An engine pre-lubrication method and system

Abstract

This application relates to the field of engine technology, and more particularly to an engine pre-lubrication method and system. The method includes: obtaining the initial engine oil temperature before pre-lubrication; if the initial engine oil temperature is lower than a preset temperature threshold, continuously injecting a first current into the motor windings of the engine's electric oil pump for pre-lubrication, and controlling the electric oil pump to remain stationary; after injecting the first current into the motor windings for a preset injection time, controlling the electric oil pump to rotate at a target speed, and injecting a second current into the motor windings for pre-lubrication. The above method can improve the reliability of engine pre-lubrication.

Description

Technical Field

[0001] This application relates to the field of engine technology, and in particular to an engine pre-lubrication method and system. Background Technology

[0002] The replacement of mechanical oil pumps with electric oil pumps is an important development trend in engine development. Electric oil pumps rely on direct motor drive and intelligent control to pre-establish lubricating oil pressure before engine start-up. However, in low-temperature environments, the viscosity of engine oil increases significantly, and the oil flow resistance increases substantially. Directly driving the electric oil pump can easily lead to motor stalling or pressure build-up failure, making it difficult to smoothly and reliably complete the pre-lubrication and pressure build-up process. Summary of the Invention

[0003] This application provides an engine pre-lubrication method and system to improve the reliability of engine pre-lubrication.

[0004] In a first aspect, embodiments of this application provide an engine pre-lubrication method, the method comprising: Obtain the initial oil temperature before engine pre-lubrication; If the initial oil temperature is lower than the preset temperature threshold, the first current is continuously injected into the motor winding of the electric oil pump of the engine for pre-lubrication, and the electric oil pump is controlled to remain stationary. After the first current is injected into the motor winding for a preset injection time, the electric oil pump is controlled to rotate at the target speed, and a second current is injected into the motor winding for pre-lubrication.

[0005] In the above method, by injecting a first current to achieve static preheating and thus prelubrication while the electric oil pump is stationary, the initial viscous resistance of the oil can be reduced, and the blockage caused by excessive load on the electric oil pump at the moment of startup can be avoided. By continuously applying a second current to perform prelubrication while the electric oil pump is rotating, the low-temperature, high-viscosity oil flowing into the pump chamber is continuously heated by the heating of the winding resistance and the eddy current loss of the iron core, thereby improving the oil fluidity under low-temperature conditions and the success rate of the oil pump in continuously drawing oil and building pressure, thus improving the reliability of engine prelubrication.

[0006] Optionally, the first current and the second current are both direct-axis currents.

[0007] Compared to existing technologies that rely on external heaters and high-pressure, high-power oil pumps to heat the engine oil, this application only injects direct-axis current into the motor windings. The Joule heat generated by the winding resistance directly heats the pump body and surrounding low-temperature engine oil, eliminating the need for additional independent oil heating hardware and reducing the cost and complexity of the engine pre-lubrication system. Furthermore, since the direct-axis current is only used to adjust the heating power and does not affect the motor output torque of the electric oil pump, injecting direct-axis current into the motor windings is sufficient to generate Joule heat, thereby heating the engine oil. Additionally, the fact that the first current is a direct-axis current allows for preheating of the engine oil without additionally driving the electric oil pump.

[0008] Optionally, the first current mentioned above is a preset ratio of the motor's rated current, and the preset ratio is less than 1.

[0009] In the above method, by injecting a constant low-energy first current into the motor winding of the electric oil pump, sufficient heat can be generated to dissipate the viscous resistance of the low-temperature oil, while avoiding the overheating problem caused by a large current. It can also prevent the insulation material from aging too quickly due to an excessive first current and excessive winding temperature, thereby reducing the motor's lifespan and mechanical performance.

[0010] Optionally, controlling the electric oil pump to rotate at the target speed includes: The electric oil pump is controlled to rotate at at least two target speeds, each of which corresponds to a preset time, and the speeds increase progressively.

[0011] In the above method, by controlling the electric oil pump to rotate at at least two target speeds in sequence, the speed of the electric oil pump can be gradually increased, preventing oil film tearing or motor stalling caused by sudden changes in the speed of the electric oil pump. At the same time, the oil temperature rise rate can be more precisely controlled to prevent local overheating of the oil.

[0012] Optionally, after injecting a second current into the motor windings for pre-lubrication, the above method further includes: Determine the target oil temperature range after pre-lubricating the engine; Based on the correspondence between the oil temperature range and the oil pressure range of the engine's main oil passage, the target oil pressure range corresponding to the target oil temperature is determined. If the oil pressure in the main oil passage of the engine is within the target oil pressure range, the engine pre-lubrication is considered complete.

[0013] In the above method, by presetting corresponding target oil pressure ranges for different oil temperature ranges, it can ensure that the main oil passage of the engine is fully filled with oil and that the engine is adequately pre-lubricated before starting; form a satisfactory oil film between the journal and the bearing to prevent the risk of dry friction during startup; and also ensure that the power consumption and electricity usage of the electric oil pump are reduced, thereby improving the reliability of the electric oil pump's safe operation.

[0014] Optionally, if the obtained oil pressure in the engine's main oil passage is within the target oil pressure range, determining that engine pre-lubrication is complete includes: Within the preset detection time, the engine main oil passage oil pressure and target oil temperature are obtained at least twice; If the oil pressure of the engine's main oil passage is obtained each time and is within the target oil pressure range corresponding to the target oil temperature, it is determined that the engine pre-lubrication is complete.

[0015] In the above method, by setting a preset detection time, the target oil temperature and the oil pressure of the engine main oil passage during engine pre-lubrication are continuously detected within the detection time. This can avoid misjudgment of pre-lubrication caused by instantaneous oil pressure fluctuations, ensure the continuous effectiveness of the oil film, and improve the reliability of pre-lubrication control.

[0016] Optionally, the above methods also include: If the oil pressure in the engine's main oil passage is not within the target oil pressure range, and the actual pre-lubrication time does not exceed the preset maximum pre-lubrication time, the electric oil pump is re-controlled to rotate at the target speed, and a second current is injected into the motor windings for pre-lubrication.

[0017] In the above method, by setting the maximum allowable duration of pre-lubrication of the engine, it is possible to prevent the electric oil pump from overheating and aging of the windings due to prolonged load operation, thereby protecting the service life of the electric oil pump and improving system safety.

[0018] Optionally, the above methods also include: If the actual number of retry attempts for pre-lubrication reaches the preset number of retry attempts, and the oil pressure of the engine main oil passage obtained each time is not within the target oil pressure range, the engine pre-lubrication is determined to have failed, and pre-lubrication is stopped.

[0019] In the above method, by not directly determining failure when the oil pressure in the engine's main oil passage does not meet the preset rules for the first time, but instead allowing the pre-lubrication process to be re-executed within a preset number of retries, the success rate of engine pre-lubrication can be improved, and false alarms of pre-lubrication failures can be prevented. At the same time, determining whether to end the pre-lubrication retry based on the preset number of retries can reduce the probability of component damage caused by unlimited retrying of pre-lubrication, and improve the service life of the equipment.

[0020] Optionally, the above methods also include: If an abnormal signal is detected, pre-lubrication shall be stopped. The abnormal signal may include at least one of the following: a fault signal of the electric oil pump, an abnormal signal of the sensor, or a communication abnormal signal.

