A flexible power take-off system and transmission control method

Abstract

The present invention belongs to the field of power transmission equipment, and discloses a flexible power take-off system, including a flexible power take-off and a control module; the flexible power take-off includes a primary transmission shaft that is transmission-connected to an external engine or electric motor for power input, and also includes a secondary transmission shaft, a first transmission unit and a second transmission unit are provided between the primary transmission shaft and the secondary transmission shaft, a first clutch is provided between the primary transmission shaft and the first transmission unit, and a second clutch is provided between the secondary transmission shaft and the second transmission unit; the control module includes a first oil cylinder and a second oil cylinder; the first clutch controls the clutch through the first oil cylinder; the second clutch controls the clutch through the second oil cylinder. At the same time, the present invention also provides a transmission control method using the flexible power take-off, which has low energy consumption, small loss to the equipment, especially the friction pair of the clutch, and can increase the life of the equipment to more than 10 years.

Description

Technical Field

[0001] The invention relates to the field of power transmission equipment, in particular to a flexible power take-off system and a transmission control method. Background Art

[0002] The fans used in sanitation vehicles, the tank drive mechanisms of cement tank trucks, and the working mechanisms of agricultural machinery all have some common features. The working mechanisms of agricultural machinery, such as the plowing mechanism of a plowing vehicle and the harvesting mechanism of a harvester, have the problem of mismatching torque and speed, especially in sloping environments or in rugged fields.

[0003] Take the fan rotor used in the road sweeper in the sanitation vehicle as an example. Its power reaches 30-50KW. In order to drive the fan, the road sweeper has to install another diesel engine specifically for driving the fan. However, in 2019, commercial vehicles will enforce the National VI emission regulations, and the diesel engine specifically used to drive the fan must be cancelled because it cannot be installed with a post-processing device or the cost of installing a post-processing device is very high. Therefore, it is imperative for the special-purpose vehicle sanitation vehicle industry to switch to a single engine. At present, there are only two driving options for sanitation vehicles and special-purpose vehicles such as road sweepers on the market after switching to single engines (only a single engine): motor drive and main engine drive.

[0004] 1. The fan is driven by power transmitted from the main engine. Since the fan starting torque is particularly large, usually reaching thousands of Nm, when the engine is idle, the fan is often started due to excessive load, causing the engine to stall. When the engine is started with load, the engine is difficult to start due to excessive load.

[0005] 2. When using a motor to drive such a high-power fan rotor, the problem of the motor being damaged and the circuit being burned out often occurs;

[0006] 3. Both of the above driving methods must use a power take-off to transmit power. In addition to the above two problems, when the power is transmitted through the power take-off to drive such a large torque fan, the friction pair of the power take-off will be severely worn due to the very large starting torque, resulting in a short service life of the power take-off.

[0007] To solve the above problems, it is feasible to use the existing mature gearboxes. However, the existing mature gearboxes will become very large if they are to carry such high-power equipment. At the same time, the problem that cannot be ignored is that the existing gearboxes on the market are very complex and very precise, especially the price is too high, which makes it difficult to promote them universally. Therefore, in the vast field of engineering vehicles or agricultural vehicles, most of them use imported components or directly use imported vehicles. According to statistics, in Xinjiang, more than 90% of plowing vehicles are imported from Europe and the United States. Domestic plowing vehicles are very rare and have poor reliability.

[0008] To solve the above problems, we must either overcome the difficulties in the gearbox production process, or find another reasonable design path to solve the corresponding problems. Summary of the invention

[0009] The purpose of the present invention is to provide a flexible power take-off system. The design idea of ​​the system is mainly to simplify the design so that the power take-off can achieve the purpose of low-speed and high-torque starting and low-torque and high-speed operation under heavy load conditions, avoiding the problem of engine stalling or motor burning when the heavy load is started at high speed and high torque, and avoiding the problem of rapid wear of the power take-off. At the same time, the problem of overly complicated production processes in traditional transmission systems is reduced, making the vision of flexible operation of variable torque and variable speed a reality. At the same time, the present invention also provides a transmission control method using the flexible power take-off, which has low energy consumption and small loss to the equipment, especially the friction pair of the clutch, and can increase the life of the equipment to more than 10 years.

