Engine anti-galloping control method, power system and vehicle

Abstract

The invention relates to the technical field of automobile control, in particular to an engine anti-galloping control method, a power system and a vehicle. The engine anti-galloping control method comprises the following steps that whether a vehicle is in a braking state or not is judged; acquiring a vehicle speed and a transmission ratio according to the braking state of the vehicle; calculating the first rotating speed of the engine according to the vehicle speed and the transmission ratio, and obtaining the actual rotating speed of the engine at the same time; checking the actual rotating speed and the first rotating speed mutually, and taking the larger value in the two as a reference rotating speed; engine overspeed is judged according to the fact that the reference rotating speed is larger than a preset rotating speed threshold; and cutting off a transmission system between the engine and the vehicle according to the overspeed of the engine. After the control method is adopted, once the potential overspeed phenomenon of the engine occurs, the system immediately gets involved in protection measures, cascading failures, such as damage to internal parts of the engine, valve breakage and connecting rod breakage, caused by galloping of the engine are effectively prevented, and safe operation of the whole vehicle is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and particularly to an engine runaway prevention control method, a power system and a vehicle. Background Art

[0002] Runaway refers to a situation where the engine speed suddenly exceeds the required speed during operation and cannot recover by itself. The engine cannot respond according to the control mode preset by the system, and the engine power cannot be fully and effectively output, which is a system failure mode. The occurrence of the runaway fault not only wastes fuel, but also the excessive speed is extremely likely to cause serious accidents such as the breakage of engine connecting rods or connecting rod bolts and cylinder scoring. Therefore, measures must be taken to stop the "runaway" as soon as possible. Summary of the Invention

[0003] The object of the present invention is to at least solve the problem of the occurrence of the engine runaway fault. This object is achieved by the following technical solutions:

[0004] The first aspect of the present invention provides an engine runaway prevention control method, including the following steps:

[0005] Judge whether the vehicle is in a braking state;

[0006] According to the vehicle being in the braking state, obtain the vehicle speed and the transmission ratio;

[0007] Calculate the first speed of the engine according to the vehicle speed and the transmission ratio, and obtain the actual speed of the engine at the same time;

[0008] Extract the maximum value of the actual speed and the first speed as the reference speed;

[0009] Judge that the engine is overspeed according to the reference speed being greater than a preset speed threshold;

[0010] Cut off the transmission system between the engine and the vehicle according to the engine being overspeed.

[0011] According to the engine runaway prevention control method of the present invention, first, the first rotational speed calculated using the vehicle speed and the transmission gear ratio when the vehicle is in the braking state is compared with the actual rotational speed, ensuring a true reflection of the current operating state of the engine and avoiding errors that may be caused by single measurement. Next, when the larger value (reference rotational speed) of the rotational speeds obtained by the two methods exceeds the preset rotational speed threshold, the system can quickly determine that the engine is in an overspeed state. By promptly cutting off the engine from the vehicle drive system, it prevents the engine from running away due to reverse dragging or misoperation, thereby significantly reducing the risk of engine damage and failure. Therefore, after adopting the engine runaway prevention control method of the present invention, once a potential overspeed phenomenon occurs in the engine, the system immediately intervenes with protective measures, effectively preventing chain failures caused by engine runaway, such as damage to internal engine components, valve breakage, connecting rod breakage, etc., and ensuring the safe operation of the entire vehicle.

[0012] In addition, the engine runaway prevention control method according to the present invention may further have the following additional technical features:

[0013] In some embodiments of the present invention, the step of determining whether the vehicle is in the braking state includes:

[0014] Obtaining the throttle pedal position signal, the exhaust brake signal, the hydraulic retarder signal, and the brake pedal position signal;

[0015] Judging that the vehicle is in the braking state according to the throttle pedal position signal being 0% and any one of the exhaust brake signal, the hydraulic retarder signal, and the brake pedal position signal being in the working state.

[0016] In some embodiments of the present invention, the calculation formula for calculating the first rotational speed of the engine according to the vehicle speed and the transmission gear ratio is:

[0017]

[0018] where n is the first rotational speed, i m is the transmission gear ratio, i tf is the final drive ratio, r is the wheel rolling radius, and v is the vehicle speed.

