Engine Controller Port Injection Ratio Adjustment

Solution Overview

Problem

In internal combustion engines with forced induction, fuel blow-through occurs when the port injection valve injects fuel during a valve overlap period, leading to insufficient fuel delivery before the intake valve closes, especially when the port injection ratio is high.

Innovation Solution

A controller adjusts the port injection ratio to be smaller and delays the start timing of fuel injection from the port injection valve when forced induction is performed and the valve overlap period is greater than zero, using a two-stage treatment to ensure adequate fuel injection without blow-through.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fuel injection from the port injection valve is started after the end of the valve overlap period to prevent fuel blow-through, then fuel blow-through is prevented, but the port injection valve may not be able to inject the required fuel amount before the intake valve is closed

Engineering Contradiction:

Improvefuel blow-through preventionVSAvoidfuel injection amount

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The control device dynamically adjusts the port injection ratio based on operating conditions (intake air amount, engine speed, acceleration state). When acceleration is detected, the port injection ratio is increased to ensure sufficient fuel delivery even with delayed injection timing. This dynamic adjustment resolves the contradiction by adapting the injection strategy to real-time engine demands.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the port injection ratio parameter according to different operating regions and acceleration states. By modifying this key parameter, the system can prevent fuel blow-through in steady-state conditions while ensuring adequate fuel supply during acceleration, thus resolving the contradiction between blow-through prevention and fuel delivery requirements.

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If the port injection ratio is increased to ensure sufficient fuel delivery before intake valve closure, then fuel delivery is improved, but fuel blow-through occurs during the valve overlap period when forced induction is active

Engineering Contradiction:

Improvefuel injection amountVSAvoidfuel blow-through

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The control device dynamically adjusts the port injection ratio based on operating conditions (intake air amount, engine speed, acceleration state). When acceleration is detected, the port injection ratio is increased to ensure sufficient fuel delivery even with delayed injection timing. This dynamic adjustment resolves the contradiction by adapting the injection strategy to real-time engine demands.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The control device uses feedback from sensors (intake air amount sensor, engine speed sensor, acceleration sensor) to determine the appropriate port injection ratio. This closed-loop control ensures that fuel injection is optimized based on actual engine conditions, preventing both fuel blow-through and insufficient fuel delivery.

Inventive Principle:

Principle #23Feedback

3Reliability

If the start timing of fuel injection from the port injection valve is delayed to prevent fuel blow-through, then fuel blow-through is prevented, but the injection duration is reduced which may insufficiently meet fuel requirements

Engineering Contradiction:

Improvefuel blow-through preventionVSAvoidinjection duration

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system changes the port injection ratio parameter according to different operating regions and acceleration states. By modifying this key parameter, the system can prevent fuel blow-through in steady-state conditions while ensuring adequate fuel supply during acceleration, thus resolving the contradiction between blow-through prevention and fuel delivery requirements.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The control device dynamically adjusts the port injection ratio based on operating conditions (intake air amount, engine speed, acceleration state). When acceleration is detected, the port injection ratio is increased to ensure sufficient fuel delivery even with delayed injection timing. This dynamic adjustment resolves the contradiction by adapting the injection strategy to real-time engine demands.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11965473B2Controller and control method for internal combustion engine

Publication Date: 2024.04.23 TOYOTA JIDOSHA KK

AI summary

An internal combustion engine includes a port injection valve, a direct injection valve, and a forced-induction device. A ratio of an amount of fuel injected from the port injection valve with respect to a total amount of fuel supplied for one fuel combustion in the cylinder is defined as a port injection ratio. The internal combustion engine is controlled such that, in a case in which a condition is satisfied that the forced-induction device is in an operation of performing forced induction and the internal combustion engine is in an engine operation region in which a valve overlap period is greater than zero, the port injection ratio is set to be small and a start timing of fuel injection from the port injection valve is delayed as compared with a case in which the condition is not satisfied.