Multilift Valve Actuation for Engine Load and Combustion Control
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Solution Overview
Problem
Existing engine valve actuation systems struggle to optimally control gas exchange and combustion processes across varying operating conditions, leading to inefficiencies in fuel consumption, emissions, and combustion quality.
Innovation Solution
Implementing a system that allows for multiple cycles of valve opening and closing, including early closing, late opening, and hybrid modes, combined in a multilift cycle, to balance fluid-dynamic and thermodynamic efficiencies, and enabling re-opening of valves during non-conventional phases for internal exhaust-gas recirculation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If early closing of intake valves is used to control engine load, then pumping work is reduced, but thermodynamic cycle efficiency and combustion quality deteriorate
Solution Approach 1:
The valve actuation cycle is segmented into multiple independent lift phases within a single engine cycle. The first lift phase (early closing) optimizes for reduced pumping work, while the second lift phase (late opening) optimizes for combustion efficiency. This segmentation allows each phase to independently optimize its specific function without compromising the other.
Solution Approach 2:
The system employs periodic valve actuation with multiple lifts within one engine cycle. The electronic control means generate periodic actuation signals that cause the valve to open and close multiple times during a single engine cycle, alternating between early-closing mode and late-opening mode to achieve both energy efficiency and combustion quality.
2Reliability
If late opening of valves is used to increase turbulence and mixing, then combustion efficiency improves, but pumping work increases
Solution Approach 1:
The valve actuation cycle is segmented into multiple independent lift phases within a single engine cycle. The first lift phase (early closing) optimizes for reduced pumping work, while the second lift phase (late opening) optimizes for combustion efficiency. This segmentation allows each phase to independently optimize its specific function without compromising the other.
Solution Approach 2:
The system employs periodic valve actuation with multiple lifts within one engine cycle. The electronic control means generate periodic actuation signals that cause the valve to open and close multiple times during a single engine cycle, alternating between early-closing mode and late-opening mode to achieve both energy efficiency and combustion quality.
3Device complexity
If conventional single-lift valve actuation is used, then system complexity is low, but ability to optimize gas exchange and combustion across varying operating conditions is limited
Solution Approach 1:
The valve actuation system transitions from a static single-lift mechanism to a dynamic multi-lift mechanism controlled by electronic control means. The system can dynamically adjust the number of lifts, timing, and duration of each lift phase based on real-time engine operating conditions, enabling adaptive optimization of gas exchange and combustion processes.
Solution Approach 2:
The electronic control means modify multiple actuation parameters including the number of lifts per cycle, opening/closing timing, lift duration, and lift amplitude. These parameter changes allow the system to adapt to varying operating conditions such as different engine speeds, loads, and temperature conditions to optimize performance.
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 approach enhances engine efficiency, combustion quality, and reduces fuel consumption and emissions by optimizing valve control strategies for specific operating conditions, achieving a wide range of regulatory possibilities.
Implementation Method 1
an electronically controlled solenoid valve with an exhaust channel, for the purpose of decoupling the valve itself from the respective tappet and causing rapid closing of the valve as a result of the respective means of elastic return
Implementation Method 2
causing rapid closing of the valve as a result of the respective means of elastic return
Implementation Method 3
the control of the load of an engine through the early closing of the intake valves is very effective in terms of reduction of the work of pumping thanks to the low speed of the piston during the period of opening of the valves and the consequent low fluid-dynamic losses at the valves
Implementation Method 4
The alternative mode of control by means of a late opening of the valves, where the speed of the piston is greater, causes an increase of the turbulence in the chamber and facilitates the process of mixing thanks to the high speed of the gases at input
Data Source
AI summary
An internal-combustion engine is equipped with a system of variable actuation of the intake valves that is controlled electronically for the purpose, of imparting on the valves different opening and closing times and different lifts according to the operating conditions of the engine. During one and the same cycle of operation of the engine, the system is able to impart on each intake valve a series of successive cycles of movements of opening and closing within the conventional cycle.