[0019] In some embodiments of the present invention, the step of calculating the first rotational speed of the engine according to the vehicle speed and the transmission gear ratio and obtaining the actual rotational speed of the engine at the same moment further includes cross-checking the actual rotational speed and the first rotational speed. The step of cross-checking the actual rotational speed and the first rotational speed includes:

[0020] Calculating the difference between the actual rotational speed and the first rotational speed;

[0021] Complete the mutual verification of the actual rotational speed and the first rotational speed according to that the absolute value of the difference value is lower than a preset threshold value.

[0022] In some embodiments of the present invention, the vehicle includes a clutch assembly and a three-position two-way valve. The step of cutting off the engine from the vehicle's transmission system according to the engine overspeed includes:

[0023] Control the switching position of the three-position two-way valve;

[0024] Drive the clutch assembly to disengage by switching the position of the three-position two-way valve.

[0025] In some embodiments of the present invention, the vehicle further includes an exhaust brake actuator. After the step of driving the clutch to disengage by switching the position of the three-position two-way valve, it further includes:

[0026] Control the exhaust brake actuator to reduce the exhaust gas emission.

[0027] In some embodiments of the present invention, after the step of cutting off the engine from the vehicle's transmission system according to the engine overspeed, it further includes:

[0028] After an interval of a first time period, acquire the actual rotational speed and the first rotational speed again;

[0029] Judge that the engine has recovered according to that both the actual rotational speed and the first rotational speed are less than the preset rotational speed threshold value;

[0030] Restore the engine to the vehicle's transmission system according to the engine recovery.

[0031] A second aspect of the present invention proposes a power system, including:

[0032] A transmission system;

[0033] A control component, the control component is in transmission connection with the transmission system;

[0034] An ECU, the ECU is electrically connected to the control component, and the ECU is used to execute the above-mentioned engine anti-runaway control method.

[0035] In some embodiments of the present invention, the transmission system includes a clutch assembly, and the clutch assembly includes a separating crank arm;

[0036] The control component includes a three-position two-way valve, and the three-position two-way valve is in transmission connection with the separating crank arm.

[0037] A third aspect of the present invention proposes an engine, including the above-mentioned power system. Description of the Drawings

[0038] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Also, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0039] Figure 1 is a flowchart of a method for controlling engine runaway prevention disclosed in an embodiment of the present application;

[0040] Figure 2 schematically shows a structural diagram of the power system in a first state of the present embodiment;

[0041] Figure 3 schematically shows a structural diagram of the power system in a second state of the present embodiment;

[0042] Figure 4 schematically shows the principle diagram of the method for controlling engine runaway prevention of the present embodiment;

[0043] Figure 5 is a control logic flowchart of a method for controlling engine runaway prevention according to an embodiment of the present application.

[0044] The reference numerals are as follows:

[0045] 100, power system;

[0046] 10, engine; 20, control component; 21, three-position two-way valve; 22, hydraulic device; 30, clutch assembly; 31, flywheel; 32, pressure plate; 33, release bearing; 34, release crank arm; 40, transmission; 50, clutch pedal; 60, exhaust brake actuator; 70, ECU. Detailed Embodiments

[0047] The following will describe the exemplary embodiments of the present disclosure in more detail with reference to the drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art.

[0048] It should be understood that the terms used herein are for the purpose of describing particular example embodiments only and are not intended to be limiting. Unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" as used herein may also include the plural forms. The terms "comprising", "including", "containing", and "having" are inclusive and thus specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless the order of performance is explicitly stated. It should also be understood that additional or alternative steps may be used.

[0049] Although the terms first, second, third, etc. may be used herein to describe multiple elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or section from another. Unless the context clearly dictates otherwise, terms such as "first", "second", and other numerical terms when used herein do not imply an order or sequence. Thus, the first element, component, region, layer, or section discussed below may be referred to as the second element, component, region, layer, or section without departing from the teachings of the example embodiments.

[0050] For ease of description, spatial relative relationship terms may be used herein to describe the relationship of one element or feature shown in the figures to another element or feature, such as "inside", "outside", "inner side", "outer side", "below", "beneath", "above", "over", etc. Such spatial relative relationship terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, an element described as "below" or "beneath" another element or feature will then be oriented "above" or "over" the other element or feature. Thus, the example term "below" can include both an upper and a lower orientation.

