Hydrostatic motor grader control method and system

Abstract

The application discloses a kind of static hydraulic pressure land leveler control method and system, belong to static hydraulic pressure land leveler control field, static hydraulic pressure land leveler includes engine, accelerator pedal, walking pump, first hydraulic motor, second hydraulic motor and transfer case;Engine selects different speed section according to load condition;After the speed section of engine is determined, the current speed of engine will only fall into current speed section;According to the opening of accelerator pedal, change the displacement of walking pump, first hydraulic motor and second hydraulic motor and the engagement state of first hydraulic motor and / or second hydraulic motor to control the speed of land leveler.The speed section of engine is adjusted according to load condition, and the displacement and engagement state of walking pump and hydraulic motor are controlled in combination with the opening of accelerator pedal, which can realize accurate control of the speed of land leveler, improve work efficiency and reduce fuel consumption.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of hydrostatic motor grader control, and particularly relates to a hydrostatic motor grader control method and system. BACKGROUND

[0002] With the rapid development of urban construction, the demand for construction machinery is increasing, especially in land leveling operation, the hydrostatic motor grader is widely used due to its high efficiency and flexibility. The traditional motor grader mostly adopts a mechanical transmission system, which has the disadvantages of slow response, low control precision, high energy consumption, etc., and is difficult to meet the requirements of modern construction for efficiency and precision. In recent years, the hydrostatic transmission technology has been widely used in the field of engineering machinery due to its smooth transmission, high efficiency and easy implementation of stepless speed change, and its application in motor graders has shown significant advantages.

[0003] For example, the invention patent with publication No. CN1405412A discloses a hydrostatic transmission motor grader. The variable hydraulic pump in the hydrostatic transmission system is connected with the engine through a shaft coupling. The output shaft of the variable hydraulic motor connected with the variable hydraulic pump is connected with the input shaft of the reduction balance box, and the output shaft of the reduction balance box is connected with the wheels.

[0004] However, the existing hydrostatic motor grader control system still has some deficiencies: the existing hydrostatic power control system mainly controls the walking pump, the walking hydraulic motor and the transfer case, but there is currently a lack of direct and effective control means for the power matching control between the walking drive system and the engine, resulting in that the two are in the non-efficient power section during most of the working time, which directly affects the oil saving effect.

[0005] Therefore, the present application is proposed. SUMMARY

[0006] The technical problem to be solved by the present application is to overcome the deficiencies of the prior art and provide a hydrostatic motor grader control method and system. The present application is realized by the following technical scheme:

[0007] A hydrostatic motor grader control method, the hydrostatic motor grader comprising an engine, an accelerator pedal, a walking pump, a first hydraulic motor, a second hydraulic motor and a transfer case;

[0008] The engine provides power to the walking pump, and the walking pump provides power to the first hydraulic motor and the second hydraulic motor. The first hydraulic motor and the second hydraulic motor drive the vehicle to travel through the transfer case;

[0009] The engine selects different speed sections according to the load condition;

[0010] After the speed section of the engine is determined, the current speed of the engine will only fall into the current speed section;

[0011] According to the opening degree of the accelerator pedal, the displacement of the traveling pump, the first hydraulic motor and the second hydraulic motor and the engagement state of the first hydraulic motor and / or the second hydraulic motor are changed to control the vehicle speed of the motor grader.

[0012] Preferably, the first hydraulic motor and the second hydraulic motor transmit power to the transfer case through the first clutch and the second clutch respectively;

[0013] By controlling the displacement of the traveling pump, the first hydraulic motor and the second hydraulic motor, the speed and torque input to the transfer case are changed;

[0014] And / or, by controlling the disengagement or engagement of the first clutch and the second clutch, the speed and torque input to the transfer case are changed.

[0015] Preferably, the speed section includes a field speed section, a parking brake speed section, a light load speed section and a heavy load speed section;

[0016] When the vehicle is in a no-load driving state, the current speed of the engine enters the field speed section;

[0017] When the vehicle is not in a driving state, the current speed of the engine enters the parking brake speed section;

[0018] When the vehicle is in a light load driving state, the current speed of the engine enters the light load speed section;

[0019] When the vehicle is in a heavy load driving state, the current speed of the engine enters the heavy load speed section.

