A walking control hydraulic system for a silage machine and a control method thereof

Abstract

The application discloses a silage machine walking control hydraulic system and a control method thereof. The silage machine walking control hydraulic system comprises a variable plunger pump, an oil supplement pump, a right front accumulator, a left front accumulator, a left front check valve, a right front check valve, a left front variable plunger motor, a rear axle variable plunger motor and a right front variable plunger motor. The variable plunger pump and the oil supplement pump are drivingly connected with a power output device. The A port of the variable plunger pump is connected with the A port of each motor respectively, and the B port of the variable plunger pump is connected with the B port of each motor respectively. The output end of the oil supplement pump is connected with the A port of the left front variable plunger motor through the left front check valve and connected with the A port of the right front variable plunger motor through the right front check valve. The left front accumulator is connected with the input end of the left front check valve in parallel, and the right front accumulator is connected with the input end of the right front check valve in parallel. The application ensures the service life of the hydraulic components, improves the braking efficiency and braking accuracy, and reduces the friction plate wear.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of agricultural equipment, in particular, relates to a walking control hydraulic system for a silage machine and a control method thereof. BACKGROUND

[0002] With the development of animal husbandry, the concentration of cattle and sheep breeding, the demand and storage capacity of farmers for feed is increasing, and the problem of low efficiency of artificial harvesting and storage of forage is highlighted. After a long time of development of agricultural mechanization, silage machines play an indispensable role in the harvesting, chopping, storage and transportation of forage. And with the rapid improvement of the level of agricultural mechanization in China in recent years, farmers have increasingly high requirements for the automation level of agricultural machinery. Therefore, the practicability and safety of silage machines are particularly important. The existing silage machine walking system generally uses hydrostatic drive. In order to ensure the brake distance, most of them are equipped with mechanical brake devices. There are mainly the following ways in the braking process of such machines: the first way is to output pressure through the foot pedal to frictionally brake the driving mechanism; the second way is the control mode of combined braking of frictional braking and hydrostatic braking.

[0003] In view of the existing braking technology, the following deficiencies exist:

[0004] 1. Mechanical braking and hydrostatic braking exist independently. Whether in deceleration or emergency braking conditions, the braking force is mainly output by stepping on the foot pedal to frictionally brake the moving parts. Frequent mechanical friction accelerates the wear of parts. In the case of emergency braking, the handle is not returned to the neutral position due to some reasons, and the hydraulic system continuously outputs driving force. Simple mechanical braking greatly reduces the safety and reliability of braking.

[0005] 2. Some machines use a combination of mechanical braking and hydrostatic braking, but mainly control the pump and motor variable displacement through the pressure feedback of the foot pedal. When the foot pedal is stepped on for deceleration, the pressure signal controls the pump and motor variable displacement, resulting in the coexistence of frictional braking during hydrostatic braking. This control mode not only accelerates the wear of the friction plate, but also easily confuses the two working conditions of deceleration and emergency braking, reducing the braking accuracy and efficiency of the whole machine.

[0006] 3. The hydrostatic braking force mainly comes from the high pressure and low pressure conversion of the hydraulic motor inlet and outlet, forming a reverse braking force. In the case of high-speed emergency braking of the vehicle, the outlet (low pressure port) of the motor will have a momentary overpressure. Due to the limitation of the flow of the high-pressure overflow valve inside the closed pump and the flow of the oil supplement pump, the high-pressure oil on the braking side cannot be instantly supplemented to the low-pressure side, resulting in a momentary loss of pressure at the motor inlet and a momentary loss of pressure at the outlet of the oil supplement pump. This sudden pressure loss condition easily leads to the failure of hydraulic elements such as variable pumps and variable motors, affecting their service life. SUMMARY

[0007] The application provides a walking control hydraulic system for a silage machine.

[0008] The technical scheme adopted by the application is as follows:

[0009] The walking control hydraulic system for the silage machine comprises a variable plunger pump, an oil supplement pump, a right front accumulator, a left front accumulator, a left front check valve, a right front check valve, a left front variable plunger motor, a rear axle variable plunger motor and a right front variable plunger motor.

[0010] The variable plunger pump and the oil supplement pump are drivingly connected with the power output device, the A port of the variable plunger pump is connected with the A port of the left front variable plunger motor, the A port of the rear axle variable plunger motor and the A port of the right front variable plunger motor respectively, the B port of the variable plunger pump is connected with the B port of the left front variable plunger motor, the B port of the rear axle variable plunger motor and the B port of the right front variable plunger motor respectively, the output end of the oil supplement pump is connected with the A port of the left front variable plunger motor through the left front check valve and connected with the A port of the right front variable plunger motor through the right front check valve, the left front accumulator is connected with the input end of the left front check valve in parallel, and the right front accumulator is connected with the input end of the right front check valve in parallel.

[0011] Preferably, the walking control hydraulic system further comprises a second overflow valve and two first overflow valves, the two first overflow valves are connected in series and then connected in parallel between the A port and the B port of the variable plunger pump, and the second overflow valve is connected with the output end of the oil supplement pump.

[0012] Preferably, the walking control hydraulic system further comprises a check valve, the output end of the check valve is connected with the output end of the oil supplement pump, and the input end of the check valve is connected with the right front accumulator and the left front accumulator respectively.

[0013] Preferably, the walking control hydraulic system further comprises a third overflow valve, and the third overflow valve is connected with the input end of the check valve in parallel.