[0021] In the above method, by detecting abnormal signals throughout the pre-lubrication process and immediately stopping pre-lubrication upon detecting an abnormal signal, damage caused by oil pump motor malfunction can be avoided, and misjudgment of engine lubrication completion due to abnormalities can also be prevented.

[0022] Secondly, embodiments of this application provide an engine pre-lubrication system, the system comprising: An oil temperature sensor is used to obtain the initial oil temperature before engine pre-lubrication. The engine control unit is used to continuously inject a first current into the motor winding of the electric oil pump of the engine for pre-lubrication if the initial oil temperature is lower than a preset temperature threshold, and to control the electric oil pump to remain stationary. The engine control unit is also used to control the electric oil pump to rotate at the target speed after injecting a first current into the motor winding for a preset injection time, and to inject a second current into the motor winding for pre-lubrication.

[0023] Optionally, the first current and the second current are both direct-axis currents.

[0024] Optionally, the first current mentioned above is a preset ratio of the motor's rated current, and the preset ratio is less than 1.

[0025] Optionally, controlling the electric oil pump to rotate at the target speed includes: The electric oil pump is controlled to rotate at at least two target speeds, each of which corresponds to a preset time, and the speeds increase progressively.

[0026] Optionally, after injecting a second current into the motor windings for pre-lubrication, the engine control unit is also used for: Determine the target oil temperature range after pre-lubricating the engine; Based on the correspondence between the oil temperature range and the oil pressure range of the engine's main oil passage, the target oil pressure range corresponding to the target oil temperature is determined. If the oil pressure in the main oil passage of the engine is within the target oil pressure range, the engine pre-lubrication is considered complete.

[0027] Optionally, if the obtained oil pressure in the engine's main oil passage is within the target oil pressure range, it is determined that engine pre-lubrication is complete. The engine control unit is specifically used for: Within the preset detection time, the engine main oil passage oil pressure and target oil temperature are obtained at least twice; If the oil pressure of the engine's main oil passage is obtained each time and is within the target oil pressure range corresponding to the target oil temperature, it is determined that the engine pre-lubrication is complete.

[0028] Optionally, the aforementioned engine control unit is also used for: If the oil pressure in the main oil passage of the engine is not within the target oil pressure range, and the actual pre-lubrication time does not exceed the preset maximum pre-lubrication time, the electric oil pump is controlled to rotate at the target speed again, and a second current is injected into the motor winding for pre-lubrication. Optionally, the aforementioned engine control unit is also used for: If the actual number of retry attempts for pre-lubrication reaches the preset number of retry attempts, and the oil pressure of the engine main oil passage obtained each time is not within the target oil pressure range, the engine pre-lubrication is determined to have failed, and pre-lubrication is stopped.

[0029] Optionally, the aforementioned engine control unit is also used for: If an abnormal signal is detected, pre-lubrication shall be stopped. The abnormal signal may include at least one of the following: a fault signal of the electric oil pump, an abnormal signal of the sensor, or a communication abnormal signal.

[0030] Thirdly, embodiments of this application also provide an engine pre-lubrication device, the device comprising: The transceiver unit is used to obtain the initial oil temperature before engine pre-lubrication. The processing unit is used to continuously inject a first current into the motor winding of the electric oil pump of the engine for pre-lubrication if the initial oil temperature is lower than a preset temperature threshold, and to control the electric oil pump to remain stationary. The processing unit is also used to control the electric oil pump to rotate at the target speed after injecting the first current into the motor winding for a preset injection time, and to inject the second current into the motor winding for pre-lubrication.

[0031] Optionally, the first current and the second current are both direct-axis currents.

[0032] Optionally, the first current mentioned above is a preset ratio of the motor's rated current, and the preset ratio is less than 1.

[0033] Optionally, the above-mentioned control electric oil pump rotates at a target speed, and the processing unit is specifically used for: The electric oil pump is controlled to rotate at at least two target speeds, each of which corresponds to a preset time, and the speeds increase progressively.

[0034] Optionally, the above apparatus further includes a determining unit, which is used for: Determine the target oil temperature range after pre-lubricating the engine; Based on the correspondence between the oil temperature range and the oil pressure range of the engine's main oil passage, the target oil pressure range corresponding to the target oil temperature is determined. If the oil pressure in the main oil passage of the engine is within the target oil pressure range, the engine pre-lubrication is considered complete.

[0035] Optionally, if the obtained oil pressure in the engine's main oil passage is within the target oil pressure range, it is determined that the engine pre-lubrication is complete. The determining unit is specifically used for: Within the preset detection time, the engine main oil passage oil pressure and target oil temperature are obtained at least twice; If the oil pressure of the engine's main oil passage is obtained each time and is within the target oil pressure range corresponding to the target oil temperature, it is determined that the engine pre-lubrication is complete.

[0036] Optionally, the above processing unit is also used for: If the oil pressure in the main oil passage of the engine is not within the target oil pressure range, and the actual pre-lubrication time does not exceed the preset maximum pre-lubrication time, the electric oil pump is controlled to rotate at the target speed again, and a second current is injected into the motor winding for pre-lubrication. Optionally, the determining unit described above is also used for: If the actual number of retry attempts for pre-lubrication reaches the preset number of retry attempts, and the oil pressure of the engine main oil passage obtained each time is not within the target oil pressure range, the engine pre-lubrication is determined to have failed, and pre-lubrication is stopped.

[0037] Optionally, the above processing unit is also used for: If an abnormal signal is detected, pre-lubrication shall be stopped. The abnormal signal may include at least one of the following: a fault signal of the electric oil pump, an abnormal signal of the sensor, or a communication abnormal signal.

[0038] Fourthly, embodiments of this application also provide a computer device, including: Memory, used to store program instructions; A processor is used to call program instructions stored in memory and execute any of the methods in the first aspect above according to the obtained program.

[0039] Fifthly, embodiments of this application also provide a computer-readable storage medium storing computer-executable instructions for causing a computer to perform the method described in any of the first aspects above.

[0040] Sixthly, embodiments of this application also provide a computer program product, the computer program product including an executable program, which is executed by a processor using the method of any one of the first aspects described above. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 A schematic diagram of an optional engine pre-lubrication system provided for an embodiment of this application; Figure 2 A schematic flowchart of an optional engine pre-lubrication method provided in an embodiment of this application; Figure 3 A schematic diagram illustrating an optional target rotational speed and time provided for an embodiment of this application; Figure 4 A schematic flowchart of an optional engine pre-lubrication method provided in an embodiment of this application; Figure 5 A schematic diagram of an optional engine pre-lubrication device provided in an embodiment of this application; Figure 6 A schematic diagram of another optional engine pre-lubrication device provided in an embodiment of this application; Figure 7 This is a schematic diagram of an optional electronic device provided in an embodiment of this application. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] The application scenarios described in this application are for the purpose of more clearly illustrating the technical solutions of this application, and do not constitute a limitation on the technical solutions provided in this application. Those skilled in the art will understand that with the emergence of new application scenarios, the technical solutions provided in this application are also applicable to similar technical problems. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0045] The terms "first," "second," etc., used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a technical feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0046] like Figure 1 As shown, this application embodiment provides a schematic diagram of an optional engine pre-lubrication system. Figure 1 It includes a Vehicle Integration Unit (VIU) 101, an Engine Management System (EMS) 102, an Electric Oil Pump (EOP), an Oil Temperature Sensor 104, and an Oil Pressure Sensor 105; wherein the Vehicle Integration Unit 101, the Engine Management System 102, and the Electric Oil Pump 103 communicate with each other via a Controller Area Network (CAN) bus.

