ECU Heat Management via Fuel Injection Segmentation

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Solution Overview

Problem

Internal combustion engine control units (ECUs) face heat-related degradation due to heat buildup from engine components and self-generated heat, which can lead to decreased drive feel and increased engine vibration when reducing engine load to manage heat.

Innovation Solution

Adjusting the number of fuel injections per cylinder event during conditions of ECU over-temperature, such as high engine speeds or loads, and using climate control system overrides to increase airflow around the ECU, while maintaining sufficient fuel delivery to maintain torque and load output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the number of fuel injections per cylinder event is reduced to decrease heat generation in the ECU, then heat-related degradation is reduced, but engine torque output and drive feel may deteriorate

Engineering Contradiction:

ImproveECU temperatureVSAvoidengine torque output

Core Design Contradiction:

TemperatureVSPower

Solution Approach 1:

The patent changes the parameter of injection timing by advancing the injection timing when reducing the number of injections. This allows the combustion process to occur at an optimal point in the compression cycle, maintaining torque output despite fewer injections. The controller adjusts injection timing dynamically based on operating conditions and the reduced injection strategy, ensuring that power delivery requirements are met while achieving heat reduction in the ECU.

Inventive Principle:

Principle #35Parameter changes

2Temperature

If fuel supply to selected cylinders is shut off or reduced to decrease heat generation, then ECU heat buildup is reduced, but engine vibration increases

Engineering Contradiction:

ImproveECU heat buildupVSAvoidengine vibration

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent implements a segmented injection strategy where different cylinders or different injection events are selectively reduced rather than uniformly reducing all injections. By strategically selecting which injections to reduce or eliminate while maintaining others, the system achieves heat reduction in the ECU while preserving sufficient combustion events to maintain smooth engine operation and minimize vibration.

Inventive Principle:

Principle #1Segmentation

3Temperature

If multiple pilot injections and split main injections are combined into fewer injections to reduce heat, then ECU heat generation is reduced, but combustion efficiency may decrease

Engineering Contradiction:

ImproveECU heat generationVSAvoidcombustion efficiency

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic injection strategies where injections are delivered at specifically timed intervals rather than continuously. By consolidating multiple pilot and split main injections into fewer, strategically timed periodic injection events, the system reduces the cumulative heat generation in the ECU while maintaining combustion efficiency through optimized timing and duration of each periodic injection event.

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

Reduces ECU heat generation and temperature, minimizing drive feel reduction and engine vibration, while effectively managing heat-related degradation through targeted fuel injection adjustments and airflow enhancements.

Implementation Method 1

a diesel engine controller with an integrated piezo fuel injector (with a piezo stack) driver circuitry may generate considerable heat in the ECU

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

increasing airflow in or around the ECU and/or its enclosure

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 3

heat from the systems adjacent to an enclosed space in which the ECU is located

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

heat energy generated by the engine and related components may be transferred to the ECU

Methodology Applied

Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentUS7240660B1Heat management for control unit

Publication Date: 2007.07.10 FORD GLOBAL TECH LLC

AI summary

A method of reducing heat generated in a fuel injector driver controlled by an engine control unit (ECU) of a vehicle engine, the injector coupled to the engine, the method comprising of varying a number of fuel injector injections in an engine cycle as a temperature of the ECU varies, where during a first ECU temperature condition said injector performs a first number of injections in an engine cycle, said first number being at least two injections, and during a second temperature condition higher than said first temperature condition said injector performs a second number of injections less than said first number of injection in an engine cycle, said second number being at least one injection.