[0014] Preferably, the walking control hydraulic system further comprises a first pressure sensor and a second pressure sensor, the first pressure sensor is connected with the output end of the oil supplement pump and used for detecting the outlet pressure of the oil supplement pump, and the second pressure sensor is connected with the pipeline between the check valve and the right front accumulator and the left front accumulator in parallel and used for detecting the pressure in the right front accumulator and the left front accumulator.

[0015] The application also provides a control method of the walking control hydraulic system for the silage machine.

[0016] The technical scheme adopted by the application is as follows:

[0017] A control method of a walking control hydraulic system of a silage machine, comprising the steps of:

[0018] Obtaining a current pedal depression angle;

[0019] According to the interval in which the actual depression angle is located, the displacement of the variable piston pump, the left front variable piston motor, the rear axle variable piston motor and the right front variable piston motor is controlled according to the corresponding displacement change slope to output corresponding size of static hydraulic braking force to gradually slow down the vehicle; and only when the actual depression angle reaches a set threshold, corresponding size of friction braking force is generated by the brake calipers to realize emergency braking of the vehicle by driving the foot brake valve to output hydraulic pressure while outputting corresponding size of static hydraulic braking force according to the size of the actual depression angle, wherein the displacement change slope and the hydraulic pressure output by the foot brake valve are positively correlated with the size of the actual depression angle.

[0020] Further, according to the interval in which the actual depression angle is located, the displacement of the variable piston pump, the left front variable piston motor, the rear axle variable piston motor and the right front variable piston motor is controlled according to the corresponding displacement change slope to output corresponding size of static hydraulic braking force to gradually slow down the vehicle; and only when the actual depression angle reaches a set threshold, corresponding size of friction braking force is generated by the brake calipers to realize emergency braking of the vehicle by driving the foot brake valve to output hydraulic pressure while outputting corresponding size of static hydraulic braking force according to the size of the actual depression angle, wherein the displacement change slope and the hydraulic pressure output by the foot brake valve are positively correlated with the size of the actual depression angle.

[0021] If the current depression angle of the pedal is θ < θ0, the vehicle is in normal driving state by default, at this time the vehicle speed is controlled by the handle, and the control system controls the vehicle speed and the handle current value to match each other in a closed loop;

[0022] If the current depression angle of the pedal is θ0≤θ≤θ1, the control system overrules the handle control, and the displacement of the variable piston pump, the left front variable piston motor, the rear axle variable piston motor and the right front variable piston motor is controlled according to the first displacement change slope K θX1 The displacement of the variable piston pump, the left front variable piston motor, the rear axle variable piston motor and the right front variable piston motor is controlled to output corresponding size of static hydraulic braking force to gradually slow down the vehicle;

[0023] If the current depression angle of the pedal is θ1<θ≤θ2, the control system overrules the handle control, and the displacement of the variable piston pump, the left front variable piston motor, the rear axle variable piston motor and the right front variable piston motor is controlled according to the second displacement change slope K θX2 The displacement of the variable piston pump, the left front variable piston motor, the rear axle variable piston motor and the right front variable piston motor is controlled to output corresponding size of static hydraulic braking force, wherein K θX1 <K θX2 ; at the same time, the foot brake valve outputs hydraulic pressure to the brake calipers to generate corresponding size of friction braking force to realize emergency braking of the vehicle, and the friction braking force is positively correlated with the size of the actual depression angle.

[0024] Further, the first displacement change slope K θX1 and the second displacement change slope K θX2 Specifically:

[0025]

[0026]

[0027] Wherein: θ X1 is the real-time feedback value of the pedal pedal angle in the interval [θ0, θ1], K θX1 is the first displacement change slope required to control the pump and motor displacement change when the pedal pedal angle is θ X1 ; k0 and k1 are respectively the displacement change slopes required to control the pump and motor displacement change when the pedal pedal angle is θ0 and θ1; θ X2 is the real-time feedback value of the pedal pedal angle in the interval (θ1, θ2], K θX2 is the second displacement change slope required to control the pump and motor displacement change when the pedal pedal angle is θ X2 ; k2 is the displacement change slope required to control the pump and motor displacement change when the pedal pedal angle is θ2.

[0028] Further, if the current pedal pedal angle θ0≤θ≤θ1, the control system overrides the handle control, and controls the displacement of the variable plunger pump, left front variable plunger motor, rear axle variable plunger motor, and right front variable plunger motor with the first displacement change slope K θX1 to output corresponding size of static hydraulic braking force to realize gradual speed reduction of the vehicle, specifically including the steps of:

[0029] If the motor current I m =0, each motor is at maximum displacement, and the hydraulic system is in pump speed regulation state, at this time, the variable plunger pump is controlled to reduce the pump displacement with the first displacement change slope K θX1 until the vehicle is reduced to 0;

[0030] If the motor current I m ≠0, the hydraulic system is in pump maximum displacement and motor variable displacement speed regulation state, at this time, each motor is first controlled to increase to maximum displacement with the first displacement change slope K θX1 , and then the variable plunger pump is controlled to reduce the pump displacement with the first displacement change slope K θX1 until the vehicle is reduced to 0.

