Combustion state monitoring method and device and engine

Abstract

The invention discloses a combustion state monitoring method. The method comprises the steps that engine operation parameters are collected; judging whether the engine combustion state is normal according to the operation parameters; when it is judged that the combustion state is abnormal, engine control parameters are adjusted; wherein the adjusted engine control parameters comprise the ignition advance angle and the fuel injection pulse width, and when it is judged that the combustion state of the engine is abnormal, the ignition advance angle is reduced, and the fuel injection pulse width is increased at the same time till the combustion state of the engine returns to normal. The combustion state of the engine is judged by collecting the operation parameters of the engine, the control parameters of the engine are adjusted when it is judged that combustion of the engine is abnormal, the ignition advance angle and the fuel injection pulse width of the engine are adjusted at the same time, and the combustion state of the engine is improved till combustion returns to normal; therefore, risks caused by knocking, such as serious abrasion of a cylinder hole, melting of a piston and breakage of a connecting rod, can be reduced in time, damage to an engine can be reduced, and the service life of the engine can be prolonged.

Description

Technical Field

[0001] This invention relates to the field of engine control technology, specifically to a combustion state monitoring method, device, and engine. Background Technology

[0002] As a type of engine, a gasoline engine uses gasoline as fuel to convert internal energy into kinetic energy. Because gasoline has low viscosity and evaporates quickly, it can be injected into the cylinder using a gasoline injection system. After compression to a certain temperature and pressure, it is ignited by a spark plug, causing the gas to expand and perform work. Gasoline engines are characterized by high speed, simple structure, light weight, low cost, smooth operation, and ease of use and maintenance. Gasoline engines are widely used in automobiles, especially small cars. During engine use, various malfunctions can easily occur due to environmental factors or human error, affecting the normal operation of the engine.

[0003] Knock, an abnormal combustion phenomenon in engines, leads to decreased engine power, increased temperature, increased noise, poorer fuel economy, and increased exhaust emissions. Chinese patent document CN108915883A discloses a super-knock monitoring system and suppression method for spark-ignition engines. Its signal processing module is connected to the input of a super-knock detection area selection module. The outputs of the knock detection area selection module and the signal processing module are connected to the inputs of a background vibration assessment module and a judgment threshold correction module. The outputs of the background vibration assessment module and the judgment threshold correction module are connected to the input of a knock calculation and judgment module. The knock calculation and judgment module outputs the knock power signal to the knock judgment module to determine the knock intensity. The judgment threshold correction module predicts the engine operating parameter threshold for super-knock. Based on various engine operating parameters and the judgment of the engine's super-knock intensity, corresponding measures can be taken to suppress super-knock, effectively reducing its occurrence, extending engine life, and improving vehicle fuel economy, reliability, and safety. However, this existing technology is quite complex, and if the knock intensity is misjudged, incorrect suppression measures will be taken, which may result in poor suppression effect, or even aggravate the knock intensity, or even cause engine damage. Summary of the Invention

[0004] This invention provides a combustion state monitoring method that can effectively suppress engine knock, including collecting engine operating parameters; Determine whether the engine combustion status is normal based on the operating parameters; When an abnormal combustion condition is detected, adjust the engine control parameters; The adjusted engine control parameters include ignition advance angle and injection pulse width. When an abnormal engine combustion state is detected, the ignition advance angle is reduced and the injection pulse width is increased simultaneously until the engine combustion state returns to normal.

[0005] Compared with existing technologies, this solution determines the engine's combustion state by collecting engine operating parameters. When an abnormal combustion is detected, the engine control parameters are adjusted, including the ignition advance angle and injection pulse width, to improve the engine's combustion state until combustion returns to normal. This can promptly reduce the risks caused by knocking, such as severe cylinder bore wear, piston melting, and connecting rod breakage, thereby reducing engine damage and extending engine life.

[0006] Preferably, during the adjustment process, the ignition advance angle and injection pulse width are simultaneously reduced according to a preset adjustment amount. This solution can avoid the impact of sudden changes in ignition advance angle and injection pulse width on the engine.

[0007] Preferably, during the adjustment process, the engine combustion state is reassessed after each adjustment. If the engine combustion state is normal, the adjustment operation ends; if the engine combustion state is abnormal, the adjustment is performed again. This solution can avoid the impact on the engine caused by excessive adjustments to the ignition advance angle and fuel injection pulse width.

[0008] Preferably, after each adjustment, the degree of adjustment completed is statistically analyzed and it is determined whether the degree of adjustment exceeds the standard. If it exceeds the standard and the engine combustion state is abnormal, the adjustment operation is exited, the ignition advance angle and fuel injection pulse width are restored to their initial states, and the throttle opening is adjusted to 80-90% of the rated power opening. This solution can avoid the impact on the engine caused by excessive adjustment of the ignition advance angle and fuel injection pulse width.

