Engine Combustion Control for Vibration Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control devices for internal combustion engines struggle to maintain a two-peak pressure waveform shape due to deviations in ignition timing, leading to increased combustion noise when the peak interval deviates from a predetermined interval, resulting in ineffective vibration reduction.
Innovation Solution
A control device that includes a combustion control system using a fuel injector and vibration sensor to adjust fuel injection amounts and timings based on engine state, ensuring a two-peak pressure waveform by calculating vibration levels at specific frequency bands and correcting injection parameters to maintain the target peak interval, thereby suppressing vibration acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the peak interval is controlled to a predetermined interval to reduce vibration acceleration, then combustion noise is reduced, but if ignition timing deviates from target timing, the pressure waveform shape changes and the peak interval can no longer be controlled, causing combustion noise to increase
Solution Approach 1:
The patent applies feedback control by detecting the actual peak interval from the pressure waveform and comparing it with the target peak interval. When a deviation is detected, the system adjusts the injection timing to correct the peak interval, ensuring stable vibration reduction even when ignition timing varies. This closed-loop feedback mechanism resolves the contradiction by making the peak interval control reliable despite ignition timing deviations.
2Reliability
If the pressure waveform shape is not corrected after ignition timing deviation, then the peak interval deviates from the reference interval, but correcting the shape is necessary to maintain vibration reduction efficacy
Solution Approach 1:
The system uses feedback control to detect deviations in the pressure waveform shape and automatically adjusts injection parameters to restore the target two-peak shape. This maintains reliable combustion control without requiring complex manual intervention or additional hardware, resolving the contradiction between control accuracy and system complexity.
3Object-affected harmful factors
If multiple fuel injections are performed to create a two-peak pressure waveform, then vibration acceleration is suppressed, but if the peak interval deviates, the vibration suppression becomes ineffective
Solution Approach 1:
The patent employs feedback control to continuously monitor the peak interval and adjust the injection timing to maintain precise control. This ensures that the two-peak pressure waveform maintains the correct peak interval for effective vibration suppression, resolving the contradiction between achieving vibration reduction and maintaining precise peak interval control.
Solution Approach 2:
The system dynamically adjusts the injection timing based on real-time detection of the pressure waveform characteristics. This dynamic adjustment capability allows the system to maintain precise peak interval control despite variations in engine operating conditions, ensuring consistent vibration suppression effectiveness.
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 solution effectively judges and corrects the pressure waveform shape to maintain the target two-peak pattern, reducing combustion noise and vibration levels by ensuring the peak interval aligns with the reference peak interval, thus enhancing noise reduction efficacy.
Implementation Method 1
a vibration sensor detecting vibration acceleration of the engine body
Implementation Method 2
a fuel injector injecting fuel for combustion inside a combustion chamber
Implementation Method 3
control an injection amount and injection timing of fuel injected from the fuel injector to a target injection amount and target injection timing set based on an engine operating state to cause the fuel to burn by self ignition
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A combustion control part of a control device (200) for an internal combustion engine (100) configured to calculate a first vibration level of an engine body (1) at a first judgment frequency band of a second overtone of a specific frequency band based on vibration acceleration detected by a vibration sensor (210) and, when the first vibration level is less than a predetermined first reference vibration level set in advance according to the engine operating state, to correct one or both of a target injection amount and target injection timing so that the first vibration level becomes the first reference vibration level or more.