Start-stop protection method and system for hybrid engine

Abstract

A hybrid engine start-stop protection method and system belongs to the field of hybrid engine start-stop control, and comprises the following steps: under a cold engine start working condition, collecting engine oil pressure, coolant temperature and first operation time of an engine, judging whether the engine oil pressure, the coolant temperature and the first operation time are all smaller than respective cold engine start safety thresholds, if yes, starting the engine oil pressure, the coolant temperature and the first operation time; if yes, the engine dragging rotating speed and the engine rotating speed climbing speed are limited to be below respective cold machine starting safety limit values; if not, not limiting; under the heat engine shutdown working condition, the load rate and the second running time of the engine are collected, whether the load rate and the second running time are both larger than respective heat engine shutdown safety threshold values or not is judged, and if yes, the engine torque is limited to be below the heat engine shutdown safety threshold values; the engine is controlled to stop until the load rate is smaller than the corresponding heat engine stop safety threshold value and the second operation time is larger than the corresponding heat engine stop safety threshold value; if not, the engine is controlled to stop. According to the invention, the reliability problem of cold start and hot stop of the engine can be solved.

Description

Technical Field

[0001] The present application relates to the field of start-stop control of hybrid engines, and specifically to a hybrid engine start-stop protection method and system. Background Art

[0002] In the field of hybrid vehicles, regarding the engine start-stop process:

[0003] 1) When the vehicle driving mode is switched from pure electric drive to engine direct drive or engine + motor combined drive, the motor usually directly drives the engine to the economic speed, which can reduce the power response time and the fuel consumption of the vehicle;

[0004] 2) When the vehicle's driving mode switches from engine direct drive or engine + motor combined drive to pure electric drive, the hybrid control unit (HCU) usually sends a shutdown signal to the engine control unit (ECU) to control the engine to shut down, which can reduce the vehicle's fuel consumption.

[0005] During the operation of hybrid vehicles, the engine starts and stops frequently, so the reliability requirements for the engine are extremely stringent:

[0006] 1) For traditional internal combustion engines, the lubrication system mainly forms an oil film between metal surfaces to reduce friction and wear, thereby protecting the various components of the engine and extending its service life.

[0007] When the engine is stopped, the oil inside the engine will flow back to the oil pan from the friction surfaces of various components through the main oil gallery and cylinder wall and be stored in the oil pan;

[0008] When the engine is working, the oil pump is driven by the rotation of the crankshaft to extract oil from the oil pan and pressurize it, and then deliver the oil to various parts of the engine that need lubrication. Under the action of pressure, the oil is delivered to the friction surfaces of various components through the main oil channel, such as the main journal and main bearing, connecting rod journal and connecting rod bearing, etc. An oil film is formed between the friction surfaces, which can reduce the friction between engine parts and thus prevent wear of engine parts. The lubricated oil will flow back to the oil pan along the cylinder wall and other locations, completing a cycle. In this process, the oil not only plays a lubricating role, but also helps cool the engine and clean impurities.

[0009] For each engine part, the oil pressure in the engine main oil channel needs to reach a certain safety limit to ensure the thickness of the oil film on the friction surface of each component, so as to prevent the wear of engine parts.

[0010] 2) During the operation of a hybrid vehicle, when the engine is in a shutdown state for a long time, the engine needs to intervene and work. Usually, the engine is dragged by the vehicle motor, and the engine speed will directly climb from 0 to a higher speed. Since the engine oil pump pumps oil from the oil pan to the main oil channel, it takes a certain amount of time, that is, the engine oil pressure reaches the safety limit, and it takes a certain amount of time. If the engine oil pressure is lower than the safety limit, the engine speed climbing rate and the operating speed are too high, which may cause abnormal wear of the engine friction pair;

[0011] 3) During the operation of a hybrid vehicle, when the engine is in operation for a long time, the engine needs to stop working. Usually, the engine is controlled by the engine ECU, and the engine speed will drop directly from a higher speed to 0; if the oil temperature is high before the engine stops, the engine is directly stopped at this time, which may cause the engine oil to coke, thereby reducing the life of the engine oil, and further affecting the normal operation of the engine lubrication system, and also causing abnormal wear of the engine friction pair. Summary of the invention

[0012] The present application provides a hybrid engine start-stop protection method, device / system, equipment and computer-readable storage medium, which can solve the reliability problems of engine cold engine start and hot engine shutdown existing in the prior art.

