Hydraulic Intake Valve Actuation for Engine Combustion Control

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Solution Overview

Problem

Existing internal combustion engine technologies face challenges in achieving high engine power and low fuel consumption while meeting stringent CO2 and particulate emission regulations, particularly due to limitations in airflow management within the engine cylinders, including reduced filling coefficients and increased friction from powerful electromagnets used for valve actuation.

Innovation Solution

The implementation of a system that controls two intake valves per cylinder using a single cam and hydraulic circuit, with a three-way/three-position control valve or two on/off control valves, allowing for efficient generation of tumble and swirl motions within the combustion chamber, reducing the need for separate actuating systems and minimizing electric current usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate actuating systems with powerful electromagnets are used for each intake valve to enable differentiated control, then the engine can achieve optimal airflow patterns (tumble and swirl motions), but the friction and electric current consumption greatly increase

Engineering Contradiction:
Improvedifferentiated control of intake valvesVSAvoidelectric current consumption
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent combines the actuation of two intake valves into a single hydraulic circuit controlled by one electromagnet. The hydraulic system uses a single control valve to regulate fluid pressure that actuates both intake valves through hydraulic motors, replacing what would traditionally require two separate electromagnetic actuating systems. This merging reduces the number of electromagnets from two to one, significantly reducing electric current consumption and friction losses while maintaining the ability to independently control each intake valve's opening timing and duration through hydraulic pressure regulation.

Inventive Principle:
Principle #5Merging (Combining)

2Speed

If high tumble ratio and masked intake valves are used to improve combustion, then combustion speed increases, but the filling coefficient of the cylinder decreases resulting in reduced engine power

Engineering Contradiction:
Improvecombustion speedVSAvoidengine power
Core Design Contradiction:
SpeedVSPower

Solution Approach 1:

The patent implements dynamic control of intake valve timing and duration using a hydraulic actuation system. The system can adjust the opening and closing timing of each intake valve independently based on engine operating conditions. During conditions requiring high power output, the system optimizes valve timing to maximize the filling coefficient by allowing earlier opening and longer duration. During conditions requiring efficient combustion, the system adjusts timing to enhance tumble motion. This dynamic adaptability resolves the contradiction by allowing the engine to optimize for either power or combustion efficiency depending on the specific operating condition.

Inventive Principle:
Principle #15Dynamics

3Reliability

If swirl motion is generated to prevent fuel jet impingement on cylinder walls, then fuel evaporation improves, but the complexity of the intake conduit configuration increases

Engineering Contradiction:
Improvefuel evaporationVSAvoidintake conduit configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the airflow control function by providing separate intake conduits for each intake valve, with each conduit independently configured to generate specific flow patterns. One intake conduit is designed to generate primarily tumble motion while the other generates swirl motion. This segmentation allows the engine to activate only the necessary conduit based on operating conditions, reducing the effective complexity at any given time while maintaining the benefits of both flow patterns when needed. The hydraulic actuation system enables selective activation of each conduit-intake valve pair.

Inventive Principle:
Principle #1Segmentation

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 Turbulent Kinetic Energy (TKE) within the combustion chamber, leading to faster combustion propagation and improved engine efficiency, power, and reduced emissions, while maintaining operational flexibility and cost-effectiveness.

Implementation Method 1

each said intake valve being driven by a respective tappet against the action of said return spring with the interposition of a hydraulic circuit including a volume of a fluid under pressure

Methodology Applied
Scientific EffectHydraulic actuation: Hydraulic Press

Implementation Method 2

the airflow entering into the cylinder is almost entirely conveyed on one side of the intake valve and gives rise to a tumble vortex

Methodology Applied
Scientific EffectVortex flow: Vortex Ring

Implementation Method 3

impart a swirl motion to the airflow entering into the cylinder, i.e. a spiral-like motion around the axis of the cylinder

Methodology Applied
Scientific EffectSwirl flow: Vortex Ring

Implementation Method 4

Internal combustion engine with fast combustion

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP4015787B1Internal combustion engine with fast combustion, and method for controlling the engine
Publication Date: 2024.01.24 CENTRO RICERCHE FIAT SCPA
  • EP4015787B1 patent drawingFigure 1
  • EP4015787B1 patent drawingFigure 2
  • EP4015787B1 patent drawingFigure 3~4

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 (VT, VS), associated with two intake conduits. A first intake conduit (4T) is configured so as to generate, within the cylinder, a main tumble motion, a cross-tumble motion and a swirl motion of the airflow. A second intake conduit (4S) has a scroll-type configuration, so as to generate a swirl motion of the airflow within the cylinder in a direction opposite to that of the swirl motion induced by the first intake conduit (4T). An electronic controller (25) is configured to partially or entirely open the intake valve (VT) associated to the first intake conduit in a condition of reduced operation of the engine, below a predetermined engine load and/or below a predetermined engine rotational speed, and to always open both the intake valves (VT, VS) in the remaining conditions of operation of the engine.