[0047] The vehicle main controller is used to wake up the engine control unit after receiving a start signal that triggers the engine pre-lubrication process; it is also used to receive information uploaded by the engine control unit (such as the operating status of engine pre-lubrication and fault information).

[0048] The engine control unit is used to access and receive signals from sensors, including at least one of an oil temperature sensor and an oil pressure sensor; to send control commands to the electric oil pump via the CAN bus and to receive feedback information from the electric oil pump (such as fault information of the electric oil pump); and to provide feedback information to the vehicle main controller (for example, the feedback information may include at least one of the engine pre-lubrication operating status and fault information).

[0049] The electric oil pump is used to receive commands from the engine control unit (for example, the commands may include at least one of target speed, target torque, heating the motor windings, and injecting current into the motor windings) based on the CAN bus, and to perform local motor drive control; at the same time, it provides real-time feedback on its own operating status to the engine control unit, and provides fault information on its own operation to the engine control unit when a fault occurs.

[0050] The following explanation uses the controller executing the engine pre-lubrication method provided in this application as an example. Figure 2 As shown in the figure, this application embodiment provides a schematic flowchart of an optional engine pre-lubrication method, including the following steps: Step S201: Obtain the initial oil temperature before engine pre-lubrication.

[0051] In some embodiments, the controller may receive a start signal to trigger the engine pre-lubrication process, for example, when the driver presses the vehicle start button. Another example is a start signal sent by a mobile application associated with the vehicle. The controller responds to the start signal; obtains the initial oil temperature before engine pre-lubrication based on the oil temperature sensor in the engine pre-lubrication system; and then compares the initial oil temperature with a preset temperature threshold. It is understood that the preset temperature threshold can be preset by those skilled in the art or flexibly changed based on different application scenarios. For example, the preset temperature threshold may be 5 degrees Celsius; or, for example, 6 degrees Celsius.

[0052] In one possible scenario, after comparing the initial oil temperature with a preset temperature threshold, if the oil temperature is greater than or equal to the preset temperature threshold, the controller can determine that the electric oil pump does not require preheating. That is, step S202 is not required; the controller can directly control the electric oil pump to rotate at the target speed and inject a second current into the motor windings for pre-lubrication. For example, suppose the initial oil temperature before engine pre-lubrication is 15°C; the preset temperature threshold is 5°C. Since the initial oil temperature of 15°C is greater than the preset temperature threshold of 5°C, the controller can directly execute step S203, controlling the electric oil pump to rotate at the target speed and injecting a second current into the motor windings for pre-lubrication. As another example, suppose the initial oil temperature before engine pre-lubrication is 6°C; the preset temperature threshold is 6°C. Since the initial oil temperature of 6°C is equal to the preset temperature threshold of 6°C, the controller can control the electric oil pump to rotate at the target speed and inject a second current into the motor windings for pre-lubrication.

[0053] In another possible scenario, after comparing the initial oil temperature with a preset temperature threshold, if the oil temperature is lower than the preset temperature threshold, then step S202 is executed. For example, suppose the initial oil temperature before engine pre-lubrication is -5°C; the preset temperature threshold is 6°C. Since the initial oil temperature of -5°C is lower than the preset temperature threshold of 6°C, the controller can execute step S202.

[0054] Step S202: If the initial oil temperature is lower than the preset temperature threshold, continuously inject the first current into the motor winding of the electric oil pump of the engine for pre-lubrication, and control the electric oil pump to maintain a stationary state.

[0055] In some embodiments, the effects of the direct-axis current (Id) and the quadrature-axis current (Iq) on the output torque of the electric oil pump can be determined based on the motor electromagnetic torque formula; wherein, the direct-axis current is used to control the magnitude of the magnetic field, and the quadrature-axis current is used to control the magnitude of the electromagnetic torque. The motor electromagnetic torque formula is:

[0056] in, This represents the electromagnetic torque of the motor. P represents the number of pole pairs. This indicates a permanent magnet flux linkage. This indicates direct-axis inductance (d-axis inductance). This indicates quadrature-axis inductance (q-axis inductance). This represents the direct-axis current (d-axis current). This represents the quadrature-axis current (q-axis current).

[0057] Based on the above formula for the electromagnetic torque of the motor, it can be determined that: when the q-axis current... When =0, regardless of the d-axis current The electromagnetic torque remains zero regardless of the chosen value; at this point, the electric oil pump remains stationary. While the electric oil pump remains stationary, a constant direct-axis current is injected into the motor windings of the electric oil pump. The d-axis current flows through the resistance of the motor windings (stator windings). Joule heating Among them, Joule heating Satisfy the following formula:

[0058] in, It indicates Joule heating. This represents the d-axis current. This indicates the winding resistance.

[0059] Based on the above Joule heating The formula satisfies the following: the heating power is only affected by the d-axis current and not by the magnitude of the q-axis current. Therefore, the first current in this application can be the d-axis current. The controller can set the q-axis current to 0, so that the motor of the electric oil pump does not output torque, thereby controlling the electric oil pump to maintain a stationary state. Then, based on the current closed-loop proportional-integral (PI) control, the actual d-axis current reaches the preset d-axis current. Finally, the d-axis current is injected into the motor winding (stator winding) of the electric oil pump. At this time, the injected d-axis current flows through the resistance of the motor winding (stator winding) to generate Joule heat, thereby achieving engine preheating.

[0060] Compared to existing technologies that rely on external heaters and high-pressure, high-power oil pumps to heat the engine oil, this application sets the q-axis current to zero, thus reducing the motor's electromagnetic torque to zero and keeping the electric oil pump stationary. It injects only a low-energy d-axis current into the motor windings, relying on the winding resistance to generate Joule heat to directly heat the pump body and surrounding low-temperature engine oil. This eliminates the need for additional independent oil heating hardware, reducing the cost and complexity of the engine pre-lubrication system. Furthermore, this application uses closed-loop PI control to achieve the preset d-axis current, reducing the risk of motor stall and starting failure under low-temperature conditions and improving the reliability of the low-temperature pre-lubrication process.

[0061] Optionally, to prevent excessively high first current and winding temperature from accelerating the aging of insulation materials, reducing motor lifespan, and compromising motor mechanical performance, the first current in this embodiment can be set to a preset proportion of the motor's rated current. The preset proportion is less than 1, meaning the first current is less than the rated current of the motor within the electric oil pump. In this way, by injecting a constant, low-energy first current into the motor windings of the electric oil pump, this application can generate sufficient heat to dissipate the viscous resistance of the low-temperature oil while avoiding overheating problems caused by high current. It is understood that the preset proportion and the first current can also be preset by those skilled in the art or flexibly changed based on different application scenarios. For example, the preset proportion can be 10%, and the first current can be 10% of the motor's rated current; the first current value is 5A. Another example is that the preset proportion can be 28%, and the first current can be 28% of the rated current of the motor within the electric oil pump; the first current value is 6A. Yet another example is that the preset proportion can be any proportion between 10% and 30%, and the first current can be any current corresponding to 10% to 30% of the motor's rated current.

