Compression Ignition Engine Fuel Injection Control for Resonance Avoidance
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Solution Overview
Problem
Compression ignition engines, such as diesel engines, face challenges in reducing resonance-induced vibrations and torque fluctuations after passing through the resonance speed range, which can lead to increased vibration levels and potential resonance induction.
Innovation Solution
A method and system for controlling a compression ignition engine that adjusts fuel injection amounts based on engine speed, setting a higher injection amount when the engine speed is below the resonance range and reducing it afterwards to minimize torque fluctuations and resonance induction, using a fuel injection valve to supply fuel into the combustion chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a relatively large fuel injection amount is set from the start of the engine to the completion of the start, then the engine speed can quickly pass through the resonance speed range, but resonance may be induced after passing through the resonance speed range and the vibration level may be relatively increased
Solution Approach 1:
The fuel injection amount is dynamically adjusted based on the engine speed relative to the resonance speed range. The control system switches between a first fuel injection amount (when engine speed is below the resonance speed range) and a second fuel injection amount (when engine speed is above the resonance speed range), making the injection amount adaptive to the current operating condition to avoid resonance while ensuring quick start-up
Solution Approach 2:
The patent changes the fuel injection amount parameter based on the engine speed parameter. By detecting whether the engine speed is above or below the resonance speed range, the system adjusts the fuel injection amount between two distinct values, using parameter change to resolve the contradiction between quick start-up and resonance avoidance
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
This approach effectively reduces the influence of resonance and vibration levels by managing fuel injection amounts to stabilize engine speed and torque, ensuring smooth operation beyond the resonance speed range.
Implementation Method 1
a compression ignition engine having a fuel injection valve which supplies fuel into a combustion chamber
Data Source
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AI summary
A system for controlling a compression ignition engine includes: a speed obtaining section (102) which obtains an engine speed; and an injection amount setting section (105) which sets, in a start period after the start of cranking, a fuel injection amount to be injected by injectors (6) in next and subsequent cycles. If an engine speed achieved by combustion in an (n - 1)-th cycle is higher than or equal to a determination threshold value (R0) and lower than a lower limit (R1) of the resonance range (Br), the injection amount setting section (105) sets the fuel injection amount for the n-th cycle to a jump-over injection amount (F2), and sets the fuel injection amount for the (n + 1)-th cycle to a resonance induction reducing amount (F3), which is smaller than the jump-over injection amount (F2).