[0009] Preferably, the adjustment degree includes the reduction of the ignition advance angle and the increase of the fuel injection pulse width. The reduction of the ignition advance angle and the increase of the fuel injection pulse width are compared with preset reduction thresholds and increase thresholds, respectively. If the reduction and increase exceed the reduction thresholds and increase thresholds, the adjustment degree is determined to be excessive.

[0010] Preferably, when determining whether the engine combustion state is normal, the collected operating parameters are compared with the engine's calibration threshold. If the parameters exceed the calibration threshold, the combustion state is determined to be abnormal.

[0011] Secondly, the present invention provides a combustion state monitoring device, including a detection unit, a processing unit, and an execution unit, which operates using the above-described combustion state monitoring method. The detection unit collects engine operating parameters, the processing unit determines whether the engine combustion state is normal based on the operating parameters, and adjusts the engine control parameters when the combustion state is determined to be abnormal; the execution unit outputs according to the engine control parameters. The adjusted engine control parameters include ignition advance angle and injection pulse width. When the processing unit determines that the engine combustion state is abnormal, the execution unit simultaneously reduces the ignition advance angle and increases the injection pulse width until the engine combustion state returns to normal.

[0012] Thirdly, the present invention provides an engine, which includes the above-mentioned combustion state monitoring device, wherein the detection unit is installed at the engine cylinder bore, and the execution unit includes an igniter, a throttle valve, and a fuel injector.

[0013] The present invention has the following beneficial effects: 1. By collecting engine operating parameters, the combustion state of the engine is determined. When an abnormal combustion is detected, the engine control parameters are adjusted, including the ignition advance angle and fuel injection pulse width, to improve the combustion state until combustion returns to normal. This can reduce the risks caused by knocking, such as severe cylinder bore wear, piston melting, and connecting rod breakage, thereby reducing engine damage and extending engine life.

[0014] 2. It can avoid the impact on the engine caused by excessive adjustment of ignition advance angle and fuel injection pulse width. Attached Figure Description

[0015] Figure 1 This is a flowchart of the monitoring method in an embodiment of a combustion state monitoring method, device, and engine according to the present invention. Detailed Implementation

[0016] The following detailed description illustrates the specific implementation method: 1. Definition Operating parameters: The engine operating parameters in this invention include the frequency and amplitude of engine vibration.

[0017] Ignition advance angle: Ignition advance means that the spark plug ignites the combustible mixture in the combustion chamber before the piston reaches top dead center of the compression stroke. The angle through which the crankshaft rotates from the moment of ignition to the moment the piston reaches top dead center of the compression stroke is called the ignition advance angle.

[0018] Injection pulse width: refers to the length of time for each injection of fuel by the engine's on-board computer, and is the most important indicator of whether the engine's fuel injectors are working properly.

[0019] 2. The basic implementation method is as shown in the attached figure. Figure 1 As shown: A combustion state monitoring method includes collecting engine operating parameters. In this embodiment, the operating parameters include the frequency and amplitude of engine vibration, but other operating parameters can also be selected.

[0020] The engine combustion status is determined based on the operating parameters. Specifically, the collected operating parameters are compared with the engine's calibration thresholds. If the parameters exceed the calibration thresholds, the combustion status is determined to be abnormal.

[0021] When an abnormal combustion state is detected, engine control parameters, including ignition advance angle and injection pulse width, are adjusted. When an abnormal engine combustion state is detected, the ignition advance angle and injection pulse width are simultaneously decreased and increased by preset adjustment amounts until the engine combustion state returns to normal. In this embodiment, the preset adjustment amount for the ignition advance angle is 1°, and the preset adjustment amount for the injection pulse width is 0.1ms.

[0022] During the adjustment process, the engine combustion state is reassessed after each adjustment. If the engine combustion state is normal, the adjustment operation ends; if the engine combustion state is abnormal, the adjustment is repeated. After each adjustment, the current adjustment level is tallied and it is determined whether the adjustment level exceeds the limit. If it exceeds the limit and the engine combustion state is abnormal, the adjustment operation is exited, the ignition advance angle and fuel injection pulse width are restored to their initial states, and the throttle opening is adjusted to 80-90% of the rated power opening. The adjustment level includes the reduction of the ignition advance angle and the increase of the fuel injection pulse width. The reduction of the ignition advance angle and the increase of the fuel injection pulse width are compared with preset reduction and increase thresholds, respectively. If the reduction and increase exceed the reduction and increase thresholds, the adjustment level is determined to be excessive. In this embodiment, the reduction threshold for the ignition advance angle is 10°, and the increase threshold for the fuel injection pulse width is 1ms.

[0023] Based on the above combustion state monitoring method, this embodiment also discloses a combustion state monitoring device, including a detection unit, a processing unit, and an execution unit. When the above combustion state monitoring method is used, the detection unit collects engine operating parameters, the processing unit determines whether the engine combustion state is normal based on the operating parameters, and adjusts the engine control parameters when the combustion state is determined to be abnormal; the execution unit outputs according to the engine control parameters. The adjusted engine control parameters include ignition advance angle and injection pulse width. When the processing unit determines that the engine combustion state is abnormal, the execution unit simultaneously reduces the ignition advance angle and increases the injection pulse width until the engine combustion state returns to normal.