[0031] Further, if the current pedal pedal angle θ1<θ≤θ2, the control system overrides the handle control, and controls the displacement of the variable plunger pump, left front variable plunger motor, rear axle variable plunger motor, and right front variable plunger motor with the second displacement change slope K θX2Controlling the displacement of the variable plunger pump, the left front variable plunger motor, the rear axle variable plunger motor and the right front variable plunger motor to output corresponding size of hydrostatic braking force to gradually reduce the speed of the vehicle, specifically comprising the steps of:

[0032] If the motor current I m = 0, each motor is at maximum displacement, and the hydraulic system is in pump speed regulation state, at this time, the second displacement change slope K θX2 Controlling the variable plunger pump to reduce the pump displacement until the vehicle is reduced to 0;

[0033] If the motor current I m ≠ 0, the hydraulic system is in pump maximum displacement and motor variable displacement speed regulation state, at this time, the second displacement change slope K θX2 Controlling each motor to increase the displacement and the variable plunger pump to reduce the pump displacement at the same time until the vehicle is reduced to 0;

[0034] Or,

[0035] If the motor current I m ≠ 0, the hydraulic system is in pump maximum displacement and motor variable displacement speed regulation state, at this time, first controlling each motor to increase to maximum displacement at the second displacement change slope K θX2 Then controlling the variable plunger pump to reduce the pump displacement at the second displacement change slope K θX2 Until the vehicle is reduced to 0.

[0036] Compared with the prior art, the application has the following beneficial effects:

[0037] The application provides a silage machine walking control hydraulic system and a control method thereof. The control method differentiates control of a pure deceleration working condition and an emergency braking working condition of the vehicle through optimization design of a control logic: in the pure deceleration working condition, static hydraulic braking of the system is adopted; and in the emergency braking working condition, static hydraulic braking + friction braking of the system is adopted, thereby avoiding the problem of early damage of friction plates caused by a large amount of friction braking, and increasing the service life of the elements; in the emergency braking condition, if the handle is not returned to the neutral position due to some reasons, the hydraulic system will continuously output driving force, and at this time, only the friction braking mode of the foot brake will cause a great increase in the braking distance, the control method of the application controls by force after the current pedal depression angle is obtained, thereby avoiding the occurrence of the situation, and improving the braking safety and reliability of the whole machine; the control method of the application controls the displacement of each pump and motor according to the size of the actual depression angle in the interval according to the positive correlation of the displacement change slope to output the corresponding size of the static hydraulic braking force, that is, the smaller the actual depression angle, the smaller the displacement change slope of the control of the displacement of each pump and motor to output the smaller static hydraulic braking force to realize the gradual speed reduction of the vehicle, and the larger the actual depression angle, the larger the displacement change slope of the control of the displacement of each pump and motor to output the larger static hydraulic braking force, and at the same time, hydraulic pressure is output to the brake caliper to generate larger friction braking force to realize the emergency braking of the vehicle together, that is, the application can output braking forces of different sizes and types according to different working conditions, thereby greatly improving the braking precision and braking efficiency of the whole machine.

[0038] The application provides other purposes, features and advantages in addition to the above-described purposes, features and advantages. The application will be further described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0039] The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the application, and are incorporated herein for purposes of illustrating the illustrative embodiments of the present application and the explanations provided herein. In the drawings:

[0040] Figure 1 is a schematic diagram of the structure principle of the silage machine walking control hydraulic system of the application.

[0041] Figure 2 is a schematic diagram of the control method flow of the preferred embodiment of the application.

[0042] Figure 3Fig. 1 is a schematic diagram of the relationship between the pedal angle signal and the output hydraulic pressure of the foot brake valve in the preferred embodiment of the present application.

[0043] Figure 4 Fig. 2 is a schematic diagram of the relationship between the pedal angle signal and the displacement change slope in the preferred embodiment of the present application.

[0044] Figure 5 Fig. 3 is a schematic diagram of the relationship between the pedal angle signal and the vehicle braking force in the preferred embodiment of the present application.

[0045] Figure 6 Fig. 4 is a schematic diagram of the control device module in the preferred embodiment of the present application.

[0046] Figure 7 Fig. 5 is a schematic diagram of the electronic device entity in the preferred embodiment of the present application.

[0047] Figure 8 Fig. 6 is a schematic diagram of the computer device composition in the preferred embodiment of the present application.

[0048] In the figure: 1, variable plunger pump; 2, oil supplement pump; 3, first overflow valve; 4, second overflow valve; 5, first pressure sensor; 6, third overflow valve; 7, check valve; 8.1, right front accumulator; 8.2, left front accumulator; 9.2, left front check valve; 9.1, right front check valve; 10, left front variable plunger motor; 11, rear axle variable plunger motor; 12, right front variable plunger motor; 13, second pressure sensor. DETAILED DESCRIPTION

[0049] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0050] As shown in Figure 1 the preferred embodiment of the present application provides a walking control hydraulic system for a silo, which comprises a variable plunger pump 1, an oil supplement pump 2, a right front accumulator 8.1, a left front accumulator 8.2, a left front check valve 9.2, a right front check valve 9.1, a left front variable plunger motor 10, a rear axle variable plunger motor 11, and a right front variable plunger motor 12, wherein:

[0051] The variable plunger pump 1, the oil supplement pump 2 and the power output device are drivingly connected, the A port of the variable plunger pump 1 is connected with the A port of the left front variable plunger motor 10, the rear axle variable plunger motor 11 and the right front variable plunger motor 12 respectively, the B port of the variable plunger pump 1 is connected with the B port of the left front variable plunger motor 10, the rear axle variable plunger motor 11 and the right front variable plunger motor 12 respectively; the output end of the oil supplement pump 2 is connected with the A port of the left front variable plunger motor 10 through the left front one-way valve 9.2 and the A port of the right front variable plunger motor 12 through the right front one-way valve 9.1, the left front accumulator 8.2 is connected with the input end of the left front one-way valve 9.2 in parallel, and the right front accumulator 8.1 is connected with the input end of the right front one-way valve 9.1 in parallel.

