Engine Timing Map Control for Fuel Efficiency and Stable Combustion

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Solution Overview

Problem

Existing engine control methods do not optimize fuel efficiency while considering various restrictions such as preignition, knocking, and combustion stability, leading to suboptimal performance.

Innovation Solution

A method for controlling an engine by selecting a control point on a parameter map that combines injection timing and ignition timing, within a defined parameter region bounded by limit lines for preignition, smoke, knocking, and combustion stability, allowing the ignition timing to be maximally advanced within these constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the ignition timing is advanced to improve fuel efficiency, then fuel efficiency is improved, but preignition and knocking occur

Engineering Contradiction:
Improvefuel efficiencyVSAvoidpreignition and knocking
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the ignition timing and injection timing adjustable and interrelated. The control device dynamically adjusts the ignition timing based on the injection timing and operating conditions, allowing the system to adapt to different states. This is evident in the parameter map that defines different ignition timing settings based on injection timing and engine operating conditions, enabling optimal fuel efficiency while avoiding preignition and knocking through continuous adaptation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs parameter changes by modifying ignition timing and injection timing parameters based on operating conditions. The control device uses a parameter map that correlates injection timing with optimal ignition timing settings, allowing systematic adjustment of these parameters to achieve maximum fuel efficiency while preventing harmful combustion events. The parameter map contains pre-calculated optimal settings that change based on engine load, speed, and temperature conditions.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the injection timing is advanced to improve fuel efficiency, then fuel efficiency is improved, but combustion stability deteriorates

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

Solution Approach 1:

The patent implements feedback control by using a control device that monitors engine operating conditions and adjusts ignition timing and injection timing accordingly. The system receives feedback from sensors monitoring engine load, speed, temperature, and combustion characteristics, then references the parameter map to determine optimal timing settings. This closed-loop control ensures combustion stability is maintained while optimizing fuel efficiency, as the system continuously adapts to changing conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the relationship between injection timing and ignition timing based on real-time operating conditions. The parameter map provides a framework for dynamic control, where the optimal ignition timing is not fixed but varies with injection timing and engine state. This dynamic adjustment allows the system to maintain combustion stability across different operating ranges while maximizing fuel efficiency.

Inventive Principle:
Principle #15Dynamics

3Reliability

If multiple restrictions (preignition limit, smoke limit, knocking limit, retard limit) are considered, then combustion quality is improved, but control complexity increases

Engineering Contradiction:
Improvecombustion qualityVSAvoidcontrol complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple control functions into a single integrated control device that simultaneously manages injection timing and ignition timing. The parameter map consolidates multiple restriction limits (preignition, smoke, knocking, retard limits) into a unified control framework. By combining these controls and using the parameter map as a reference, the system simplifies the control process while ensuring all combustion quality requirements are met, reducing overall control complexity despite the multiple constraints.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control device performs multiple functions through a single system: it manages injection timing, ignition timing, and enforces multiple combustion limits simultaneously. The parameter map serves as a universal control tool that provides optimal settings for various operating conditions while incorporating all restriction limits. This multi-functional approach reduces the need for separate control systems for each parameter, simplifying the overall control architecture while maintaining high combustion quality.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 optimizes fuel efficiency by balancing engine performance with various restrictions, ensuring stable combustion and minimizing adverse effects like preignition and knocking.

Implementation Method 1

a spark plug that ignites an air-fuel mixture containing the fuel injected from the injector

Methodology Applied
Scientific EffectElectrical discharge ignition: Electric Spark

Implementation Method 2

an injector that injects fuel into the cylinder

Methodology Applied
Scientific EffectFuel injection: Injector

Data Source

PatentEP4585797A1Method for controlling engine and engine system
Publication Date: 2025.07.16 MAZDA MOTOR CORP
  • EP4585797A1 patent drawingFigure 1
  • EP4585797A1 patent drawingFigure 2
  • EP4585797A1 patent drawingFigure 3

AI summary

A method includes a step of selecting a control point consisting of a combination of an injection timing of injecting fuel and an ignition timing of igniting an air-fuel mixture, corresponding to a selection on a parameter map Mlim having the injection timing as a first axis and the ignition timing as a second axis, defines a parameter region Rlim surrounded by a first limit line Li1 indicating an advance limit at which preignition is restrained, a second limit line Li2 indicating an advance limit at which smoke is restrained, a third limit line Li3 indicating an advance limit at which knocking is restrained, and a fourth limit line Li4 indicating a retard limit at which combustion stability is ensured on the parameter map Mlim, and further includes a step of selecting the control point so that the ignition timing is brought to maximum advance within the parameter region Rlim.