[0020] Preferably, an idle time Ts is set, and when the time of no action of the vehicle exceeds the set idle time Ts, the control engine speed enters the parking brake speed section.

[0021] Preferably, the vehicle speed is calculated according to the opening degree of the accelerator pedal, and whether the accelerator synchronization deviation SY meets the condition is judged through the two voltage signals APS1 and APS2 output by the accelerator pedal, wherein the formula for calculating the accelerator synchronization deviation SY is:

[0022]

[0023] If the two voltage signals APS1 and APS2 do not satisfy this relationship, it is concluded that the accelerator pedal has a fault, the vehicle speed is reduced to a safe speed, and an alarm is sent to the operator.

[0024] Preferably, according to the current speed section of the engine, the intermediate vehicle speed Va is set, the corresponding opening degree of the accelerator pedal is a when calculating the intermediate vehicle speed, when the actual vehicle speed Vb satisfies 0<=Vb<=Va, the displacement of the first hydraulic motor and the second hydraulic motor remains unchanged, the displacement of the walking pump is adjusted according to the power curve of the walking pump to realize the target vehicle speed.

[0025] Preferably, according to the current speed section of the engine, the intermediate vehicle speed Va is set, the corresponding opening degree of the accelerator pedal is a when calculating the intermediate vehicle speed, when the actual vehicle speed Vb satisfies Va<Vb<=Vmax, the displacement of the walking pump remains unchanged, the displacement of the first hydraulic motor and the second hydraulic motor is adjusted according to the power curve of the first hydraulic motor and the second hydraulic motor to realize the target vehicle speed.

[0026] Preferably, a mode knob is arranged on the hydrostatic motor grader, and rotating the mode knob is used to adjust the speed section of the engine.

[0027] Preferably, a speed sensor is arranged on the engine, the walking pump, the first hydraulic motor and the second hydraulic motor.

[0028] The walking pump, the first hydraulic motor and the second hydraulic motor are each provided with a pressure sensor for monitoring the hydraulic oil pressure.

[0029] The walking pump, the first hydraulic motor and the second hydraulic motor are each provided with a temperature sensor for monitoring the hydraulic oil temperature.

[0030] According to the values of the various speed sensors, pressure sensors and temperature sensors, the speed section of the engine is adjusted, and / or the displacement of the walking pump, the first hydraulic motor and the second hydraulic motor is adjusted.

[0031] The application also provides a hydrostatic motor grader system, which applies the hydrostatic motor grader control method as described above.

[0032] Compared with the prior art, the application has the following beneficial effects:

[0033] 1. According to the load working condition, the application adjusts the speed section of the engine, and controls the displacement and engagement state of the walking pump and the hydraulic motor in combination with the opening degree of the accelerator pedal, so that the vehicle speed of the motor grader can be accurately controlled, the operation efficiency is improved, the fuel consumption is reduced, and the environmental pollution is reduced.

[0034] 2. The application can more flexibly adjust the speed and torque input to the transfer case by controlling the first clutch and the second clutch, so that the demand under different working conditions can be better adapted, and the reliability and durability of the system are improved.

[0035] 3、The engine speed section is subdivided into four sections of rotation field, parking brake, light load and heavy load, so that the engine can run at the most suitable speed under various working conditions, not only improving the working efficiency, but also prolonging the service life of the engine.

[0036] 4、The idle time Ts is set, and the engine speed is automatically adjusted to the parking brake speed section, which can effectively reduce unnecessary energy waste.

[0037] 5、The two voltage signals output by the accelerator pedal are compared, which can timely find and handle the accelerator pedal fault, ensure the safe operation of the vehicle and improve the reliability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is the control relationship diagram of the present application;

[0039] Figure 2 is the control flow diagram of the present application;

[0040] Figure 3 is the accelerator pedal opening curve diagram of the present application;

[0041] Figure 4 is the walking pump power curve diagram of the present application;

[0042] Figure 5 is the hydraulic motor power curve diagram of the present application.

[0043] In the figure: 1, walking pump; 2, first hydraulic motor; 3, second hydraulic motor; 4, gear selector; 5, accelerator pedal; 6, oil temperature sensor; 7, pressure sensor; 8, speed sensor; 9, transfer controller; 10, transfer case; 11, engine controller; 12, display; 13, whole vehicle controller; 14, mode knob; 15, interactive panel. DETAILED DESCRIPTION

[0044] The present application will be further described and illustrated below in conjunction with the accompanying drawings.