[0051] Before describing the present application in detail, the engine reverse-dragging and overspeed phenomena that may occur in two cases and the resulting failure risks will be described in detail. In the first case, when the vehicle is driving on a long downhill section with a full load, due to the steep road section and high vehicle speed, the driver may not react in time or the braking force may be insufficient, resulting in the foot brake or auxiliary braking (such as a hydraulic retarder and engine exhaust braking) not being able to play an adequate role in time. At this time, due to the inertia of the vehicle, the wheels drive the transmission system, and the engine is reversely dragged passively, causing the engine speed to rise rapidly and exceed the designed maximum safe speed. The reverse-dragging and overspeed phenomenon will cause severe impacts on the internal components of the engine, which may then lead to serious faults such as valves hitting pistons, valve fractures, connecting rod bending or fractures, and even cylinder block damage. In the second case, when the vehicle is driving at a high speed, if the driver mistakenly shifts the transmission into a low gear, due to the large transmission ratio of the low gear, the wheels rotating at a high speed will drive the engine at a relatively high speed, causing the engine to be reversely dragged and overspeed. Similar situations will also trigger the reverse-dragging and overspeed phenomenon, increasing the risk of damage to the internal components of the engine, such as valves hitting pistons, valve damage, and abnormal forces on the connecting rods. Therefore, a control method is needed to solve the problem of engine overspeed that may be caused by the above two situations.

[0052] As Figures 1 to 5 shown, according to an embodiment of the present invention, an engine anti-overspeed control method is proposed, including the following steps:

[0053] Determine whether the vehicle is in a braking state;

[0054] According to the vehicle being in a braking state, obtain the vehicle speed and the transmission ratio;

[0055] Calculate the first speed of the engine 10 according to the vehicle speed and the transmission ratio, and obtain the actual speed of the engine 10 at the same moment;

[0056] Extract the maximum value of the actual speed and the first speed as the reference speed;

[0057] Judge that the engine 10 is overspeed according to the reference speed being greater than the preset speed threshold;

[0058] According to the engine 10 being overspeed, cut off the transmission system between the engine 10 and the vehicle.

[0059] According to the engine 10 runaway prevention control method of the present embodiment, first, the first rotational speed calculated using the vehicle speed and the transmission gear ratio when the vehicle is in the braking state is verified with the actual rotational speed, ensuring a true reflection of the current operating state of the engine 10 and avoiding errors that may be caused by single measurement. Next, when the larger value (reference rotational speed) of the rotational speeds obtained by the two methods exceeds the preset rotational speed threshold, the system can quickly determine that the engine 10 is in an overspeed state. By promptly cutting off the engine 10 from the vehicle transmission system, it is possible to prevent the engine 10 from running away due to reverse dragging or misoperation, thereby greatly reducing the risk of damage and failure of the engine 10. Therefore, after adopting the engine 10 runaway prevention control method of the present invention, once a potential overspeed phenomenon occurs in the engine 10, the system immediately intervenes with protective measures to effectively prevent chain failures caused by the engine 10 running away, such as damage to internal components of the engine 10, valve breakage, connecting rod breakage, etc., ensuring the safe operation of the entire vehicle.

[0060] It can be understood that the step of determining whether the vehicle is in the braking state includes obtaining the throttle pedal position signal, the exhaust brake signal, the hydraulic retarder signal, and the brake pedal position signal; and determining that the vehicle is in the braking state according to the throttle pedal position signal being 0% and any one of the exhaust brake signal, the hydraulic retarder signal, and the brake pedal position signal being in the working state. Through the comprehensive acquisition and judgment of multiple signals, errors or failures that may exist in a single signal can be effectively excluded, ensuring a more accurate determination of the braking state. At the same time, the multi-signal redundant judgment improves the adaptability of the system to complex working conditions, ensuring that the braking state can be accurately captured in various braking scenarios of the vehicle, providing a reliable guarantee for preventing the engine 10 from running away due to overspeed.

