Asynchronous Fuel Injection Timing for Intake Manifold Evaporation
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Solution Overview
Problem
Internal combustion engines with two injectors per cylinder face challenges in achieving a homogeneous air-fuel mixture due to incomplete evaporation of fuel sprays at the ignition instant, leading to inhomogeneous distribution and reduced evaporation rates, especially under higher loads.
Innovation Solution
The method involves asynchronous actuation of the two injectors to inject fuel into the intake manifold during the intake valve opening phase, allowing partial evaporation within the cylinder, enhancing turbulence and mixing of the air-fuel mixture, and allowing only one intake valve to inject fuel during certain phases, with injection periods ranging from 2% to 30% of the total injection phase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If fuel is injected into the intake manifold ahead of time for evaporation, then a certain period is available for fuel droplet evaporation, but the air-fuel mixture distribution becomes inhomogeneous and evaporation is incomplete at ignition instant
Solution Approach 1:
The patent applies preliminary action by injecting fuel into the intake manifold before the intake stroke, allowing evaporation to begin in advance. The control unit is configured to actuate the injector to inject fuel into the intake manifold preceding the intake stroke, ensuring that evaporation starts before the air-fuel mixture enters the cylinder, thus improving evaporation rate while maintaining mixture homogeneity through controlled timing
Solution Approach 2:
The patent implements dynamics by making the injection timing variable based on engine operating conditions. The control unit adjusts the injection timing relative to the intake stroke according to detected engine parameters, allowing the system to optimize between evaporation rate and mixture homogeneity dynamically across different operating ranges, including part throttle and high load conditions
2Loss of substance
If two injectors are provided per cylinder to reduce fuel deposition at branching points, then fuel deposition is reduced, but the dosing of precise fuel quantity becomes more difficult
Solution Approach 1:
The patent applies segmentation by dividing the fuel injection function into two separate injectors, each serving specific cylinders. The injection system is segmented such that a first injector serves first cylinders and a second injector serves second cylinders, allowing independent control and precise dosing for each injector while collectively reducing fuel deposition at intake manifold branching points
Solution Approach 2:
The patent implements feedback through the control unit that detects engine operating parameters and adjusts the injection timing and duration accordingly. The control unit uses feedback from engine sensors to optimize the injection strategy, ensuring precise fuel quantity dosing while adapting to varying engine loads and speeds, thereby maintaining accuracy despite the complex two-injector configuration
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 improves the evaporation rate of the air-fuel mixture, enabling higher exhaust-gas recirculation rates and reduced fuel consumption, particularly in the part throttle range, while minimizing inhomogeneous distribution and incomplete evaporation issues.
Implementation Method 1
The fuel spray injected by the injectors into the corresponding intake manifold region evaporates there and is aspirated into the individual cylinder
Implementation Method 2
an asynchronous actuation of the injectors is provided in addition, so that better turbulence is achieved in the fuel in the cylinders or in the intake manifold, and thus better mixing of the air-fuel mixture
Data Source
AI summary
A method and a device for supplying fuel into a combustion chamber of a cylinder of an internal combustion engine, in which an air-fuel mixture is supplied to the cylinder via at least two intake sections, which are connected to the cylinder via an intake valve, and each of the intake sections is assigned an injector, fuel being injected into the intake sections in at least intermittently asynchronous manner.