Actuator Piston Disc Control for Engine Valve Lift
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Solution Overview
Problem
Conventional actuator systems for gas exchange valves in high-performance internal combustion engines face challenges in accurately and reliably adjusting valve lift at both low and high engine revolution frequencies, especially under high counter pressure conditions.
Innovation Solution
An actuator system comprising an actuator piston disc, a cylinder volume divided into two portions, an actuator piston rod, and controllable inlet and outlet valves, allowing for precise axial displacement control through the management of pressure fluid flow, enabling reliable operation at high frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional actuator systems are used for gas exchange valves in high-performance engines, then the system can operate at high engine revolution frequencies, but the valve lift adjustment accuracy deteriorates at both low and high frequencies under high counter pressure conditions
Solution Approach 1:
The actuator system is segmented into multiple controllable inlet valves (first inlet valve and second inlet valve) and a controllable outlet valve, allowing independent control of pressure fluid flow paths. This segmentation enables precise control of the piston disc position by managing pressure distribution in different cylinder portions separately, resolving the contradiction between reliability and precision in valve lift adjustment.
Solution Approach 2:
The system dynamically adjusts the valve lift by controlling the timing and sequence of opening/closing the inlet and outlet valves during the actuation cycle. The dynamic control of pressure fluid flow allows the system to maintain accurate valve lift adjustment across varying engine speeds and counter pressure conditions, improving both reliability and precision simultaneously.
2Speed
If high pressure fluid (8-30 bar) is used to achieve fast valve opening at high frequencies, then the valve opening speed improves, but the system complexity and energy consumption increase
Solution Approach 1:
The pressure fluid control system is segmented into multiple valves (first inlet valve, second inlet valve, outlet valve) that can be independently controlled. This allows the system to manage high pressure fluid flow more efficiently, achieving fast valve opening speeds while distributing the control complexity across multiple simpler, individually controllable components rather than requiring a single complex high-pressure valve.
Solution Approach 2:
The controllable outlet valve acts as an intermediary element that regulates the release of pressure fluid from the cylinder volume. By controlling the outlet valve timing, the system can rapidly reduce pressure to achieve fast valve closing while maintaining simpler overall system architecture compared to direct high-pressure control mechanisms.
3Measurement precision
If multiple controllable valves are used for precise axial displacement control, then the positioning accuracy improves, but the number of controlling elements increases
Solution Approach 1:
The control system is segmented into multiple valves (first inlet valve, second inlet valve, outlet valve) that can be independently controlled. This segmentation allows precise axial displacement control by managing pressure fluid flow through different paths, achieving high positioning accuracy while distributing the control complexity across multiple simpler, individually controllable valve elements.
Solution Approach 2:
The system uses controllable valves to regulate pressure fluid (pneumatic or hydraulic) flow to the piston disc. By controlling the timing and sequence of valve operations, the system achieves precise axial displacement control through fluid pressure management, reducing the need for complex mechanical positioning mechanisms and multiple actuators.
4Reliability
If electrical synchronization is implemented for controlling multiple valves, then the coordination between valves improves, but the system complexity and energy consumption increase
Solution Approach 1:
The controllable inlet valves and outlet valve are operated in a periodic sequence during each actuation cycle, with the first inlet valve, second inlet valve, and outlet valve opening and closing in a predetermined timing pattern. This periodic operation ensures reliable coordination between valves without requiring continuous electrical synchronization signals, reducing energy consumption while maintaining reliable valve coordination.
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
The system provides adjustable and reliable axial displacement control at high actuating frequencies, ensuring accurate positioning of the actuator piston disc and reducing energy consumption by minimizing the number of controlling elements and eliminating the need for electrical synchronization.
Implementation Method 1
a pressure fluid, such as a liquid or a gas, is used to achieve a displacement/opening of one or more engine valves
Implementation Method 2
the force that is required to open the valve actuator to open the, in relation to the combustion chamber inward opening, engine valve is consequently also increased proportional to an increased angular momentum output
Data Source
AI summary
An actuator and a method for controlling such an actuator suitable for operating at least one gas exchange valve arranged in a cylinder head of an internal combustion engine. The actuator includes: an actuator piston disc, a cylinder volume adapted for the actuator piston disc, where the actuator piston disc divides the cylinder volume in a first portion and a second portion, an inlet channel arranged between a pressure fluid inlet and the first portion of the cylinder volume, a controllable first inlet valve arranged in the inlet channel, a controllable second inlet valve arranged downstream the controllable first inlet valve, an outlet channel arranged between the first portion of the cylinder volume and a pressure fluid outlet, and a controllable outlet valve arranged in the outlet channel.