[0061] Specifically, the throttle pedal position signal, exhaust brake signal, hydraulic retarder signal, and brake pedal position signal are all collected by their respective dedicated sensors and transmitted through the vehicle internal network to the engine 10 control unit (ECU70) for processing. Specifically, the throttle pedal position signal is obtained by the throttle pedal position sensor. When the driver presses the throttle pedal, the change in resistance or magnetic field inside the sensor is converted into a corresponding voltage or digital signal, which reflects the actual displacement percentage of the pedal and is transmitted to the ECU70 in real time. The ECU70 determines the current throttle opening based on this signal and determines the fuel injection amount and output power of the engine 10. A throttle pedal position signal of 0% indicates that the driver has not pressed the throttle pedal, that is, the pedal is in a fully released state. In this state, the engine 10 will not receive an instruction to increase fuel injection and only maintains a minimum idle or idling operation. The exhaust brake signal is fed back by the exhaust brake actuator 60. The exhaust brake actuator 60 monitors the working state of the exhaust valve or brake valve. When the exhaust brake system is activated, the exhaust brake actuator 60 outputs a digital or analog signal indicating that the exhaust brake is in an activated state. The hydraulic retarder signal is obtained by the hydraulic retarder. The hydraulic retarder is equipped with a pressure sensor or a flow sensor, or a signal can also be provided by a dedicated retarder control module. When the hydraulic retarder starts to work, the sensor detects the change in hydraulic oil pressure or flow rate and converts this change into an electrical signal and feeds it back to the ECU70. The brake pedal position signal is obtained by the brake pedal position sensor. When the driver presses the brake pedal, the sensor detects the displacement of the pedal and generates a voltage or digital signal proportional to the pedal travel, and then transmits it to the ECU70.

[0062] It can be understood that the calculation formula for the first rotational speed of the engine 10 based on the vehicle speed and the transmission ratio is where n is the first rotational speed, i m is the transmission ratio, i tf is the final drive ratio, r is the wheel rolling radius, and v is the vehicle speed. First, the vehicle speed v is converted into the linear speed of the tire rotating per minute, that is (unit: meters per minute). The circumference of the tire is 2πr, so the number of revolutions of the tire per minute is The first rotational speed is the product of the tire rotational speed and the transmission ratio and the final drive ratio, that is, the above formula is obtained.

[0063] It can be understood that the steps of calculating the first speed of the engine according to the vehicle speed and the transmission ratio and obtaining the actual speed of the engine at the same moment further include cross-checking the actual speed and the first speed. The cross-checking steps include calculating the difference between the actual speed and the first speed. When the absolute value of the difference is lower than the preset threshold, the cross-checking of the actual speed and the first speed is completed, that is, it is considered that the error between the actual speed and the calculated first speed is within the allowable range, and the cross-checking passes. By comparing the actual measurement value with the calculated value, abnormal data caused by single measurement error or sensor failure can be effectively excluded, ensuring the accuracy of the engine 10 speed judgment. At the same time, by adopting a dual speed acquisition method (sensor measurement and calculation based on vehicle speed) and using a preset threshold for verification, the robustness and adaptive regulation ability of the system under various working conditions are enhanced. The preset threshold is generally in the range of 50 to 200 revolutions per minute, and the specific value is usually selected according to the working conditions of different engines 10.

[0064] The reason for cross-checking between the actual speed and the first speed is that if one of the actual measurement value or the first speed (calculated value) underestimates the true speed, selecting the larger value can ensure that the operating state of the engine 10 is not underestimated, so as to intervene in protection in time when a potential overspeed risk appears. Moreover, there may be errors in both sensor measurement and calculation based on vehicle speed. Using the larger value as a reference can offset the risk brought by the underestimation of one of the data to a certain extent.