[0045] Example one

[0046] As shown in the figure, the present embodiment provides a kind of hydrostatic motor grader control method, and hydrostatic motor grader includes engine, accelerator pedal 5, walking pump 1, first hydraulic motor 2, second hydraulic motor 3 and transfer case 10; Figures 1-5 The engine provides power for walking pump 1, and the walking pump 1 provides power for first hydraulic motor 2 and second hydraulic motor 3, and the first hydraulic motor 2 and second hydraulic motor 3 drive vehicle travel through transfer case 10;

[0047] ​

[0048] The engine selects different speed sections according to load conditions;

[0049] After the speed section of the engine is determined, the current speed of the engine will only fall into the current speed section;

[0050] According to the opening degree of the accelerator pedal 5, the displacement of the travel pump 1, the first hydraulic motor 2 and the second hydraulic motor 3, and the engagement state of the first hydraulic motor 2 and / or the second hydraulic motor 3 are changed to control the speed of the motor grader.

[0051] Adjusting the engine speed section according to the load condition, and controlling the displacement and engagement state of the travel pump 1 and the hydraulic motor according to the opening degree of the accelerator pedal 5, can realize accurate control of the speed of the motor grader, improve the work efficiency, reduce fuel consumption and environmental pollution.

[0052] The first hydraulic motor 2 and the second hydraulic motor 3 respectively transmit power to the transfer case 10 through the first clutch and the second clutch;

[0053] By controlling the displacement of the travel pump 1, the first hydraulic motor 2 and the second hydraulic motor 3, the speed and torque input to the transfer case 10 are changed.

[0054] And / or, by controlling the disengagement or engagement of the first clutch and the second clutch, the speed and torque input to the transfer case 10 are changed.

[0055] By controlling the first clutch and the second clutch, the speed and torque input to the transfer case 10 can be more flexibly adjusted, so as to better adapt to the needs under different conditions and improve the reliability and durability of the system.

[0056] Further, the first hydraulic motor 2 and the second hydraulic motor 3 are both provided with clutches, which can prevent sudden situations. In the case of an emergency, the first clutch and the second clutch are both disengaged, so that the power output is disconnected. For economic cost consideration, only one hydraulic motor can be provided with a clutch device. In the starting or heavy load stage of the vehicle, two hydraulic motors are used to provide maximum torque to obtain sufficient power. When it is necessary to increase the speed, such as in the case of scene change, the clutch device is disengaged. At this time, only one hydraulic motor provides power, which can increase the output speed and reduce the torque to avoid power waste.

[0057] Preferably, the speed section includes a scene change speed section, a parking brake speed section, a light load speed section and a heavy load speed section;

[0058] When the vehicle is in a no-load driving state, the current speed of the engine enters the scene change speed section;

[0059] When the vehicle is not in the driving state, the current speed of the engine enters the parking brake speed section;

[0060] When the vehicle is in the light load driving state, the current speed of the engine enters the light load speed section;

[0061] When the vehicle is in the heavy load driving state, the current speed of the engine enters the heavy load speed section.

[0062] The speed section of the engine is subdivided into four sections of the field, the parking brake, the light load and the heavy load, so that the engine can operate at the most suitable speed in various working states, not only improving the working efficiency, but also prolonging the service life of the engine.

[0063] Further, by continuously simulating various working conditions, the high-efficiency speed section of the engine in different working conditions is calculated according to the actual vehicle and engine data, and four high-efficiency speed sections are matched with four working modes. The mode knob 14 is introduced to select the high-efficiency speed section, and the transfer controller 9 judges the current mode matching the high-efficiency speed section of the engine according to the input signal, and transmits the required engine target speed to the engine controller 11 through the CAN bus, so that the vehicle works at the optimal engine power.

[0064] When the engine speed matches the high-efficiency speed section, unlike the existing load power control scheme, the engine speed does not need to be controlled by the accelerator pedal 5 or the accelerator knob at this time, and the opening degree of the accelerator pedal 5 only corresponds to the current vehicle speed, avoiding the driver repeatedly stepping on the accelerator pedal 5 to adjust the engine power during vehicle operation, reducing the labor intensity of the driver.