[0010] The specific technical solution of the present invention is: a flexible power take-off system, including a flexible power take-off and a control module; the flexible power take-off includes a primary transmission shaft connected to an external engine or electric motor for power input, and also includes a secondary transmission shaft, a first transmission unit for increasing the output torque from the primary transmission shaft to the secondary transmission shaft and a second transmission unit for increasing the transmission speed from the primary transmission shaft to the secondary transmission shaft are provided between the primary transmission shaft and the secondary transmission shaft, a first clutch is provided between the primary transmission shaft and the first transmission unit, and a second clutch is provided between the secondary transmission shaft and the second transmission unit;

[0011] The control module comprises a first oil cylinder and a second oil cylinder; the first clutch is controlled by the first oil cylinder; the second clutch is controlled by the second oil cylinder.

[0012] In the above-mentioned flexible power take-off system, the control module also includes a three-position four-way valve and a controller. The three-position four-way valve is provided with a P port (oil inlet), a T port (oil return port), an A port and a B port. The A port is connected to the first oil cylinder, the B port is connected to the second oil cylinder, and the P port is connected to the oil pump; the oil pump and the T port are both connected to the hydraulic oil tank; the controller controls the action of the three-position four-way valve.

[0013] The above-mentioned flexible power take-off system further comprises a pressure regulating valve, the inlet of the pressure regulating valve is connected to the oil pump, and the outlet of the pressure regulating valve is connected to the hydraulic oil tank.

[0014] In the above-mentioned flexible power take-off system, the first transmission unit comprises a first gear and a second gear that are meshed and matched, and the diameter of the first gear is smaller than the diameter of the second gear;

[0015] The second transmission unit comprises a third gear and a fourth gear that are meshed with each other, and the diameter of the third gear is greater than the diameter of the fourth gear;

[0016] The first gear is connected to the first clutch; the second gear is fixedly connected to the secondary transmission shaft;

[0017] The third gear is fixedly connected to the primary transmission shaft, and the fourth gear is connected to the second clutch.

[0018] It should be noted that in the present invention, only the realization of the secondary transmission shaft is listed. In actual application, it may also involve a third-stage transmission or a fourth-stage transmission. Regardless of the number of transmissions, the control of the dual clutch will be involved, and the addition of the control module as described above can also be realized. The present invention does not make too many restrictions on this. Similarly, the following method is also applicable to the case of a third-stage transmission and a fourth-stage transmission.

[0019] At the same time, the present invention also provides a variable torque and variable speed transmission control method, which uses the above-mentioned flexible power take-off system to realize the transmission between the external engine or motor of the power input and the external working equipment; comprising the following steps:

[0020] Step 1: During the period from when the peripheral working equipment is started to when the speed reaches the first preset value, the P port and the A port of the three-position four-way valve are connected or intermittently connected and the T port and the B port of the three-position four-way valve are connected, the first clutch is closed or intermittently closed and the second clutch is continuously separated, so that the first transmission unit works and the second transmission unit does not work;

[0021] Step 2: When the speed of the peripheral working equipment reaches the first preset value, the P port and the B port of the three-position four-way valve are connected and the T port and the A port of the three-position four-way valve are connected, the second clutch is closed or intermittently closed and the first clutch is continuously separated, so that the second transmission unit works and the first transmission unit does not work;

[0022] Step 3: When the speed of the peripheral working equipment reaches the second preset value, the P port and the B port of the three-position four-way valve remain in the conducting state, and the T port and the A port of the three-position four-way valve remain in the conducting state, the second clutch is continuously closed and the first clutch is continuously separated, and the power is output from the primary transmission shaft to the secondary transmission shaft through the second transmission unit, and the secondary transmission shaft drives the peripheral working equipment to operate;

[0023] The first preset value is smaller than the second preset value.

[0024] In the above-mentioned variable torque and variable speed transmission control method, when the main body of the power input is an external engine, it also includes step 4 which can be executed at any time: when a signal that the external working equipment stops working is received, or the external engine ignition signal disappears, or the speed of the external engine is lower than the lower speed limit and lasts for 1.5-2.5s, or the speed of the external engine is higher than the upper speed limit; the lower speed limit and the upper speed limit are user preset values;

[0025] The P port of the three-position four-way valve returns to the middle position (when the P port returns to the middle position, the oil supply to the P port is cut off), and the A port, B port, and T port are connected;

[0026] When the peripheral working device sends a start signal again, the engine is re-ignited, the engine recovers to above the lower speed limit, and the engine recovers to the working range speed, execute step 1, or if the following step 1s is set, execute step 1s.

