A method and apparatus for protecting a limited torsion shock absorber

Abstract

This application provides a protection method for a torque-limiting damper, comprising: using a vehicle electronic control unit (VECU) to monitor engine speed in real time; when the engine speed exceeds a first speed limit, monitoring the speed difference between the input end of the torque-limiting damper and the output end of the shift mechanism in real time; and, if the torque-limiting damper is determined to be in an abnormal state based on the speed difference, sending a target gear to the hybrid transmission control unit (HTCU) while simultaneously limiting the engine's output torque. This application also discloses a protection device for a torque-limiting damper. This application identifies slippage of the torque-limiting damper in advance through reasonable anomaly monitoring and intervenes in a timely manner, thereby suppressing wear and even burnout of the torque-limiting damper.

Description

Technical Field

[0001] This application relates to the field of shock absorber technology, and in particular to a protection method and device for a torsion-limiting shock absorber. Background Technology

[0002] The main function of a torque-limiting damper is to reduce the torsional stiffness of the connection between the engine crankshaft and the transmission system, thereby lowering a certain natural frequency of the transmission system, effectively dissipating vibration energy, preventing the peak value of impact torque from causing crankshaft breakage, and reducing or eliminating torsional vibration and noise in the transmission system. However, during use, torque-limiting dampers may experience insufficient friction and slippage due to wear or excessive grease during assembly. When the torque-limiting damper slips, engine power will be lost, and the vehicle will experience insufficient power when in high gear or under heavy load. During acceleration, the engine speed will increase but the vehicle speed will not increase. In severe cases, the torque-limiting damper will burn out. Summary of the Invention

[0003] This application provides a method and device for protecting a torsion-limiting shock absorber. By identifying slippage in advance and intervening promptly, the wear and even burnout of the torsion-limiting shock absorber can be suppressed. Thus, based on reasonable anomaly monitoring and intervention, the service life of the torsion-limiting shock absorber can be extended, while ensuring smooth vehicle power delivery.

[0004] The technical solution of this application embodiment is implemented as follows:

[0005] This application provides a protection method for a torsion-limiting shock absorber, the method comprising:

[0006] The vehicle electronic control unit (VECU) is used to monitor engine speed in real time.

[0007] When the engine speed is greater than the first speed limit, the speed difference between the input end of the torque limiting damper and the output end of the shift mechanism is monitored in real time.

[0008] If the torque-limiting damper is determined to be in an abnormal state based on the speed difference, the target gear is sent to the hybrid transmission control unit (HTCU), while the output torque of the engine is limited.

[0009] In some embodiments of this application, when the speed difference is greater than a first speed difference threshold, the running time of the engine is timed, and after a first preset time is reached, it is determined that the torque limiting damper is in an abnormal state.

[0010] In this way, by determining the abnormal state of the torsion damper based on the first speed difference threshold and the first preset time, the abnormal warning can be accurately output, thereby activating the corresponding protection control in a timely manner.

[0011] In some embodiments of this application, when the speed difference is less than the first speed difference threshold and greater than the second speed difference threshold, the running time of the engine is timed, and after a second preset time is reached, the speed change rate of the engine is determined; when the speed change rate is greater than the first speed change rate threshold, the torque limiting damper is determined to be in an abnormal state.

[0012] In some embodiments of this application, when the speed change rate is less than the first speed change rate threshold and greater than the second speed change rate threshold, the engine running time is timed, and after a third preset time is reached, the torque limiting damper is determined to be in an abnormal state.

[0013] In this way, based on the judgment of the engine speed change rate, the abnormal condition of the torque limiting damper can be monitored in a timely manner when the speed difference does not exceed the first speed difference threshold, which improves the sensitivity of the abnormal warning output during operation and allows for timely intervention.

[0014] In some embodiments of this application, based on the maximum permissible output torque of the engine and the output torque limit values ​​corresponding to each power mode of the vehicle, the permissible torque limit value of the engine in different power modes is determined; the output torque limit value of the engine is determined by multiplying the maximum permissible output torque of the engine by a limit coefficient; wherein the limit coefficient is less than 1; when each of the permissible torque limit values ​​in the different power modes is less than the output torque limit value, the VECU is used to limit the actual output torque of the engine to the permissible torque limit value corresponding to the current power mode of the vehicle; when any of the permissible torque limit values ​​in the different power modes is greater than the output torque limit value, the VECU is used to limit the actual output torque of the engine to the output torque limit value.

[0015] In this way, by determining the actual output torque value of the engine in the control process based on the maximum allowable output torque of the engine and the allowable torque under different power modes, the reasonableness of the actual output torque value can be ensured to the greatest extent, and the potential impact of extremely large or small limit values ​​on the engine and its operation on the vehicle can be avoided.

[0016] In some embodiments of this application, when the speed difference is less than a target speed difference threshold and the speed change rate is less than a target speed change rate threshold, the HTCU gear is restored, and the output torque limit of the engine is removed.

[0017] In this way, by timely terminating the activated protective control measures and restoring the engine's output torque and gear position, it is possible to ensure smooth power delivery during vehicle operation while suppressing wear or even burnout of the torque-limiting shock absorber.

[0018] In some embodiments of this application, the target speed difference threshold includes at least a third speed difference threshold and a fourth speed difference threshold, wherein the fourth speed difference threshold is less than the third speed difference threshold; the target speed change rate threshold includes a third speed change rate threshold; when the speed difference is less than the target speed difference threshold and the speed change rate is less than the target speed change rate threshold, restoring the HTCU gear and simultaneously canceling the output torque limitation on the engine includes: when the speed difference is less than the third speed difference threshold and greater than the fourth speed difference threshold, and the speed change rate is less than the third speed change rate threshold, restoring the HTCU gear and simultaneously canceling the output torque limitation on the engine.

[0019] In this way, by determining the speed difference threshold and engine speed change rate during the protection control process, the abnormal warning of the torque limiting damper can be accurately output, thereby timely stopping the corresponding protection control measures and starting the recovery mechanism.

[0020] In some embodiments of this application, the target speed change rate threshold further includes a fourth speed change rate threshold, wherein the fourth speed change rate threshold is greater than the third speed change rate threshold; when the speed difference is less than the target speed difference threshold and the speed change rate is less than the target speed change rate threshold, the HTCU gear is restored, and the output torque limitation on the engine is removed, further comprising: when the speed difference is less than the third speed difference threshold and greater than the fourth speed difference threshold; and when the speed change rate is less than the fourth speed change rate threshold and greater than the third speed change threshold, timing the engine's running time until a fourth preset time is reached, then restoring the HTCU gear and removing the output torque limitation on the engine; when the speed difference is less than the fourth speed difference threshold, timing the engine's running time until a fifth preset time is reached, then restoring the HTCU gear and removing the output torque limitation on the engine.