[0065] It can be understood that the step of cutting off the transmission system between the engine 10 and the vehicle according to the overspeed of the engine 10 includes controlling the switching valve position of the three-position two-way valve 21, and driving the clutch assembly 30 to disengage by switching the valve position of the three-position two-way valve 21. Specifically, first, when it is detected that the reference speed exceeds the preset speed threshold, the ECU 70 outputs a control signal. Then, the ECU 70 drives the three-position two-way valve 21 in the hydraulic device 22 to perform valve position switching through the control signal, so that the hydraulic oil flows along the predetermined oil path. After the valve position switching, the hydraulic oil is guided to the hydraulic cylinder, causing the hydraulic cylinder to generate a directional linear displacement. The linear displacement of the hydraulic cylinder is transmitted to the clutch release lever 34 through a mechanical connection device (such as a connecting rod), forcing it to rotate. The rotation of the release lever 34 drives the release bearing 33 to move, thereby realizing the forced disengagement of the clutch assembly 30. After the clutch assembly 30 is forced to disengage, the mechanical connection between the engine 10 and the vehicle transmission system is cut off, thereby avoiding the overspeed and runaway phenomenon of the engine 10 due to reverse dragging. In this embodiment, the precise switching of the hydraulic oil path is achieved by controlling the three-position two-way valve 21, ensuring that the clutch can be quickly and accurately driven to disengage when the engine 10 is overspeed, thereby effectively cutting off the connection between the engine 10 and the transmission system and preventing the engine 10 from running away caused by reverse dragging. At the same time, the combined action of the hydraulic device 22 and the mechanical transmission structure can achieve a rapid response, enabling the protection measure to be activated within an extremely short time when the engine 10 speed exceeds the limit, minimizing the damage risk of the engine 10 and related transmission components.

[0066] Further, after the step of driving the clutch to disengage by switching the valve position, it also includes controlling the exhaust brake actuator 60 to reduce the exhaust gas displacement. Specifically, after the clutch forced disengagement step is completed, the ECU 70 continues to output a control signal to drive the exhaust brake actuator 60 to start. After the exhaust brake actuator 60 starts, by adjusting the working state of key components in the exhaust system (such as exhaust valves or special brake valves), the exhaust gas emission is restricted, the reverse pressure inside the engine 10 is increased, the resistance of the engine 10 is increased, and the engine 10 speed is assisted to decrease.

[0067] Further, since the clutch in this embodiment is drivingly connected to the clutch pedal 50, when the driver steps on the clutch pedal 50, the separation swing arm 34 rotates to separate the clutch assembly 30. Therefore, the application premise of this embodiment is that the driver does not respond to the engine 10 overspeeding, that is, does not step on the clutch pedal 50. Because the driver may fail to step on the clutch pedal 50 in time before the engine 10 overspeeds due to reaction delay or misjudgment. Even if the driver steps on the clutch pedal 50, the separation state of the clutch may be incomplete or delayed, and the engine 10 anti-runaway control method of this embodiment can force the separation of the clutch assembly 30 through the hydraulic system to ensure that the transmission system is truly disconnected. At the same time, the automatic monitoring and control of the ECU 70 can provide an additional layer of redundant protection beyond the driver's operation to ensure that the engine 10 is protected from damage due to reverse-dragging overspeeding under any circumstances.

[0068] It can be understood that after the step of cutting off the transmission system between the engine 10 and the vehicle according to the engine 10 overspeeding, it further includes obtaining the actual speed and the first speed again after an interval of the first time period, and then judging that the engine 10 has recovered according to both the actual speed and the first speed being less than the preset speed threshold. Finally, according to the recovery of the engine 10, the transmission system between the engine 10 and the vehicle is restored. The above steps are specifically as follows: after the engine 10 overspeeding protection measure is executed and the transmission system between the engine 10 and the vehicle is cut off, the system enters a waiting state and sets a first time period, which can be any value within the range of 1 to 10 seconds, so that the engine 10 has enough time to reduce the speed. After the end of the first time period, the ECU 70 collects the actual speed and the first speed of the engine 10 again. Compare the collected actual speed and the first speed. If both are lower than the preset speed threshold, it is judged that the engine 10 has recovered to the safe operating state. After confirming the recovery of the engine 10, the ECU 70 outputs a recovery control signal to switch back to the normal working state by controlling the three-way two-way valve 21, and at the same time releases the exhaust brake, prompts the hydraulic cylinder to reset, and drives the separation swing arm 34 and the release bearing 33 to return to their original positions, thereby restoring the mechanical connection of the transmission system between the engine 10 and the vehicle. This embodiment not only quickly cuts off the abnormal transmission, but also can be reset in time when the engine 10 recovers, enabling the vehicle system to both quickly protect the engine 10 and restore normal transmission as soon as possible when dealing with sudden overspeeding states, taking into account both safety and efficiency.

