An engine control method and an electronically controlled engine

Abstract

This invention relates to the field of engine technology and discloses an engine control method and an electronically controlled engine. The control method is applied to an electronically controlled engine equipped with a closed-loop breather. The control method includes: in response to an ignition switch on signal, the engine controller acquires the vehicle speed; when the vehicle speed is 0, the engine controller performs the following steps: acquiring the difference between the crankcase internal pressure and the atmospheric pressure; if the difference is greater than 0 and exceeds a first threshold, controlling the electronically controlled engine to shut down; if the difference is greater than 0 and does not exceed the first threshold, and the difference persists for a first preset time, controlling the electronically controlled engine to shut down. This solution can reduce or even avoid situations such as synthetic material oil pan cracking, valve cover cracking, and oil seal bulging.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to an engine control method and an electronically controlled engine. Background Technology

[0002] An electronically controlled engine equipped with a closed-loop breather refers to an engine that uses an engine controller (ECM) for operation control and is equipped with a closed crankcase ventilation system. The air-fuel mixture in the crankcase is treated by the closed-loop breather and then completely reintroduced into the engine's intake system for combustion, without being directly emitted into the atmosphere. Taking an electronically controlled engine with a synthetic material oil pan and a closed-loop breather as an example, during engine start-up and operation, an abnormal increase in crankcase pressure can easily cause the oil pan to rupture, resulting in engine damage.

[0003] In related technologies, two main protection methods are used to prevent oil pan rupture. The first is to install a pressure relief valve on the valve cover, which releases pressure from the crankcase, thus preventing pressure buildup and damage to the oil pan. The second is to monitor oil pressure during engine start-up; when the oil pressure exceeds a set threshold, the engine is shut down to protect the oil pan. However, both of these control logics have significant drawbacks and cannot effectively prevent oil pan rupture caused by high crankcase pressure during engine start-up. Specifically: Regarding the protective measures for the pressure relief valve installed on the valve cover, in cold regions, the pressure relief valve is prone to freezing. Before the ice melts, even if the crankcase pressure rises abnormally, the pressure relief valve cannot open normally to effectively relieve pressure, thus losing its protective function for the engine and easily causing the oil pan to rupture due to excessive pressure. As for the protective measures for monitoring oil pressure during starting, the oil pressure is affected by a combination of factors such as ambient temperature, oil type, oil pump capacity, and manufacturing deviations, resulting in a weak correlation with crankcase pressure. It cannot directly and accurately reflect the actual pressure situation in the crankcase, and is prone to protection failure.

[0004] Therefore, there is an urgent need to propose a new oil pan protection solution to address the aforementioned deficiencies in related technologies. Summary of the Invention

[0005] This invention provides an engine control method and an electronically controlled engine to reduce or even avoid situations such as synthetic material oil pan cracking, valve cover cracking, and oil seal protrusion.

[0006] To achieve the above objectives, the present invention provides the following technical solution: An engine control method is applied to an electronically controlled engine equipped with a closed-circuit breather. The control method includes: in response to an ignition switch on signal, an engine controller acquires vehicle speed; when the vehicle speed is 0, the engine controller performs the following steps: Obtain the difference between the internal pressure of the crankcase and the atmospheric pressure; If the difference is greater than 0 and exceeds the first threshold, the electronically controlled engine is shut down; if the difference is greater than 0 and does not exceed the first threshold, and the difference persists for a first preset duration, the electronically controlled engine is shut down.

[0007] Optionally, after obtaining the difference between the internal pressure of the crankcase and the atmospheric pressure, the process includes: If the difference is equal to the initial difference and the difference persists for a second preset duration, then the electronically controlled engine is controlled to stop.

[0008] Optionally, before obtaining the difference between the crankcase internal pressure and the atmospheric pressure, the following steps are included: By comparing the engine speed with a first preset value and a second preset value, it is determined that the engine speed is greater than the first preset value and less than the second preset value.

[0009] Optionally, if after comparing the engine speed with the first preset value, it is determined that the engine speed is less than or equal to the first preset value, then the electronically controlled engine is controlled to continue ignition.

[0010] Optionally, before comparing the engine speed with the first preset value and the second preset value, the following steps are included: Get vehicle speed; The vehicle speed is determined to be 0 by comparing it with 0.

[0011] Optionally, the first preset duration is 5 to 60 seconds.

[0012] Optionally, the second preset duration is 5 to 60 seconds.