[0021] In this way, when the speed difference is less than the third speed difference threshold and greater than the fourth speed difference threshold, a step-by-step threshold judgment of the engine speed change rate can be achieved, which can effectively increase the accuracy of the judgment of the abnormal state of the torque limiting damper. Through multi-layer abnormal state judgment backup, the efficiency of the recovery mechanism implementation is ensured.

[0022] This application provides a protection device for a torque-limiting damper, comprising: an information acquisition unit, a speed difference monitoring unit, and an abnormal intervention unit; wherein the information acquisition unit is used to monitor the engine speed in real time using a vehicle electronic control unit (VECU); the speed difference monitoring unit is used to monitor the speed difference between the input end of the torque-limiting damper and the output end of the shift mechanism in real time when the engine speed is greater than a first speed limit; and the abnormal intervention unit is used to send a target gear to the hybrid transmission control unit (HTCU) and limit the output torque of the engine when it is determined that the torque-limiting damper is in an abnormal state based on the speed difference.

[0023] The embodiments of this application have the following beneficial effects:

[0024] This application's embodiments prevent wear and even burnout of the torsion-limiting damper by identifying slippage in advance and intervening promptly. Thus, based on reasonable anomaly monitoring and intervention, the service life of the torsion-limiting damper can be extended, while ensuring smooth vehicle power delivery. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the power transmission of a hybrid power system provided in an embodiment of this application;

[0026] Figure 2 A schematic flowchart illustrating a protection method for a torsion-limiting damper provided in an embodiment of this application;

[0027] Figure 3 A schematic flowchart illustrating another protection method for a torsion-limiting damper provided in an embodiment of this application;

[0028] Figure 4 A schematic flowchart illustrating another protection method for a torsion-limiting damper provided in an embodiment of this application;

[0029] Figure 5 A schematic flowchart illustrating another protection method for a torsion-limiting damper provided in an embodiment of this application;

[0030] Figure 6 This is a schematic diagram of the protective device for the torsion damper provided in the embodiments of this application. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application are further described in detail below with reference to the accompanying drawings and embodiments. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] In the following description, references to "some embodiments" refer to a subset of all possible embodiments. It is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. The terms "first / second / third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this application.

[0034] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] In the series-parallel hybrid powertrain of hybrid electric vehicles, to enable more switching of operating modes, a planetary gear shift mechanism (i.e., the shift mechanism) and a torque-limiting damper are used to replace the main clutch, realizing power mode switching and torque-limiting damping functions. The main function of the torque-limiting damper is to dampen vibrations during the transmission process between the engine and the planetary gear shift mechanism. By reducing the torsional stiffness of the connection between the engine crankshaft output end and the transmission system, it lowers the natural frequency of torsional vibration in the transmission system, dissipates vibration energy, avoids crankshaft breakage that may be caused by peak impact torque, and reduces or eliminates torsional vibration and noise in the transmission system; at the same time, it provides some protection for the engine when the engine is overloaded.

[0036] In the power split operation of a hybrid powertrain, due to the unique structure of the planetary gear set, the speed and torque of any two components can be adjusted to reduce the speed and torque of the other component to zero, thus disengaging the main clutch. This adjustment of the planetary gear set's speed and torque achieves a smooth engine start-up. The engine and electric motor are connected to the transmission system via planetary gear sets. The torque generated by the engine is transmitted to the electric motor through the engagement of the planetary gears with the rings connecting to the electric motor; simultaneously, power is transmitted to the electric motor through the engagement of the planetary gears with the rings connecting to the internal combustion engine. This creates a power circulation between the two engines, enabling the selection of multiple power modes. For example... Figure 1As shown, in different power transmission processes of the hybrid power system, the torque generated by the engine 101 is output after passing through the torque limiting damper 102, and then through the planetary gear shifting mechanism 103. Based on different power transmission methods, the following different power modes can be distinguished: (1) Parking generator / pure electric drive / series drive: The torque generated by the engine 101 is output after passing through the torque limiting damper 102, and then connected to the generator 104 through the planetary gear shifting mechanism 103; (2) Engine direct drive: The torque generated by the engine 101 is output after passing through the torque limiting damper 102, and then connected to the generator 104 through the planetary gear shifting mechanism 103; (3) Parallel drive: The torque generated by the engine 101 is output after passing through the torque limiting damper 102, and then connected to the generator 104 after passing through the planetary gear shifting mechanism 103; and the torque generated by the engine 101 is output after passing through the torque limiting damper 102, and then connected to the reduction mechanism 105 and the wheel 106 after passing through the planetary gear shifting mechanism 103; (4) Electronically Controlled Continuously Variable Transmission (ECVT) drive: The engine 101 is connected to the reduction mechanism 105 and the wheel 106 after passing through the torque limiting damper 102 and the planetary gear shifting mechanism 103, and the generator 104 is connected to the reduction mechanism 105 and the wheel 106 after passing through the torque limiting damper 102 and the planetary gear shifting mechanism 103. Based on the different power modes in the hybrid power system described above, the following relationships exist between the output speed n1 of engine 101, the output speed n2 of torque-limiting damper 102, the output speed n3 of generator 104, and the input speed n4 of reduction mechanism 105:

[0037] (1) In the parking power generation / pure electric drive / series drive power mode, n1=n2+e1=n3 / i1+e1+e2;

[0038] Where e1 is the speed difference between the engine output end and the torque-limiting damper output end; e2 is the speed difference between the engine output end and the generator output end; and i1 is the speed ratio between the torque-limiting damper output end and the generator output end.

[0039] (2) In the direct drive mode of the engine, n1=n2+e1=n4 / i2+e1+e3;

[0040] Where i2 is the speed ratio between the output end of the torsion damper and the input end of the reduction mechanism; e3 is the speed difference between the output end of the engine and the input end of the reduction mechanism;

[0041] (3) In parallel drive power mode, n1=n2+e1=n3 / i1+e1+e2, n1=n2+e1=n4 / i2+e1+e3;

[0042] (4) In ECVT drive power mode, n1=n2+e1=n4 / i2+e1+e3, n3=n4 / i3+e4;

[0043] Where i3 is the speed ratio between the generator output end and the reduction mechanism input end; e4 is the speed difference between the engine output end and the generator output end.

[0044] However, during use, the torque limiting shock absorber may experience insufficient friction and slippage due to wear or excessive grease during assembly. When the torque limiting shock absorber slips, the engine power will be lost, and the vehicle will experience insufficient power when it is in a high gear or under heavy load. During acceleration, the engine speed will increase but the vehicle speed will not increase. In severe cases, the torque limiting shock absorber will be burned out.

