Fuel Injection Control Device Current Increase Speed Correction

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Solution Overview

Problem

In partial lift injection, the fuel injection quantity cannot be controlled with high accuracy due to variations in electromagnetic coil resistance and current increase speed with temperature, leading to an invalid injection period and varying injection characteristics.

Innovation Solution

A fuel injection control device that includes a detection unit for current increase speed, a correction value calculation unit to adjust the requested injection quantity based on detected speed, and a conduction time calculation unit to optimize conduction time for the electromagnetic coil, ensuring accurate fuel injection quantity control despite temperature variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If partial lift injection is used to reduce injection quantity, then fuel injection flexibility is improved, but injection quantity control accuracy deteriorates due to temperature variations in electromagnetic coil

Engineering Contradiction:
Improveinjection flexibilityVSAvoidinjection quantity control accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by detecting the current increase speed of the electromagnetic coil and using this parameter to calculate a correction value for the conduction time. The control unit adjusts the conduction time based on the detected current increase speed, which varies with temperature, thereby maintaining accurate injection quantity control across different temperature conditions while preserving partial lift injection flexibility

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback by detecting the actual current increase speed of the electromagnetic coil during operation and using this detected value to correct the conduction time. The control unit continuously monitors the current increase speed and adjusts the injection timing accordingly, creating a closed-loop control system that compensates for temperature-induced variations and maintains injection accuracy

Inventive Principle:
Principle #23Feedback

2Reliability

If conduction time is extended to ensure sufficient electromagnetic force, then valve opening reliability is improved, but invalid injection period increases reducing injection efficiency

Engineering Contradiction:
Improvevalve opening reliabilityVSAvoidinjection efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by making the conduction time variable rather than fixed. The control unit dynamically adjusts the conduction time based on the real-time detected current increase speed of the electromagnetic coil. When current increases slowly (cold conditions), conduction time is extended to ensure reliable valve opening. When current increases quickly (warm conditions), conduction time is reduced to minimize the invalid injection period, thereby optimizing both reliability and efficiency dynamically

Inventive Principle:
Principle #15Dynamics

3Temperature

If electromagnetic coil resistance varies with temperature, then electromagnetic force generation is affected, but this natural physical behavior cannot be avoided

Engineering Contradiction:
Improvecoil temperatureVSAvoidinjection characteristic consistency
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The patent uses feedback to counteract the natural temperature-induced resistance changes in the electromagnetic coil. By detecting the current increase speed, which reflects the actual coil resistance at any given temperature, the system calculates an appropriate conduction time correction value that compensates for the resistance variation, maintaining consistent injection characteristics across the operating temperature range

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent compensates for temperature-induced resistance changes by dynamically changing the conduction time parameter based on the detected current increase speed. This parameter adjustment ensures that despite natural variations in electromagnetic force generation due to temperature, the actual fuel injection quantity remains consistent and accurate

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 enables precise control of fuel injection quantity in partial lift injection by accounting for temperature-induced changes in electromagnetic coil behavior, reducing the impact of invalid injection periods and improving the accuracy of fuel injection.

Implementation Method 1

a valve body to open and close an injection hole to inject a fuel and an electric actuator that has an electromagnetic coil and a movable core to move by being attracted by an electromagnetic force generated by conducting the electromagnetic coil

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP3453862B1Fuel injection control device
Publication Date: 2020.07.29 DENSO CORP
  • EP3453862B1 patent drawingFigure 1
  • EP3453862B1 patent drawingFigure 2
  • EP3453862B1 patent drawingFigure 3

AI summary

A fuel injection control device has a detection unit (56), a correction value calculation unit (S12, S13), and a conduction time calculation unit (S15). The detection unit detects a current increase speed that is a speed of increasing an electric current flowing in an electromagnetic coil in accordance with the start of conducting the electromagnetic coil during partial lift injection in which a valve body starts valve closing operation before the valve body reaches a maximum valve opening position after the valve body starts valve opening operation. The correction value calculation unit calculates a correction value for a requested injection quantity on the basis of the detected current increase speed. The conduction time calculation unit calculates a conduction time of the electromagnetic coil during the partial lift injection on the basis of the requested injection quantity corrected by the correction value.