[0062] Optionally, the first current can be a constant current, for example, 5A; or, for example, 3A. The first current can also be a variable current, for example, it can include at least two levels of current, each level corresponding to a preset duration, and increasing progressively. This progressively increasing the first current allows the engine's heat output to increase gradually, resulting in a smooth rise in oil temperature; simultaneously, it prevents rapid high-current energization, overheating of the motor windings, and oil film deterioration caused by sudden increases in local oil film temperature. For example, the first current can include three levels: a first level of 3A, injected into the motor windings for 2 seconds; a second level of 4A, injected into the motor windings for 2 seconds; and a third level of 5A, injected into the motor windings for 2 seconds. Alternatively, the first current can include two levels: a first level of 5A, injected into the motor windings for 3 seconds; and a second level of 7A, injected into the motor windings for 2 seconds.

[0063] Step S203: After injecting the first current into the motor winding for a preset injection time, control the electric oil pump to rotate at the target speed and inject the second current into the motor winding for pre-lubrication.

[0064] It is understood that the preset heating time can be pre-set by those skilled in the art or can be flexibly changed based on different application scenarios. For example, if the preset heating time is 2 seconds, then the first current is continuously injected into the motor winding for 2 seconds; or if the preset heating time is 3 seconds, then the first current is continuously injected into the motor winding for 3 seconds.

[0065] Because the q-axis current (not zero) generates electromagnetic torque when the motor is rotating, driving the rotor to rotate; the d-axis current has no effect on the driving torque, only used to generate heat and losses in the stator windings and core. That is, the heat generation power is controlled solely by the d-axis current. Therefore, the second current can be a high-frequency pulsating d-axis current. It is understood that the second current can also be preset by those skilled in the art, or flexibly changed based on different application scenarios. The first and second currents can be the same or different; the second current can be a constant current or a varying current. For example, if the first current is 5A, then the second current can be the same as the first current and constant, also 5A. For another example, to prevent overheating of the motor windings and oil film deterioration caused by a sudden rise in local oil film temperature due to rapid high-current energization, the second current can include at least two levels of current, each corresponding to a preset duration, and increasing progressively. For example, the first current can be 4A; the second current can be different from the first current and can include three levels of current: the first level current is 3A, injected into the motor winding for 3 seconds (s); the second level current is 5A, injected into the motor winding for 2 seconds; and the third level current is 6A, injected into the motor winding for 3 seconds. As another example, the first current can be 4A; the second current can be different from the first current and can include two levels of current: the first level current is 3A, injected into the motor winding for 3 seconds; and the second level current is 6A, injected into the motor winding for 5 seconds. As yet another example, the first current can be 5A; the second current can be the same as the first current, or it can be 5A. As yet another example, the first current can be 2A; the second current can be different from the first current and is constant; the second current can be 3A.

[0066] Optionally, this application can control the electric oil pump to rotate at at least two target speeds, each target speed corresponding to a preset duration, and increasing progressively. By controlling the electric oil pump to rotate sequentially at at least two target speeds, the pump's speed can be gradually increased, preventing oil film tearing or motor stalling caused by sudden changes in pump speed. Simultaneously, the oil's temperature rise rate can be more precisely controlled, preventing localized overheating. For example, in an engine pre-lubrication system, the engine control unit sends a command to the electric oil pump, controlling the motor to drive the pump to rotate at a target speed and continuously injecting d-axis current (a second current) into the rotating motor windings; wherein the target speed includes three levels; such as... Figure 3 As shown, this application provides a schematic diagram of an optional target rotational speed and time. Figure 3 The first-level target speed is 150 rpm, with a corresponding duration of 2 seconds; the second-level target speed is 300 rpm, with a corresponding duration of 2 seconds; and the third-level target speed is 500 rpm, with a corresponding duration of 3 seconds.

[0067] It is understood that the target rotational speed and the corresponding preset duration for each target rotational speed can be preset by those skilled in the art, or can be flexibly changed based on different application scenarios. For example, the controller controls the electric oil pump to rotate at two target rotational speeds, where the first target rotational speed is 150 rpm with a corresponding duration of 2 seconds; and the second target rotational speed is 300 rpm with a corresponding duration of 2 seconds. As another example, the controller controls the electric oil pump to rotate at three target rotational speeds, where the first target rotational speed is 110 rpm with a corresponding duration of 2 seconds; the second target rotational speed is 200 rpm with a corresponding duration of 3 seconds; and the third target rotational speed is 300 rpm with a corresponding duration of 5 seconds.

[0068] In some embodiments, based on the oil film thickness calculation formula, the oil film formation pattern under different temperature conditions can be determined: In a low-temperature, high-viscosity oil environment, even if the oil pressure in the engine's main oil passage is low, a relatively large oil film thickness can still be formed, making it easy to enter a full oil film lubrication state; while in a high-temperature, low-viscosity oil environment, the oil fluidity increases, and the oil film is easily lost, requiring higher oil pressure to maintain the required oil film thickness; wherein, the oil film thickness calculation formula is:

[0069] in, This refers to the thickness of the oil film. This refers to the minimum engineering oil film thickness between the journal and the rough surface of the bearing bush. This is the root mean square deviation of the journal surface profile. This is the root mean square deviation of the journal surface profile.

[0070] Therefore, based on the oil film formation patterns under different temperature conditions, a pre-defined correspondence between the oil temperature range and the oil pressure range of the engine's main oil passage can be established. In some embodiments, the controller can acquire the target oil temperature and the oil pressure of the engine's main oil passage after pre-lubrication. After acquiring the target oil temperature, the controller can determine the target oil temperature range within which the target oil temperature falls. Then, based on the correspondence between the oil temperature range and the oil pressure range of the engine's main oil passage, the controller can determine the target oil pressure range corresponding to the target oil temperature. Finally, the controller determines whether the oil pressure of the engine's main oil passage is within the target oil pressure range. If the oil pressure of the engine's main oil passage is within the target oil pressure range, the engine pre-lubrication is determined to be complete. If the oil pressure of the engine's main oil passage is not within the target oil temperature range, the engine pre-lubrication is determined to be incomplete.

[0071] In the above method, by presetting corresponding target oil pressure ranges for different oil temperature ranges, it is possible to ensure that the main oil passage of the engine is fully filled with oil, and that an oil film that meets the requirements is formed between the journal and the bearing to prevent the risk of dry friction during startup; it is also possible to reduce the operating power consumption and electricity consumption of the electric oil pump and improve the reliability of the electric oil pump's safe operation.

[0072] The following example illustrates how to determine whether engine pre-lubrication is complete based on the correspondence between the engine oil temperature range and the engine main oil pressure range:

[0073] For example, the correspondence between the engine oil temperature range and the engine oil pressure range in the main oil passage satisfies Table 1:

[0074] In Table 1, T_oil represents the target oil temperature. When the target oil temperature is less than or equal to -10 degrees Celsius (°C), the corresponding oil pressure range is 0.8 MPa to 0.10 MPa. When the target oil temperature is greater than -10°C and less than or equal to 25°C, the corresponding oil pressure range is 0.10 MPa to 0.13 MPa. When the target oil temperature is greater than 25°C, the corresponding oil pressure range is greater than 0.13 MPa.