[0045] Based on this, embodiments of this application provide a method and apparatus for protecting a torsion-limiting shock absorber. By identifying slippage of the torsion-limiting shock absorber in advance and intervening in a timely manner, wear and even burnout of the torsion-limiting shock absorber can be suppressed. In this way, based on reasonable anomaly monitoring and intervention, the service life of the torsion-limiting shock absorber can be extended, while ensuring smooth power delivery of the entire vehicle.

[0046] Based on this, this embodiment provides a protection method for a torsion-limiting shock absorber, such as... Figure 2 The diagram shown is a schematic flowchart of a protection method for a torsion-limiting damper provided in an embodiment of this application. (Refer to...) Figure 2 The steps shown are explained as follows:

[0047] Step S201: Use the vehicle electronic control unit (VECU) to monitor engine speed in real time.

[0048] In some embodiments of this application, the Vehicle Electronic Control Unit (VECU) is the powertrain controller of the vehicle's powertrain and can refer to all electronic control systems on the vehicle. The vehicle can refer to hybrid electric vehicles and pure electric vehicles, and can be any type of vehicle such as a large vehicle, a small vehicle, or a special-purpose vehicle.

[0049] In some embodiments of this application, step S201 may include: when the vehicle is detected to be started and the vehicle's shift state is determined to be in gear, and the vehicle's voltage is stable and greater than a first voltage value, using a VECU to perform real-time monitoring of engine speed.

[0050] For example, the first voltage value could be 300V.

[0051] In some feasible implementations, after the vehicle is started, it is required that the vehicle be supplied with high voltage and the voltage be stable at around 300V. At the same time, the VECU needs to recognize that the vehicle is in gear. The vehicle's gear shifting status is generally divided into gear shifting in progress, gear shifting completed, and gear shifting failed. When the gear shifting status is displayed as gear shifting completed, the vehicle is determined to be in gear.

[0052] In some embodiments of this application, before the VECU performs real-time engine speed monitoring when the vehicle is started and in gear, the VECU switches between different power modes based on driver needs (i.e., accelerator pedal, brake pedal, gear and driving mode selection) and energy management. In some embodiments of this application, the power mode may include at least one of the following: parking generator / pure electric drive / series drive, engine direct drive, parallel drive, and ECVT drive.

[0053] Step S202: When the engine speed is greater than the first speed limit, monitor the speed difference between the input end of the torque limiting damper and the output end of the shift mechanism in real time.

[0054] In some embodiments of this application, the first speed limit is a speed threshold preset by the vehicle's VECU. For example, the first speed limit may be 700 rpm.

[0055] In some embodiments of this application, engine torque can be monitored in real time when the vehicle is started and in gear; correspondingly, when the engine torque exceeds a first torque limit, the speed difference between the input end of the torque-limiting damper and the output end of the shift mechanism is also monitored in real time. In some embodiments of this application, the first torque limit is a preset speed threshold at the vehicle's VECU. For example, the first torque limit can be 5 Nm.

[0056] In some embodiments of this application, the VECU can monitor the speed difference between the input end of the torque-limiting damper and the output end of the shift mechanism in real time under different power modes. Here, based on the power transmission method under different power modes, the speed difference e between the input end of the torque-limiting damper and the output end of the shift mechanism can be calculated according to the different power transmission processes under different modes. It should be noted that during the real-time monitoring of the speed difference e between the input end of the torque-limiting damper and the output end of the shift mechanism, when the torque-limiting damper is functioning well, the speed difference e is e1. At this time, e1 is close to zero and can be ignored. At this time, n1 = n2, that is, the engine output speed = the torque-limiting damper output speed. In some feasible embodiments, the real-time calculation process of the speed difference e under different modes is as follows:

[0057] (i) In the parking generator / pure electric drive / series drive power modes, when the engine speed and drive motor speed are effective, the speed difference is achieved through formula (1):

[0058] e = e2 = |n1 - n3 / i1| Formula (1);

[0059] Where e is e2, e2 is the speed difference between the engine output and the generator output, n1 is the engine output speed, n3 is the generator output speed, and i1 is the speed ratio between the torque limiting damper output and the generator output. In this embodiment, speed monitoring is not performed when the engine speed is invalid.

[0060] (ii) In the engine direct drive mode, when the engine speed and drive motor speed are effective, the speed difference is achieved through formula (2):

[0061] e=e3=|n1-n4 / i2|=|n1-n5 / i2 / i4| Formula (2);

[0062] Where e is e3, e3 is the speed difference between the engine output end and the reduction mechanism input end, n4 = n5 / i4, n4 is the speed at the input end of the reduction mechanism, n5 is the speed at the output end of the drive motor, i2 is the speed ratio between the output end of the torque limiting damper and the input end of the reduction mechanism, and i4 is the speed ratio between the input end of the reduction mechanism and the output end of the drive motor.

[0063] When the engine speed is effective, the drive motor speed is ineffective, but the wheel speed is effective, the speed difference is achieved through formula (3):

[0064] e=e3=|n1-n4 / i2|=|n1-n6 / i2 / i4 / i5| Formula (3);

[0065] Where e is e3, n5 = n6 / i5, n6 is the wheel speed, and i5 is the speed ratio between the output of the drive motor and the input of the wheel.

[0066] (iii) In parallel drive power mode, when the engine speed and generator speed are effective, the speed difference is achieved by formula (1);

[0067] When the generator speed is invalid, but the engine speed and drive motor speed are valid, the speed difference is achieved through formula (4):

[0068] e = e3 = |n1 - n5 / i2 / i4| Formula (4)

[0069] Where e is e3;

[0070] The generator speed and drive motor speed are invalid, but the wheel speed n6 is valid. The speed difference is achieved through formula (3).

[0071] (iv) In ECVT drive power mode, when the engine speed and drive motor speed are effective, the speed difference is achieved by formula (4);

[0072] When the drive motor speed is invalid, but the engine speed and generator speed are valid, the speed difference is achieved through formula (5):

[0073] e=e3=|n1-n4 / i2|=|n1-(n3-n4)×i3 / i2| Formula (5)

[0074] When the generator speed and drive motor speed are invalid, but the wheel speed n6 is valid, the speed difference is achieved through formula (3).

[0075] It should be noted that engine speed monitoring will not be performed when engine speed is invalid.

[0076] Step S203: If it is determined that the torque limiting damper is in an abnormal state based on the speed difference, the target gear is sent to the hybrid transmission control unit (HTCU), and the output torque of the engine is limited.

[0077] In some embodiments of this application, the abnormal state can refer to a state where the torque-limiting damper continues to operate at the original speed even when the real-time monitored speed difference is excessively large. In some feasible implementations, the excessively large value can be a value greater than the maximum speed difference allowed by the vehicle system.