[0013] In a first aspect, an embodiment of the present application provides a hybrid engine start-stop protection method, the method comprising:

[0014] Under the cold engine start condition, the engine oil pressure, coolant temperature, and first running time are collected to determine whether the oil pressure, coolant temperature, and first running time are all less than their respective cold engine start safety thresholds. If so, the engine drag speed and engine speed climbing rate are limited to below their respective cold engine start safety limits; if not, the engine drag speed and engine speed climbing rate are not limited;

[0015] Under the hot engine shutdown condition, the engine load rate and the second operating time are collected to determine whether the load rate and the second operating time are both greater than their respective hot engine shutdown safety thresholds. If so, the engine torque is limited below the hot engine shutdown safety limit until the load rate is less than the corresponding hot engine shutdown safety threshold and the second operating time is greater than the corresponding hot engine shutdown safety threshold, and the engine is controlled to shut down; if not, the engine is controlled to shut down.

[0016] In combination with the first aspect, in one embodiment, the method includes:

[0017] The cold engine start safety limits for the engine drag speed and the engine speed climb rate are set according to the absolute value of the difference between the oil pressure, the coolant temperature, and the first operating time and the respective cold engine start safety thresholds. The larger the absolute value of the difference, the smaller the cold engine start safety limit.

[0018] In combination with the first aspect, in one implementation, the first operating time is the duration for the motor to drive the engine to rotate.

[0019] In combination with the first aspect, in one embodiment, the method includes:

[0020] The thermal engine shutdown safety limit of the engine torque is set according to the absolute value of the difference between the load rate and the second operating time and the respective thermal engine shutdown safety thresholds. The larger the absolute value of the difference, the smaller the thermal engine shutdown safety limit.

[0021] In combination with the first aspect, in one implementation, the second operating time is the operating time of the engine at a corresponding load rate.

[0022] In a second aspect, an embodiment of the present application provides a hybrid engine start-stop protection system, the system comprising:

[0023] A cold engine start module, which is used to collect the engine oil pressure, coolant temperature, and first running time of the engine under the cold engine start condition, and determine whether the oil pressure, coolant temperature, and first running time are all less than their respective cold engine start safety thresholds. If so, the engine drag speed and engine speed climbing rate are limited to below their respective cold engine start safety limits; if not, the engine drag speed and engine speed climbing rate are not limited;

[0024] The thermal engine shutdown module is used to collect the engine load rate and the second operating time under the thermal engine shutdown condition, and determine whether the load rate and the second operating time are both greater than their respective thermal engine shutdown safety thresholds. If so, the engine torque is limited to below the thermal engine shutdown safety limit until the load rate is less than the corresponding thermal engine shutdown safety threshold and the second operating time is greater than the corresponding thermal engine shutdown safety threshold, and the engine is controlled to shut down; if not, the engine is controlled to shut down.

[0025] In combination with the second aspect, in one embodiment, the cold engine start module sets the cold engine start safety limits of the engine drag speed and the engine speed climb rate according to the absolute value of the difference between the oil pressure, the coolant temperature, and the first operating time and the respective cold engine start safety thresholds. The larger the absolute value of the difference, the smaller the cold engine start safety limit.

[0026] In combination with the second aspect, in one implementation, the first operating time is the duration for the motor to drive the engine to rotate.

[0027] In combination with the second aspect, in one embodiment, the thermal engine shutdown module sets the thermal engine shutdown safety limit of the engine torque according to the absolute value of the difference between the load rate and the second operating time and the respective thermal engine shutdown safety thresholds. The larger the absolute value of the difference, the smaller the thermal engine shutdown safety limit.

[0028] In combination with the second aspect, in one implementation, the second operating time is the operating time of the engine at a corresponding load rate.

