HCCI Engine Cylinder Combustion Control via Sensor Feedback

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Solution Overview

Problem

Homogeneous charge compression ignition (HCCI) internal combustion engines face challenges in controlling ignition and combustion across multiple cylinders, leading to variations in combustion states and a limited operating range due to difficulties in controlling self-ignition, which complicates the engine structure and control mechanisms.

Innovation Solution

The implementation of sensors to detect combustion states, a control apparatus that adjusts valve timing and fuel injection for each cylinder, and the selective use of assisted ignition by spark plugs to maintain consistent combustion states across all cylinders, thereby reducing variations and expanding the engine's operating range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If individual valve timing and fuel injection control is implemented for each cylinder, then combustion state consistency is improved, but device complexity increases

Engineering Contradiction:

Improvecombustion state consistencyVSAvoidcontrol structure complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The control system is segmented by implementing individual valve timing control and fuel injection control for each cylinder separately, allowing independent adjustment of combustion parameters in each cylinder to achieve consistent combustion states across all cylinders

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different valve timing and fuel injection parameters are applied locally to each cylinder based on its specific combustion state, enabling precise control of combustion characteristics in each cylinder to maintain overall consistency

Inventive Principle:

Principle #3Local quality

2Stability of the object's composition

If individual valve timing and fuel injection control is implemented for each cylinder, then combustion state consistency is improved, but manufacturing cost increases

Engineering Contradiction:

Improvecombustion state consistencyVSAvoidmanufacturing simplicity

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

3Use of energy by moving object

If HCCI operation is maintained in all cylinders, then fuel efficiency is improved, but combustion control difficulty increases

Engineering Contradiction:

Improvefuel efficiencyVSAvoidcombustion control difficulty

Core Design Contradiction:

Use of energy by moving objectVSEase of operation

Solution Approach 1:

The control system adjusts combustion parameters including valve timing, fuel injection timing, and fuel injection amount for each cylinder to maintain HCCI operation within the optimal combustion range, achieving both high fuel efficiency and controllable combustion

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

This approach allows for efficient operation with reduced NOx emissions by ensuring consistent combustion states across all cylinders, eliminating the need for complex structures that vary valve timing and fuel injection for each cylinder, thus enhancing engine efficiency and emission control.

Implementation Method 1

fuel and air is premixed before reaching cylinders. The mixture is compressed by pistons to self-ignite

Methodology Applied

Scientific EffectCombustion: Combustion

Implementation Method 2

controls at least one of the valve timing of intake valves (14) and exhaust valves (15)

Methodology Applied

Scientific EffectValve timing control: Valve

Implementation Method 3

controls at least one of the valve timing of intake valves (14) and exhaust valves (15), and a fuel injection amount

Methodology Applied

Scientific EffectFuel injection: Injector

Implementation Method 4

the spark plugs (32) which perform assisted ignition

Methodology Applied

Scientific EffectElectrical discharge ignition: Electric Spark

Implementation Method 5

The mixture is compressed by pistons to self-ignite

Methodology Applied

Scientific EffectCompression ignition: Compression

Data Source

PatentUS7210457B2Homogeneous charge compression ignition internal combustion engine

Publication Date: 2007.05.01 TOYOTA INDUSTRIES CORP

AI summary

An engine includes cylinders, a sensor for detecting information related to combustion states of the cylinders. Each cylinder is provided with an ignition device, an intake valve, and an exhaust valve. The engine also includes a control apparatus that obtains the information from the sensor. Based on the information from the sensor, the control apparatus identifies a cylinder of the most violent combustion. The control apparatus controls at least one of the valve timing of the intake valves, the valve timing of the exhaust valves, and a fuel injection amount to the cylinders, thereby suppressing the combustion of all the cylinders, such that the combustion state of the identified cylinder becomes an appropriate combustion state. As for a cylinder the combustion state of which is out of a predetermined range and is a state causing misfire, the control apparatus selectively activates the corresponding ignition device to perform assisted ignition. This configuration reduces variation in the combustion states among the cylinders.