[0078] In some embodiments of this application, the target gear is the gear used for unified protection adjustment during the torque limiting damper protection process. Specifically, when the vehicle is in ECVT drive power mode, the VECU can send the target ECVT gear to the HTCU; when the shift mechanism has no ECVT gear, the VECU sends the target gear in series to the HTCU, thereby switching the vehicle power mode to ECVT drive power mode or series drive power mode.

[0079] In some embodiments of this application, the VECU limits the engine's output torque according to a preset limit value.

[0080] This application provides a protection method for a torsion-limiting shock absorber. By identifying slippage in advance and intervening promptly, the wear and even burnout of the torsion-limiting shock absorber can be suppressed. Thus, based on reasonable anomaly monitoring and intervention, the service life of the torsion-limiting shock absorber can be extended, while ensuring smooth vehicle power delivery.

[0081] In some embodiments, the step S203 provided in the above embodiment, "determining that the torque limiting damper is in an abnormal state based on the speed difference", can be implemented in the following way: when the speed difference is greater than a first speed difference threshold, the running time of the engine is timed, and after a first preset time is reached, the torque limiting damper is determined to be in an abnormal state.

[0082] In some embodiments of this application, the first speed difference threshold may be a speed difference threshold preset by the vehicle's VECU. Considering the vehicle's operating conditions and the service life of the torque-limiting damper, the speed difference threshold can be adjusted periodically.

[0083] In some feasible implementations, the first speed difference threshold can be 1000 rpm.

[0084] In some embodiments of this application, the running time is the running time exceeding the first speed difference threshold when the speed difference exceeds the first speed difference threshold during actual operation, that is, the maximum allowable duration when the speed difference exceeds the first speed difference threshold.

[0085] In some embodiments of this application, the first preset time may be a time preset by the vehicle's VECU. In some feasible implementations, during the process of the VECU starting to monitor the speed difference between the input end of the torque-limiting damper and the output end of the shift mechanism in real time, when the speed difference exceeds a first speed difference threshold, the engine running time is started, until the engine running time with the speed difference continuously exceeding the first speed difference threshold reaches the first preset time, at which point the torque-limiting damper is determined to be in an abnormal state. For example, when the speed difference exceeds the first speed difference threshold, the engine running time is started, and when the engine running time reaches 1 second after the start of timing while the speed difference continuously exceeds the first speed difference threshold, the torque-limiting damper can be determined to be in an abnormal state.

[0086] In this embodiment, the abnormal state of the torsion damper is determined based on the first speed difference threshold and the first preset time, which can accurately output abnormal warning and then activate the corresponding protection control in a timely manner.

[0087] In some embodiments, the step S203 above, "determining that the torsion-limiting damper is in an abnormal state based on the speed difference," can be achieved through steps S301 and S302, combining... Figure 3 The steps shown are explained below:

[0088] Step S301: When the speed difference is less than the first speed difference threshold and greater than the second speed difference threshold, the running time of the engine is timed, and after the second preset time is reached, the speed change rate of the engine is determined.

[0089] In some embodiments of this application, the second speed difference threshold is less than the first speed difference threshold; the second speed difference threshold may be a speed difference threshold preset by the vehicle VECU. For example, the second speed difference threshold may be 500 rpm.

[0090] In some embodiments of this application, the second preset time may be the same as or different from the first preset time. In some feasible implementations, during the process of the VECU starting to monitor the speed difference between the input end of the torque limiting damper and the output end of the shift mechanism in real time, when the speed difference exceeds the second speed difference threshold, the engine running time is started to be timed until the running time reaches the second preset time; then the rate of change of engine speed when the second preset time is reached is judged, during which the speed difference data does not exceed the first speed difference threshold.

[0091] In some embodiments of this application, the rate of change of engine speed refers to the ratio of the speed drop caused when the load changes from ideal no-load to rated value when the engine is running at a certain speed to the ideal no-load speed.

[0092] Step S302: If the rotational speed change rate is greater than the first rotational speed change rate threshold, determine that the torsion damper is in an abnormal state.

[0093] In some embodiments of this application, the first speed change rate threshold may be an engine speed change rate threshold preset by the vehicle's VECU. For example, the first speed change rate threshold may be 2500 rpm / s.

[0094] In some embodiments of this application, when the speed difference exceeds the second speed difference threshold, during the process of timing the engine's running time until the second preset time is reached, the following situation may also occur: when the running time has not reached the second preset time, the speed difference data shows that the speed difference between the input end of the torque damper and the output end of the shift mechanism has exceeded the first speed difference threshold. At this time, the VECU can start to restart timing the engine's running time until the running time reaches the first preset time, thereby determining that the torque damper is in an abnormal state.

[0095] In some embodiments of this application, the step S203 above, "determining that the torque limiting damper is in an abnormal state based on the speed difference", may further include: when the speed change rate is less than the first speed change rate threshold and greater than the second speed change rate threshold, timing the engine's running time, and after reaching a third preset time, determining that the torque limiting damper is in an abnormal state.

[0096] In some embodiments of this application, when the speed difference is less than the first speed difference threshold and greater than the second speed difference threshold, the engine running time is timed, and after a second preset time is reached, the engine speed change rate is determined; then, when the speed change rate is less than the first speed change rate threshold and greater than the second speed change rate threshold, the engine running time is timed, and after a third preset time is reached, the torque limiting damper is determined to be in an abnormal state.

[0097] In some embodiments of this application, the second speed change rate threshold is less than the first speed change rate threshold. For example, the second speed change rate threshold may be 1000 rpm / s. In some embodiments of this application, the third preset time may be the same as or different from the second preset time. For example, the third preset time may be 2 seconds.

[0098] In this embodiment of the application, based on the judgment of the engine speed change rate, the abnormal condition of the torque limiting damper can be monitored in a timely manner when the speed difference does not exceed the first speed difference threshold, thereby improving the sensitivity of the abnormal warning output during operation and enabling timely intervention.

[0099] In some embodiments, the "limiting engine output torque" in step S203 provided in the above embodiments can be achieved through steps S401 to S404, combined with Figure 4 Explanation:

[0100] Step S401: Based on the maximum allowable output torque of the engine and the output torque limit values ​​corresponding to each power mode of the vehicle, determine the allowable torque limit values ​​of the engine in different power modes.

[0101] In some embodiments of this application, the maximum allowable output torque is an engine parameter, referring to the maximum rotational torque that the engine can output at a specific speed, measured in N·m. The maximum allowable output torque T1 can be determined based on different engines in different vehicle configurations.