[0065] The engine overspeed protection and anti-flameout protection are set, and when the transfer controller 9 detects that the engine abnormally overspeeds or drops speed greater than the limit value in special working conditions, the protection function is triggered, and the control signal is output to adjust the displacement of the walking pump 1, the vehicle speed, the engine load and the like, so as to reduce the damage to the engine.

[0066] When the mode knob 14 is in P gear, the starter is started, and the transfer controller 9 automatically matches the parking brake speed section for the engine speed.

[0067] When the vehicle is only in the driving state, the mode knob 14 is set to T gear, and the transfer controller 9 automatically matches the field speed section for the engine speed.

[0068] When the vehicle is in the working state and the working load is small, the mode knob 14 is set to W gear, and the transfer controller 9 automatically matches the light load speed section for the engine speed.

[0069] When the vehicle is in the working state and the working load is large, the mode knob 14 is set to C gear, and the transfer controller 9 automatically matches the heavy load speed section for the engine speed.

[0070] Preferably, an idling time Ts is set. When the vehicle remains inactive for longer than the set idling time Ts, the engine speed is controlled to enter the parking brake speed range. By setting the idling time Ts and automatically adjusting the engine speed to the parking brake speed range, unnecessary energy waste can be effectively reduced.

[0071] Specifically, the transfer case 9 detects signals from the gear selector 4, accelerator pedal 5, pressure sensor 7, speed sensor 8, vehicle controller 13, and mode knob 14 to determine whether the vehicle is currently engaged in gear shifting, steering, or electronic control operations. When the transfer case 9 detects that the vehicle has been inactive for more than the set idling time Ts, the engine speed automatically returns to the parking brake speed range.

[0072] Furthermore, the display 12 receives messages transmitted by the transfer controller 9 via the CAN bus, and can display the real-time parameters of the whole machine under vehicle operation. It has the function of fault alarm, and realizes human-machine interaction through the CAN bus and interactive panel. The automatic idle switch and idle time Ts are set in the instrument, which can be modified by the driver according to his own driving habits.

[0073] Preferably, such as Figure 3 As shown (the two curves correspond to APS1 and APS2 respectively), the vehicle speed is calculated based on the opening of the accelerator pedal 5, and the throttle synchronization deviation SY is determined by the two voltage signals APS1 and APS2 output from the accelerator pedal 5. The formula for calculating the throttle synchronization deviation SY is as follows:

[0074]

[0075] If the two voltage signals APS1 and APS2 do not satisfy this relationship, it is determined that the accelerator pedal 5 is faulty, the vehicle speed is reduced to a safe speed, and an alarm is issued to the operator. By comparing the two voltage signals output by the accelerator pedal 5, faults in the accelerator pedal 5 can be detected and dealt with in a timely manner, ensuring the safe operation of the vehicle and improving the reliability of the system.

[0076] Preferably, based on the current engine speed range, an intermediate vehicle speed Va is set. When calculating the intermediate vehicle speed, the corresponding opening of the accelerator pedal 5 is a. When the actual vehicle speed Vb satisfies 0 ≤ Vb ≤ Va, the displacement of the first hydraulic motor 2 and the second hydraulic motor 3 remains unchanged. According to the power curve of the travel pump 1 (e.g., ... Figure 4 As shown in the figure, adjust the displacement of the walking pump 1 to achieve the target vehicle speed.

[0077] At this time, the output power of the first hydraulic motor 2 and the second hydraulic motor 3 remains constant, and the target vehicle speed is achieved by adjusting the displacement of the travel pump 1 in the low-speed range, which can ensure stability and accuracy during low-speed operation.

[0078] Preferably, according to the current speed section of the engine, the intermediate vehicle speed Va is set, and the corresponding opening degree a of the accelerator pedal 5 is calculated when calculating the intermediate vehicle speed, when the actual vehicle speed Vb satisfies Va < Vb ≤ Vmax, the displacement of the travel pump 1 remains unchanged, and the displacement of the first hydraulic motor 2 and the second hydraulic motor 3 is adjusted according to the power curve (as shown in Figure 5 ), of the first hydraulic motor 2 and the second hydraulic motor 3 to achieve the target vehicle speed.

