EGR Valve Control Module for Catalyst Overheating Prevention

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Solution Overview

Problem

Internal combustion engine systems with exhaust gas recirculation face issues where foreign matter like soot can cause the exhaust regulating valve to malfunction, leading to incomplete closure, resulting in overheating of the exhaust purification catalyst and worsened emissions due to insufficient recirculation.

Innovation Solution

Incorporating a closing abnormality detection module and a control module that adjusts fuel injection to increase fuel flow when the exhaust regulating valve is not fully closed, especially during high-load operation, to prevent catalyst overheating and maintain efficient recirculation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If fuel supply amount is corrected to be larger to prevent catalyst overheating, then catalyst temperature control is improved, but fuel consumption increases

Engineering Contradiction:
Improvecatalyst temperatureVSAvoidfuel consumption
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The control module continuously monitors the exhaust regulating valve position and compares it with the target position. When a closing abnormality is detected (valve position deviates from target), the system automatically adjusts fuel injection to increase fuel supply for catalyst temperature control, and reverses the adjustment when the abnormality is resolved, creating a closed-loop feedback system that balances temperature control with fuel efficiency

Inventive Principle:
Principle #23Feedback

2Object-generated harmful factors

If exhaust recirculation is increased to reduce NOx emissions, then emission control is improved, but catalyst overheating risk increases

Engineering Contradiction:
ImproveNOx emissionsVSAvoidcatalyst temperature
Core Design Contradiction:
Object-generated harmful factorsVSTemperature

Solution Approach 1:

The closing abnormality detection module proactively detects potential valve malfunction before it causes complete recirculation failure. When an abnormality is detected, the control module preemptively increases fuel supply to prevent catalyst overheating, rather than waiting for temperature to rise to dangerous levels or recirculation to completely fail

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts fuel injection based on real-time valve position monitoring. The control module continuously modifies the fuel supply amount according to the degree of valve closure abnormality, transitioning smoothly between normal operation and abnormality compensation modes to maintain both emission control and temperature management

Inventive Principle:
Principle #15Dynamics

3Object-generated harmful factors

If exhaust regulating valve is controlled to be totally closed to maximize recirculation, then emission control is improved, but system reliability decreases due to foreign matter accumulation

Engineering Contradiction:
ImproveemissionsVSAvoidvalve operation reliability
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The closing abnormality detection module provides continuous feedback on valve position accuracy. When the valve fails to reach the target closed position due to foreign matter, the system detects this deviation and automatically compensates by adjusting fuel injection, maintaining system reliability without sacrificing emission control performance

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-diagnosis through the closing abnormality detection module that continuously monitors valve position. When foreign matter causes valve malfunction, the system automatically detects and compensates without requiring external intervention, maintaining reliable operation throughout the service life

Inventive Principle:
Principle #25Self-service

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 solution effectively prevents unexpected overheating of the exhaust purification catalyst, thereby reducing emissions and ensuring consistent engine performance even with foreign matter-induced valve malfunctions.

Implementation Method 1

an exhaust purifying catalyst that purifies the exhaust of the internal combustion engine

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

the degree of clogging in an exhaust gas recirculation conduit or the exhaust gas recirculation valve becomes more against the smaller differential pressure between the pressure in the air intake conduit while opening the exhaust recirculation valve and the pressure in the air intake conduit while closing the exhaust recirculation valve

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP2284377B1Internal combustion device, control method thereof, and vehicle
Publication Date: 2012.07.25 TOYOTA JIDOSHA KK
  • EP2284377B1 patent drawingFigure 1
  • EP2284377B1 patent drawingFigure 2
  • EP2284377B1 patent drawingFigure 3~4

AI summary

Upon no detection of the closing abnormality where the EGR valve does not become in the totally closed state (when the flag Fa is value '0'), the engine is controlled using the target fuel injection amount Qf* obtained from the correction of the basic fuel injection amount Qftmp toward the increase direction, in the case that the engine is operated together with the recirculation of the exhaust in the preset high-load operation range (when the flag Fi is '1') (S220, S230, S250 and S260). Upon detection of the closing abnormality (when the flag Fa is value '1'), the engine is controlled using the target fuel injection amount Qf* obtained from the correction of the basic fuel injection amount Qftmp toward the increase direction, in the case that the engine is operated together with the recirculation of the exhaust in the whole range that the engine is operable together with the recirculation of the exhaust (S220, S250, S260).