[0102] In some embodiments of this application, the allowable torque limit value of the engine in different power modes can be determined based on the allowable torque of the engine in different power modes of the vehicle. Thus, the set of allowable torques based on speed difference under different power transmission methods is Tn = (T2, T3, T4, T5), where Tn is the set of allowable torques that can be included under different power transmission methods; T2 is the allowable torque in the parking generator / pure electric drive / series drive power modes, T3 is the allowable torque in the engine direct drive power mode, T4 is the allowable torque in the parallel drive power mode, and T5 is the allowable torque in the ECVT drive power mode.

[0103] In some feasible implementations, the permissible torque limit value of the engine in different power modes is Tmax1, where Tmax1 = (min(T1,T2), min(T1,T3), min(T1,T4), min(T1,T5)). This means that the maximum permissible output torque T1 of the engine is compared with the permissible torque in different power modes, and the minimum value is taken to form the permissible torque limit value of the engine in different power modes. In other words, the permissible torque limit value Tmax1 of the engine in different power modes can include the four values ​​min(T1,T2), min(T1,T3), min(T1,T4), and min(T1,T5). It should be noted that T2, T3, T4, and T5 can be determined during the vehicle design phase by controlling the speed difference within the permissible range under heavy load driving in different power modes.

[0104] Step S402: The product of the maximum allowable output torque of the engine and the limiting coefficient is determined as the output torque limit value of the engine; wherein the limiting coefficient is a positive number less than 1.

[0105] In some embodiments of this application, the engine output torque limit value Tmax2 can be a preset engine torque limit parameter. In this embodiment, the output torque limit value Tmax2 can be determined by multiplying the maximum allowable output torque of the engine by a limit coefficient, wherein Tmax2 must be less than the maximum allowable output torque; for example, the limit coefficient can be 0.75, then Tmax2 is 75% of the maximum allowable output torque.

[0106] Step S403: If each of the allowable torque limit values ​​in the different power modes of the engine is less than the output torque limit value, the VECU is used to limit the actual output torque of the engine to the allowable torque limit value corresponding to the current power mode of the vehicle.

[0107] Step S404: If any of the allowable torque limit values ​​in different power modes of the engine is greater than the output torque limit value, the VECU is used to limit the actual output torque of the engine to the output torque limit value.

[0108] In some embodiments of this application, the actual output torque Tmax used to limit the engine during actual operation can be calculated as follows: Tmax = min(Tmax1, Tmax2), where Tmax is the torque value used to limit the engine during actual operation. This is achieved by comparing the allowable torque limit value of the engine in different power modes with the engine's output torque limit value, determining the minimum of the two, thereby determining the actual output torque used to limit the engine during actual operation. The VECU then limits the engine's output torque to this torque value to protect the torque-limiting damper. That is, if each of the allowable torque limit values ​​Tmax1 in different power modes is less than the output torque limit value Tmax2, then Tmax is determined to be the allowable torque limit value corresponding to the vehicle's current power mode; if each of the allowable torque limit values ​​Tmax1 in different power modes is greater than the output torque limit value Tmax2, then Tmax is determined to be the output torque limit value Tmax2.

[0109] For example, when the engine is in different power modes, Tmax1 can include four values: A1, A2, A3, and A4. A1 is the minimum value determined by comparing the engine's permissible torque T2 with the engine's maximum permissible output torque T1 when the vehicle is in parking generator / pure electric drive / series drive power modes; that is, A1 is the permissible torque limit value for the vehicle in parking generator / pure electric drive / series drive power modes. Similarly, A2 is the permissible torque limit value for the vehicle in engine direct drive mode, A3 is the permissible torque limit value for the vehicle in parallel drive mode, and A4 is the permissible torque limit value for the vehicle in ECVT drive mode. Furthermore, Tmax2 is preset to be B, which can be determined by multiplying the engine's maximum permissible output torque T1 by a limit factor of 75%. When it is necessary to determine the actual output torque Tmax during actual operation, if A1, A2, A3, and A4 are all less than B, Tmax is determined to be the allowable torque limit value corresponding to the current power mode of the vehicle. For example, when the current power mode is the engine direct drive mode, Tmax is determined to be A1; if A1, A2, A3, and A4 are greater than B, Tmax is determined to be B, and then the engine output torque is limited to B.

[0110] In this embodiment, the actual output torque value of the engine is determined based on the maximum allowable output torque of the engine and the allowable torque under different power modes. This can maximize the reasonableness of the actual output torque value and avoid the possible impact of extremely large or small limit values ​​on the engine and its operation.

[0111] In some embodiments, the protection method for the torsion damper provided in this application may further include the following after step S203:

[0112] If the speed difference is less than the target speed difference threshold and the speed change rate is less than the target speed change rate threshold, the HTCU gear is restored, and the output torque limit on the engine is removed.

[0113] In some embodiments of this application, when the protection control measures are activated, the target gear is sent to the hybrid transmission control unit (HTCU), and the output torque of the engine is limited. When the protection control reaches a certain level, the speed difference can be restored to the normal value. Through the VECU's real-time monitoring of the speed difference and the engine speed change rate, if the speed difference is less than the target speed difference threshold and the engine speed change rate is less than the target speed normalization rate, the torque limiting damper can be judged to be in a non-abnormal state.

[0114] In some embodiments of this application, the target speed difference threshold and the target speed change rate threshold are parameters preset in the vehicle VECU. The target speed difference threshold may be the same as or different from the first speed difference threshold; the target speed change rate threshold may be the same as or different from the first speed change rate threshold.

[0115] In this embodiment of the application, by timely terminating the activated protection control measures, the output torque and gear of the engine are restored, which can ensure smooth power during vehicle operation while suppressing the wear or even burnout of the torque-limiting shock absorber.

[0116] In some embodiments, the target speed difference threshold includes at least a third speed difference threshold and a fourth speed difference threshold, wherein the fourth speed difference threshold is less than the third speed difference threshold; the target speed change rate threshold includes the third speed change rate threshold; the aforementioned "when the speed difference is less than the target speed difference threshold and the speed change rate is less than the target speed change rate threshold, restore the HTCU gear and simultaneously cancel the output torque limit on the engine" can be achieved through step S411 or step S421:

[0117] Step S411: When the speed difference is less than the third speed difference threshold and greater than the fourth speed difference threshold, and the speed change rate is less than the third speed change rate threshold, restore the HTCU gear and simultaneously remove the output torque limit on the engine.

[0118] In some embodiments of this application, the third speed difference threshold and the fourth speed difference threshold may be the same as the first speed difference threshold and the second speed difference threshold, respectively, or they may be different from the first speed difference threshold and the second speed difference threshold, respectively. The third speed change rate threshold may be the same as the second speed change rate threshold, or it may be different from the second speed change rate threshold. For example, the third speed change rate threshold may be less than the second speed change rate threshold.