[0027] In the above-mentioned variable torque and variable speed transmission control method, the step 1 also includes step 1s before the step 1: determining whether the speed of the engine of the external device reaches the speed of the working range; if so, proceeding to step 1; if not, repeating step 1s until the speed of the engine reaches the speed of the working range;

[0028] The speed in the working range is greater than a lower speed limit and less than an upper speed limit.

[0029] In the above variable torque and variable speed transmission control method, when the main body of power input is an external engine, it also includes step 5 which can be executed at any time: when it is detected that the vehicle equipped with the above system sends a braking signal, the P port of the three-position four-way valve returns to the middle position, and the A port, the B port, and the T port are connected;

[0030] When the detected brake signal disappears and the speed of the engine of the peripheral device is in the working range, or when the detected brake signal does not disappear and the speed of the engine of the peripheral device reaches the lower limit of the speed in the working range, step 2 is performed.

[0031] In the above-mentioned variable torque and variable speed transmission control method, the lower speed limit is 500r / min; the upper speed limit is 1600r / min; and the working range speed is 800-1500r / min.

[0032] In the above-mentioned variable torque and variable speed transmission control method, the switching time from step 1 to step 2 does not exceed 1 second.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The system of the present invention is divided into two parts. One part is a flexible power take-off, which uses two clutches to achieve the purpose of changing torque and changing speed respectively, which will simplify the structure of the transmission system, especially using one clutch to change torque and one clutch to change speed, so that the working time of the clutch for changing torque is shortened to a very short time, and its service life is improved. Therefore, the system has the advantages of simple structure and long service life. Another part is that the present invention introduces a set of control modules, which control the first clutch and the second clutch through independent oil cylinders, which can significantly improve its response speed.

[0035] The method of the present invention has two schemes, namely, two different clutches adopt intermittent or non-intermittent closure, which has the advantage of avoiding excessive burden on the clutch caused by continuous engagement under high torque or during acceleration, thereby increasing the service life of the equipment.

[0036] As a further improvement, the present invention takes into account technical control difficulties not involved in traditional technical solutions, such as low-speed conditions, high-speed conditions, and braking conditions. By further refining the control process, the wear of the peripheral working equipment on the transmission system can be reduced, and the damage to the peripheral engine, the transmission system, and the peripheral working equipment caused by changes in power or external environmental factors can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the flexible power take-off of Example 1;

[0038] Figure 2 is a schematic diagram of the structure of the control module of Example 1;

[0039] Figure 3 This is a control flow chart of Example 2. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is further described in detail below in conjunction with specific implementation methods, but does not constitute any limitation to the present invention.

[0041] Example 1

[0042] like Figure 1-2 As shown, a flexible power take-off system includes a flexible power take-off and a control module;

[0043] The flexible power take-off includes a primary transmission shaft 1 that is transmission-connected to an external engine, and also includes a secondary transmission shaft 2. A first transmission unit for increasing the output torque from the primary transmission shaft 1 to the secondary transmission shaft 2 and a second transmission unit for increasing the transmission speed from the primary transmission shaft 1 to the secondary transmission shaft 2 are provided between the primary transmission shaft 1 and the secondary transmission shaft 2. A first clutch 3 is provided between the primary transmission shaft 1 and the first transmission unit, and a second clutch 4 is provided between the secondary transmission shaft 2 and the second transmission unit.

[0044] The first transmission unit comprises a first gear 5 and a second gear 6 which are meshed with each other, and the diameter of the first gear 5 is smaller than the diameter of the second gear 6;

[0045] The second transmission unit comprises a third gear 7 and a fourth gear 8 that are meshed with each other, and the diameter of the third gear 7 is greater than the diameter of the fourth gear 8;

[0046] The first gear 5 is connected to the first clutch 3; the second gear 6 is fixedly connected to the secondary transmission shaft 2;

[0047] The third gear 7 is fixedly connected to the primary transmission shaft 1 , and the fourth gear 8 is connected to the second clutch 4 .