[0075] For example, assume the correspondence between the engine oil temperature range and the engine main oil pressure range satisfies Table 1. The target engine oil temperature after pre-lubrication is -15℃, and the engine main oil pressure is 0.9MPa. The target oil temperature of -15℃ falls within the target oil temperature range of less than -10℃, corresponding to a target oil pressure range of 0.8MPa to 0.10MPa. Since the engine main oil pressure of 0.9MPa is within the target oil temperature range, engine pre-lubrication is considered complete.

[0076] Assume that the correspondence between the engine oil temperature range and the engine main oil pressure range satisfies Table 1. The target engine oil temperature after pre-lubrication is 30℃, and the engine main oil pressure is 0.1MPa. The target oil temperature is above 25℃, corresponding to a target oil pressure range above 0.13MPa. Since the engine main oil pressure of 0.1MPa is not within the target oil temperature range, the comparison result does not meet the preset rules, confirming that engine pre-lubrication is incomplete.

[0077] Optionally, to continuously track changes in engine oil temperature in real time and prevent data lag, the controller can acquire the target engine oil temperature and the engine main oil passage oil pressure during engine pre-lubrication in real time to determine whether engine pre-lubrication is complete. To continuously track oil temperature changes and prevent misjudgments caused by instantaneous oil pressure fluctuations, thus improving the reliability of determining the success of engine pre-lubrication, the controller can also periodically acquire the target engine oil temperature and the engine main oil passage oil pressure based on a preset time period to determine whether engine pre-lubrication is complete. It is understood that the aforementioned preset time period can be pre-set by those skilled in the art or flexibly changed based on different application scenarios. For example, if the preset time period is 500ms, the controller acquires the target engine oil temperature and the engine main oil passage oil pressure every 500ms to determine whether engine pre-lubrication is complete. Or, for example, if the preset time period is 600ms, the controller acquires the target engine oil temperature and the engine main oil passage oil pressure every 600ms to determine whether engine pre-lubrication is complete.

[0078] Optionally, if the controller can acquire the engine main oil passage oil pressure and target oil temperature at least twice within the preset detection time, and if the acquired engine main oil passage oil pressure is within the target oil pressure range corresponding to the target oil temperature each time, then engine pre-lubrication is determined to be complete. The preset detection time is the time window for continuous sampling verification. For example, if the preset detection time is 1 second, and the target oil temperature of 25℃ corresponds to a target oil pressure range of 0.13MPa~0.18MPa, then the engine main oil passage oil pressure of 0.14MPa is within the target oil pressure range. In a subsequent sampling, if the target oil temperature remains unchanged, and the subsequent sampled engine main oil passage oil pressure of 0.11MPa is not within the target oil pressure range, then engine pre-lubrication is determined to be incomplete. For example, with a preset detection time of 3 seconds, the target oil pressure range corresponding to a target oil temperature of -5℃ is 0.8MPa~0.10MPa. At this time, the oil pressure in the engine's main oil passage, 0.8MPa, is within the target oil pressure range. In the subsequent sampling, the target oil temperature remains unchanged, and the sampled oil pressure of 0.95MPa is also within the target oil pressure range. If the oil pressure in the engine's main oil passage is within the target oil pressure range corresponding to the target oil temperature in each sampling within 3 consecutive seconds, it is determined that the engine pre-lubrication is complete, and the engine can be ignited and started.

[0079] In the above method, by setting a preset detection time, the target oil temperature and the oil pressure of the engine main oil passage during engine pre-lubrication are continuously detected within the detection time. This can avoid misjudgment of pre-lubrication caused by instantaneous oil pressure fluctuations, ensure the continuous effectiveness of the oil film, and improve the reliability of pre-lubrication control.

[0080] Optionally, during engine start-up pre-lubrication, the actual pre-lubrication duration can be determined based on a timer. If the target oil temperature and main oil pressure during engine pre-lubrication do not meet preset rules, and the actual pre-lubrication duration does not exceed the maximum allowable duration for engine pre-lubrication, step S203 is re-executed to control the electric oil pump to rotate at the target speed and inject a second current into the motor windings for pre-lubrication. The actual pre-lubrication duration is the time accumulated by the timer from the start of engine pre-lubrication. If the actual pre-lubrication duration reaches the maximum allowable duration for engine pre-lubrication, engine pre-lubrication is deemed a failure. It is understood that the pre-lubrication duration can be preset by those skilled in the art or flexibly changed based on different application scenarios. For example, the pre-lubrication duration could be 10 seconds. Or, for example, 15 seconds.

[0081] In the above method, by setting the maximum allowable duration of pre-lubrication of the engine, it is possible to prevent the electric oil pump from overheating and aging of the windings due to prolonged load operation, thereby protecting the service life of the electric oil pump and improving system safety.

[0082] Optionally, the controller can also count the actual number of retry attempts for engine pre-lubrication. If the actual number of retry attempts does not reach the preset number of retry attempts, and the latest acquired target oil temperature and engine main oil passage oil pressure meet the preset rules, the engine pre-lubrication is determined to be complete. The actual number of retry attempts is the cumulative number of times the engine pre-lubrication process is re-executed during the pre-lubrication process. The preset number of retry attempts is the maximum number of retry attempts allowed for engine pre-lubrication. If the actual number of retry attempts reaches the preset number of retry attempts, and the engine main oil passage oil pressure is not within the target oil pressure range in each acquisition, the engine pre-lubrication is determined to have failed, and pre-lubrication is stopped.

[0083] In the above method, by not directly determining engine pre-lubrication failure when the oil pressure in the engine's main oil passage does not meet the preset rules for the first time, but instead allowing the pre-lubrication process to be re-executed within a preset number of retries, the probability of successful engine pre-lubrication can be improved. Determining whether to end the retry pre-lubrication based on the preset number of retries can reduce the probability of component damage caused by unlimited retry pre-lubrication, thereby extending the equipment's lifespan.

[0084] The following example illustrates this: Assume the maximum allowable pre-lubrication time for the engine is 15 seconds, and the preset number of retry attempts is 3. The target oil temperature during engine pre-lubrication is 10℃, falling within the target oil temperature range of -10℃ to 25℃, corresponding to a target oil pressure range of 0.1MPa to 0.13MPa. The engine main oil passage pressure is 0.08MPa, outside the target oil pressure range, and therefore does not meet the preset rules. In this case, the actual pre-lubrication time is 3 seconds, which does not exceed the maximum allowable pre-lubrication time of 15 seconds. During the first retry of engine pre-lubrication: the controller returns to controlling the electric oil pump to rotate at the target speed and injects direct-axis current (the second current) into the motor windings. The controller then obtains the latest target oil temperature of 23℃, which falls within the target oil temperature range of -10℃ to 25℃, corresponding to a target oil pressure range of 0.1MPa to 0.13MPa. The latest obtained engine main oil pressure is 0.09 MPa, which is still outside the target oil pressure range and does not meet the preset rules. At this time, the actual pre-lubrication time is 5 seconds, which does not exceed the maximum allowable pre-lubrication time of 15 seconds for the engine. The actual number of retry (1 time) does not reach the preset number of retry (3 times). For the second retry of engine pre-lubrication: the controller returns to execute the control of the electric oil pump to rotate at the target speed and inject direct-axis current (second current) into the motor winding. The controller obtains the latest target oil temperature again, which is 24℃. The latest obtained target oil temperature of 24℃ is within the target oil temperature range of greater than -10℃ and less than 25℃, corresponding to a target oil pressure range of 0.1 MPa to 0.13 MPa. The latest obtained engine main oil pressure is 0.12 MPa, which is within the target oil pressure range, and it can be confirmed that the engine pre-lubrication is complete.