[0079] After the speed exceeds Va, the power of the travel pump 1 cannot continue to increase, and the target vehicle speed is achieved by adjusting the displacement of the first hydraulic motor 2 and the second hydraulic motor 3 in the high-speed range, which can reduce the load of the travel pump 1 while ensuring efficient operation, and prolong the service life of the travel pump 1.

[0080] Preferably, the hydrostatic motor grader is provided with a mode knob 14, and rotating the mode knob 14 is used to adjust the speed section of the engine. By directly adjusting the speed section of the engine through the mode knob 14, the operation process is simplified, the operation is more intuitive and convenient, and the user experience is improved.

[0081] Preferably, the engine, the travel pump 1, the first hydraulic motor 2 and the second hydraulic motor 3 are all provided with a speed sensor 8;

[0082] The travel pump 1, the first hydraulic motor 2 and the second hydraulic motor 3 are all provided with a pressure sensor 7 for monitoring the hydraulic oil pressure;

[0083] The travel pump 1, the first hydraulic motor 2 and the second hydraulic motor 3 are all provided with a temperature sensor for monitoring the temperature of the hydraulic oil;

[0084] According to the values of the various speed sensors 8, pressure sensors 7 and temperature sensors, the speed section of the engine is adjusted, and / or the displacement of the travel pump 1, the first hydraulic motor 2 and the second hydraulic motor 3 is adjusted.

[0085] Setting multiple sensors to monitor key parameters can dynamically adjust the speed section of the engine and the displacement of the hydraulic components according to the actual situation, which not only improves the intelligent level of the system, but also enhances the safety and stability of the system.

[0086] Further, the present application provides an operation step for the above-mentioned hydrostatic motor grader control method:

[0087] Step one: The transfer controller 9 detects the signals of the gear selector 4, the pressure sensor 7, the speed sensor 8, the vehicle controller 13, and the mode knob 14, judges whether the current vehicle has the actions such as gear hanging, steering, or electric control operation, and matches the corresponding engine constant speed, such as parking brake speed, turning field speed, light load speed, and heavy load speed.

[0088] Step two: The transfer controller 9 matches the current displacement of the walking pump 1, the first hydraulic motor 2, and the second hydraulic motor 3 through the speed signals transmitted by the accelerator pedal 5, the oil temperature sensor 6, the pressure sensor 7, the speed sensor 8, the oil temperature signals of the transfer box 10, the first hydraulic motor 2, and the second hydraulic motor 3, the system pressure signals, and the speed signals of the first hydraulic motor 2 and the second hydraulic motor 3.

[0089] Step three: The transfer controller 9 detects whether the gear shifting condition is met, outputs a control signal to drive the transfer box 10 clutch gear shifting solenoid, thereby controlling the transfer box 10 clutch to drive the first hydraulic motor 2 to disengage / engage, and realizing the vehicle upshift and downshift.

[0090] Step four: For special working conditions, the overspeed protection start and stop speed points are set. When the transfer controller 9 detects that the engine speed exceeds the set value, a control signal is output to increase the displacement of the walking pump 1 and increase the vehicle speed, thereby preventing the engine from being damaged.

[0091] Step five: In the heavy load working condition, the transfer controller 9 detects that the engine speed drop amplitude is too large, which triggers the protection function, outputs a control signal to reduce the displacement of the walking pump 1, reduces the vehicle speed, and reduces the load applied by the walking pump 1 to the engine, thereby preventing the engine from stalling due to excessive speed drop.

[0092] Embodiment two

[0093] As shown in Figure 1 , the embodiment provides a hydrostatic motor grader system which applies the hydrostatic motor grader control method as described in embodiment one.

[0094] The hydrostatic motor grader system includes a walking pump 1, a first hydraulic motor 2, a second hydraulic motor 3, a gear selector 4, an accelerator pedal 5, an oil temperature sensor 6, a pressure sensor 7, a speed sensor 8, a transfer controller 9, a transfer box 10, an engine controller 11, a display 12, a vehicle controller 13, a mode knob 14, an interactive panel, and other components, which cooperate with the control method to realize various control functions of the vehicle.

