A method for detecting and distinguishing engine pre-ignition and carbon deposition based on ion current
An ion current and engine technology, applied in combustion engine, engine control, machine/engine, etc., can solve the problem that the threshold judgment method is easy to cause misjudgment, and achieve the effect of protecting the engine structure, high timeliness, and reducing additional emissions
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Publication Date
- 2021-12-31
Smart Images

Figure 1 
Figure 2 
Figure 3
Abstract
Description
technical field
[0001] The invention relates to the technical field of internal combustion engines, in particular to a method for detecting and distinguishing engine pre-ignition and carbon deposits based on ion current. Background technique
[0002] When the supercharged engine works in the low-speed and high-load range, it is prone to sporadic pre-ignition, and the occurrence of pre-ignition is relatively random without obvious symptoms. The main hazard of pre-ignition is that it may cause super knock. Since super knock has extremely high peak cylinder pressure (greater than 20MPa) and strong cylinder pressure oscillation (amplitude greater than 2MPa), it may be damaged within a single combustion cycle. engine.
[0003] Therefore, there is a need for a low-cost real-time diagnosis strategy that can be quickly judged at the early stage of pre-ignition, so as to facilitate subsequent measures to suppress super knock and obtain better engine performance.
[0004] In the exi...
Examples
Embodiment
[0042] like figure 1 As shown, the present invention provides a kind of engine pre-ignition detection method based on ion current, comprises the following steps:
[0043] A. Collect ion current signals and cylinder pressure signals under different working conditions of the engine (normal, pre-ignition, carbon deposition), where the ion current signals come from the electric field applied between the positive and negative electrodes of the spark plug. ;
[0044] B. Process the collected signal, and use the ion current signal to initially distinguish the pre-ignition cycle and the carbon deposition cycle, specifically: distinguish the pre-ignition and carbon deposition cycles from all data by the ion current signal amplitude in a period of time before the ignition time carbon cycle;
[0045] C. Use the cylinder pressure signal to mark the pre-ignition cycle and the pre-ignition time, specifically: calculate the heat release rate and combustion phase through the cylinder pressu...