[0052] Preferably, the silo walking control hydraulic system further comprises a second overflow valve 4 and two first overflow valves 3, the two first overflow valves 3 are connected in series and then connected in parallel between the A port and the B port of the variable plunger pump 1; the second overflow valve 4 is connected with the output end of the oil supplement pump 2.

[0053] Preferably, the silo walking control hydraulic system further comprises a one-way valve 7, the output end of the one-way valve 7 is connected with the output end of the oil supplement pump 2, and the input end of the one-way valve 7 is connected with the right front accumulator 8.1 and the left front accumulator 8.2 respectively.

[0054] Preferably, the silo walking control hydraulic system further comprises a third overflow valve 6, the third overflow valve 6 is connected with the input end of the one-way valve 7 in parallel.

[0055] Preferably, the silo walking control hydraulic system further comprises a first pressure sensor 5 and a second pressure sensor 13, the first pressure sensor 5 is connected with the output end of the oil supplement pump 2 and used for detecting the outlet pressure of the oil supplement pump 2, and the second pressure sensor 13 is connected with the pipeline between the one-way valve 7 and the right front accumulator 8.1 and the left front accumulator 8.2 in parallel and used for detecting the pressure in the right front accumulator 8.1 and the left front accumulator 8.2.

[0056] In the above embodiment, the variable plunger pump 1 is the power source of the hydraulic walking system, and the swash plate can be bidirectional variable; the oil supplement pump 2 is a gear pump, and in the hydraulic system, the main functions of the oil liquid of the oil supplement pump 2 are as follows: low-pressure side oil supplement of the hydraulic system, motor housing flushing and control of the swash plate variable of the variable plunger pump 1; the first overflow valve 3 is a high-pressure overflow valve, and the main function is that when the oil pressure of one side of the hydraulic system is higher than the set value of the overflow valve, the first overflow valve 3 is opened, the high-pressure side oil liquid enters the low-pressure side, and the pump inlet and outlet oil liquid circulates; the second overflow valve 4 is an oil supplement overflow valve, which controls the outlet pressure of the oil supplement pump; the first pressure sensor 5 is an oil supplement pressure sensor, which detects the outlet pressure of the oil supplement pump 2 at any time;

[0057] The third overflow valve 6 is a safety valve. If the leakage of the right front one-way valve 9.1 or the left front one-way valve 9.2 is relatively large, long-time walking will cause the high-pressure side oil to leak to the single-way valve 7 and between the right front accumulator 8.1 or the left front accumulator 8.2 through the right front one-way valve 9.1 or the left front one-way valve 9.2, resulting in the continuous increase of the pressure of each accumulator. If the right front one-way valve 9.1 or the left front one-way valve 9.2 has a problem, the high-pressure side oil can directly enter each accumulator when advancing. Therefore, when the pressure increases to the set pressure of the third overflow valve 6, the third overflow valve 6 is unloaded, protecting each accumulator and improving the safety and reliability of the use of each accumulator.

[0058] The right front one-way valve 9.1 or the left front one-way valve 9.2 is a one-way check valve, reversely stopping the high-pressure oil of the left front variable piston motor 10 and the right front variable piston motor 12. When the oil inlet of the left front variable piston motor 10 and the right front variable piston motor 12 loses pressure, the oil in the right front accumulator 8.1 or the left front accumulator 8.2 is quickly supplemented to the low-pressure side of the left front variable piston motor 10 and the right front variable piston motor 12 through the right front one-way valve 9.1 or the left front one-way valve 9.2.

[0059] The left front variable piston motor 10 and the right front variable piston motor 12 are front axle left and right wheel edge driving motors, and the rear axle variable piston motor 11 is a rear axle driving motor. Each motor is a variable displacement motor. When the left front variable piston motor 10 and the right front variable piston motor 12 lose power, the displacement is maximum. Since high-speed emergency braking usually occurs in two-drive (front-drive) mode, each accumulator oil supplement is only provided on the oil circuit of the left and right front walking motors.

[0060] The second pressure sensor 13 is arranged on the pipeline between each accumulator and the single-way valve 7. The second pressure sensor 13 can perform safety warning in advance. The alarm pressure of the second pressure sensor 13 is greater than the oil supplement pressure and slightly less than the setting pressure of the third overflow valve 6. When the right front one-way valve 9.1 or the left front one-way valve 9.2 has relatively large leakage or other problems, resulting in the continuous increase of the pressure of each accumulator and reaching the alarm pressure of the second pressure sensor 13, the system prompts that the pressure of each accumulator is too high and needs to be repaired.

[0061] It can be seen that the walking control hydraulic system for silo provided by the above embodiments aims at the problem of instantaneous pressure loss of the original high-pressure port of the closed system caused by high-speed emergency braking of the vehicle. By setting the oil supplementing accumulator and the one-way valve in the circuit, the oil is quickly supplemented to the pressure loss side, which avoids the working failure of the variable pump and the variable motor, ensures the service life of the hydraulic elements, and realizes the requirements of silo driving deceleration and emergency braking by using a small number of commonly used elements.