[0013] Optionally, the first preset value is 90~110 revolutions per minute.

[0014] Optionally, the second preset value is: engine idle speed + (70~90) rpm.

[0015] The present invention also provides an electronically controlled engine, including an engine controller and a relative pressure sensor, a speed sensor and a vehicle speed sensor respectively connected to the engine controller. The relative pressure sensor is used to detect the difference between the internal pressure of the crankcase and the atmospheric pressure. The speed sensor is used to detect the speed of the electronically controlled engine and the vehicle speed sensor is used to detect the vehicle speed. The engine controller executes any one of the engine control methods provided in the above technical solutions.

[0016] In this scheme, during the start-up of an electronically controlled engine equipped with a closed-loop breather, the pressure inside the crankcase is directly monitored. If the difference between the internal crankcase pressure and the ambient pressure is greater than 0 (i.e., the crankcase is under positive pressure), and this difference exceeds a first threshold; or if the difference is greater than 0 but does not exceed the first threshold, and this difference persists for a first preset duration, it indicates that the crankcase ventilation system is blocked. In this case, the engine controller shuts down the electronically controlled engine to prevent further increases in crankcase pressure, thereby reducing or even preventing issues such as synthetic oil pan rupture, valve cover rupture, and oil seal bulge. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an electronically controlled engine provided in an embodiment of the present invention; Figure 2 A control flowchart of an engine control method provided in an embodiment of the present invention; Figure 3 A control flowchart of an engine control method provided in an embodiment of the present invention; Icons: 1-Engine controller; 2-Relative pressure sensor; 3-Speed ​​sensor; 4-Vehicle speed sensor. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Figure 1 This application provides a schematic diagram of the structure of an electronically controlled engine according to an embodiment of the present application. Figure 1As shown in the illustration, an electronically controlled engine provided in this application includes an engine controller 1, a relative pressure sensor 2, a speed sensor 3, and a vehicle speed sensor 4. All three sensors are connected to the engine controller 1. The relative pressure sensor 2 is used to detect the difference between the pressure inside the crankcase and the atmospheric pressure. Exemplarily, the measuring port of the relative pressure sensor 2 is connected to the inside of the crankcase, and the reference port is directly connected to the atmosphere. The relative pressure sensor 2 outputs a real-time signal indicating the difference between the crankcase pressure and atmospheric pressure, thereby directly capturing and detecting the pressure difference between the crankcase and atmospheric pressure. The speed sensor 3 is used to detect the speed of the electronically controlled engine. In a specific implementation, the speed sensor 3 can be mounted on the crankshaft pulley. It is understood that the crankshaft pulley is fixed to the front end of the crankshaft (i.e., the end with the timing belt / chain) and rotates synchronously with the crankshaft. The main function of the crankshaft pulley is to drive external accessories such as generators, water pumps, and air conditioning compressors via a transmission belt. Vehicle speed sensor 4 is used to detect vehicle speed. In practice, vehicle speed sensor 4 can be installed on the output shaft of the transmission.

[0020] The electronically controlled engine mentioned in this embodiment can be an electronically controlled engine equipped with a closed breathing apparatus. The engine control method will be described below using an electronically controlled engine equipped with a closed breathing apparatus as an example. In other words, the engine control method mentioned below is applied to an electronically controlled engine equipped with a closed breathing apparatus.

[0021] like Figure 2 As shown, an engine control method includes: in response to an ignition switch on signal, engine controller 1 acquires vehicle speed; when the vehicle speed is 0, engine controller 1 performs the following steps: Step S1: Obtain the difference between the internal pressure of the crankcase and the atmospheric pressure; Step S2: If the difference between the internal pressure of the crankcase and the atmospheric pressure is greater than 0 and exceeds the first threshold, then control the electronically controlled engine to stop; if the difference between the internal pressure of the crankcase and the atmospheric pressure is greater than 0 and does not exceed the first threshold, and the difference between the internal pressure of the crankcase and the atmospheric pressure continues for a first preset time, then control the electronically controlled engine to stop.

[0022] For example, the first preset duration can be 5 to 60 seconds, such as 5 seconds, 10 seconds, 35 seconds or 60 seconds.

[0023] It is worth noting that the first threshold is the limit of the difference between the internal pressure of the crankcase and the atmospheric pressure. For example, the first threshold can be 0.5 kPa-200 kPa, such as 4.5 kPa or 5.5 kPa.

