Engine Control Device Waste Gate Valve Dynamics

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Solution Overview

Problem

In engines with turbochargers, low load operating conditions lead to insufficient fuel-air mixing, resulting in decreased combustion efficiency and potential fuel deposits, which affect fuel economy and engine oil dilution.

Innovation Solution

A control apparatus that adjusts the injection amounts and ratios of fuel injection valves and controls the waste gate valve to optimize turbocharger boost pressure, enhancing combustion stability and fuel economy by managing the waste gate valve's opening based on engine operating states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the injection amount from the second fuel injection valve is increased to improve combustion stability, then combustion stability improves, but fuel economy deteriorates due to insufficient fuel-air mixing in low load conditions

Engineering Contradiction:
Improvecombustion stabilityVSAvoidfuel economy
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The waste gate valve opening degree is dynamically adjusted based on the injection amount from the first fuel injection valve. When the injection amount increases, the valve opening degree increases to allow more exhaust gas to bypass the turbine, reducing turbine drive load and improving fuel-air mixing efficiency, thereby maintaining combustion stability while improving fuel economy

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control method changes the opening degree parameter of the waste gate valve in response to changes in the injection amount parameter. By adjusting the valve opening degree parameter according to the injection amount, the system optimizes the balance between combustion stability and fuel economy

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the waste gate valve is kept open to reduce turbine drive load and improve fuel economy, then fuel economy improves, but combustion stability deteriorates due to insufficient supercharging effect

Engineering Contradiction:
Improvefuel economyVSAvoidcombustion stability
Core Design Contradiction:
Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The waste gate valve opening degree is dynamically controlled based on real-time injection amount data. When injection amount is low, the valve opening is reduced to maintain supercharging effect and combustion stability. When injection amount increases, the valve opening increases to reduce turbine load and improve fuel economy

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control method uses feedback from the injection amount sensor to automatically adjust the waste gate valve opening degree. This closed-loop control ensures that the valve opening is optimized according to actual injection conditions, balancing combustion stability and fuel economy

Inventive Principle:
Principle #23Feedback

3Stability of the object's composition

If the injection amount from the first fuel injection valve is increased to improve fuel-air mixing, then fuel-air mixing improves, but turbine drive load increases due to reduced exhaust gas flow through the turbine

Engineering Contradiction:
Improvefuel-air mixingVSAvoidturbine drive load
Core Design Contradiction:
Stability of the object's compositionVSForce

Solution Approach 1:

The waste gate valve acts as an intermediary device that manages the trade-off between fuel-air mixing and turbine drive load. By providing an exhaust bypass path, it allows the system to increase injection amount for improved fuel-air mixing while the valve compensates for the reduced exhaust flow through the turbine by adjusting the bypass amount

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the opening degree parameter of the waste gate valve in response to changes in injection amount. When injection amount increases to improve fuel-air mixing, the valve opening degree increases proportionally to maintain appropriate turbine drive load

Inventive Principle:
Principle #35Parameter changes

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 solution improves combustion stability and fuel economy by reducing turbine drive load and enhancing supercharging effects, ensuring better fuel-air mixing and minimizing fuel deposits.

Implementation Method 1

drives an exhaust turbine by an exhaust gas flowing through an exhaust passage

Methodology Applied
Scientific EffectTurbine: Turbine

Implementation Method 2

supercharges air by a compressor coupled to the exhaust turbine

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

adjusting the boost pressure of the turbocharger

Methodology Applied
Scientific EffectPressure control: Pressure Increase

Data Source

PatentEP3015678B1Engine control device
Publication Date: 2019.11.27 MITSUBISHI MOTORS CORP
  • EP3015678B1 patent drawingFigure 1
  • EP3015678B1 patent drawingFigure 2
  • EP3015678B1 patent drawingFigure 3

AI summary

In a control apparatus of an engine having a first fuel injection valve for injecting fuel into an intake path of the engine, a second fuel injection valve for injecting fuel into a combustion chamber of the engine, a supercharger for supercharging intake air for the engine, and a waste gate valve for opening and closing an exhaust bypass passage for bypassing a turbine of the supercharger, the waste gate valve is controlled to act in a closing direction in response to an increase in the injection amount of fuel injected from the first fuel injection valve, in a region where the injection amount of fuel from the first fuel injection valve is larger than the injection amount of fuel from the second fuel injection valve.