Direct-Injection Engine Fuel Control for Stable Purge
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Solution Overview
Problem
Existing fuel injection control methods for direct-injection internal combustion engines struggle to maintain stable fuel injection without restricting the purge process, leading to potential vaporized fuel discharge into the atmosphere.
Innovation Solution
A control method that switches between multiple-stage and single-stage fuel injection based on the operating region, narrowing the multiple-stage injection region when excess evaporated fuel is supplied, ensuring injection pulse widths remain above the minimum stable width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the amount of purge is restricted to maintain minimum pulse width, then fuel injection stability is improved, but vaporized fuel discharge to atmosphere increases
Solution Approach 1:
The patent applies dynamics by making the injection strategy adaptive rather than fixed. The control device dynamically switches between multiple-stage injection and single-stage injection based on real-time operating conditions (engine load, speed, purge amount). This allows the system to optimize injection pulse widths for stability while accommodating varying purge amounts that prevent vaporized fuel discharge to atmosphere.
Solution Approach 2:
The patent changes the injection parameter (injection stage configuration) based on operating conditions. By switching between multiple-stage and single-stage injection modes, the system adjusts the injection pulse width characteristics to maintain stability even when purge amounts vary, thereby allowing maximum purge without atmospheric discharge.
2Object-generated harmful factors
If multiple-stage injection is used to reduce particulate number, then emission is improved, but injection pulse width may fall below minimum stable width
Solution Approach 1:
The system dynamically selects between multiple-stage and single-stage injection based on operating conditions. When engine load and speed indicate suitable conditions, multiple-stage injection is used to reduce particulate number. When purge amounts or other parameters suggest risk of pulse width falling below minimum, the system switches to single-stage injection to maintain stability.
Solution Approach 2:
The injection strategy parameter (number of stages) is changed based on operating conditions. The control device monitors engine load, speed, and purge amount to determine when to switch between injection modes, optimizing the balance between particulate reduction and injection stability.
3Reliability
If single-stage injection is used to maintain minimum pulse width, then fuel injection stability is improved, but particulate number increases
Solution Approach 1:
Rather than permanently using single-stage injection, the system dynamically switches to multiple-stage injection when operating conditions permit. This allows the system to achieve lower particulate numbers during suitable operating conditions while maintaining stability during conditions where purge amounts or other parameters require larger pulse widths.
Data Source
AI summary
A direct-injection internal combustion engine is controlled such that an injection count of multiple-stage injection is switched according to an operating region, and the multiple-stage injection is performed. The multiple-stage injection divides fuel into multiple times in one combustion cycle, and injects the fuel. Fuel vapor generated in a fuel tank as evaporated fuel is supplied to the internal combustion engine. An operating region in which the injection count of the multiple-stage injection is large is controlled to be narrower when an amount of the evaporated fuel supplied to the internal combustion engine is large, compared with a case of the amount of the evaporated fuel being not large.