Variable Intake Valve Actuation via Series Control Valves
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Solution Overview
Problem
Existing internal combustion engine systems for variable intake valve actuation are complex and costly, lacking the ability to control intake valves independently within a cylinder, which limits operational flexibility and air flow optimization.
Innovation Solution
A system utilizing a single cam and hydraulic circuit for both intake valves of a cylinder, with two electrically operated control valves in series to control communication between the hydraulic actuators and a discharge channel, allowing for differentiated actuation modes and reduced system complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a separate cam and hydraulic circuit are provided for each intake valve, then independent control of each valve is achieved, but system complexity and cost increase
Solution Approach 1:
The patent merges the control of two intake valves by providing a single camshaft with a single cam profile that actuates both valves through one hydraulic circuit. Two control valves are placed in series to independently control the discharge channel for each valve, enabling differentiated actuation modes while reducing overall system complexity compared to separate cam and hydraulic circuit configurations.
Solution Approach 2:
The single camshaft and hydraulic circuit serve multiple functions by controlling both intake valves through series-connected control valves. This universal arrangement allows the system to achieve independent valve control capability while using a unified actuation mechanism, thereby reducing system complexity and cost.
2Device complexity
If a single cam and hydraulic circuit are used for both intake valves, then system complexity is reduced, but the ability to control valves independently is lost
Solution Approach 1:
The patent segments the control function by placing two control valves in series within the single hydraulic circuit, where each control valve independently manages the discharge channel for its respective valve. This segmentation allows independent control capability to be maintained while using a single cam and hydraulic circuit, thus reducing overall system complexity.
Solution Approach 2:
The control valves act as intermediaries between the single hydraulic circuit and the two intake valves. By positioning control valves in series, the system enables differentiated actuation modes for each valve while maintaining a unified hydraulic circuit, thereby achieving independent control without increasing system complexity.
3Reliability
If traditional valve control systems are used, then reliable valve actuation is achieved, but operational flexibility and air flow optimization are limited
Solution Approach 1:
The patent implements dynamic valve control by enabling the system to switch between different actuation modes (single valve open, both valves open, both valves closed) through electronic control of the series-connected control valves. This dynamic capability allows optimization of air flow patterns such as tumble and swirl motions based on operational requirements while maintaining reliable valve actuation through the hydraulic circuit.
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
Enables simplified and cost-effective control of intake valves with enhanced operational flexibility, optimizing air flow patterns such as tumble and swirl motions within the cylinder, improving engine efficiency and reducing fuel consumption.
Implementation Method 1
a hydraulic circuit including a volume of fluid under pressure towards which a pumping piston associated to the valve tappet is facing, said volume of fluid under pressure being adapted to communicate with a chamber of a hydraulic actuator associated to said intake valve
Implementation Method 2
first and second intake valves associated to said first and second intake conduits respectively and at least one exhaust valve associated to said at least one exhaust conduit, said intake and exhaust valves being provided with respective return springs which bias them towards a closed position
Data Source
AI summary
In an internal combustion engine provided with an electro-hydraulic system for variable actuation of the intake valves of the engine, each cylinder has two intake valves, which are associated with two intake conduits and are controlled by a single cam of a camshaft through a single hydraulic circuit. The communication of the hydraulic actuators of the two intake valves with a discharge channel is controlled by two electrically-actuated control valves, both of an on/off two-position type, arranged in series with each other along a hydraulic line for communication between the a pressure volume and the discharge channel.