[0062] As shown in Figure 2 Another preferred embodiment of the present application provides a control method of a walking control hydraulic system for silo, comprising the steps of:

[0063] S1, obtaining the current pedal depression angle, for example, setting an angle sensor on the pedal, and using the angle sensor to detect the current pedal depression angle in real time;

[0064] S2, according to the interval where the actual depression angle is located, controlling the displacement of the variable plunger pump 1, the left front variable plunger motor 10, the rear axle variable plunger motor 11 and the right front variable plunger motor 12 according to the corresponding displacement change slope to output the corresponding size of the static hydraulic braking force to realize the gradual speed reduction of the vehicle; and only when the actual depression angle reaches the set threshold value, while outputting the corresponding size of the static hydraulic braking force, the friction braking force corresponding to the size of the actual depression angle is also generated by driving the foot brake valve to output the hydraulic pressure to the brake caliper to realize the emergency braking of the vehicle, wherein the displacement change slope and the hydraulic pressure output by the foot brake valve are positively correlated with the size of the actual depression angle.

[0065] The control method provided in this embodiment optimizes the control logic to differentiate between pure deceleration and emergency braking conditions. For example, in pure deceleration, hydrostatic braking is used; while in emergency braking, hydrostatic braking combined with friction braking is used. This avoids premature damage to the friction pads caused by excessive friction braking and increases the service life of the components. In emergency braking, if the lever does not return to the neutral position for some reason, the hydraulic system will continue to output driving force. If only friction braking is applied by the foot brake, the braking distance will increase significantly. The control method of this application obtains the current pedal angle and then performs overriding control to avoid this situation and improve the overall braking safety and reliability. The control method of this embodiment controls the displacement of each pump and motor according to the displacement change slope of the actual pedal angle range to output a corresponding amount of hydrostatic braking force. That is, the smaller the actual pedal angle, the smaller the displacement change slope of each pump and motor is used to control the displacement of each pump and motor to output a smaller amount of hydrostatic braking force to gradually reduce the vehicle speed. The larger the actual pedal angle, the larger the displacement change slope of each pump and motor is used to control the displacement of each pump and motor to output a larger amount of hydrostatic braking force. At the same time, hydraulic pressure is also output to the brake caliper to generate a larger friction braking force to jointly achieve emergency braking of the vehicle. That is, this application can output different sizes and types of braking force according to different working conditions, thereby greatly improving the braking accuracy and braking efficiency of the whole machine.

[0066] Preferably, the step of controlling the displacement of the variable displacement piston pump 1, the left front variable displacement piston motor 10, the rear axle variable displacement piston motor 11, and the right front variable displacement piston motor 12 according to the displacement change slope within the range of the actual pedal angle to output a corresponding amount of hydrostatic braking force to gradually reduce the vehicle speed; and only after the actual pedal angle reaches a set threshold, while outputting a corresponding amount of hydrostatic braking force, also driving the foot brake valve to output hydraulic pressure to the brake caliper to generate a corresponding amount of frictional braking force to achieve emergency braking of the vehicle, specifically includes the following steps:

[0067] S21. If the current pedal angle θ < θ0, the vehicle is in normal driving mode by default. At this time, the vehicle speed is controlled by the handle. The control system controls the vehicle speed and the handle current value in a closed loop.

[0068] S22. If the current pedal angle θ0 ≤ θ ≤ θ1, the control system overrides the handle control and uses the first displacement change slope K. θX1 The displacement of the variable displacement piston pump 1, the left front variable displacement piston motor 10, the rear axle variable displacement piston motor 11, and the right front variable displacement piston motor 12 are controlled to output a corresponding amount of hydrostatic braking force to gradually reduce the vehicle speed.

[0069] S23. If the current pedal angle θ1 < θ ≤ θ2, the control system overrides the lever control and uses the second displacement change slope K. θX2 The displacement of the variable displacement piston pump 1, the left front variable displacement piston motor 10, the rear axle variable displacement piston motor 11, and the right front variable displacement piston motor 12 are controlled to output a corresponding amount of hydrostatic braking force, wherein K θX1 <K θX2 Simultaneously, the foot brake valve outputs hydraulic pressure based on the actual pedal angle, which acts on the brake caliper to generate a corresponding frictional braking force to achieve emergency braking of the vehicle. The frictional braking force is positively correlated with the actual pedal angle.

[0070] like Figure 3 As shown, the foot pedal is connected to an angle sensor. The horizontal axis represents the actual pedal pressing angle, corresponding to the angle sensor feedback signal and the angle brake valve output pressure. The interval 0 to θ0 is set as a dead zone. Within this interval, slight changes in the pedal pressing angle will not trigger an output signal from the angle sensor, preventing erroneous operation caused by external environment or human factors. Within the interval θ0 to θ1, the angle sensor output signal corresponds to 0 to I1, at which point no pressure oil is output from the pedal to the brake caliper. Within the interval θ1 to θ2, the angle sensor output signal corresponds to I1-I2, at which point the pedal output pressure range is 0 to P. max As can be seen, in this embodiment, the pressure and angle sensor signals output by the pedal are positively correlated with the pedal angle.

[0071] like Figure 4 As shown, when the controller detects the electrical signal fed back by the angle sensor, it overrides the control handle. When the angle signal is within the range θ0 to θ1, the system defaults to a slow deceleration condition. The system controls the pump and motor variables with a low slope (the motor increases the displacement, and the pump decreases the displacement). The displacement change slope is set to the first displacement change slope K. θX1 ,like Figure 5 As shown, the entire mechanism is braked by hydrostatic braking within this range, with the braking force located between 0 and F1. Under this condition, the speed is reduced slowly only through hydrostatic braking, avoiding the rapid wear of the friction pads caused by repeated mechanical friction braking.