[0069] In some embodiments, the ECU 70 continuously monitors the actual speed and the first speed. When both the actual speed and the first speed are less than the preset speed threshold, it is judged that the engine 10 has recovered. Finally, according to the recovery of the engine 10, the transmission system between the engine 10 and the vehicle is restored. The function of this embodiment is to continuously collect and compare the speed data, enabling the system to adapt to changes in different working conditions, timely adjust the protection and recovery strategies, and ensure the stable operation of the vehicle under various driving states.

[0070] It can be understood that the range of the preset rotational speed threshold mainly depends on the design, operating conditions, and safety requirements of the engine 10. For heavy-duty diesel engines, it is usually set between approximately 2500 and 3000 revolutions per minute; for other types of engines, the preset rotational speed threshold may be in the range of 2000 to 4000 revolutions per minute or even a wider range. It needs to be determined according to the specific parameters of the engine 10 and experimental calibration to ensure that the engine 10 operates within a safe range before the protection measure is triggered.

[0071] This embodiment also provides a power system 100, which includes a transmission system, a control component 20, and an ECU 70. The control component 20 is in transmission connection with the transmission system, and the ECU 70 is electrically connected to the control component 20 for executing the above-mentioned engine 10 runaway prevention control method. Among them, the transmission system includes a clutch assembly 30, and the clutch assembly 30 further includes a friction plate, a pressure plate 32, and a clutch release mechanism. The clutch release mechanism further includes a release lever 34 and a release bearing 33. The release lever 34 is connected to a hydraulic cylinder through a connecting rod and is used to convert the linear motion generated by the hydraulic oil drive into rotational motion, thereby pushing the clutch release bearing 33. The release bearing 33 plays a buffering role during the separation process, reducing friction and assisting the clutch to complete the separation. The hydraulic device 22 includes a hydraulic cylinder, a connecting rod connected to the hydraulic cylinder, and a hydraulic oil circuit. The hydraulic cylinder generates a linear displacement under the action of the hydraulic oil and transmits the motion to the release lever 34 through the connecting rod. A three-position two-way valve 21 is provided in the hydraulic oil circuit for switching the oil circuit state. Specifically, the three-position two-way valve 21, as the core component in the control component 20, functions to switch between different valve positions according to the control signal of the ECU 70 and change the flow direction of the hydraulic oil. The three-position two-way valve 21 is in transmission connection with the clutch release lever 34 through the hydraulic cylinder and the connecting rod, so that the valve position conversion directly drives the release lever 34 to move, thereby realizing the forced separation of the clutch. The ECU 70 is connected to the hydraulic device 22 through an electrical interface and is responsible for collecting information such as the rotational speed of the engine 10, vehicle speed, gear position, accelerator pedal, braking, and auxiliary braking signals. According to the preset control algorithm, the ECU 70 determines whether the engine 10 is overspeed and outputs a control signal. The control signal is transmitted to the three-position two-way valve 21 in the hydraulic device 22 through an electrical circuit, driving the valve position conversion, thereby realizing the forced separation of the clutch and subsequent recovery actions. At the same time, the ECU 70 also controls auxiliary devices such as the exhaust brake actuator 60 to provide further protection for the engine 10.

[0072] Specifically, when the clutch is in the normal connection state, the flywheel 31 is fixedly installed on the crankshaft of the engine 10. When rotating, it provides stable power output and provides a friction base surface for the clutch system. The clutch pressure plate 32 applies pressure to the friction plate through a spring group or other devices, firmly clamping it between the flywheel 31 and the pressure plate 32. The friction plate is located between the flywheel 31 and the pressure plate 32, and transmits the torque of the engine 10 to the transmission 40 through friction. When the clutch is in the engaged state, the power of the engine 10 is transmitted to the friction plate via the flywheel 31 and then pressed by the pressure plate 32 to achieve the connection between the engine 10 and the transmission system. When the three-position two-way valve 21 drives the valve position conversion and the clutch is in the disengaged state, the separation crank arm 34 rotates. The release bearing 33 is pushed by the separation crank arm 34, contacts and applies a force to the release surface of the clutch pressure plate 32. When the release bearing 33 applies a force, it will force the pressure plate 32 to move backward, weakening the pressure on the friction plate.