[0029] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0030] Through hybrid engine start-stop protection, the engine friction pair can be protected from abnormal wear and tear, thereby increasing the service life of the hybrid engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of an embodiment of a hybrid engine start-stop protection method of the present application;

[0032] Figure 2 This is a schematic diagram of the architecture of an embodiment of a hybrid engine start-stop protection system of the present application;

[0033] Figure 3 This is one of the schematic diagrams of the cold machine startup process in the embodiment of the present application;

[0034] Figure 4 This is the second schematic diagram of the process of starting the cold machine in the embodiment of the present application;

[0035] Figure 5 This is the third flow diagram of the cold machine startup in the embodiment of the present application;

[0036] Figure 6 This is one of the schematic diagrams of the process of shutting down a thermal engine in the embodiment of the present application;

[0037] Figure 7 This is the second schematic diagram of the process of shutting down the thermal engine in the embodiment of the present application;

[0038] Figure 8 This is the third flow chart of thermal engine shutdown in the embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0041] In a first aspect, an embodiment of the present application provides a hybrid engine start-stop protection method.

[0042] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of an embodiment of a hybrid engine start-stop protection method of the present application. Figure 1 As shown, the hybrid engine start-stop protection method includes:

[0043] Step S1: Under the cold engine start condition, collect the engine oil pressure, coolant temperature, and first running time of the engine, and determine whether the oil pressure, coolant temperature, and first running time are all less than their respective cold engine start safety thresholds. If so, limit the engine drag speed and engine speed climbing rate to below their respective cold engine start safety limits. If not, do not limit the engine drag speed and engine speed climbing rate.

[0044] Step S2: Under the hot engine shutdown condition, collect the load rate and the second running time of the engine, determine whether the load rate and the second running time are both greater than their respective hot engine shutdown safety thresholds, and if so, limit the engine torque below the hot engine shutdown safety limit until the load rate is less than the corresponding hot engine shutdown safety threshold and the second running time is greater than the corresponding hot engine shutdown safety threshold, and control the engine to shut down. If not, control the engine to shut down.

[0045] In this embodiment, under the cold engine start condition, that is, when the vehicle drive mode is switched from pure electric drive to engine direct drive or engine + motor combined drive condition, the cold engine start safety threshold of the engine oil pressure, the cold engine start safety threshold of the engine coolant temperature, the cold engine start safety threshold of the engine first running time, the cold engine start safety limit of the engine drag speed, and the cold engine start safety limit of the engine speed climb rate are set respectively.

[0046] When it is determined that the real-time oil pressure, coolant temperature, and first operating time are all less than their respective cold engine start safety thresholds, the engine dragging speed and the engine speed climbing rate are limited to below their respective cold engine start safety limits, thereby preventing the engine from being dragged to a higher speed too quickly and avoiding abnormal wear of the engine friction pair caused by the engine oil pressure being lower than the safety limit and the engine speed climbing rate and operating speed being too high.

[0047] In the hot engine shutdown condition, that is, when the vehicle driving mode switches from engine direct drive or engine + motor combined drive to pure electric drive, the hot engine shutdown safety threshold of the engine load rate, the hot engine shutdown safety threshold of the engine second operating time, and the hot engine shutdown safety limit of the engine torque are set respectively.

[0048] When it is judged that the real-time load rate and the second operation time are both greater than their respective thermal engine shutdown safety thresholds, the engine is in a high-power state, and the engine torque is limited to below the thermal engine shutdown safety limit until the real-time load rate is less than the corresponding thermal engine shutdown safety threshold and the second operation time is greater than the corresponding thermal engine shutdown safety threshold, at which point the engine becomes a low-power state and the engine is controlled to shut down. If it is judged that the load rate and the second operation time are both less than their respective thermal engine shutdown safety thresholds, the engine is directly controlled to shut down, thereby avoiding engine oil coking caused by directly shutting down the engine when the oil temperature is high.

[0049] In summary, during the operation of a hybrid vehicle, when engine intervention is required and the engine is in a cold state, the HCU determines whether to limit the engine drag speed and the engine speed climbing rate based on the engine oil pressure, coolant temperature and running time to achieve the engine cold engine protection function.

[0050] During the operation of a hybrid vehicle, when the engine needs to be shut down and the engine is in a hot state, the ECU determines whether to execute a shutdown command based on the engine load rate and running time to achieve the engine hot engine protection function.

[0051] Through hybrid engine start-stop protection, the engine friction pair can be protected from abnormal wear and tear, thereby increasing the service life of the hybrid engine.