[0072] like Figure 4 As shown, when the angle signal is within the interval θ1 to θ2, the system defaults to an emergency braking condition, requiring rapid deceleration and stopping. The system controls the pump and motor variables with a high slope (increasing the motor's displacement and decreasing the pump's displacement). The displacement change slope is set to the second displacement change slope K. θX2 The greater the hydrostatic braking force generated at this time, the greater the vehicle's deceleration. Simultaneously, the braking pressure output by the foot brake valve also increases with the increase in the pedal angle, acting on the brake caliper to generate frictional braking force, such as... Figure 5As shown, the whole machine braking in the interval θ1~θ2 includes hydrostatic braking + mechanical friction braking, the braking force is located in the interval F1~F2, the whole vehicle braking force F is larger, and the rapid emergency stop of the vehicle is realized.

[0073] Specifically, the first displacement change slope K θX1 and the second displacement change slope K θX2 Specifically:

[0074]

[0075]

[0076] Wherein: θ X1 is the real-time feedback value of the pedal depression angle located in the interval [θ0, θ1], K θX1 is the first displacement change slope required to control the pump and motor displacement change when the pedal depression angle is θ X1 ; k0 and k1 are respectively the displacement change slopes required to control the pump and motor displacement change when the pedal depression angle is θ0 and θ1 during deceleration; θ X2 is the real-time feedback value of the pedal depression angle located in the interval (θ1, θ2], K θX2 is the second displacement change slope required to control the pump and motor displacement change when the pedal depression angle is θ X2 ; and k2 is the displacement change slope required to control the pump and motor displacement change when the pedal depression angle is θ2 during deceleration.

[0077] Preferably, if the current pedal depression angle θ0≤θ≤θ1, the control system controls the handlebar, and controls the displacement of the variable plunger pump 1, the left front variable plunger motor 10, the rear axle variable plunger motor 11 and the right front variable plunger motor 12 at the first displacement change slope K θX1 to output corresponding size of hydrostatic braking force to gradually reduce the speed of the vehicle, specifically including the following steps:

[0078] S221, if the motor current I m =0, each motor is at maximum displacement, and the hydraulic system is in pump speed regulation state, at this time, the variable plunger pump 1 is controlled to reduce the pump displacement at the first displacement change slope K θX1 until the vehicle is decelerated to 0.

[0079] S222, if the motor current I m ≠0, the hydraulic system is in pump maximum displacement and motor variable displacement speed regulation state, at this time, each motor is first controlled to increase to maximum displacement at the first displacement change slope K θX1 , and then the variable plunger pump 1 is controlled to reduce the pump displacement at the first displacement change slope K θX1 until the vehicle is decelerated to 0.

[0080] Preferably, if the current pedal angle θ1 < θ ≤ θ2, the control system overrides the lever control and uses the second displacement change slope K. θX2 The displacement of the variable displacement piston pump 1, the left front variable displacement piston motor 10, the rear axle variable displacement piston motor 11, and the right front variable displacement piston motor 12 is controlled to output a corresponding amount of hydrostatic braking force to gradually reduce the vehicle speed. The specific steps include:

[0081] S2301, If ​​the motor current I m When the displacement is 0, all motors are at maximum displacement, and the hydraulic system is in pump speed regulation mode. At this time, the second displacement change slope K is used. θX2 Control the variable displacement piston pump 1 to reduce the pump displacement until the vehicle decelerates to 0;

[0082] S2302, if the motor current I m When the displacement is not equal to 0, the hydraulic system is in a state of maximum pump displacement and variable motor displacement speed regulation. At this time, the second displacement change slope K is used. θX2 Simultaneously, each motor is controlled to increase its displacement, while the variable displacement piston pump 1 is reduced until the vehicle decelerates to 0.

[0083] Preferably, if the current pedal angle θ1 < θ ≤ θ2, the control system overrides the lever control and uses the second displacement change slope K. θX2 The displacement of the variable displacement piston pump 1, the left front variable displacement piston motor 10, the rear axle variable displacement piston motor 11, and the right front variable displacement piston motor 12 is controlled to output a corresponding amount of hydrostatic braking force to gradually reduce the vehicle speed. The specific steps include:

[0084] S2311, If ​​the motor current I m When the displacement is 0, all motors are at maximum displacement, and the hydraulic system is in pump speed regulation mode. At this time, the second displacement change slope K is used. θX2 Control the variable displacement piston pump 1 to reduce the pump displacement until the vehicle decelerates to 0;

[0085] S2312, If the motor current I m When the value is not equal to 0, the hydraulic system is in a state of maximum pump displacement and variable motor displacement speed regulation. At this time, the second displacement change slope K is used first. θX2 After controlling each motor to increase to its maximum displacement, then using the second displacement change slope K... θX2 The variable displacement piston pump 1 is controlled to reduce the pump displacement until the vehicle decelerates to 0.

[0086] like Figure 6 As shown, a preferred embodiment of this application also provides a control device for a walking control hydraulic system for a silage harvester, comprising:

[0087] The pedal angle acquisition module is used to acquire the current pedal angle.