[0073] Specifically, the power system 100 includes an engine 10, a clutch, a transmission, a hydraulic device 22, and a three-position two-way valve 21. The engine 10 outputs mechanical power through its flywheel 31. The flywheel 31 is installed on the crankshaft of the engine 10, providing rotational inertia for power transmission and serving as a friction surface of the clutch system. The transmission 40 is connected to the output end of the clutch assembly 30, changes the transmission ratio of the transmission according to the gear selected by the driver, and transmits the power of the engine 10 to the wheels to achieve vehicle driving. The clutch pedal is installed on the driver's operation platform, and the clutch pedal 50 is connected to the separation crank arm 34 through a mechanical connection system (such as a connecting rod). When the driver steps on the clutch pedal 50, the clutch separation mechanism is activated, causing the release bearing 33 to act on the pressure plate 32 through the separation crank arm 34, thereby disconnecting the clutch for easy gear shifting operation.

[0074] Specifically, the working principle of the power system 100 when detecting that the engine 10 is overspeed is that when the overspeed of the engine 10 is detected by the ECU 70, the ECU 70 issues a control signal. This control signal causes the three-position two-way valve 21 in the hydraulic device 22 to switch to a predetermined valve position, and the hydraulic oil is guided to the hydraulic cylinder. The linear displacement generated by the hydraulic cylinder is transmitted to the clutch separation crank arm 34 through a connecting rod, forcing the release bearing 33 of the clutch to move, thereby achieving the forced separation of the clutch and cutting off the connection between the engine 10 and the transmission system. At the same time, the ECU 70 activates the exhaust brake actuator 60 to further reduce the engine 10 speed by adjusting the exhaust system. When the engine 10 speed returns to the safe range, the ECU 70 will cause the three-position two-way valve 21 to return to the normal state through a corresponding signal, and at the same time, the hydraulic cylinder will reset, and the clutch separation crank arm 34 and the release bearing 33 will reset, thereby restoring the connection between the engine 10 and the transmission system.

[0075] Specifically, such as Figure 21 is a schematic diagram of the structure when the power system 100 receives a control signal from the ECU 70 and the separation arm 34 pushes the separator to separate. Figure 3 It is a schematic diagram of the structure when the power system 100 receives the control signal of the ECU 70 to reset the separation crank arm 34, wherein the direction of the arrow is the movement direction of the hydraulic cylinder. Figures 2 to 4 The three-position two-way valve 21 includes two valve positions, namely 1YA and 2YA.

[0076] Further, the engine 10 anti-runaway control method is in the activation stage (eg Figure 2 When the ECU 70 detects the risk of overspeed or reverse drag of the engine 10, the ECU 70 outputs a control signal. The ECU 70 first switches the three-position two-way valve 21 in the hydraulic device 22 to the 1YA valve position, at which time the 1YA solenoid valve is closed. After the 1YA solenoid valve is closed, the hydraulic oil flows along the predetermined oil path to the working chamber of the hydraulic cylinder, causing the hydraulic cylinder to generate a driving force, and its piston begins to move left (as shown in FIG. 1 ). Figure 2 The linear displacement of the hydraulic cylinder is transmitted to the clutch release arm 34 through the mechanical connection, forcing it to rotate, thereby pushing the release bearing 33 to contact the clutch pressure plate 32, forcing the clutch to be separated, and then cutting off the connection between the engine 10 and the transmission system. At this time, the overspeed state of the engine 10 is released, avoiding damage to the engine 10 components (such as valves, pistons, connecting rods, etc.) caused by reverse dragging. When the power system 100 is in the recovery stage (such as Figure 3 When the ECU 70 detects that the engine 10 speed has returned to a safe range, the ECU 70 sends a reset control signal. The reset signal switches the three-position two-way valve 21 to the 2YA valve position, and the 2YA solenoid valve is closed. In the 2YA valve position state, the flow direction of the hydraulic oil changes, causing the pressure in the hydraulic cylinder to decrease, and the hydraulic cylinder begins to return to its original position, that is, the piston moves to the right (as shown in FIG. Figure 3 The arrow in the middle points to the opposite direction). The return movement of the hydraulic cylinder drives the clutch release arm 34 to reset through the mechanical connection, and the release bearing 33 returns to the initial position, so that the clutch pressure plate 32 is tightly combined with the friction plate again, thereby restoring the connection between the engine 10 and the transmission system. At the same time, the exhaust brake actuator 60 stops working, the power system 100 function is fully released, and the vehicle power system 100 returns to normal.