[0052] Furthermore, in one embodiment, the method includes:

[0053] The cold engine start safety limits for the engine drag speed and the engine speed climb rate are set according to the absolute value of the difference between the oil pressure, the coolant temperature, and the first operating time and the respective cold engine start safety thresholds. The larger the absolute value of the difference, the smaller the cold engine start safety limit.

[0054] In this embodiment, taking the oil pressure as an example, if the absolute value of the difference between the oil pressure and the cold engine start safety threshold is large, it means that the current oil pressure is small. At this time, the cold engine start safety limit should be adjusted down, and the upper limits of the engine drag speed and the engine speed climbing rate should be set smaller to improve the safety of cold engine start.

[0055] Furthermore, in one embodiment, the first running time is the duration for which the motor drives the engine to rotate.

[0056] In this embodiment, the engine running time is the engine working time. As this time increases, the engine drag speed will slowly increase. For example, when the engine working time is 0s, similar to the first time the engine is started, the engine drag speed can only reach 1000rpm. When the engine working time is 10s, it means that the engine lubrication system and cooling system have been circulated, and the engine has initially achieved lubrication and cooling, then the drag speed can reach 1500rpm.

[0057] Furthermore, in one embodiment, the method includes:

[0058] The thermal engine shutdown safety limit of the engine torque is set according to the absolute value of the difference between the load rate and the second operating time and the respective thermal engine shutdown safety thresholds. The larger the absolute value of the difference, the smaller the thermal engine shutdown safety limit.

[0059] In this embodiment, taking the load rate as an example, if the absolute value of the difference between the load rate and the thermal engine shutdown safety threshold is large, it means that the current engine power is high. At this time, the thermal engine shutdown safety limit should be adjusted down, the upper limit of the engine torque should be set smaller, the engine power should be reduced to low power faster, and then the engine should be shut down after it is reduced to low power to improve the safety of thermal engine shutdown.

[0060] Furthermore, in one embodiment, the second operating time is the operating time of the engine at a corresponding load rate.

[0061] In a specific embodiment, during the operation of the hybrid vehicle, when the engine needs to be intervened and is in a cold state, the engine cold engine protection function is turned on.

[0062] 1) HCU receives the engine oil pressure signal, engine coolant temperature signal and engine running time signal from the vehicle CAN bus network. The above signals are broadcast from ECU to the vehicle CAN bus.

[0063] 2) HCU outputs engine drag speed and engine speed climbing rate signals to the motor.

[0064] 3) The HCU controls the motor to drive the engine. When the following conditions are met at the same time, the engine speed and engine speed climbing rate will be limited to below the safety limit:

[0065] A: When the engine oil pressure is lower than the safety limit.

[0066] B: When the engine coolant temperature is below the safety limit.

[0067] C: When the engine running time is below the safety limit.

[0068] 4) The HCU controls the motor to drive the engine. When any of the following conditions is met, the engine drive speed and engine speed climbing rate limit will be exited:

[0069] A: When the engine oil pressure is higher than the safety limit.

[0070] B: When the engine coolant temperature is higher than the safety limit.

[0071] C: When the engine running time is higher than the safety limit.

[0072] During the operation of the hybrid vehicle, when the engine needs to be shut down and is in a hot state, the engine hot engine protection function is turned on.

[0073] 1) HCU sends a shutdown request to ECU according to the hybrid mode.

[0074] 2) The ECU outputs an engine load rate signal and determines whether to execute an engine stop request.

[0075] 2) When the engine load rate exceeds the safety limit 1 for a certain period of time 1, the engine is considered to be in a high-load operating state.

[0076] 3) When the engine load rate is lower than the safety limit 2 for a certain period of time 2, the engine is considered to be in a low-load operating state.

[0077] 4) When the ECU receives a shutdown request, if the engine is in a high-load operation state, the following conditions must be met before the engine can be shut down:

[0078] A: The HCU sends a smaller torque request to the ECU, and the engine load rate is lower than the safety limit 2 for a certain time 2, that is, the engine is in a low-load operation state.

[0079] 5) When the ECU receives a shutdown request, if the engine is in a low-load operating state at this time, the engine can be shut down immediately.

