat member (1.4, 2.4), and can be compressed downwards by fluid pressures... by comprising a spring like cross-sectional geometric profile
Implementation Method 3
a set of arrow shaped metallic members (1.6, 2.6) which stop the flat member (1.4, 2.4) from moving higher than required due to inertial forces when reaching the top dead centre at the exhaust stroke
Data Source
Figure 1~2
Figure 3~4
AI summary
The present invention comprises the use of a flat member (1.4, 2.4) which connects to a flexible member (1.3, 2.3) which attaches both said flat member (1.4, 2.4) and the top surface (1.10, 2.10) of the surface of the piston head (1.12, 2.12) which is positioned lower than the edge surfaces (1.1, 2.1) of said piston head (1.12, 2.12), such that said flat member (1.4, 2.4) is mounted on the lower surface (1.10, 2.10) of the piston head (1.12, 2.12). The aim of this design is to eliminate the exhaust fumes remaining inside the clearance volume by eliminating said clearance volume when the piston head (1.12, 2.12) reaches the top dead centre in the exhaust stroke, while keeping the clearance volume cleared when the piston head (1.12, 2.12) reaches top dead centre at the compression stroke. This designs therefore removes more than 90 % of the clearance volume when it is required at top dead centre at the end of the exhaust stroke, while leaving the clearance volume clear at the compression and ignition strokes in order for the compressed gases to be housed inside the cylinder as required, hence maximising the combustion efficiency of the internal combustion engine. Said design can be applied to both two-stroke and four-stroke internal combustion engine designs.