Fuel Injection Control Under Low Boost Voltage
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Solution Overview
Problem
Conventional fuel injection systems for internal-combustion engines face challenges in maintaining multiple injections due to cost limitations of the control circuit, requiring a simple configuration that can adjust fuel injection conditions even when setup parameters are lowered.
Innovation Solution
A fuel injection system with an engine control unit, booster circuit, boost voltage driver, driver IC, and controller that extends the valve open time of the fuel injection valve when the boost voltage is below a predefined normal voltage, ensuring reliable multiple injections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of multiple injections is increased to meet growing demands, then fuel injection performance is improved, but control circuit complexity and cost increase
Solution Approach 1:
The patent combines the voltage boosting function and fuel injection control into a single integrated control circuit. The booster circuit generates a boosted voltage from the battery voltage, and this boosted voltage is used by the fuel injection valve driver to control multiple injections. This integration allows the system to achieve multiple injection capability without requiring separate complex control circuits for each injection event, thereby reducing overall circuit complexity while maintaining the ability to perform multiple injections.
Solution Approach 2:
The patent implements dynamic control of the fuel injection valve by adjusting the valve open time based on the boosted voltage level. The control circuit dynamically modifies the injection parameters (valve open time Pi) in response to changing voltage conditions, allowing the system to adaptively provide multiple injections with varying durations. This dynamic adjustment enables flexible multiple injection strategies without requiring additional hardware complexity.
2Use of energy by moving object
If the boost voltage is lowered to reduce power consumption or cost, then energy efficiency is improved, but the ability to maintain required number of multiple injections deteriorates
Solution Approach 1:
The patent changes the voltage parameter by using a booster circuit to generate a boosted voltage from the battery voltage. Even when the battery voltage is lowered to reduce power consumption, the booster circuit compensates by transforming it into a sufficiently high boosted voltage. This parameter transformation allows the system to maintain the required number of multiple injections with lower input power, effectively decoupling power consumption from injection capability.
Solution Approach 2:
The control circuit monitors the boosted voltage level and adjusts the valve open time Pi accordingly. When the boosted voltage is sufficient, the controller can maintain the required number of multiple injections. This feedback mechanism ensures that even with variable or reduced input voltage, the system can adaptively maintain reliable multiple injection performance by adjusting control parameters based on real-time voltage conditions.
3Reliability
If the valve open time is extended to compensate for low boost voltage, then injection reliability is improved, but injection timing precision deteriorates
Solution Approach 1:
The patent implements dynamic adjustment of the valve open time Pi based on the actual boosted voltage level. Rather than using a fixed extended valve open time, the control circuit dynamically calculates and applies the appropriate valve open time duration needed to achieve the required fuel injection quantity at the current voltage level. This dynamic control maintains injection timing precision while ensuring sufficient valve open time for reliable injection even at lower voltages.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system provides the maximum possible number of injections even when the boost voltage is lowered, maintaining injection characteristics without increasing circuit complexity or cost.
Implementation Method 1
a booster circuit that boosts the voltage of the battery to generate a boost voltage for the engine control unit
Implementation Method 2
a fuel injection valve electromagnetically driven to provide multiple fuel injection to a combustion chamber
Data Source
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AI summary
Disclosed is a fuel injection system that is used with an internal-combustion engine 1 to reliably perform a requested fuel injection operation a requested number of times even when a boost voltage is lowered. The fuel injection systemmonitors the boost voltage immediatelybefore the start of fuel injection, and varies a valve open time in accordance with the monitored boost voltage. Even when the boost voltage is lowered, the fuel injection system performs a fuel injection operation the requested number of times.