[0024] In this scheme, during the start-up of the electronically controlled engine equipped with a closed-loop breather, the pressure inside the crankcase is directly detected. When the difference between the internal pressure of the crankcase and the ambient pressure is greater than 0 (i.e., the crankcase is under positive pressure), and this difference exceeds a first threshold; or, when the difference is greater than 0 but does not exceed the first threshold, and this difference persists for a first preset duration, it indicates that the crankcase ventilation device is blocked. In this case, the engine controller 1 shuts down the electronically controlled engine to prevent further increases in the internal pressure of the crankcase, thereby reducing or even preventing situations such as the synthetic material oil pan cracking, valve cover cracking, and oil seal bulging.

[0025] In some embodiments, after step S1: obtaining the difference between the internal pressure of the crankcase and the atmospheric pressure, the method includes: Step S01: If the difference between the internal pressure of the crankcase and the atmospheric pressure is equal to the initial difference, and the difference between the internal pressure of the crankcase and the atmospheric pressure continues for a second preset duration, then the electronically controlled engine is shut down. For example, the second preset duration can be 5 to 60 seconds, such as 5 seconds, 10 seconds, 35 seconds, or 60 seconds.

[0026] If the pressure difference between the crankcase and atmospheric pressure equals the initial pressure difference, and this pressure difference persists for a second preset duration, it indicates a malfunction in relative pressure sensor 2. In this case, engine controller 1 shuts down the electronically controlled engine to prevent it from continuing to operate under conditions of protection failure. This avoids protection failure and pressure runaway caused by the malfunction of relative pressure sensor 2, and prevents damage due to overload caused by the lack of monitoring of crankcase pressure.

[0027] It is worth noting that the initial difference is the difference between the pressure inside the crankcase and the atmospheric pressure before the ignition switch is turned on. The initial difference can be an empirical value or it can be detected by the relative pressure sensor 2. Step S01 can be placed before step S2, or it can be a parallel strategy with step S2.

[0028] In some embodiments, before step S1: obtaining the difference between the crankcase internal pressure and the atmospheric pressure, the following steps are included: Step S02: By comparing the engine speed with the first preset value and the second preset value, it is determined that the engine speed is greater than the first preset value and less than the second preset value.

[0029] This scheme keeps the engine speed within an appropriate range to maximize the detection of crankcase ventilation system malfunctions while minimizing the possibility of oil pan damage. For example, the first preset value is 90-110 rpm, such as 90 rpm, 100 rpm, 105 rpm, or 110 rpm. The second preset value is engine idle speed + (70-90) rpm, such as engine idle speed + 70 rpm, engine idle speed + 80 rpm, or engine idle speed + 90 rpm. It is understood that the engine idle speed is a design value for the electronically controlled engine; for example, some electronically controlled engines have an idle speed of 500 rpm, some 550 rpm, and some 600 rpm, etc.

[0030] Step S02 can be located before or after step S01. In some embodiments, the engine control method includes: in response to an ignition switch on signal, engine controller 1 acquires vehicle speed; when the vehicle speed is 0, engine controller 1 performs the following steps: Step S02: By comparing the engine speed with the first preset value and the second preset value, it is determined that the engine speed is greater than the first preset value and less than the second preset value.

[0031] Step S01: If the difference between the internal pressure of the crankcase and the ambient pressure is equal to the initial difference, and the difference between the internal pressure of the crankcase and the ambient pressure continues for a second preset time, then control the electronically controlled engine to shut down. If the difference between the internal pressure of the crankcase and the ambient pressure is not equal to the initial difference, then execute step S1: obtain the difference between the internal pressure of the crankcase and the ambient pressure. After step S1, step S2 is executed. If the difference between the internal pressure of the crankcase and the atmospheric pressure is greater than 0 and exceeds the first threshold, the electronically controlled engine is shut down. If the difference between the internal pressure of the crankcase and the atmospheric pressure is greater than 0 and does not exceed the first threshold, and the difference lasts for a first preset time, the electronically controlled engine is shut down.

[0032] In some embodiments, if the engine speed is compared with a first preset value and it is determined that the engine speed is less than or equal to the first preset value, the electronically controlled engine is controlled to continue ignition.

[0033] When the engine speed is less than or equal to the first preset value, it indicates that the engine is in the ignition process. The electronically controlled engine is then controlled to continue ignition until ignition is successful, thereby ensuring the smooth execution of the engine control method and the reliability of the oil pan protection strategy.