[0119] In some embodiments of this application, when the speed difference between the input end of the torque limiting damper and the output end of the shift mechanism recovers to less than the third speed difference threshold but still greater than the fourth speed difference threshold, the value of the engine speed change rate is also considered. When the engine speed change rate is less than the third speed change rate, the HTCU gear is restored, and the output torque limitation on the engine is removed.

[0120] Step S421: When the speed difference is less than the fourth speed difference threshold, the engine running time is timed until the fifth preset time is reached, then the HTCU gear is restored and the output torque limit of the engine is removed.

[0121] In some embodiments of this application, the fifth preset time may be the same as or different from the first preset time. For example, the fifth preset time may be 1 second; when the speed difference is less than the fourth speed difference threshold, the engine running time is started, until the engine running time reaches 1 second after the start of timing when the speed difference continues to be lower than the fourth speed difference threshold, it can be determined that the torque limiting damper is in a non-abnormal state.

[0122] In some embodiments of this application, the speed difference must meet the third speed difference threshold and the speed change rate must meet the third speed change rate threshold, or the speed difference must meet the fourth speed difference threshold for a continuous period of time. When any of the above conditions are met, it can be determined that the torque limiting damper is in a non-abnormal state, thereby performing recovery measures, that is, restoring the HTCU gear and canceling the output torque limit on the engine.

[0123] In this embodiment, by determining the speed difference threshold and engine speed change rate during the protection control process, a non-abnormal prompt for the torque limiting damper can be accurately output, thereby enabling timely termination of the corresponding protection control measures and activation of the recovery mechanism.

[0124] In some embodiments, the target speed change rate threshold may further include a fourth speed change rate threshold, wherein the fourth speed change rate threshold is greater than the third speed change rate threshold; the aforementioned "when the speed difference is less than the target speed difference threshold and the speed change rate is less than the target speed change threshold, restore the HTCU gear and simultaneously remove the output torque limit on the engine" may further include:

[0125] When the speed difference is less than the third speed difference threshold and greater than the fourth speed difference threshold, and the speed change rate is less than the fourth speed change rate threshold and greater than the third speed change rate threshold, the engine running time is timed until the fourth preset time is reached.

[0126] In some embodiments of this application, the fourth speed change rate threshold may be the same as or different from the first speed change rate threshold. For example, the fourth speed change rate threshold may be greater than the first speed change rate threshold. The fourth preset time may be the same as or different from the third preset time.

[0127] In this embodiment, when the speed difference is less than the third speed difference threshold and greater than the fourth speed difference threshold, a step-wise threshold judgment is made on the engine speed change rate, which can effectively increase the accuracy of the judgment of the abnormal state of the torque limiting damper. Through multi-layer abnormal state judgment backup, the efficiency of the recovery mechanism implementation is ensured.

[0128] In some embodiments, this application provides a protection method for a torsion-limiting damper, such as... Figure 5 As shown, it includes the following steps:

[0129] Step S501: Start the vehicle.

[0130] In this embodiment of the application, it is required that the vehicle be connected to a high voltage, and the vehicle is started when the vehicle voltage is stable at around 300V.

[0131] Step S502: VECU confirms the gear information.

[0132] In this embodiment, the VECU identifies the gear information based on the gear shifting status. The gear shifting status is generally divided into gear shifting in progress, gear shifting completed, and gear shifting failed. When the gear shifting status is displayed as gear shifting completed, it is confirmed that the gear is in gear.

[0133] Step S503: Engine torque / speed monitoring.

[0134] In this embodiment of the application, after confirming that the gear information is in gear, when the engine torque is greater than threshold 1 or the engine speed is greater than threshold 2, step S504 is executed.

[0135] For example, threshold 1 can be 5 Nm; threshold 2 can be 700 rpm.

[0136] Step S504: Determine the actual output torque of the engine.

[0137] In this embodiment of the application, the actual output torque of the engine can be determined based on the engine characteristics and the allowable torque of the engine under different power modes. The allowable torque of the engine under different power modes is determined so that the speed difference between the input end of the torsion damper and the output end of the shift mechanism can be controlled within the allowable range when the engine is under heavy load.

[0138] In this embodiment, the maximum allowable output torque T1 of the engine (determined during the design phase based on engine characteristics) is defined by the torque limit Tn = (T2, T3, T4, T5) based on the speed difference, and the engine torque limit Tmax1 = (min(T1, T2), min(T1, T3), min(T1, T4), min(T1, T5)). Here, T2 is the allowable torque in parking generator / pure electric drive / series drive modes, T3 is the allowable torque in engine direct drive mode, T4 is the allowable torque in parallel drive mode, and T5 is the allowable torque for ECVT drive. T2, T3, T4, and T5 can be determined by controlling the speed difference within the allowable range (determined during the design phase) through heavy load driving in different modes. Furthermore, when determining the actual output torque Tmax of the engine, the minimum value is taken as Tmax by comparing the allowable torque limit Tmax1 in different power modes with the engine output torque limit Tmax2.

[0139] In this embodiment, the maximum allowable output torque T1 of the engine is first compared with the allowable torque of the hybrid vehicle under different power modes, and the minimum value is taken to form the allowable torque limit value Tmax1 of the engine under different power modes; then, by comparing each value in Tmax1 with the output torque limit value Tmax2 of the engine, the minimum value of the two is taken to determine the actual output torque Tmax of the engine.

[0140] In this embodiment of the application, when each of the allowable torque limit values ​​Tmax1 in different power modes of the engine is less than the output torque limit value Tmax2, Tmax is determined to be the allowable torque limit value corresponding to the current power mode of the vehicle; when each of the allowable torque limit values ​​Tmax1 in different power modes of the engine is greater than the output torque limit value Tmax2, Tmax is determined to be the output torque limit value Tmax2.

[0141] Step S505: Monitoring the speed difference between the input end of the torque damper and the output end of the shift mechanism.

[0142] In this embodiment, during the VECU's speed difference monitoring, the VECU selects the vehicle's current power mode based on driver needs and energy management. Then, the VECU uses the calculation method for the speed difference 'e' under the corresponding power mode to monitor the speed difference. In this embodiment, the power modes include at least four categories: parking generator / pure electric drive / series drive, engine direct drive, parallel drive, and ECVT drive.

[0143] It should be noted that when the torsion damper is functioning properly, the speed difference e is close to zero and can be ignored. In this embodiment, the speed difference e of the vehicle under different power modes is calculated in the same way as the speed difference e of the vehicle under different power modes in step S202 of the above embodiment, and will not be repeated here.