[0088] The brake force control module is configured to control the displacement of the variable displacement plunger pump 1, the left front variable displacement plunger motor 10, the rear axle variable displacement plunger motor 11, and the right front variable displacement plunger motor 12 according to the displacement variation slope corresponding to the interval in which the actual pedal angle is located to output the static hydraulic brake force of the corresponding size to gradually slow down the vehicle, and only when the actual pedal angle reaches the set threshold, the brake valve is driven to output the hydraulic pressure to the brake caliper to generate the friction brake force of the corresponding size to realize the emergency braking of the vehicle while outputting the static hydraulic brake force of the corresponding size, wherein the displacement variation slope and the hydraulic pressure output by the brake valve are positively correlated with the size of the actual pedal angle.

[0089] As shown in Figure 7 The preferred embodiment of the present application also provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the control method of the walking control hydraulic system of the silo in the above embodiment when executing the program.

[0090] As shown in Figure 8 The preferred embodiment of the present application also provides a computer device, which can be a terminal or a living body detection server, and its internal structure diagram can be as shown in Figure 8 The computer device includes a processor, a memory, and a network interface connected through a system bus. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The network interface of the computer device is configured to communicate with other computer devices outside through a network connection. The computer program is executed by the processor to implement the steps of the control method of the walking control hydraulic system of the silo.

[0091] Those skilled in the art can understand that Figure 8 The structure shown in

[0092] The preferred embodiment of the present application also provides a storage medium, which includes a stored program, and when the program runs, the device where the storage medium is located executes the steps of the control method of the walking control hydraulic system of the silo in the above embodiment.

[0093] It is to be understood that the steps illustrated in the flowchart of the drawings can be performed in a computer system such as a set of computer readable instructions executed by a computer system and while logic associated with the steps is being executed, processes can inadvertently be performed in an order other than that described herein. However, it is the results that are important for the aspects of the described embodiments.

[0094] If the functions described in the method of the embodiments are implemented in software, and the software is sold or used as an independent product, the software can be stored in one or more computer-readable storage media. Based on such an understanding, the part of the present application embodiments that contribute to the prior art or part of the technical solutions can be embodied in the form of a software product, which is stored in a storage medium, and includes a number of instructions for causing one or more computers to perform all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk, and various other media that can store program codes.

[0095] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present application can be implemented in various computer languages, such as object-oriented programming languages Java and interpreted scripting languages JavaScript.

[0096] The present application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as combinations of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the computer or other programmable data processing apparatus produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one flow or multiple flows and / or blocks Figure 1 The functions specified in one flow or multiple flows and / or blocks

[0097] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0098] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that are executed on the computer or other programmable apparatus provide steps for implementing the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0099] Although preferred embodiments of the application have been described herein, substitutions and alterations are possible in view of the disclosure of this application without departing from the spirit and scope of the present application. Therefore, it is intended that the appended claims be interpreted as including all such alternatives and modifications as fall within the true spirit and scope of the present application.

[0100] It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application cover modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

Claims

1. A hydraulic system for walking control of a silage harvester, characterized in that, The hydraulic system comprises a variable plunger pump (1), an oil supplement pump (2), a front left accumulator (8.1), a front right accumulator (8.2), a front left check valve (9.2), a front right check valve (9.1), a front left variable plunger motor (10), a rear axle variable plunger motor (11), and a front right variable plunger motor (12), wherein the variable plunger pump (1) and the oil supplement pump (2) are drivingly connected to a power output device, the A port of the variable plunger pump (1) is connected to the A port of the front left variable plunger motor (10), the rear axle variable plunger motor (11), and the front right variable plunger motor (12) respectively, and the B port of the variable plunger pump (1) is connected to the B port of the front left variable plunger motor (10), the rear axle variable plunger motor (11), and the front right variable plunger motor (12) respectively; the output end of the oil supplement pump (2) is connected to the A port of the front left variable plunger motor (10) through the front left check valve (9.2) and to the A port of the front right variable plunger motor (12) through the front right check valve (9.1), the front left accumulator (8.2) is connected to the input end of the front left check valve (9.2) in parallel, and the front right accumulator (8.1) is connected to the input end of the front right check valve (9.1) in parallel; the hydraulic system further comprises a second overflow valve (4), two first overflow valves (3), the two first overflow valves (3) being connected in series and then connected in parallel between the A port and the B port of the variable plunger pump (1), the second overflow valve (4) being connected to the output end of the oil supplement pump (2), a check valve (7), the output end of the check valve (7) being connected to the output end of the oil supplement pump (2), the input end of the check valve (7) being connected to the front right accumulator (8.1) and the front left accumulator (8.2) respectively, a third overflow valve (6), the third overflow valve (6) being connected to the input end of the check valve (7) in parallel, a first pressure sensor (5), and a second pressure sensor (13), the first pressure sensor (5) being connected to the output end of the oil supplement pump (2) and used for detecting the outlet pressure of the oil supplement pump (2), and the second pressure sensor (13) being connected to the pipeline between the check valve (7) and the front right accumulator (8.1) and the front left accumulator (8.2) in parallel and used for detecting the pressure in the front right accumulator (8.1) and the front left accumulator (8.2).

2. A method of controlling a travel control hydraulic system for a silo according to claim 1, characterized in that, The hydraulic system comprises the following steps: obtaining a current pedal depression angle; controlling the displacement of the variable plunger pump (1), the front left variable plunger motor (10), the rear axle variable plunger motor (11), and the front right variable plunger motor (12) according to the displacement variation slope corresponding to the interval in which the actual pedal depression angle is located to output a corresponding size of hydrostatic braking force and realize gradual speed reduction of the vehicle, and only when the actual pedal depression angle reaches a set threshold, driving the foot brake valve to output a hydraulic pressure to the brake caliper to generate a corresponding size of friction braking force to realize emergency braking of the vehicle while outputting a corresponding size of hydrostatic braking force, wherein the displacement variation slope and the hydraulic pressure output by the foot brake valve are positively correlated with the size of the actual pedal depression angle.