[0077] This embodiment also includes a vehicle, and the engine 10 includes the above-mentioned power system 100.

[0078] As described above, it is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An engine runaway prevention control method, characterized in that The steps include: Determine whether the vehicle is in a braking state; According to the vehicle being in the braking state, obtaining the vehicle speed and the transmission ratio; Calculating a first speed of the engine according to the vehicle speed and the transmission ratio of the transmission, and obtaining an actual speed of the engine at the same time; extracting a maximum value between the actual rotation speed and the first rotation speed as a reference rotation speed; According to the reference speed being greater than a preset speed threshold, determining that the engine is overspeeding; According to the engine overspeed, a transmission system between the engine and the vehicle is cut off.

2. The engine runaway prevention control method according to claim 1, characterized in that The steps of determining whether the vehicle is in a braking state include: Acquire an accelerator pedal position signal, an exhaust brake signal, a hydraulic retarder signal, and a brake pedal position signal; According to the accelerator pedal position signal being 0% and any one of the exhaust brake signal, the hydraulic retarder signal and the brake pedal position signal being in a working state, it is determined that the vehicle is in the braking state.

3. The engine runaway prevention control method according to claim 1, wherein The calculation formula for calculating the first speed of the engine according to the vehicle speed and the transmission ratio is: where n is the first rotational speed, i m is the transmission gear ratio, i tf is the final drive ratio, r is the wheel rolling radius, and v is the vehicle speed.

4. The engine runaway prevention control method according to claim 1, wherein The step of calculating a first speed of the engine according to the vehicle speed and the transmission ratio and obtaining the actual speed of the engine at the same time also includes mutually verifying the actual speed and the first speed. The step of mutually verifying the actual speed and the first speed includes: Calculating a difference between the actual rotation speed and the first rotation speed; According to the absolute value of the difference being lower than a preset threshold, the actual rotation speed and the first rotation speed are mutually verified.

5. The engine runaway prevention control method according to claim 1, wherein The vehicle includes a clutch assembly and a three-position two-way valve, and the steps of cutting off the transmission system between the engine and the vehicle according to the engine overspeed include: Controlling the switching valve position of the three-position two-way valve; The clutch assembly is driven to be disengaged by switching the valve position of the three-position two-way valve.

6. The engine runaway prevention control method according to claim 5, characterized in that, The vehicle further includes an exhaust brake actuator, and after the step of driving the clutch to be disengaged by switching the valve position of the three-position two-way valve, the step further includes: The exhaust brake actuator is controlled to reduce the amount of exhaust gas emissions.

7. The engine runaway prevention control method according to any one of claims 1 to 6, characterized in that, According to the engine overspeed, after the step of cutting off the engine from the transmission system of the vehicle, the step further includes: After a first time period, obtaining the actual rotation speed and the first rotation speed again; According to the actual speed and the first speed being both less than the preset speed threshold, determining that the engine is restored; According to the engine recovery, the engine and the transmission system of the vehicle are recovered.

8. A power system, characterized in that, include: Transmission system; A control component, the control component is in driving connection with the transmission system; ECU, the ECU is electrically connected to the control component and is used to execute the engine anti-runaway control method according to any one of claims 1 to 7.

9. The power system according to claim 8, characterized in that, The transmission system includes a clutch assembly, and the clutch assembly includes a release crank arm; The control assembly comprises a three-position two-way valve, and the three-position two-way valve is transmission-connected to the separation crank arm.

10. A vehicle, characterized in that, Comprising a power system according to claim 8 or 9.

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