[0144] In this embodiment, when the speed difference is greater than a first speed difference threshold, the engine's running time is timed. After a first preset time is reached, the torque-limiting damper is determined to be in a first abnormal state (i.e., abnormality 1), thereby executing step S507, i.e., activating the protection control mechanism. For example, the first speed difference threshold can be 1000 rpm, and the first preset time can be 1 second.

[0145] In this embodiment of the application, if the speed difference is less than the first speed difference threshold, greater than the second speed difference threshold, and continues until a second preset time is reached, the torque limiting damper can be determined to be in a second abnormal state (i.e., abnormality 2), thereby executing step S506. For example, the second speed difference threshold can be 500 rpm, and the second preset time can be 1 second.

[0146] Step S506: Monitoring the rate of change of engine speed.

[0147] After determining that the torsion damper is in the second abnormal state (i.e., abnormality 2), the engine speed change rate is further judged. If the engine speed change rate is greater than the first speed change rate threshold, or if the engine speed change rate is less than the first speed change rate threshold but greater than the second speed change rate threshold until a third preset time is reached, the torsion damper is determined to be in the third abnormal state (i.e., abnormality 3), and step S507 is executed, i.e., the protection control mechanism is activated. For example, the first speed change rate threshold can be 2500 rpm / s, the second speed change rate threshold can be 1000 rpm / s, and the third preset time can be 2s.

[0148] Step S507: Activate the protection control mechanism.

[0149] In this embodiment, when the torque-limiting damper is determined to be in a first abnormal state or a third abnormal state, the protection control mechanism is activated; that is, the VECU sends the target gear ECVT to the HTCU, while the VECU limits the engine output torque. If the shift mechanism has no ECVT gear, the VECU sends the target gear in series to the HTCU, and the vehicle power mode switches to ECVT drive or series drive.

[0150] Step S508: Determine the recovery mechanism.

[0151] In this embodiment of the application, after the protection and control measures are implemented, a recovery mechanism is performed to determine whether the speed difference is less than the target speed difference threshold and whether the speed change rate is less than the target speed change rate threshold; if the conditions are not met, the protection and control mechanism continues.

[0152] Step S509: Exit the protection control mechanism.

[0153] In this embodiment of the application, when the speed difference is less than the first speed difference threshold and greater than the second speed difference threshold, and the speed change rate is less than the second speed change rate threshold, the HTCU gear can be restored, and the output torque limit of the engine can be canceled, that is, the protection control mechanism can be exited.

[0154] In this embodiment of the application, the protection control mechanism can also be exited when the speed difference is less than the first speed difference threshold and greater than the second speed difference threshold, the speed change rate is less than the first speed change rate threshold and greater than the speed change rate threshold, and the duration reaches the third preset time.

[0155] In this embodiment of the application, the protection control mechanism can also be exited when the speed difference is less than the second speed difference threshold and the duration reaches the first preset time.

[0156] Based on the foregoing embodiments, this application provides a protection device for a torsion-limiting damper. The protection device includes an information acquisition unit, a speed difference monitoring unit, and an abnormality intervention unit. Figure 6 The diagram shown is a structural schematic of the protection device 600 for the torsion damper provided in this embodiment of the application, wherein:

[0157] The information acquisition unit 601 is used to monitor the engine speed in real time using the vehicle electronic control unit (VECU).

[0158] The speed difference monitoring unit 602 is used to monitor the speed difference between the input end of the torque damper and the output end of the shift mechanism in real time when the engine speed is greater than the first speed limit.

[0159] The abnormal intervention unit 603 is used to send the target gear to the hybrid transmission control unit HTCU when it is determined that the torque limiting damper is in an abnormal state based on the speed difference, and at the same time limit the output torque of the engine.

[0160] In other embodiments of this application, the information acquisition unit 601 is also configured to perform the following:

[0161] When the vehicle is detected to be started and its gear shift status is determined to be in gear, and the vehicle's voltage is stable and greater than a first voltage value, the VECU is used to monitor the engine speed in real time.

[0162] In other embodiments of this application, the anomaly intervention unit 603 is also configured to perform the following:

[0163] When the speed difference is greater than the first speed difference threshold, the engine running time is timed, and after the first preset time is reached, it is determined that the torque limiting damper is in an abnormal state.

[0164] In other embodiments of this application, the anomaly intervention unit 603 is also configured to perform the following:

[0165] If the speed difference is less than the first speed difference threshold and greater than the second speed difference threshold, the engine running time is timed. After a second preset time is reached, the engine speed change rate is determined. If the speed change rate is greater than the first speed change rate threshold, the torque limiting damper is determined to be in an abnormal state.

[0166] In other embodiments of this application, the anomaly intervention unit 603 is also configured to perform the following:

[0167] If the speed change rate is less than the first speed change rate threshold and greater than the second speed change rate threshold, the engine running time is timed, and after a third preset time is reached, the torque limiting damper is determined to be in an abnormal state.

[0168] In other embodiments of this application, the anomaly intervention unit 603 is also configured to perform the following:

[0169] Based on the maximum permissible output torque of the engine and the output torque limit values ​​corresponding to each power mode of the vehicle, the permissible torque limit value of the engine in different power modes is determined; based on the maximum permissible output torque of the engine, the output torque limit value of the engine is determined; if each of the permissible torque limit values ​​in different power modes is less than the output torque limit value, the VECU is used to limit the actual output torque of the engine to the permissible torque limit value corresponding to the current power mode of the vehicle; if any of the permissible torque limit values ​​in different power modes is greater than the output torque limit value, the VECU is used to limit the actual output torque of the engine to the output torque limit value.

[0170] In other embodiments of this application, the protection device of the torsion damper is also used to perform the following:

[0171] If the speed difference is less than the target speed difference threshold and the speed change rate is less than the target speed change rate threshold, the HTCU gear is restored, and the output torque limit on the engine is removed.

[0172] In other embodiments of this application, the protection device of the torsion damper is also used to perform the following:

[0173] If the speed difference is less than the third speed difference threshold and greater than the fourth speed difference threshold, and the speed change rate is less than the third speed change rate threshold, the HTCU gear is restored, and the output torque limit of the engine is removed.

[0174] In other embodiments of this application, the protection device of the torsion damper is also used to perform the following:

[0175] When the speed difference is less than the third speed difference threshold and greater than the fourth speed difference threshold, and the speed change rate is less than the fourth speed change rate threshold and greater than the third speed change rate threshold, the engine running time is timed until the fourth preset time is reached, the HTCU gear is restored, and the output torque limit of the engine is removed.

[0176] When the speed difference is less than the fourth speed difference threshold, the engine running time is timed until the fifth preset time is reached, the HTCU gear is restored, and the output torque limit of the engine is removed.

