Variable Valve Actuation System for Engine Mode Transition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current engine valve actuation systems for internal-combustion engines are limited in their ability to efficiently operate across a wide range of compression ratios, especially high values, and do not effectively reduce pumping work or allow for smaller engine dimensions while maintaining power delivery, nor can they seamlessly transition between four-stroke and two-stroke modes for optimal efficiency.
Innovation Solution
A system that enables selective actuation of engine valves in both four-stroke and two-stroke modes by incorporating a second cam profile, a rocker mechanism, and a selector device controlled by a unit that adjusts the solenoid valve based on engine operating conditions, allowing for optimal efficiency across varying conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional four-stroke valve actuation system is used, then the engine can operate with standard compression ratios, but the system cannot efficiently operate across a wide range of compression ratios especially high values
Solution Approach 1:
The system dynamically switches between four-stroke and two-stroke operating modes based on detected engine conditions. The control unit monitors parameters such as compression ratio, load, and speed, then activates appropriate cam profiles and solenoid valve configurations to optimize valve timing for the current operating regime, enabling efficient operation across wide compression ratio ranges
Solution Approach 2:
The invention changes critical operating parameters including valve opening/closing timing, lift duration, and cam profile selection. By adjusting these parameters based on detected engine state, the system adapts the valve actuation characteristics to match the required compression ratio and operating conditions, improving efficiency across different regimes
2Loss of energy
If conventional valve actuation systems are used, then the engine design follows standard dimensions, but the system cannot reduce pumping work or enable smaller engine dimensions while maintaining power delivery
Solution Approach 1:
The system employs periodic dual cam profiles that create alternating valve timing patterns. The first cam profile optimizes intake valve timing for four-stroke operation while the second cam profile optimizes for two-stroke operation. By periodically switching between these profiles, the system reduces pumping work during high-load two-stroke operation while maintaining efficient four-stroke operation during normal conditions
Solution Approach 2:
The valve actuation system is designed to perform multiple functions through a single integrated mechanism. The dual cam profiles, selector device, and solenoid valve configuration enable the same hardware to efficiently handle both four-stroke and two-stroke operating modes, reducing the need for separate dedicated mechanisms for each mode and thereby reducing overall system complexity
3Adaptability or versatility
If a fixed cam profile is used for four-stroke operation, then the valve timing is optimized for standard operation, but the system cannot seamlessly transition between four-stroke and two-stroke modes
Solution Approach 1:
The system uses a dynamic selector device that can switch between different cam profiles based on the desired operating mode. The control unit monitors engine conditions and activates the appropriate cam profile (first for four-stroke, second for two-stroke) through the selector device, enabling seamless transitions while maintaining precise valve timing control for each mode
Solution Approach 2:
The selector device acts as an intermediary mechanism between the camshaft and the valve actuation system. It receives input from the cam profiles and directs them to the appropriate valve timing mechanism, facilitating smooth mode transitions. The solenoid valve serves as another intermediary that controls the hydraulic connection between the master piston and slave pistons, enabling precise timing control during mode changes
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 system allows for efficient operation across a wide range of compression ratios, reduces pumping work, enables smaller engine designs, and facilitates seamless mode transitions between four-stroke and two-stroke operations, ensuring optimal engine performance under any condition.
Implementation Method 1
a slave piston that can be driven by said master piston by means of a volume of fluid set between said master piston and said slave piston
Implementation Method 2
a solenoid valve configured for assuming a state in which said volume of fluid is set in communication with an outlet
Implementation Method 3
a camshaft designed to drive said master piston in motion, which has a cam profile for governing, through said master piston, said engine valve
Implementation Method 4
a slave piston that can be driven by said master piston by means of a volume of fluid set between said master piston and said slave piston
Data Source
AI summary
Described herein is a system for variable actuation of an engine valve of an internal-combustion engine, where the system is able to actuate the engine valves, selectively, in a four-stroke operating mode and in a two-stroke operating mode, on the basis of the operating conditions of the engine.