[0085] For example, suppose the maximum allowable pre-lubrication time for the engine is 12 seconds, and the preset number of retry attempts is 3. The target oil temperature obtained during engine pre-lubrication is 8°C, which falls within the target oil temperature range of greater than -10°C and less than 25°C, corresponding to a target oil pressure range of 0.1MPa to 0.13MPa. The oil pressure in the engine's main oil passage is 0.06MPa, which is outside the target oil pressure range and does not meet the preset rules. In this case, the actual pre-lubrication time is 2 seconds, which does not exceed the maximum allowable pre-lubrication time of 12 seconds. During the first retry of engine pre-lubrication: the controller returns to control the electric oil pump to rotate at the target speed and injects direct-axis current (the second current) into the motor windings. The controller then obtains the latest target oil temperature of 10°C, which falls within the target oil temperature range of greater than -10°C and less than 25°C, corresponding to a target oil pressure range of 0.1MPa to 0.13MPa. The latest obtained engine main oil pressure is 0.07 MPa, still outside the target oil pressure range. The actual pre-lubrication time is 5 seconds, which does not exceed the maximum allowable pre-lubrication time of 12 seconds. The actual number of retry attempts (1) has not reached the preset number of retry attempts (3). For the second retry of engine pre-lubrication: the controller returns to controlling the electric oil pump to rotate at the target speed and injects direct-axis current (second current) into the motor windings. The controller again obtains the latest target oil temperature of 15℃, which falls within the target oil temperature range of greater than -10℃ and less than 25℃, corresponding to a target oil pressure range of 0.1 MPa to 0.13 MPa. The latest obtained engine main oil pressure is 0.08 MPa, still outside the target oil pressure range. At this point, the actual pre-lubrication time is 8 seconds, which does not exceed the maximum allowable pre-lubrication time of 12 seconds for the engine. The actual number of retries (2) has not reached the preset number of retries (3). For the third retry of engine pre-lubrication: the controller returns to controlling the electric oil pump to rotate at the target speed and injects direct-axis current (second current) into the motor windings. The controller then obtains the latest target oil temperature of 20°C, which falls within the target oil temperature range of greater than -10°C and less than 25°C, corresponding to a target oil pressure range of 0.1MPa to 0.13MPa. The latest obtained oil pressure in the engine's main oil passage is 0.09MPa, still outside the target oil pressure range. At this point, the actual number of retries (3) has reached the preset number of retries (3), and the oil pressure in the engine's main oil passage is not within the target oil pressure range each time. Therefore, engine pre-lubrication is determined to have failed, and pre-lubrication is stopped.

[0086] For example, suppose the maximum allowable pre-lubrication time for the engine is 8 seconds, and the preset number of retry attempts is 3. The target oil temperature obtained during engine pre-lubrication is 15℃, which falls within the target oil temperature range of greater than -10℃ and less than 25℃, corresponding to a target oil pressure range of 0.1MPa to 0.13MPa. The oil pressure in the engine's main oil passage is 0.08MPa, which is not within the target oil pressure threshold range. In this case, the actual pre-lubrication time is 4 seconds, which does not exceed the maximum allowable pre-lubrication time of 8 seconds. During the first retry of engine pre-lubrication: the controller returns to execute the control of the electric oil pump to rotate at the target speed and injects direct-axis current (second current) into the motor windings. The controller then obtains the latest target oil temperature of 24℃, which falls within the target oil temperature range of greater than -10℃ and less than 25℃, corresponding to a target oil pressure range of 0.1MPa to 0.13MPa. The latest obtained oil pressure in the engine's main oil passage is 0.09 MPa, which is still outside the target oil pressure range. At this time, the actual pre-lubrication time is 9 seconds. Since the actual pre-lubrication time of 9 seconds exceeds the maximum allowable pre-lubrication time of 8 seconds for the engine, it can be determined that the engine pre-lubrication has failed, and pre-lubrication should be stopped.

[0087] Optionally, if the controller detects an abnormal signal, it stops the engine pre-lubrication. Abnormal signals include at least one of the following: a fault signal from the electric oil pump, an abnormal signal from a sensor, or a communication abnormality. For example, if the engine control unit receives a fault signal from the electric oil pump indicating stall, overcurrent, or over / undervoltage, it stops the engine pre-lubrication. Alternatively, if the engine control unit itself diagnoses an abnormal sensor signal or communication signal, it stops the engine pre-lubrication.

[0088] In the above method, by detecting abnormal signals throughout the pre-lubrication process and immediately stopping the pre-lubrication process after detecting an abnormality, damage caused by oil pump motor failure can be avoided, and misjudgment of engine lubrication completion due to abnormality can also be prevented.

[0089] Optionally, the controller can store the abnormal signal after detecting it, and can also upload the corresponding fault information for subsequent troubleshooting and maintenance.

[0090] In some embodiments, the above Figure 1 The engine pre-lubrication system in the system can achieve the above-mentioned engine pre-lubrication method, which will be explained below: After the vehicle is powered on, the vehicle controller wakes up the engine control unit, which then performs initialization. After initialization, engine pre-lubrication is initiated: the engine control unit collects the initial oil temperature before pre-lubrication starts via an oil temperature sensor. In one possible scenario, if the initial oil temperature is greater than or equal to a preset temperature threshold, the electric oil pump is directly controlled to rotate at the target speed, and a second current is injected into the pump motor windings for pre-lubrication. In another possible scenario, if the initial oil temperature is less than the preset temperature threshold, a constant low-energy direct-axis current (first current) is injected into the electric oil pump motor windings for pre-lubrication, and the quadrature-axis current is set to 0 to keep the electric oil pump stationary. After continuously injecting direct-axis current into the motor windings for a preset heating time, the electric oil pump is controlled to rotate at the target speed, and a high-frequency pulsating direct-axis current (second current) is injected into the motor windings for pre-lubrication. Simultaneously with engine pre-lubrication, the controller can also activate a timing device to determine the actual pre-lubrication duration. The engine control unit can also acquire the target oil temperature and the oil pressure of the engine's main oil passage at 100ms intervals. It determines whether the oil pressure acquired each time within a preset detection period of 1 second falls within the target oil pressure range corresponding to the target oil temperature, thus confirming engine pre-lubrication completion. Simultaneously, the engine control unit continuously monitors whether the actual pre-lubrication time exceeds the maximum allowable pre-lubrication time. If the actual pre-lubrication time does not exceed the maximum allowable time, and the actual number of retry attempts does not reach the preset number of retry attempts, a timeout retry is recorded, and the control unit returns to execute the control of the electric oil pump to rotate at the target speed and inject direct-axis current (second current) into the motor windings. If the actual number of retry attempts reaches the preset number of retry attempts, engine pre-lubrication is determined to have failed, and pre-lubrication is stopped. When the oil pressure acquired each time within a preset detection period of 1 second falls within the target oil pressure range corresponding to the target oil temperature, engine pre-lubrication is confirmed to be complete; the engine control unit can then send a standby ready command to the vehicle. While pre-lubricating the engine, the engine control unit can also detect various abnormal signals in real time, such as electric oil pump stall, sensor malfunction, and communication malfunction. If any of the above abnormal signals are received, the engine pre-lubrication will be stopped and the corresponding fault information will be reported.