[0024] Based on the above-mentioned combustion state monitoring device, this embodiment discloses an engine including the above-mentioned combustion state monitoring device, wherein the detection unit is installed at the engine cylinder bore, and the execution unit includes an igniter, a throttle valve, and a fuel injector.

[0025] The specific implementation process is as follows: When the engine is in use, the detection unit installed at the engine cylinder bore operates to detect the frequency and amplitude of the engine vibration. Then, the processing unit determines whether the engine combustion state is normal based on the operating parameters.

[0026] When determining whether the engine combustion status is normal, the frequency and amplitude of the collected engine vibration are compared with the engine's calibration threshold. If neither the frequency nor the amplitude exceeds the calibration threshold, the combustion status is determined to be normal. If either exceeds the calibration threshold, the combustion status is determined to be abnormal.

[0027] When an abnormal combustion state is determined, the engine control parameters are adjusted, and the ignition advance angle is reduced by 1° and the injection pulse width is increased by 0.1ms. Then the engine combustion state is re-evaluated. If the engine combustion state is normal, the adjustment operation ends; if the engine combustion state is abnormal, the adjustment is performed again, that is, the ignition advance angle is reduced by another 1° and the injection pulse width is increased by another 0.1ms.

[0028] After each adjustment is completed, the degree of adjustment completed is statistically analyzed and it is determined whether the degree of adjustment exceeds the standard. The degree of adjustment includes the amount of reduction in ignition advance angle and the amount of increase in fuel injection pulse width. The amount of reduction in ignition advance angle and the amount of increase in fuel injection pulse width are compared with the preset reduction threshold and increase threshold, respectively. If the reduction and increase exceed the reduction threshold and increase threshold, the degree of adjustment is determined to exceed the standard.

[0029] If the values ​​exceed the limit and the engine combustion state is abnormal, exit the adjustment operation, restore the ignition advance angle and fuel injection pulse width to their initial states, and adjust the throttle opening to 80-90% of the rated power opening.

[0030] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for monitoring combustion status, comprising collecting engine operating parameters; Determine whether the engine combustion status is normal based on the operating parameters; When an abnormal combustion condition is detected, adjust the engine control parameters; Its features are: The adjusted engine control parameters include ignition advance angle and injection pulse width. When an abnormal engine combustion state is determined, the ignition advance angle is reduced and the injection pulse width is increased simultaneously until the engine combustion state returns to normal.

2. The combustion state monitoring method according to claim 1, characterized in that: During the adjustment process, the ignition advance angle is reduced and the injection pulse width is increased simultaneously according to the preset adjustment amount.

3. The combustion state monitoring method according to claim 1 or 2, characterized in that: During the adjustment process, the engine combustion status is reassessed after each adjustment. If the engine combustion status is normal, the adjustment operation ends; if the engine combustion status is abnormal, the adjustment is performed again.

4. The combustion state monitoring method according to claim 3, characterized in that: After each adjustment is completed, the degree of adjustment completed is counted and it is determined whether the degree of adjustment exceeds the standard. If it exceeds the standard and the engine combustion state is abnormal at this time, the adjustment operation is exited, the ignition advance angle and fuel injection pulse width are restored to the initial state, and the throttle opening is adjusted to 80-90% of the rated power opening.

5. The combustion state monitoring method according to claim 4, characterized in that: The adjustment level includes the reduction of the ignition advance angle and the increase of the fuel injection pulse width. The reduction of the ignition advance angle and the increase of the fuel injection pulse width are compared with preset reduction thresholds and increase thresholds, respectively. If the reduction and increase exceed the reduction thresholds and increase thresholds, the adjustment level is deemed to have exceeded the limit.

6. The combustion state monitoring method according to claim 5, characterized in that: When determining whether the engine combustion status is normal, the collected operating parameters are compared with the engine's calibration threshold. If the parameters exceed the calibration threshold, the combustion status is determined to be abnormal.

7. A combustion state monitoring device, comprising a detection unit, a processing unit, and an execution unit, operating using the combustion state monitoring method as described in any one of claims 1-6, wherein the detection unit collects engine operating parameters, the processing unit determines whether the engine combustion state is normal based on the operating parameters, and adjusts engine control parameters when the combustion state is determined to be abnormal; and the execution unit outputs data based on the engine control parameters. Its features are: The adjusted engine control parameters include ignition advance angle and injection pulse width. When the processing unit determines that the engine combustion state is abnormal, the execution unit simultaneously reduces the ignition advance angle and increases the injection pulse width until the engine combustion state returns to normal.

8. An engine, characterized in that: The device includes the combustion state monitoring device as described in claim 7, wherein the detection unit is installed at the engine cylinder bore, and the execution unit includes an igniter, a throttle valve, and a fuel injector.

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