[0048] The control module includes a first oil cylinder 9 and a second oil cylinder 10 ; the first clutch 3 is controlled to engage or disengage via the first oil cylinder 9 ; and the second clutch 4 is controlled to engage or disengage via the second oil cylinder 10 .

[0049] In order to improve the level of automation control, the control module also introduces a controller 11 and a multi-position multi-way solenoid valve for electrical control of the oil circuit. Specifically, the control module also includes a three-position four-way valve 12 and a controller 11. The three-position four-way valve 12 is provided with a P port 121, a T port 122, an A port 123 and a B port 124. The conduction or disconnection between the P port 121, the T port 122, the A port 123 and the B port 124 is controlled by the coil a and the coil b shown in the figure. The coil a and the coil b are controlled by the controller 11. The A port 123 is connected to the first oil cylinder 9, the B port 124 is connected to the second oil cylinder 10, and the P port 121 is connected to the oil pump 13; the oil pump 13 and the T port 122 are both connected to the hydraulic oil tank 14; the controller 11 controls the action of the three-position four-way valve 12.

[0050] Furthermore, the control module further includes a pressure regulating valve 15, the inlet of the pressure regulating valve 15 is connected to the oil pump 13, and the outlet of the pressure regulating valve 15 is connected to the hydraulic oil tank 14. The pressure regulating valve 15 has two functions, one is to adjust the oil pressure when the control module is working to prevent the oil pressure in the oil circuit from being overloaded; the other is to circulate the hydraulic oil in the oil circuit when the P port 121 of the three-position four-way valve 12 is closed and the A port 123 and the B port 124 are connected to the T port 122, and the pressure regulating valve 15 is in a fully open state.

[0051] Example 2

[0052] like Figure 3 As shown, a variable torque and variable speed transmission control method is used to realize transmission between a transmitter of an external device and a working device of the external device; the system of embodiment 1 is adopted, comprising the following steps:

[0053] Step 1s: Determine whether the speed of the peripheral engine reaches the working range speed; if so, proceed to step 1; if not, repeat step 1s until the engine speed reaches the working range speed; it should be noted that: the working range speed is greater than the lower speed limit and less than the upper speed limit; the lower speed limit and the upper speed limit are set according to the vehicle conditions. Taking the ordinary road sweeper on the market as an example, the lower speed limit is 500r / min; the upper speed limit is 1600r / min. However, in actual application, the lower speed limit and the upper speed limit are not limited to this specific value. We generally choose to set the working range speed at 800-1500r / min. Similarly, the working range speed is set according to the vehicle conditions and is not limited to this specific value.

[0054] Step 1: During the period from when the peripheral working equipment is started to when the speed reaches the first preset value, the P port 121 and the A port 123 of the three-position four-way valve 12 are turned on or intermittently turned on, and the T port 122 and the B port 124 of the three-position four-way valve 12 are turned on, the first clutch 3 is intermittently closed and the second clutch 4 is continuously separated, so that the first transmission unit works and the second transmission unit does not work;

[0055] In practical applications, it is preferred to use intermittent conduction to achieve intermittent closing of the first clutch 3, because the torque is very large at the beginning, and if the first clutch 3 is closed for a long time, it will cause irreversible damage to the first clutch 3 in the long run.

[0056] The intermittent closing mode of the first clutch 3 can be: the first oil cylinder is turned on for 1-4 seconds and then disconnected for 0.2-2 seconds, then turned on for 1-4 seconds and then disconnected for 0.2-2 seconds, and this automatic cycle is repeated. In this way, the first clutch 3 is closed for 1-4 seconds and then disconnected for 0.2-2 seconds, and then closed for 1-4 seconds and then disconnected for 0.2-2 seconds.

[0057] Step 2: When the speed of the peripheral working equipment reaches the first preset value, the P port 121 and the B port 124 of the three-position four-way valve 12 are connected, and the T port 122 and the A port 123 of the three-position four-way valve 12 are connected, the second clutch 4 is intermittently closed and the first clutch 3 is continuously separated, so that the second transmission unit works and the first transmission unit does not work;

[0058] The switching time between step 1 and step 2 should not exceed 1s, because it involves the oil pressure change of the oil circuit system, so there is a switching time between steps 1 and 2, but the time should not be too long.