3. The control method according to claim 2, characterized by, The actual pedal angle is used to control the displacement of the left front variable piston motor (10), the rear axle variable piston motor (11), the right front variable piston motor (12) and the variable piston pump (1) to output corresponding size of static hydraulic braking force to gradually slow down the vehicle; and only when the actual pedal angle reaches a set threshold, the brake valve output hydraulic pressure is driven according to the size of the actual pedal angle to generate corresponding size of friction braking force to realize emergency braking of the vehicle, specifically comprising the following steps: If the current pedal angle θ of the pedal is less than θ0, the vehicle is in normal driving state by default, at this time the vehicle speed is controlled by the handle, and the control system controls the vehicle speed and the handle current value to match each other in a closed loop; If the current pedal angle θ0≤θ≤θ1, the control system overrides the handle control and changes the first displacement variation slope K θX1 The displacements of the control variable piston pump (1), the left front variable piston motor (10), the rear axle variable piston motor (11), and the right front variable piston motor (12) are controlled to output corresponding sizes of static liquid pressure braking force to gradually reduce the speed of the vehicle. If the current pedal angle θ1< θ ≤ θ2, the control system overrides the handle control and changes the displacement of the hydraulic pump (1) and the hydraulic motors (10, 11, 12) with the second displacement change slope K θX2 The displacement of the variable displacement hydraulic pump (1), the left front variable displacement hydraulic motor (10), the rear axle variable displacement hydraulic motor (11) and the right front variable displacement hydraulic motor (12) are controlled to output corresponding hydraulic braking force, wherein K θX1 <K θX2 Meanwhile, the foot brake valve outputs hydraulic pressure according to the actual pedal angle to act on the brake calipers to generate corresponding friction braking force to realize emergency braking of the vehicle, and the friction braking force is positively correlated with the actual pedal angle.

4. The control method according to claim 3, characterized by, The first displacement change slope K θX1 And the second displacement change slope K θX2 Specifically: Wherein: θ X1 is the real-time feedback value when the pedal pedal angle is in the interval [θ0, θ1], K θX1 is the first displacement change slope when the pedal pedal angle is θ X1 , and the pump and motor displacement change needs to be controlled during deceleration; k0 and k1 are respectively the displacement change slope when the pedal pedal angle is θ0 and θ1, and the pump and motor displacement change needs to be controlled during deceleration; θ X2 is the real-time feedback value when the pedal pedal angle is in the interval (θ1, θ2], K θX2 is the second displacement change slope when the pedal pedal angle is θ X2 , and the pump and motor displacement change needs to be controlled during deceleration; k2 is the displacement change slope when the pedal pedal angle is θ2, and the pump and motor displacement change needs to be controlled during deceleration.

5. The control method according to claim 3, characterized by, The current pedal angle of the pedal is θ0≤θ≤θ1, the control system is in the handle control, and the first displacement change slope K θX1 The displacements of the control variable piston pump (1), the left front variable piston motor (10), the rear axle variable piston motor (11) and the right front variable piston motor (12) are controlled to output corresponding sizes of hydrostatic braking force to gradually reduce the speed of the vehicle, and the specific steps include the following steps. If the motor current I m = 0, each motor is at maximum displacement and the hydraulic system is in pump governed mode, at this point the first displacement variation slope K θX1 The variable piston pump (1) is controlled to reduce the pump displacement until the vehicle decelerates to 0; If the motor current I m ≠ 0, the hydraulic system is in the state of pump maximum displacement, motor variable displacement speed regulation. At this time, first change the displacement with the first displacement change slope K θX1 After controlling each motor to increase to the maximum displacement, change the displacement with the first displacement change slope K θX1 Control the variable displacement piston pump (1) to reduce the pump displacement until the vehicle decelerates to 0.

6. The control method according to claim 3, characterized by, The current pedal angle of the pedal is θ1< θ ≤ θ2, the control system is controlled by the handle, and the second displacement change slope K θX2 The displacements of the control variable piston pump (1), the left front variable piston motor (10), the rear axle variable piston motor (11) and the right front variable piston motor (12) are controlled to output corresponding sizes of hydrostatic braking force to gradually reduce the speed of the vehicle, specifically including the steps of: If the motor current I m = 0, each motor is at maximum displacement and the hydraulic system is in pump governed mode, at this point the second displacement variation slope K θX2 The variable piston pump (1) is controlled to reduce the pump displacement until the vehicle decelerates to 0; If the motor current I m ≠ 0, the hydraulic system is in the state of maximum displacement of the pump and variable displacement of the motor, at this time the second displacement variation slope K θX2 Simultaneously control the increase of the displacement of each motor and the decrease of the displacement of the variable displacement piston pump (1) until the vehicle is decelerated to 0. Or, If the motor current I m ≠ 0, the hydraulic system is in the state of pump maximum displacement, motor variable displacement speed regulation. At this time, first change the second displacement change slope K θX2 After controlling each motor to increase to the maximum displacement, change the second displacement change slope K θX2 Control the variable displacement piston pump (1) to reduce the pump displacement until the vehicle decelerates to 0.

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