[0177] The above description of the protection device embodiment for the torsion damper is similar to the description of the method embodiment described above, and has similar technical descriptions and beneficial effects as the corresponding method embodiments. Due to space limitations, please refer to the description of the method embodiments above, and therefore will not be repeated here. For technical details not disclosed in the protection device embodiment for the torsion damper provided in this application, please refer to the description of the method embodiments of this application for understanding.

[0178] It should be understood that the phrase "an embodiment" or "one embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the embodiments of this application. Therefore, "in one embodiment" or "one embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of the embodiments of this application, the sequence number of the above-described processes does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. It should be noted that in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0179] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0180] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0181] If the integrated units described above in this application's embodiments are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of this application's embodiments, essentially or in other words, the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this application's embodiments. The above descriptions are merely specific implementations of the embodiments of this application, but the protection scope of the embodiments of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the embodiments of this application should be included within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application should be determined by the protection scope of the claims.

Claims

1. A method of protecting a limited-torque shock absorber, characterized by, The method includes: The vehicle electronic control unit (VECU) is used to monitor engine speed in real time. When the engine speed is greater than the first speed limit, the speed difference between the input end of the torque limiting damper and the output end of the shift mechanism is monitored in real time. If the torque-limiting damper is determined to be in an abnormal state based on the speed difference, the target gear is sent to the hybrid transmission control unit (HTCU), while simultaneously limiting the engine's output torque; Wherein, limiting the output torque of the engine includes: Based on the maximum allowable output torque of the engine and the output torque limit values ​​corresponding to each power mode of the vehicle, the allowable torque limit values ​​of the engine in different power modes are determined. The product of the maximum permissible output torque of the engine and the limiting coefficient is determined as the output torque limit value of the engine; wherein, the limiting coefficient is a positive number less than 1; If each of the allowable torque limit values ​​in different power modes of the engine is less than the output torque limit value, the vehicle electronic control unit (VECU) is used to limit the actual output torque of the engine to the allowable torque limit value corresponding to the current power mode of the vehicle. If any of the allowable torque limit values ​​in different power modes of the engine is greater than the output torque limit value, the vehicle electronic control unit (VECU) shall be used to limit the actual output torque of the engine to the output torque limit value.

2. The method of protecting a limited-torsion shock absorber according to claim 1, characterized by, The method further includes: When the speed difference is greater than the first speed difference threshold, the engine running time is timed, and after the first preset time is reached, the torque limiting damper is determined to be in an abnormal state.

3. The method of protecting a limited-torsion shock absorber according to claim 2, characterized by, The method further includes: When the speed difference is less than the first speed difference threshold and greater than the second speed difference threshold, the running time of the engine is timed, and after the second preset time is reached, the speed change rate of the engine is determined. If the rate of change of rotational speed is greater than the first rate of change of rotational speed threshold, the torque-limiting damper is determined to be in an abnormal state.

4. The method of protecting a limited-torsion shock absorber according to claim 3, characterized by, The method further includes: If the speed change rate is less than the first speed change rate threshold and greater than the second speed change rate threshold, the engine running time is timed, and after a third preset time is reached, the torque limiting damper is determined to be in an abnormal state.

5. The protection method for the torsion-limiting damper according to any one of claims 3 to 4, characterized in that, The method further includes: When the speed difference is less than the target speed difference threshold and the speed change rate is less than the target speed change rate threshold, the hybrid transmission control unit (HTCU) is restored to its original gear position, and the output torque limit on the engine is removed.

6. The method of protecting a limited-torsion shock absorber according to claim 5, characterized by The target speed difference threshold includes at least a third speed difference threshold and a fourth speed difference threshold, wherein the fourth speed difference threshold is less than the third speed difference threshold; the target speed change rate threshold includes the third speed change rate threshold. If the speed difference is less than the target speed difference threshold and the speed change rate is less than the target speed change rate threshold, the hybrid transmission control unit (HTCU) is restored to its original gear position, and the output torque limit on the engine is removed, including one of the following: When the speed difference is less than the third speed difference threshold and greater than the fourth speed difference threshold, and the speed change rate is less than the third speed change rate threshold, the hybrid transmission control unit (HTCU) is restored to its original gear position, and the output torque limitation on the engine is removed. When the speed difference is less than the fourth speed difference threshold, the engine running time is timed until the fifth preset time is reached, the hybrid transmission control unit (HTCU) is restored to its original gear position, and the output torque limit on the engine is removed.

7. The method of protecting a limited-torsion shock absorber according to claim 6, characterized by The target speed change rate threshold also includes a fourth speed change rate threshold, wherein the fourth speed change rate threshold is greater than the third speed change rate threshold; If the speed difference is less than the target speed difference threshold and the speed change rate is less than the target speed change rate threshold, the hybrid transmission control unit (HTCU) is restored to its original gear position, and the output torque limit on the engine is removed. The system also includes: When the speed difference is less than the third speed difference threshold and greater than the fourth speed difference threshold, and the speed change rate is less than the fourth speed change rate threshold and greater than the third speed change rate threshold, the engine running time is timed until the fourth preset time is reached, the hybrid transmission control unit (HTCU) is restored to its original gear position, and the output torque limit on the engine is removed.

8. The method of protecting a limited-torsion shock absorber according to any one of claims 1 to 4, characterized in that, The use of the vehicle electronic control unit (VECU) for real-time engine speed monitoring includes: When the vehicle is detected to be starting and its gear shift status is determined to be in gear, and the vehicle's voltage is stable and greater than a first voltage value, the vehicle electronic control unit (VECU) is used to monitor the engine speed in real time.

9. A protection device for a limited-torque shock absorber, characterized by include: The information acquisition unit is used to monitor engine speed in real time using the vehicle electronic control unit (VECU). The speed difference monitoring unit is used to monitor the speed difference between the input end of the torque limiting damper and the output end of the shift mechanism in real time when the engine speed is greater than the first speed limit. An abnormal intervention unit is used to send a target gear to the hybrid transmission control unit (HTCU) when it is determined that the torque limiting damper is in an abnormal state based on the speed difference, while limiting the output torque of the engine. The abnormal intervention unit is further configured to: determine the allowable torque limit value of the engine in different power modes based on the maximum allowable output torque of the engine and the output torque limit value corresponding to each power mode of the vehicle; determine the output torque limit value of the engine by multiplying the maximum allowable output torque of the engine by a limit coefficient; wherein the limit coefficient is a positive number less than 1; when each of the allowable torque limit values ​​in different power modes is less than the output torque limit value, the vehicle electronic control unit (VECU) is used to limit the actual output torque of the engine to the allowable torque limit value corresponding to the current power mode of the vehicle; when any of the allowable torque limit values ​​in different power modes is greater than the output torque limit value, the vehicle electronic control unit (VECU) is used to limit the actual output torque of the engine to the output torque limit value.

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