CN116241353A

CN116241353A - Control strategy for realizing engine protection based on engine oil monitoring

Info

Publication number: CN116241353A
Application number: CN202211702639.5A
Authority: CN
Inventors: 王建龙; 王辉; 寇传富; 赵令猛
Original assignee: Guangxi Yuchai Machinery Co Ltd
Current assignee: Guangxi Yuchai Machinery Co Ltd
Priority date: 2022-12-28
Filing date: 2022-12-28
Publication date: 2023-06-09

Abstract

The invention discloses a control strategy for realizing engine protection based on engine oil monitoring, and relates to an engine control technology. Judging whether the engine is started successfully or not; if the engine is started successfully, collecting a real-time pressure value of engine oil, and processing the real-time pressure value by a multi-threshold protection judging method to ensure that the engine operates in a state of a normal engine oil pressure value; if the engine is not started successfully, collecting an engine oil liquid level value in the oil pan, and judging whether the engine oil liquid level value is smaller than a set engine oil liquid level extreme value or not; if the engine oil liquid level value is smaller than the engine oil liquid level extreme value, the engine is forbidden to start; otherwise, the engine is allowed to start. The engine oil level and pressure difference detection method and device achieve differentiation when the engine oil level and pressure are abnormal in different scenes, and further achieve protection of the engine through grading reminding and protection measures.

Description

Control strategy for realizing engine protection based on engine oil monitoring

Technical Field

The invention relates to an engine control technology, in particular to a control strategy for realizing engine protection based on engine oil monitoring.

Background

The lubricating function of the engine is mainly realized by engine oil, and the engine oil also takes part of the task of the cooling function. When no oil is added or leakage occurs, lubrication failure and cooling capacity of an engine system are reduced. The lubrication and cooling functions of the engine system are also impaired due to the fact that the engine oil amount is insufficient, the viscosity of the engine oil is too low, the engine oil filter is blocked, and the like, which are caused by the fact that the engine oil pressure is reduced. These problems can finally lead to poor friction and lubrication effects on the surfaces of all parts in the engine, aggravate the friction loss of all parts, can lead to overheating of all parts in the engine, finally cause serious problems such as bearing bush ablation, cylinder pulling and the like, and even lead to scrapping of the engine.

At present, the industry mainly uses an engine oil pressure sensor or a sensing plug arranged on an engine oil main oil duct to sense and detect the engine oil pressure in the running process after an engine is started, then sends pressure information to a whole vehicle instrument, and the instrument judges whether to activate an engine oil pressure low indicator lamp to prompt a driver, and the driver takes measures actively. However, in actual use, due to professional cognition of a driver and understanding of instrument signals, information deviation often occurs, so that the driver can not see or look aside the engine oil abnormality, and finally the engine is seriously damaged or even scrapped.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a control strategy for realizing engine protection based on engine oil monitoring, which realizes differentiation when the engine oil level and the pressure are abnormal in different scenes, and further realizes the protection of the engine through graded reminding and protection measures.

The control strategy for realizing engine protection based on engine oil monitoring judges whether an engine is started successfully or not;

if the engine is started successfully, collecting a real-time pressure value of engine oil, and processing the real-time pressure value by a multi-threshold protection judging method to ensure that the engine operates in a state of a normal engine oil pressure value;

if the engine is not started successfully, collecting an engine oil liquid level value in the oil pan, and judging whether the engine oil liquid level value is smaller than a set engine oil liquid level extreme value or not;

if the engine oil liquid level value is smaller than the engine oil liquid level extreme value, the engine is forbidden to start; otherwise, the engine is allowed to start.

The multi-threshold protection judging method is that,

judging whether the real-time pressure value is smaller than a first set limit value or not; if yes, monitoring the opening degree of the accelerator pedal, and when the opening degree of the accelerator pedal is the opening degree of the accelerator pedal in an idle state, sending out an engine torque limiting instruction to limit the maximum output torque of the engine to be a set torque extremum; judging whether the real-time pressure value is smaller than a second set limit value or not;

if yes, a stop instruction is sent out, and the engine stops running according to the stop instruction.

The engine stops running according to the stop instruction, specifically,

when the ECU receives the stopping instruction, the rotating speed of the engine is gradually reduced to an idle speed by a calibrated stopping step length;

when the rotation speed of the engine is reduced to idle speed, the engine is stopped and shut down after the engine is operated at idle speed for a set time.

The set time is 30s-120s.

And returning to the step of judging whether the engine is started successfully or not when the real-time pressure value is larger than or equal to the first set limit value.

And returning to the step of judging whether the engine is started successfully or not when the real-time pressure value is larger than or equal to a second set limit value.

And when the real-time pressure value is smaller than the first set limit value, activating an engine oil pressure low indicator lamp on the instrument panel.

Advantageous effects

The invention has the advantages that: the engine oil pressure in the main oil duct and the liquid level of the engine oil in the oil pan are monitored through the ECU, whether the engine oil of the engine oil meets the normal operation of the engine is judged according to the engine oil pressure value and the engine oil liquid level value, differentiation of the engine oil liquid level and abnormal pressure under different scenes is realized, and further protection of the engine is realized through graded reminding and protecting measures, driving safety and driving experience are ensured, and the problem that the engine is damaged due to abnormal engine oil in the engine is avoided.

Drawings

Fig. 1 is a schematic flow chart of a control strategy according to the present invention.