[0059] Step 3: When the speed of the peripheral working equipment reaches the second preset value, the P port 121 and the B port 124 of the three-position four-way valve 12 remain in the on state, and the T port 122 and the A port 123 of the three-position four-way valve 12 remain in the on state, the second clutch 4 is continuously closed and the first clutch 3 is continuously separated, and the power is output from the primary transmission shaft 1 to the secondary transmission shaft 2 through the second transmission unit, and the secondary transmission shaft 2 drives the peripheral working equipment to operate;

[0060] The first preset value is smaller than the second preset value.

[0061] The intermittent closure of the first clutch 3 overcomes the problem of increased wear caused by large torque in the initial stage of starting, and the intermittent closure of the second clutch 4 overcomes the problem of increased wear caused by rapid acceleration in the acceleration stage in the middle and late stages of starting.

[0062] However, we should also pay attention to some special application situations. Most of the technical solutions in this field have not received enough attention for these extreme situations.

[0063] Specifically, the following situations are included:

[0064] Case 1

[0065] A signal to stop working of the peripheral device is received; this situation means that the peripheral device has finished working, and the operator presses the stop button in the vehicle, and a stop signal is generated at this time.

[0066] Case 2

[0067] The peripheral engine ignition signal disappears; this situation means that the peripheral engine has stalled. At this time, it is necessary to promptly cut off the connection between the engine and the peripheral working equipment to prevent the peripheral working equipment from continuing to drive the engine to rotate and damage the engine. At the same time, it is also to ensure the safety of this system and the peripheral working equipment.

[0068] Case 3

[0069] The speed of the peripheral engine is lower than the lower speed limit and lasts for 1.5-2.5 seconds; this situation means that the engine is about to stall, refer to situation 2. If it is only a momentary low speed, the present invention will not take this situation into consideration for cutting off the connection between the engine and the peripheral working equipment. However, the continuation of the low speed means that the engine is very likely to stall, and this situation should be taken into consideration.

[0070] Case 4

[0071] The engine speed of the peripheral device is higher than the upper speed limit; this situation means that the engine is in an extreme condition, such as sudden emergency acceleration, which may indicate an overspeed situation. At this time, if the connection between the engine and the peripheral working equipment is not disconnected, it will not only affect the emergency acceleration of the vehicle, but may also cause damage to the peripheral working equipment due to overspeed operation.

[0072] In the above situations one to four, the connection between the engine and the peripheral working equipment should be disconnected; the specific operation is: the P port 121 of the three-position four-way valve 12 returns to the middle position, and the A port 123, the B port 124, and the T port 122 are connected.

[0073] The lower speed limit and the upper speed limit of the present invention are set according to the vehicle conditions. For example, for a common road sweeper on the market, the lower speed limit is 500r / min and the upper speed limit is 1600r / min. However, in actual application, the lower speed limit and the upper speed limit are not limited to the specific values.

[0074] When the above situations 1-4 disappear, such as when the peripheral working equipment sends a start signal again, the engine is re-ignited, the engine recovers to above the lower speed limit, and the engine recovers to the working range speed, execute step 1s.

[0075] In addition to the above situations, there is another situation that needs to be considered, namely:

[0076] Case 5

[0077] When it is detected that the vehicle equipped with the system sends a braking signal, the connection between the engine and the peripheral working equipment should be disconnected; the specific operation is: the P port 121 of the three-position four-way valve 12 returns to the middle position, and the A port 123, the B port 124, and the T port 122 are connected;

[0078] When the detected brake signal disappears and the speed of the engine of the peripheral device is in the working range, or when the detected brake signal does not disappear and the speed of the engine of the peripheral device reaches the lower limit of the speed in the working range, step 2 is performed.

[0079] The structure of this embodiment is simple and the service life is long. Although the method appropriately prolongs the start-up time, the service life is significantly increased.

