Engine Control Device for Filter Temperature Management

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Solution Overview

Problem

Existing internal combustion engine systems face challenges in maintaining filter temperature within a safe range during particulate matter regeneration, leading to potential filter deterioration due to excessive temperature rises when secondary air is introduced in large amounts.

Innovation Solution

A control device that alternates between regeneration and temperature raising processes, adjusting air-fuel ratios and secondary air flow rates to maintain the filter temperature within a safe range, ensuring efficient particulate matter removal without excessive temperature increases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If secondary air is introduced in a large amount to raise filter temperature to regeneration temperature, then particulate matter can be burned off, but the filter temperature will excessively rise and the filter will be deteriorated

Engineering Contradiction:
Improvefilter temperatureVSAvoidfilter durability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The control device alternates between temperature raising process (introducing secondary air to burn particulate matter) and temperature control process (reducing or stopping secondary air introduction to prevent excessive temperature rise). This periodic switching between two operational states allows the system to achieve regeneration while preventing filter deterioration from excessive heat

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The control device monitors the filter temperature and adjusts the secondary air flow rate accordingly. When the temperature reaches the regeneration threshold, the control device switches from temperature raising mode to temperature control mode, reducing secondary air flow to maintain temperature within a safe range. This feedback-based control prevents excessive temperature rise while ensuring effective regeneration

Inventive Principle:
Principle #23Feedback

2Productivity

If secondary air flow rate is increased to ensure complete particulate matter removal, then regeneration efficiency improves, but temperature control becomes difficult and filter deterioration risk increases

Engineering Contradiction:
Improveregeneration efficiencyVSAvoidtemperature control difficulty
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The control device dynamically adjusts the secondary air flow rate based on the current operational phase and temperature conditions. During the temperature raising process, secondary air is introduced at a higher flow rate to efficiently burn particulate matter. When the temperature approaches the regeneration threshold, the flow rate is dynamically reduced to maintain temperature control. This dynamic adjustment optimizes both regeneration efficiency and temperature control

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system periodically switches between high flow rate operation (temperature raising) and low flow rate operation (temperature control), allowing efficient particulate matter removal while preventing excessive temperature rise that would make control difficult and risk filter deterioration

Inventive Principle:
Principle #19Periodic action

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

Effectively removes particulate matter from the filter while preventing excessive temperature rises, thereby extending the filter's lifespan and maintaining engine performance.

Implementation Method 1

unburned fuel in the exhaust gas reacts with the air and burns whereby the temperature of the filter can be raised to equal to or more than a regeneration temperature

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

the particulate matter deposited on the filter will react with the oxygen

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP3636892B1Control device of internal combustion engine, internal combustion engine, and vehicle
Publication Date: 2021.04.28 TOYOTA JIDOSHA KK
  • EP3636892B1 patent drawingFigure 1
  • EP3636892B1 patent drawingFigure 2A~2B
  • EP3636892B1 patent drawingFigure 3

AI summary

An internal combustion engine comprises a filter 24 and is configured to enable attachment of a secondary air feed system 26 feeding air into exhaust gas flowing into the filter. A control device of the engine is configured, in the PM removal control for removing particulate matter deposited on the filter, to perform temperature raising processing for controlling the engine so that the air-fuel ratio of the exhaust gas discharged from the engine body 1 is a rich air-fuel ratio and for feeding air from the secondary air feed system, and to perform regeneration processing for controlling the engine so that the air-fuel ratio of the exhaust gas discharged from the engine body is a stoichiometric air-fuel ratio and for feeding air from the secondary air feed system so that the air-fuel ratio of the exhaust gas flowing into the filter is a lean air-fuel ratio.