Multi-Port Injection Resuming via Intake Stroke Torque
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Solution Overview
Problem
The existing multi-port injection (MPI) system experiences engine RPM drops during fuel cut-in due to fuel injection timing calculated in the exhaust stroke, leading to inefficient fuel usage and engine performance.
Innovation Solution
The method involves resuming fuel injection in the intake stroke of the engine, using the earliest cylinder that does not pass through the injection abortion angle, with immediate start of ignition (SOI) injection followed by exhaust injection based on the end of injection (EOI) command angle, minimizing RPM drops and improving fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fuel injection angle is calculated in exhaust stroke, then injection timing can be determined, but engine RPM drops occur due to delayed refueling
Solution Approach 1:
The patent performs preliminary calculation of the injection angle during the exhaust stroke, then executes the fuel injection during the intake stroke. This preliminary action ensures that the injection timing is predetermined with high precision while enabling earlier actual injection execution, thus resolving the contradiction between timing accuracy and RPM stability.
2Manufacturing precision
If refueling is performed at EOI command angle, then injection timing is precise, but refueling occurs behind one or two cylinders causing RPM drop
Solution Approach 1:
The injection angle is preliminarily calculated during the exhaust stroke, allowing the system to prepare the precise injection timing in advance. This enables the actual fuel injection to be executed during the intake stroke at the optimal moment, preventing delayed refueling and subsequent RPM drops.
Solution Approach 2:
The patent dynamically adjusts the injection timing by performing refueling during the intake stroke rather than strictly at the EOI command angle. This dynamic adjustment allows the system to adapt to different cylinder positions and engine states, ensuring timely refueling across all cylinders while maintaining injection precision.
3Productivity
If engine RPM is set high at fuel cut-in, then RPM drop problem is resolved, but fuel efficiency deteriorates
Solution Approach 1:
By preliminarily calculating injection timing during the exhaust stroke and executing injection during the intake stroke, the system ensures timely refueling that stabilizes engine RPM without requiring high RPM settings. This resolves the contradiction between RPM stability and fuel efficiency.
Solution Approach 2:
The patent ensures continuous and timely fuel injection during the intake stroke, maintaining steady engine operation without RPM fluctuations. This continuous useful action eliminates the need to maintain high RPM for stability, thereby improving fuel efficiency while keeping RPM stable.
Data Source
AI summary
A method of resuming multi-port injection using an intake stroke of an engine includes performing a first refueling with immediate start of ignition injection at the time when an injection abortion angle does not pass through an intake stroke, when injection is determined to be resumed after coasting by a controller. The method can minimize an engine RPM drop caused by the early generation of torque. The method improves fuel efficiency while being advantageous to calibration of the engine by setting the engine RPM to be low at the time of fuel cut-in.