Claims

1. A method of controlling a hydrostatic land leveler, characterized by: The hydrostatic motor grader comprises an engine, an accelerator pedal (5), a traveling pump (1), a first hydraulic motor (2), a second hydraulic motor (3) and a transfer case (10); The engine provides power for the traveling pump (1), and the traveling pump (1) provides power for the first hydraulic motor (2) and the second hydraulic motor (3), and the first hydraulic motor (2) and the second hydraulic motor (3) drive the vehicle to travel through the transfer case (10); The engine selects different speed sections according to the load conditions; After the speed section of the engine is determined, the current speed of the engine will only fall into the current speed section; According to the opening degree of the accelerator pedal (5), the vehicle speed of the motor grader is controlled by changing the displacement of the traveling pump (1), the first hydraulic motor (2) and the second hydraulic motor (3) and the engagement state of the first hydraulic motor (2) and / or the second hydraulic motor (3). The speed section comprises a turning speed section, a parking brake speed section, a light load speed section and a heavy load speed section; When the vehicle is in the no-load driving state, the current speed of the engine enters the turning speed section; When the vehicle is not in the driving state, the current speed of the engine enters the parking brake speed section; When the vehicle is in the light load driving state, the current speed of the engine enters the light load speed section; When the vehicle is in the heavy load driving state, the current speed of the engine enters the heavy load speed section; According to the current speed section of the engine, the intermediate vehicle speed Va is set, and when the corresponding opening degree of the accelerator pedal (5) is a, the actual vehicle speed Vb satisfies 0≤Vb≤Va, the displacement of the first hydraulic motor (2) and the second hydraulic motor (3) remains unchanged, the displacement of the traveling pump (1) is adjusted according to the power curve of the traveling pump (1) to realize the target vehicle speed; When the actual vehicle speed Vb satisfies Va<Vb≤Vmax, the displacement of the traveling pump (1) remains unchanged, the displacement of the first hydraulic motor (2) and the second hydraulic motor (3) is adjusted according to the power curve of the first hydraulic motor (2) and the second hydraulic motor (3) to realize the target vehicle speed.

2. A method of controlling a hydrostatic motor grader according to claim 1, characterized in that: The first hydraulic motor (2) and the second hydraulic motor (3) respectively transmit power to the transfer case (10) through the first clutch and the second clutch; By controlling the displacement of the traveling pump (1), the first hydraulic motor (2) and the second hydraulic motor (3), the speed and torque input to the transfer case (10) are changed; And / or, by controlling the disengagement or engagement of the first clutch and the second clutch, the speed and torque input to the transfer case (10) are changed.

3. A method of controlling a hydrostatic motor grader according to claim 1, characterized in that: The idle time Ts is set, and when the vehicle is idle for more than the set idle time Ts, the engine speed is controlled to enter the parking brake speed section.

4. The method of claim 1, wherein: The vehicle speed is calculated according to the opening degree of the accelerator pedal (5), and whether the accelerator synchronization deviation SY satisfies the condition is judged through the two voltage signals APS1 and APS2 output by the accelerator pedal (5), wherein the accelerator synchronization deviation SY is calculated according to the following formula: If the two voltage signals APS1 and APS2 do not satisfy this relationship, it is determined that the accelerator pedal (5) has a fault, the vehicle speed is reduced to a safe speed, and an alarm is sent to the operator.

5. The method of claim 1, wherein: The hydrostatic motor grader is provided with a mode knob (14), and rotating the mode knob (14) is used to adjust the engine speed section.

6. A method of controlling a hydrostatic land leveler according to claim 1, characterized by: The engine, the walking pump (1), the first hydraulic motor (2) and the second hydraulic motor (3) are all provided with a speed sensor (8); The walking pump (1), the first hydraulic motor (2) and the second hydraulic motor (3) are all provided with a pressure sensor (7) for monitoring the hydraulic oil pressure; The walking pump (1), the first hydraulic motor (2) and the second hydraulic motor (3) are all provided with a temperature sensor for monitoring the hydraulic oil temperature; According to the values of the various speed sensors (8), pressure sensors (7) and temperature sensors, the engine speed section is adjusted, and / or the displacement of the walking pump (1), the first hydraulic motor (2) and the second hydraulic motor (3) is adjusted.

7. A hydrostatic land leveler system characterized by: The hydrostatic motor grader system applies a hydrostatic motor grader control method as claimed in any one of claims 1-6.

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