[0080] In summary, directly modifying the internal control strategies of the HCU and ECU is simple and efficient without increasing hardware costs.

[0081] In a second aspect, an embodiment of the present application also provides a hybrid engine start-stop protection system.

[0082] In one embodiment, referring to Figure 2 , Figure 2 This is a functional module diagram of an embodiment of the hybrid engine start-stop protection system of the present application. Figure 2 As shown, the hybrid engine start-stop protection system includes:

[0083] The cold engine start module 1 is used to collect the engine oil pressure, coolant temperature, and first running time of the engine under the cold engine start condition, and determine whether the oil pressure, coolant temperature, and first running time are all less than their respective cold engine start safety thresholds. If so, the engine drag speed and engine speed climbing rate are limited to below their respective cold engine start safety limits. If not, the engine drag speed and engine speed climbing rate are not limited.

[0084] The thermal engine shutdown module 2 is used to collect the load rate and the second running time of the engine under the thermal engine shutdown condition, and determine whether the load rate and the second running time are both greater than their respective thermal engine shutdown safety thresholds. If so, the engine torque is limited to below the thermal engine shutdown safety limit until the load rate is less than the corresponding thermal engine shutdown safety threshold and the second running time is greater than the corresponding thermal engine shutdown safety threshold, and the engine is controlled to shut down. If not, the engine is controlled to shut down.

[0085] In this embodiment, Figure 3 As shown, during the operation of the hybrid vehicle, when the vehicle driving mode is switched from pure electric to engine direct drive or engine + motor combined drive, the HCU sends engine drag speed and engine speed climbing rate instructions to the motor, and the motor drags the engine to the specified speed to realize the engine driving the vehicle.

[0086] The engine drag speed and engine speed climbing rate are affected by the engine oil pressure signal, engine coolant temperature signal and engine running time signal:

[0087] 1) The engine oil pressure sensor and engine coolant temperature sensor transmit signals to the ECU through the engine wiring harness. The engine running time signal is calculated by the ECU.

[0088] 2) ECU broadcasts the engine oil pressure signal, engine coolant temperature signal and engine running time signal to the vehicle CAN network.

[0089] 3) HCU receives engine oil pressure signal, engine coolant temperature signal and engine running time signal from the vehicle CAN network.

[0090] 4) The HCU outputs engine drag speed and engine speed climbing rate instructions based on the engine oil pressure signal, engine coolant temperature signal and engine running time signal.

[0091] like Figure 4 As shown, the HCU outputs the engine drag speed 1 and engine speed climbing rate 1 instructions. At this time, the following three conditions must be met at the same time:

[0092] 1) The actual measured value of the engine oil pressure minus the engine oil pressure safety limit 1 is equal to a negative number, that is, the actual measured value of the engine oil pressure is less than the engine oil pressure safety limit 1, where the engine oil pressure safety limit 1 is related to the friction resistance of engine components and can be defined by different engines.

[0093] 2) The actual measured value of the engine coolant temperature minus the engine coolant temperature safety limit 1 is equal to a negative number, that is, the actual measured value of the engine coolant temperature is less than the engine coolant temperature safety limit 1, where the actual measured value of the engine coolant temperature safety limit 1 is related to the engine oil viscosity. The oil viscosity will affect the adhesion of the oil film and can be defined by different engines.

[0094] 3) The actual value of the engine running time minus the engine running time safety limit 1 is equal to a negative number, that is, the actual value of the engine running time is less than the engine running time safety limit 1, where the engine running time safety limit 1 is related to the engine oil pump capacity. The oil pump will affect the time for the oil to reach the friction surface of the components from the oil pan, and different engines can define it.

[0095] like Figure 5 As shown, the HCU outputs the engine drag speed 2 and engine speed climbing rate 2 instructions, and any one of the following three conditions must be met:

[0096] 1) The actual measured value of the engine oil pressure minus the engine oil pressure safety limit 1 is equal to a positive number, that is, the actual measured value of the engine oil pressure is greater than the engine oil pressure safety limit 1, where the engine oil pressure safety limit 1 is related to the friction resistance of engine components and can be defined by different engines.