[0091] Optionally, to facilitate more precise control of the pre-lubrication phase, the engine control unit may also include a state machine. Before pre-lubrication, the state machine can switch to an idle state, representing the initial state after the vehicle is powered on and initialized. During engine pre-lubrication, the state machine switches to preheating, indicating that pre-lubrication is in progress. If the actual number of retries reaches the preset number, the state machine can switch to a fault state and report a fault, indicating an unrecoverable anomaly. Once engine pre-lubrication is complete, the state machine switches to pre-lubrication complete (Ready), indicating that the oil pressure in the engine's main oil passage has reached the required level, and the electric oil pump enters standby mode.

[0092] Based on the same technological concept, such as Figure 4 As shown, this application also provides a schematic flowchart of an optional engine pre-lubrication method, including the following steps: Step S401: Obtain the initial oil temperature before engine pre-lubrication; Step S402: Determine whether the initial oil temperature is lower than the preset temperature threshold. If yes, proceed to step S403; otherwise, proceed to step S404.

[0093] Step S403: Continuously inject a constant first current into the motor windings of the engine's electric oil pump for pre-lubrication.

[0094] Step S404: After injecting the first current into the motor winding for a preset injection time, control the electric oil pump to rotate at at least two target speeds and inject a second current into the motor winding for pre-lubrication. Each of the at least two target speeds corresponds to a preset time and increases progressively.

[0095] Step S405: Within a preset detection time, based on the preset time period, at least twice periodically acquire the oil pressure and target oil temperature of the engine main oil passage.

[0096] Step S406: Determine whether the oil pressure of the main oil passage of the engine obtained each time is within the target oil pressure range corresponding to the target oil temperature. If yes, proceed to step S407; otherwise, proceed to step S408.

[0097] Step S407: Confirm that engine pre-lubrication is complete.

[0098] Step S408: Determine whether the actual pre-lubrication time exceeds the preset maximum pre-lubrication time. If yes, proceed to step S409; otherwise, proceed to step 404.

[0099] Step S409: Determine whether the actual number of retry attempts for pre-lubrication has reached the preset number of retry attempts. If yes, proceed to step S404; otherwise, proceed to step S410.

[0100] Step S410: Determine that the engine pre-lubrication has failed.

[0101] Based on the same technical concept, embodiments of this application provide an engine pre-lubrication system, the system comprising: An oil temperature sensor is used to obtain the initial oil temperature before engine pre-lubrication. The engine control unit is used to continuously inject a first current into the motor winding of the electric oil pump of the engine for pre-lubrication if the initial oil temperature is lower than a preset temperature threshold, and to control the electric oil pump to remain stationary. The engine control unit is also used to control the electric oil pump to rotate at the target speed after injecting a first current into the motor winding for a preset injection time, and to inject a second current into the motor winding for pre-lubrication.

[0102] Optionally, the first current and the second current are both direct-axis currents.

[0103] Optionally, the first current mentioned above is a preset ratio of the motor's rated current, and the preset ratio is less than 1.

[0104] Optionally, controlling the electric oil pump to rotate at the target speed includes: The electric oil pump is controlled to rotate at at least two target speeds, each of which corresponds to a preset time, and the speeds increase progressively.

[0105] Optionally, after injecting a second current into the motor windings for pre-lubrication, the engine control unit is also used for: Determine the target oil temperature range after pre-lubricating the engine; Based on the correspondence between the oil temperature range and the oil pressure range of the engine's main oil passage, the target oil pressure range corresponding to the target oil temperature is determined. If the oil pressure in the main oil passage of the engine is within the target oil pressure range, the engine pre-lubrication is considered complete.

[0106] Optionally, if the obtained oil pressure in the engine's main oil passage is within the target oil pressure range, it is determined that engine pre-lubrication is complete. The engine control unit is specifically used for: Within the preset detection time, the engine main oil passage oil pressure and target oil temperature are obtained at least twice; If the oil pressure of the engine's main oil passage is obtained each time and is within the target oil pressure range corresponding to the target oil temperature, it is determined that the engine pre-lubrication is complete.

[0107] Optionally, the aforementioned engine control unit is also used for: If the oil pressure in the main oil passage of the engine is not within the target oil pressure range, and the actual pre-lubrication time does not exceed the preset maximum pre-lubrication time, the electric oil pump is controlled to rotate at the target speed again, and a second current is injected into the motor winding for pre-lubrication. Optionally, the aforementioned engine control unit is also used for: If the actual number of retry attempts for pre-lubrication reaches the preset number of retry attempts, and the oil pressure of the engine main oil passage obtained each time is not within the target oil pressure range, the engine pre-lubrication is determined to have failed, and pre-lubrication is stopped.

[0108] Optionally, the aforementioned engine control unit is also used for: If an abnormal signal is detected, pre-lubrication shall be stopped. The abnormal signal may include at least one of the following: a fault signal of the electric oil pump, an abnormal signal of the sensor, or a communication abnormal signal.

[0109] Based on the same technological concept Figure 5 An exemplary schematic diagram of an optional engine pre-lubrication device provided in an embodiment of this application is shown, such as... Figure 5 As shown, the device specifically includes: The transceiver unit 501 is used to acquire the initial oil temperature before engine pre-lubrication. The processing unit 502 is used to continuously inject a first current into the motor winding of the electric oil pump of the engine for pre-lubrication if the initial oil temperature is less than a preset temperature threshold, and to control the electric oil pump to remain stationary. The processing unit 502 is also used to control the electric oil pump to rotate at the target speed after injecting the first current into the motor winding for a preset injection time, and to inject the second current into the motor winding for pre-lubrication.

[0110] Optionally, the first current and the second current are both direct-axis currents.

[0111] Optionally, the first current mentioned above is a preset ratio of the motor's rated current, and the preset ratio is less than 1.

[0112] Optionally, the above-mentioned control electric oil pump rotates at a target speed, and the processing unit 502 is specifically used for: The electric oil pump is controlled to rotate at at least two target speeds, each of which corresponds to a preset time, and the speeds increase progressively.

[0113] Optional, such as Figure 6 The diagram shown illustrates the structure of another optional engine pre-lubrication device provided in this embodiment of the application. Figure 6 The engine pre-lubrication device may further include a determining unit 503, which is used for: Determine the target oil temperature range after pre-lubricating the engine; Based on the correspondence between the oil temperature range and the oil pressure range of the engine's main oil passage, the target oil pressure range corresponding to the target oil temperature is determined. If the oil pressure in the main oil passage of the engine is within the target oil pressure range, the engine pre-lubrication is considered complete.

[0114] Optionally, if the obtained oil pressure in the engine's main oil passage is within the target oil pressure range, it is determined that the engine pre-lubrication is complete. Specifically, the determining unit 503 is used for: Within the preset detection time, the engine main oil passage oil pressure and target oil temperature are obtained at least twice; If the oil pressure of the engine's main oil passage is obtained each time and is within the target oil pressure range corresponding to the target oil temperature, it is determined that the engine pre-lubrication is complete.