[0034] In some embodiments, before comparing the engine speed with a first preset value and a second preset value, the following steps are included: Get vehicle speed; By comparing the vehicle speed with 0, the vehicle speed is determined to be 0, ensuring that the vehicle is in the process of waiting for the engine to start.

[0035] Using the engine control method provided in this embodiment, if the crankcase ventilation device is normal, it will not affect the normal starting of the engine; if there is blockage such as icing in the crankcase ventilation device, it can be identified in advance and cleared in time, avoiding significant losses such as the cracking of the oil pan and other components, and saving maintenance costs.

[0036] Figure 3 A control flowchart of an engine control method provided in an embodiment of this application is shown, as follows: Figure 3 As shown, in one specific implementation, the engine control method includes the engine controller performing the following steps: Step S100: In response to the ignition switch on signal; Step S200: Obtain vehicle speed and confirm that the vehicle speed is 0; Step S300: Determine whether the engine speed is greater than the first preset value; if yes, proceed to step S400; if no, control the electronically controlled engine to continue ignition. Step S400: Determine whether the engine speed is less than the second preset value; if yes, proceed to step S500; if no, proceed to step S900; indicating that the crankcase ventilation device is normal and the engine can continue to run.

[0037] Step S500: Determine whether the difference between the internal pressure of the crankcase and the atmospheric pressure is not equal to the initial difference. If yes, proceed to step S600; if no, and within the second preset time period, the difference between the internal pressure of the crankcase and the atmospheric pressure is equal to the initial difference, proceed to step S800. Step S600: Determine whether the difference between the internal pressure of the crankcase and the atmospheric pressure is greater than 0. If yes, proceed to step S700; otherwise, proceed to step S900, indicating that the crankcase ventilation device is normal and the engine can continue to run.

[0038] Step S700: Determine whether the difference between the internal pressure of the crankcase and the atmospheric pressure exceeds a first threshold. If yes, proceed to step S800. If no, and the difference between the internal pressure of the crankcase and the atmospheric pressure continues for a first preset duration, proceed to step S800. Step S800: Control the electronically controlled engine to stop; Step S900, process ends.

[0039] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An engine control method, characterized in that, An electronically controlled engine equipped with a closed-circuit respirator is provided, the control method comprising: in response to an ignition switch on signal, the engine controller acquires the vehicle speed; when the vehicle speed is 0, the engine controller performs the following steps: Obtain the difference between the internal pressure of the crankcase and the atmospheric pressure; If the difference is greater than 0 and exceeds the first threshold, the electronically controlled engine is shut down; if the difference is greater than 0 and does not exceed the first threshold, and the difference persists for a first preset duration, the electronically controlled engine is shut down.

2. The control method according to claim 1, characterized in that, After obtaining the difference between the internal pressure of the crankcase and the atmospheric pressure, the process includes: If the difference is equal to the initial difference and the difference persists for a second preset duration, then the electronically controlled engine is stopped.

3. The control method according to claim 1, characterized in that, Before obtaining the difference between the internal pressure of the crankcase and the atmospheric pressure, the following steps are included: By comparing the engine speed with a first preset value and a second preset value, it is determined that the engine speed is greater than the first preset value and less than the second preset value.

4. The control method according to claim 3, characterized in that, If, after comparing the engine speed with the first preset value, it is determined that the engine speed is less than or equal to the first preset value, then the electronically controlled engine is controlled to continue ignition.

5. The control method according to claim 3 or 4, characterized in that, Before comparing the engine speed with the first preset value and the second preset value, the process includes: Get vehicle speed; The vehicle speed is determined to be 0 by comparing it with 0.

6. The control method according to claim 1, characterized in that, The first preset duration is 5 to 60 seconds.

7. The control method according to any one of claims 2-4, characterized in that, The second preset duration is 5 to 60 seconds.

8. The control method according to claim 3 or 4, characterized in that, The first preset value is 90~110 revolutions per minute.

9. The control method according to claim 3 or 4, characterized in that, The second preset value is: engine idle speed + (70~90) rpm.

10. An electronically controlled engine, characterized in that, It includes an engine controller and a relative pressure sensor, a speed sensor and a vehicle speed sensor respectively connected to the engine controller. The relative pressure sensor is used to detect the difference between the internal pressure of the crankcase and the atmospheric pressure. The speed sensor is used to detect the speed of the electronically controlled engine. The vehicle speed sensor is used to detect the vehicle speed. The engine controller performs the engine control method according to any one of claims 1-9.

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