Detailed Description

The invention is further described below in connection with the examples, which are not to be construed as limiting the invention in any way, but rather as falling within the scope of the claims.

Referring to fig. 1, the control strategy for implementing engine protection based on engine oil monitoring of the present invention first determines whether an engine is successfully started. If the engine is started successfully, the ECU acquires a real-time pressure value of engine oil in the main oil duct.

Then, whether the real-time pressure value is smaller than the first set limit value is judged. If so, the opening degree of the accelerator pedal is monitored, and when the opening degree of the accelerator pedal is the opening degree of the accelerator pedal in an idle state, an engine torque limiting command is sent out to limit the maximum output torque of the engine to be a set torque extremum. The method has the advantages that the problem that the judgment of the vehicle state by the driver is influenced by abrupt change of the output of the engine to the idle state in the process of accelerating the accelerator pedal by the driver is avoided, and the driving safety is ensured. And when the engine oil pressure is insufficient, the maximum output torque is limited, so that the problem of lubricating capacity reduction caused by insufficient engine oil in the engine during high-speed operation can be avoided, the effect of preventing the engine from being damaged easily is achieved, and the operation safety of the engine is ensured.

When the real-time pressure value is smaller than the first set limit value, in addition to limiting the output torque of the engine, an engine oil pressure low indicator lamp on the instrument panel is activated to give a corresponding prompt to a driver.

If the real-time pressure value is smaller than the first set limit value, then judging whether the real-time pressure value is smaller than the second set limit value. And when the real-time pressure value is smaller than the second set limit value, a stop command is sent out so as to stop the engine.

Considering that the running environments of the vehicle in different regions are different, if the engine is directly and actively stopped, road safety hidden trouble is easily brought to some road sections such as an ascending road section or a turning road section. Therefore, in the present embodiment, the specific implementation in which the engine is stopped due to insufficient oil pressure is divided into two steps.

Firstly, when the ECU receives a stop command, the engine is controlled to gradually reduce the rotating speed of the engine to idle speed by a calibrated stop step length. The active deceleration action can play a role in reminding a driver of vehicle faults, and meanwhile, the running stability of the vehicle is ensured.

Secondly, when the rotating speed of the engine is reduced to idle speed, the engine is stopped and flameout after the engine runs at the idle speed for a set time, so that a driver can conveniently make emergency operations such as stopping by side or opening double flashes.

In addition, the set time is 30s-120s. The time is mainly set to ensure that the driver has enough time to make emergency operation and ensure the safety of parking. And the specific time setting can be judged according to the current road condition of the vehicle. For example, when the vehicle is on a flat road, the driver can realize quick parking, so the set time is 30 seconds, and the engine can be protected in a large amount while the parking safety is ensured. When the vehicle is on a ramp section, particularly an uphill section, the vehicle is slow in running speed and takes a long time to ensure that the vehicle is safely stopped, so the ramp section is preferable for 120s. And monitoring of the road grade may be collected by associated sensors on the vehicle.

Consider the situation where there may be leakage of engine oil during the running of the vehicle. Therefore, when the real-time pressure value is greater than or equal to the first set limit value, the step of judging whether the engine is started successfully is returned to continuously judge whether the engine oil pressure is normal or not, and the condition of insufficient oil pressure caused by engine oil leakage is avoided.

Considering that the oil pressure is weather-dependent, for example, in an environment where the air temperature is low, the viscosity of the oil is large, and the oil pressure in the main oil gallery is liable to be insufficient when the vehicle starts. But after the engine oil warms up for a certain time when the vehicle is started, the pressure of the engine oil is restored to a normal value. Therefore, when the real-time pressure value is between the two set limits, the step of judging whether the engine is started successfully is returned to continue to judge the engine oil pressure. Avoiding the problem of misjudgment caused by weather factors.

If the engine is not started successfully, the ECU collects the oil liquid level value in the oil pan and judges whether the oil liquid level value is smaller than a set oil liquid level extreme value. If the engine oil liquid level value is smaller than the engine oil liquid level extreme value, the engine is forbidden to start; otherwise, the engine is allowed to start.

While only the preferred embodiments of the present invention have been described above, it should be noted that modifications and improvements can be made by those skilled in the art without departing from the structure of the present invention, and these do not affect the effect of the implementation of the present invention and the utility of the patent.

Claims

1. A control strategy for realizing engine protection based on engine oil monitoring is characterized by judging whether an engine is started successfully or not;

2. A control strategy for engine protection based on oil monitoring as set forth in claim 1, wherein said multi-threshold protection determination is,

3. A control strategy for engine protection based on oil monitoring according to claim 2, wherein the engine is stopped according to a stop command, in particular,

4. A control strategy for engine protection based on oil monitoring as claimed in claim 3, wherein said set time is 30s-120s.

5. The control strategy for engine protection based on oil monitoring of claim 2, wherein the step of determining whether the engine has been successfully started is returned when the real-time pressure value is greater than or equal to a first set limit.

6. The control strategy for engine protection based on oil monitoring of claim 2, wherein the step of determining whether the engine has been started successfully is returned when the real-time pressure value is greater than or equal to a second set limit.

7. The control strategy for engine protection based on oil monitoring of claim 2, wherein a low oil pressure indicator on the dashboard is activated when the real-time pressure value is less than a first set limit.