[0097] 2) The actual measured value of the engine coolant temperature minus the engine coolant temperature safety limit 1 is equal to a positive number, that is, the actual measured value of the engine coolant temperature is greater than the engine coolant temperature safety limit 1, where the actual measured value of the engine coolant temperature safety limit 1 is related to the engine oil viscosity. The oil viscosity will affect the adhesion of the oil film and can be defined by different engines.

[0098] 3) The actual value of the engine running time minus the engine running time safety limit 1 is equal to a positive number, that is, the actual value of the engine running time is greater than the engine running time safety limit 1, where the engine running time safety limit 1 is related to the engine oil pump capacity. The oil pump will affect the time for the oil to reach the friction surface of the components from the oil pan, and different engines can define it.

[0099] like Figure 6As shown, during the operation of the hybrid vehicle, when the vehicle driving mode is switched from engine direct drive or engine + motor combined drive to pure electric drive, the HCU sends a shutdown request command to the ECU, and the ECU controls the engine to shut down.

[0100] After the ECU receives the shutdown request command from the HCU, it also needs to determine whether to execute the engine shutdown command based on the engine load rate:

[0101] 1) HCU sends a shutdown request signal to the vehicle CAN network.

[0102] 2) ECU receives the shutdown request signal from the vehicle CAN network.

[0103] 3) The ECU determines whether to execute the engine shutdown command based on the engine load rate signal.

[0104] like Figure 7 As shown, when the ECU detects that the engine load rate is high, it needs to be reduced to a low load rate before the engine shutdown command can be executed:

[0105] 1) The engine load rate minus the engine load rate safety limit 1 is equal to a positive number, that is, the engine load rate is higher than the engine load rate safety limit 1. The synchronous engine running time minus the engine running time safety limit 1 is equal to a positive number, that is, the engine running time is greater than the engine running time safety limit 1. At this time, the ECU determines that the engine load rate is a high load rate, wherein the engine load rate safety limit 1 and the engine running time safety limit 1 support calibration, such as 60% load rate, 30s.

[0106] 2) ECU sends engine load rate signal to the vehicle CAN network.

[0107] 3) HCU receives the engine load rate signal from the vehicle CAN network.

[0108] 4) After receiving the engine high load rate signal, the HCU sends an engine low torque request signal to the vehicle CAN network.

[0109] 5) ECU receives the engine low torque request signal from the vehicle CAN network and controls the engine to reduce the load rate. When the engine load rate minus the engine load rate safety limit 1 is equal to a negative number, the engine load rate is lower than the engine load rate safety limit 1. The synchronous engine running time minus the engine running time safety limit 1 is equal to a positive number, that is, the engine running time is greater than the engine running time safety limit 1. At this time, ECU determines that the engine load rate is a low load rate, where the engine load rate safety limit 1 and the engine running time safety limit 1 support calibration, such as 60% load rate, 30s.

[0110] 6) ECU sends engine load rate signal to the vehicle CAN network.

[0111] 7) HCU receives the engine load rate signal from the vehicle CAN network.

[0112] 8) After receiving the engine low load rate signal, the HCU sends an engine shutdown request signal to the vehicle CAN network.

[0113] 9) ECU receives the engine shutdown request signal from the vehicle CAN network and controls the engine to shut down.

[0114] like Figure 8 As shown, when the ECU detects that the engine load rate is a low load rate, the engine shutdown command can be executed immediately:

[0115] 1) The engine load rate minus the engine load rate safety limit 1 is equal to a negative number, that is, the engine load rate is lower than the engine load rate safety limit 1. The synchronous engine running time minus the engine running time safety limit 1 is equal to a positive number, that is, the engine running time is greater than the engine running time safety limit 1. At this time, the ECU determines that the engine load rate is a low load rate, where the engine load rate safety limit 1 and the engine running time safety limit 1 support calibration, such as 60% load rate, 30s.

[0116] 2) ECU sends engine load rate signal to the vehicle CAN network.

[0117] 3) HCU receives the engine load rate signal from the vehicle CAN network.

[0118] 4) After receiving the engine low load rate signal, the HCU sends an engine shutdown request signal to the vehicle CAN network.

[0119] 5) ECU receives the engine shutdown request signal from the vehicle CAN network and controls the engine to shut down.

