Fuel Injection Timing Control for Engine Drivability
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Solution Overview
Problem
Conventional fuel injection systems face challenges in balancing fuel economy and drivability, particularly when the driver accelerates, as the timing of main injection struggles to meet expected acceleration demands.
Innovation Solution
A fuel injection control system that includes a throttle valve opening detector, crank angle detector, and fuel injection controller, which calculates the rate of change in throttle valve opening values to adjust the fuel injection timing from a first timing after intake valve closure to a second timing preceding intake valve opening, or during intake valve opening, based on acceleration conditions, thereby enhancing both fuel economy and drivability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If fuel injection is controlled at a first timing following closing of the intake valve to prioritize fuel economy, then fuel economy is improved, but drivability and acceleration response deteriorate when the driver accelerates
Solution Approach 1:
The fuel injection timing is made dynamically adjustable based on detected driving conditions. The controller switches between a first timing (following intake valve closure) for fuel economy and a second timing (preceding intake valve opening) for acceleration, allowing the system to adapt to varying driver demands and optimize both fuel economy and drivability
Solution Approach 2:
The system changes the fuel injection timing parameter based on detected throttle valve opening changes. When the throttle valve opening increases by a predetermined amount or more, the controller switches to the second timing to provide better acceleration response, while maintaining the first timing under normal operating conditions to optimize fuel economy
2Use of energy by moving object
If fuel injection timing is fixed at a first timing following intake valve closure, then fuel economy is optimized, but the system cannot respond adequately to sudden acceleration demands
Solution Approach 1:
The system performs preliminary detection of throttle valve opening changes to anticipate acceleration demands. When the throttle valve opening increases by a predetermined amount, the controller proactively switches to the second fuel injection timing before the driver fully demands acceleration, ensuring smooth and responsive acceleration while maintaining fuel efficiency during normal operation
Data Source
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AI summary
A fuel injection control system and a program for achieving a fuel injection are provided for enhancing both fuel economy and drivability. A fuel injection controller (52) of a fuel injection control system (10) judges opening and closing states of an intake valve (36) provided in an engine (22) on the basis of a rotational angle value of a crankshaft (44); judges whether fuel injection is in a fuel economy prioritized condition or in an acceleration transition condition on the basis of detected opening values of a throttle valve (20); controls a fuel injector (26), thereby causing the fuel injector (26) to inject fuel at a first timing following the closing of the intake valve (36) while in the fuel economy prioritized condition; and controls the fuel injector (26), thereby causing the fuel injector (26) to inject the fuel at a second timing preceding the opening of the intake valve (36), or both at the first timing and sometime during the opening of the intake valve (36) when judging as being in the fuel economy prioritized condition. The second timing is a timing later than the first timing in an interval of time from the first timing to the opening of the intake valve (36).