Four-Cycle Engine Curtailed Intake Process for High Compression
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Solution Overview
Problem
Standard four-cycle gasoline internal combustion engines are limited by low compression ratios to avoid pre-ignition, leading to reduced efficiency, larger engine size, and restricted fuel types due to auto-ignition temperature constraints.
Innovation Solution
A four-cycle engine design with a curtailed intake process, allowing for higher compression ratios and controlled pre-ignition temperatures, achieved through a shortened intake cycle that maintains atmospheric pressure and uses a smaller combustion chamber, eliminating the need for turbochargers or other pressure-enhancing devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a standard four-cycle engine uses a compression ratio greater than 11:1, then pre-ignition temperature exceeds fuel auto-ignition threshold, but engine efficiency is reduced and knocking occurs
Solution Approach 1:
The intake valve closes before the piston reaches bottom dead center, preemptively limiting the volume of air-fuel mixture entering the cylinder. This preliminary action sets up the conditions for higher compression ratios without exceeding auto-ignition temperature thresholds, as the reduced mixture volume results in lower compression temperatures while maintaining higher pressure.
Solution Approach 2:
The invention changes the timing parameter of intake valve closure from the conventional position (at or near bottom dead center) to an earlier position (before bottom dead center). This parameter change fundamentally alters the compression process, enabling compression ratios above 11:1 while keeping pre-ignition temperatures below the auto-ignition threshold through controlled volume reduction.
2Reliability
If a standard four-cycle engine uses a compression ratio between 9.5:1 and 11.8:1, then pre-ignition temperature remains below auto-ignition threshold, but engine size increases and weight increases
Solution Approach 1:
By closing the intake valve before bottom dead center, the invention preemptively reduces the air-fuel mixture volume entering the cylinder. This allows the engine to achieve higher compression ratios in a more compact configuration, reducing overall engine size and weight while maintaining reliable temperature control below auto-ignition thresholds.
3Power
If a standard four-cycle engine uses a compression ratio greater than 11:1, then power output increases, but knocking effect impairs efficiency and reduces engine life
Solution Approach 1:
The early closure of the intake valve before bottom dead center preemptively limits the air-fuel mixture volume, enabling higher compression ratios that increase power output while preventing compression temperatures from reaching the auto-ignition threshold. This eliminates knocking effects and protects engine life.
4Productivity
If a standard four-cycle engine is designed for higher compression ratio, then engine efficiency improves, but the type of fuel that can be combusted without knocking is restricted
Solution Approach 1:
By changing the intake valve closure timing to occur before bottom dead center, the invention fundamentally alters the compression process. This parameter change enables the engine to achieve high compression ratios while maintaining compression temperatures below the auto-ignition threshold, thereby improving efficiency without restricting fuel type compatibility.
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 enables higher engine efficiency, power generation equivalent to or greater than standard engines in a smaller, lighter form, with the ability to combust any liquid hydrocarbon fuel without knocking, and achieves compression ratios up to 30:1, significantly improving efficiency compared to standard engines.
Implementation Method 1
the piston moves upward and compresses the air-fuel mixture to its pre-ignition compression pressure
Implementation Method 2
The compression cycle culminates in a spark ignition of the air/fuel mixture
Implementation Method 3
the ignited air-fuel mixture expands within the cylinder, causing its pressure to drop
Data Source
AI summary
A four-cycle internal combustion engine has a permanent curtailed intake process, which allows the temperature and pressure of intake air to the combustion cylinders to be tightly controlled, and enables a very small combustion chamber so that a much higher compression ratio and pre-ignition compression pressure can be achieved without approaching the air/fuel mixture auto-ignition threshold. The maximum threshold of curtailed intake volume is determined to be 68% of engine cylinder volume to achieve a compression ratio CR of 22.1 or higher. Because this design can effectively regulate and set the maximum pre-ignition temperature of the fuel-air mixture, it can combust virtually any type of liquid hydrocarbon fuel without knocking. This four-cycle engine, due to its higher compression ratio, generates power equivalent to or greater than a standard four-cycle engine in a smaller and lighter engine and at a much higher efficiency.