[0120] Among them, the functional implementation of each module in the above-mentioned hybrid engine start-stop protection device corresponds to the various steps in the above-mentioned hybrid engine start-stop protection method embodiment, and its functions and implementation processes are no longer repeated here one by one.

[0121] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0122] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0123] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0124] In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B. "And / or" in the text is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0125] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0126] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as mentioned above, and includes a number of instructions for a terminal device to execute the above-mentioned methods of each embodiment of the present application.

[0127] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A hybrid engine start-stop protection method, characterized in that: The method comprises: Under the cold engine start condition, the engine oil pressure, coolant temperature, and first running time are collected to determine whether the oil pressure, coolant temperature, and first running time are all less than their respective cold engine start safety thresholds. If so, the engine drag speed and engine speed climbing rate are limited to below their respective cold engine start safety limits; if not, the engine drag speed and engine speed climbing rate are not limited; Under the hot engine shutdown condition, the engine load rate and the second operating time are collected to determine whether the load rate and the second operating time are both greater than their respective hot engine shutdown safety thresholds. If so, the engine torque is limited below the hot engine shutdown safety limit until the load rate is less than the corresponding hot engine shutdown safety threshold and the second operating time is greater than the corresponding hot engine shutdown safety threshold, and the engine is controlled to shut down; if not, the engine is controlled to shut down.

2. The hybrid engine start-stop protection method according to claim 1, characterized in that: The method comprises: The cold engine start safety limits for the engine drag speed and the engine speed climb rate are set according to the absolute value of the difference between the oil pressure, the coolant temperature, and the first operating time and the respective cold engine start safety thresholds. The larger the absolute value of the difference, the smaller the cold engine start safety limit.

3. The hybrid engine start-stop protection method according to claim 1, characterized in that: The first running time is the duration during which the motor drives the engine to rotate.

4. The hybrid engine start-stop protection method according to claim 1, characterized in that: The method comprises: The thermal engine shutdown safety limit of the engine torque is set according to the absolute value of the difference between the load rate and the second operating time and the respective thermal engine shutdown safety thresholds. The larger the absolute value of the difference, the smaller the thermal engine shutdown safety limit.

5. The hybrid engine start-stop protection method according to claim 1, characterized in that: The second operating time is the operating time of the engine at a corresponding load rate.

6. A hybrid engine start-stop protection system, characterized in that: The system comprises: A cold engine start module, which is used to collect the engine oil pressure, coolant temperature, and first running time of the engine under the cold engine start condition, and determine whether the oil pressure, coolant temperature, and first running time are all less than their respective cold engine start safety thresholds. If so, the engine drag speed and engine speed climbing rate are limited to below their respective cold engine start safety limits; if not, the engine drag speed and engine speed climbing rate are not limited; The thermal engine shutdown module is used to collect the engine load rate and the second operating time under the thermal engine shutdown condition, and determine whether the load rate and the second operating time are both greater than their respective thermal engine shutdown safety thresholds. If so, the engine torque is limited to below the thermal engine shutdown safety limit until the load rate is less than the corresponding thermal engine shutdown safety threshold and the second operating time is greater than the corresponding thermal engine shutdown safety threshold, and the engine is controlled to shut down; if not, the engine is controlled to shut down.

7. The hybrid engine start-stop protection system according to claim 6, characterized in that: The cold engine start module sets the cold engine start safety limits of the engine drag speed and the engine speed climb rate according to the absolute value of the difference between the oil pressure, the coolant temperature, and the first operating time and the respective cold engine start safety thresholds. The larger the absolute value of the difference, the smaller the cold engine start safety limit.

8. The hybrid engine start-stop protection system according to claim 6, characterized in that: The first running time is the duration during which the motor drives the engine to rotate.

9. The hybrid engine start-stop protection system according to claim 6, characterized in that: The thermal engine shutdown module sets the thermal engine shutdown safety limit of the engine torque according to the absolute value of the difference between the load rate and the second operating time and the respective thermal engine shutdown safety thresholds. The larger the absolute value of the difference, the smaller the thermal engine shutdown safety limit.

10. The hybrid engine start-stop protection system according to claim 6, characterized in that: The second operating time is the operating time of the engine at a corresponding load rate.

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