[0080] The above description is only a preferred embodiment of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A flexible power take-off system, characterized in that: It comprises a flexible power take-off and a control module; the flexible power take-off comprises a primary transmission shaft connected to an external engine or electric motor for power input, and also comprises a secondary transmission shaft, a first transmission unit for increasing the output torque from the primary transmission shaft to the secondary transmission shaft and a second transmission unit for increasing the transmission speed from the primary transmission shaft to the secondary transmission shaft are arranged between the primary transmission shaft and the secondary transmission shaft, a first clutch is arranged between the primary transmission shaft and the first transmission unit, and a second clutch is arranged between the secondary transmission shaft and the second transmission unit; The control module includes a first oil cylinder and a second oil cylinder; the first clutch is controlled by the first oil cylinder; the second clutch is controlled by the second oil cylinder; The flexible power take-off system realizes the transmission between the external engine or motor of the power input and the external working equipment; and comprises the following steps: Step 1: During the period from when the peripheral working equipment is started to when the speed reaches the first preset value, the P port and the A port of the three-position four-way valve are connected or intermittently connected and the T port and the B port of the three-position four-way valve are connected, the first clutch is closed or intermittently closed and the second clutch is continuously separated, so that the first transmission unit works and the second transmission unit does not work; Step 2: When the speed of the peripheral working equipment reaches the first preset value, the P port and the B port of the three-position four-way valve are connected and the T port and the A port of the three-position four-way valve are connected, the second clutch is closed or intermittently closed and the first clutch is continuously separated, so that the second transmission unit works and the first transmission unit does not work; Step 3: When the speed of the peripheral working equipment reaches the second preset value, the P port and the B port of the three-position four-way valve remain in the conducting state, and the T port and the A port of the three-position four-way valve remain in the conducting state, the second clutch is continuously closed and the first clutch is continuously separated, and the power is output from the primary transmission shaft to the secondary transmission shaft through the second transmission unit, and the secondary transmission shaft drives the peripheral working equipment to operate; The first preset value is smaller than the second preset value.

2. The flexible power take-off system according to claim 1, characterized in that: The control module also includes a three-position four-way valve and a controller. The three-position four-way valve is provided with a P port, a T port, an A port and a B port. The A port is connected to the first oil cylinder, the B port is connected to the second oil cylinder, and the P port is connected to the oil pump; the oil pump and the T port are both connected to the hydraulic oil tank; the controller controls the action of the three-position four-way valve.

3. The flexible power take-off system according to claim 2, characterized in that: It also includes a pressure regulating valve, the inlet of the pressure regulating valve is connected to the oil pump, and the outlet of the pressure regulating valve is connected to the hydraulic oil tank.

4. The flexible power take-off system according to any one of claims 1 to 3, characterized in that: The first transmission unit comprises a first gear and a second gear that are meshed and matched, and the diameter of the first gear is smaller than the diameter of the second gear; The second transmission unit comprises a third gear and a fourth gear that are meshed with each other, and the diameter of the third gear is greater than the diameter of the fourth gear; The first gear is connected to the first clutch; the second gear is fixedly connected to the secondary transmission shaft; The third gear is fixedly connected to the primary transmission shaft, and the fourth gear is connected to the second clutch.

5. The flexible power take-off system according to claim 1, characterized in that: When the subject of the power input is an external engine, the method further includes step 4 which can be executed at any time: when a signal indicating that the external working equipment stops working is received, or the ignition signal of the external engine disappears, or the speed of the external engine is lower than the lower speed limit and lasts for 1.5-2.5s, or the speed of the external engine is higher than the upper speed limit; the lower speed limit and the upper speed limit are user preset values; The P port of the three-position four-way valve returns to the middle position, and the A port, B port, and T port are connected.

6. The flexible power take-off system according to claim 5, characterized in that: The step 1 also includes step 1s before step 1: determining whether the speed of the engine of the peripheral device reaches the speed of the working range; if so, proceeding to step 1; if not, repeating step 1s until the speed of the engine reaches the speed of the working range; The speed in the working range is greater than a lower speed limit and less than an upper speed limit.

7. The flexible power take-off system according to claim 5, characterized in that: When the main body of power input is an external engine, it also includes step 5 which can be executed at any time: when it is detected that the vehicle equipped with the flexible power take-off system sends a braking signal, the P port of the three-position four-way valve returns to the middle position, and the A port, the B port, and the T port are connected; When the detected brake signal disappears and the speed of the engine of the peripheral device is in the working range, or when the detected brake signal does not disappear and the speed of the engine of the peripheral device reaches the lower limit of the speed in the working range, step 2 is performed.

8. The flexible power take-off system according to claim 5, characterized in that: The lower speed limit is 500r / min; the upper speed limit is 1600r / min; and the working range speed is 800-1500r / min.

9. The flexible power take-off system according to claim 1, characterized in that: The switching time from step 1 to step 2 does not exceed 1s.

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