Fuel Injection Valve Closing Time Detection Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In injection control systems for internal combustion engines, accurately learning the valve closing time is challenging due to overlapping injections between cylinders, which can lead to inaccuracies in fuel injection and increased manufacturing costs from additional detection circuits.
Innovation Solution
An injection control device is configured with an energization instruction switch, cylinder designation switches, a valve closing detection unit, and a stage number designation unit to selectively measure and learn the valve closing time, avoiding the need for multiple detection circuits and reducing calculation and communication loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple detection circuits are added to accurately detect valve closing time for each cylinder, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The single valve closing detection circuit is designed to universally detect valve closing times for multiple cylinders by selectively monitoring different cylinders at different times. The control unit switches the detection circuit between cylinders based on injection timing, allowing one circuit to perform the function of multiple circuits would otherwise be needed.
Solution Approach 2:
The detection circuit operates periodically, selecting different cylinders for detection at different time intervals. The control unit switches which cylinder is being monitored based on the injection schedule, creating a periodic detection pattern that covers all cylinders over time without requiring simultaneous detection of all cylinders.
2Measurement precision
If valve closing detection is performed for all cylinders simultaneously, then measurement precision is improved, but calculation load and communication load increase
Solution Approach 1:
The valve closing detection process is segmented into separate time intervals for different cylinders. Instead of processing all cylinder data simultaneously, the system divides the detection into discrete segments, learning valve closing times for one cylinder at a time based on its specific injection timing, thereby reducing the simultaneous calculation and communication load.
Solution Approach 2:
The control unit preliminarily determines which cylinder should be detected next based on predicted injection timing before the actual detection occurs. By anticipating which cylinder will need detection and preparing the detection circuit in advance, the system optimizes the timing and reduces processing delays.
Data Source
AI summary
A first switch designates one of energization instruction signals to designate a valve closing detection cylinder. A valve closing detection unit monitors downstream voltages of the fuel injection valves to detect occurrence of an inflection point in change of the downstream voltages and detects valve closing. A second switch designates one of the downstream voltages and designates the valve closing detection cylinder. A stage number designation unit designates a valve closing detection stage number. A valve closing time measuring unit measures a valve closing time, which is from a switching timing at which the energization instruction signal is switched from ON to OFF to a valve closing detection timing of the valve closing, for injection of the valve closing detection stage number of the valve closing detection cylinder. A valve closing time learning unit learns the valve closing time measured by the valve closing time measuring unit.