[0115] Optionally, the processing unit 502 described above is further configured to: If the oil pressure in the main oil passage of the engine is not within the target oil pressure range, and the actual pre-lubrication time does not exceed the preset maximum pre-lubrication time, the electric oil pump is controlled to rotate at the target speed again, and a second current is injected into the motor winding for pre-lubrication. Optionally, the determining unit 503 is further configured to: If the actual number of retry attempts for pre-lubrication reaches the preset number of retry attempts, and the oil pressure of the engine main oil passage obtained each time is not within the target oil pressure range, the engine pre-lubrication is determined to have failed, and pre-lubrication is stopped.

[0116] Optionally, the processing unit 502 described above is further configured to: If an abnormal signal is detected, pre-lubrication shall be stopped. The abnormal signal may include at least one of the following: a fault signal of the electric oil pump, an abnormal signal of the sensor, or a communication abnormal signal.

[0117] Based on the same technical concept, embodiments of this application also provide an electronic device. Figure 7 This is a schematic diagram of an optional electronic device provided in an embodiment of this application.

[0118] At least one processor 701 and a memory 702 connected to at least one processor 701. In this embodiment, the specific connection medium between the processor 701 and the memory 702 is not limited. Figure 7 The example shown is the connection between processor 701 and memory 702 via bus 700. Bus 700 is... Figure 7 The connections between other components are indicated by thick lines and are for illustrative purposes only, not as limiting information. The 700 bus can be divided into address bus, data bus, control bus, etc., for ease of representation. Figure 7The term is represented by a single thick line, but this does not imply that there is only one bus or one type of bus. Alternatively, the processor 701 can also be called a controller; there is no restriction on the name.

[0119] In this embodiment, memory 702 stores instructions executable by at least one processor 701. By executing the instructions stored in memory 702, at least one processor 701 can perform an engine pre-lubrication method as described above. Processor 701 can implement... Figure 5 or Figure 6 The functions of each unit in the device shown.

[0120] The processor 701 is the control center of the device. It can connect to various parts of the control device through various interfaces and lines. By running or executing instructions stored in memory 702 and calling data stored in memory 702, the processor can perform various functions and process data, thereby monitoring the device as a whole.

[0121] In one possible design, processor 701 may include one or more processing units. Processor 701 may integrate an application processor and a modem processor, wherein the application processor mainly handles the operating system, driver interface, and applications, and the modem processor mainly handles wireless communication. It is understood that the modem processor may also not be integrated into processor 701. In some embodiments, processor 701 and memory 702 may be implemented on the same chip; in some embodiments, they may also be implemented on separate chips.

[0122] The processor 701 can be a general-purpose processor, such as a central processing unit (CPU), digital signal processor, application-specific integrated circuit, field-programmable gate array or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the engine pre-lubrication method disclosed in the embodiments of this application can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0123] Memory 702, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. Memory 702 may include at least one type of storage medium, such as flash memory, hard disk, multimedia card, card-type memory, random access memory (RAM), static random access memory (SRAM), programmable read-only memory (PROM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic storage, magnetic disk, optical disk, etc. Memory 702 can be any other medium capable of carrying or storing desired program code in the form of instructions or data structures that can be accessed by a computer, but is not limited thereto. In the embodiments of this application, memory 702 can also be a circuit or any other device capable of implementing storage functions for storing program instructions and / or data.

[0124] By designing and programming the processor 701, the code corresponding to the engine pre-lubrication method described in the foregoing embodiments can be embedded into the chip, enabling the chip to execute the code during operation. Figure 2 The illustrated embodiment provides an engine pre-lubrication method. How to design and program the processor 701 is a technique well-known to those skilled in the art and will not be described further here.

[0125] It should be noted that the electronic device provided in this application embodiment can implement all the method steps implemented in the above method embodiment and can achieve the same technical effect. Here, the parts that are the same as those in the method embodiment and the beneficial effects will not be described in detail.

[0126] This application also provides a computer-readable storage medium storing computer-executable instructions for causing a computer to perform an engine pre-lubrication method as described in the above embodiments.

[0127] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0128] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable intelligent device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable intelligent device, generate instructions for implementing the flowchart. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the function specified in one or more boxes.

[0129] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable intelligent device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0130] These computer program instructions can also be loaded onto a computer or other programmable intelligent device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable device for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0131] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. An engine pre-lubrication method, characterized in that, The method includes: Obtain the initial oil temperature before engine pre-lubrication; If the initial oil temperature is lower than the preset temperature threshold, a first current is continuously injected into the motor winding of the electric oil pump of the engine for pre-lubrication, and the electric oil pump is controlled to remain stationary. After the first current is injected into the motor winding for a preset injection time, the electric oil pump is controlled to rotate at the target speed, and a second current is injected into the motor winding for pre-lubrication.

2. The method according to claim 1, characterized in that, The first current is a direct-axis current, and the second current is a direct-axis current.

3. The method according to claim 1 or 2, characterized in that, The first current is a preset ratio of the motor's rated current, and the preset ratio is less than 1.

4. The method according to claim 1, characterized in that, Controlling the electric oil pump to rotate at a target speed includes: The electric oil pump is controlled to rotate at at least two target speeds, each of which corresponds to a preset time duration and increases progressively.

5. The method according to claim 1, characterized in that, After injecting a second current into the motor windings for pre-lubrication, the method further includes: Determine the target oil temperature range within which the target oil temperature falls after pre-lubrication of the engine; Based on the correspondence between the oil temperature range and the oil pressure range of the engine's main oil passage, the target oil pressure range corresponding to the target oil temperature is determined. If the oil pressure in the main oil passage of the engine is within the target oil pressure range, the engine pre-lubrication is considered complete.

6. The method according to claim 5, characterized in that, If the obtained oil pressure in the engine's main oil passage is within the target oil pressure range, determining that the engine pre-lubrication is complete includes: Within the preset detection time, the engine main oil passage oil pressure and target oil temperature are obtained at least twice; If the oil pressure of the engine's main oil passage is obtained each time and is within the target oil pressure range corresponding to the target oil temperature, then the engine pre-lubrication is considered complete.

7. The method according to claim 5, characterized in that, The method further includes: If the oil pressure in the main oil passage of the engine is not within the target oil pressure range, and the actual pre-lubrication time does not exceed the preset maximum pre-lubrication time, the electric oil pump is re-controlled to rotate at the target speed, and a second current is injected into the motor winding for pre-lubrication.

8. The method according to claim 7, characterized in that, The method further includes: If the actual number of retry attempts for pre-lubrication reaches the preset number of retry attempts, and the oil pressure of the engine main oil passage obtained each time is not within the target oil pressure range, the engine pre-lubrication is determined to have failed, and pre-lubrication is stopped.

9. The method according to any one of claims 4 to 8, characterized in that, The method further includes: If an abnormal signal is detected, pre-lubrication shall be stopped. The abnormal signal includes at least one of the following: a fault signal of the electric oil pump, an abnormal signal of the sensor, and a communication abnormal signal.

10. An engine pre-lubrication system, characterized in that, The system includes: An oil temperature sensor is used to obtain the initial oil temperature before engine pre-lubrication. The engine control unit is used to continuously inject a first current into the motor winding of the electric oil pump of the engine for pre-lubrication if the initial oil temperature is less than a preset temperature threshold, and to control the electric oil pump to remain stationary. The engine control unit is also used to control the electric oil pump to rotate at a target speed and inject a second current into the motor winding for pre-lubrication after injecting the first current into the motor winding for a preset injection time.

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