Loader automatic bucket control method and system

Abstract

This invention discloses an automatic bucket-folding control method and system for loaders. Based on the bucket's angle range, the power allocation between the bucket-folding hydraulic system and the front and rear wheels is determined: when the bucket is in the first range, the bucket-folding hydraulic system is prioritized to operate at full power, with the remaining power allocated to the front wheels, and no power allocation to the rear wheels; when the bucket is in the second range, the power load of the bucket-folding hydraulic system is prioritized, with the remaining power allocated to ensure full-load operation of the front wheels first, and then the remaining power allocated to the rear wheels; when the bucket is in the third range, power allocation is only applied to the hydraulic system, and power allocation to the travel system is stopped. This invention controls the main valve and the electronically controlled pump through multiple solenoid valves, thereby controlling the flow output of the bucket-folding cylinder, resulting in higher bucket-folding efficiency, higher automation, and higher overall productivity.

Description

Technical Field

[0001] This invention relates to an automatic bucket-collecting control method and system for loaders, belonging to the field of loader control technology. Background Technology

[0002] Current loaders use manual control for bucket closing. The operator simultaneously operates the handle and throttle, using the handle to control bucket closing and the throttle to control drive. Operation relies entirely on the operator's experience. When the handle is moved inward to close the bucket, the simultaneous application of hydraulic and drive power results in an uncertain power distribution from the engine. If the handle is moved first and then the throttle is pressed, more engine power is allocated to bucket closing and less to travel; conversely, if the throttle is pressed first and then the handle is moved, more engine power is allocated to travel and less to bucket closing. When more travel power is allocated, noticeable tire slippage occurs, as power is not fully utilized for operation. This is accompanied by weak bucket digging, and significant fluctuations in engine speed with throttle input, leading to large variations in bucket flow rate, slower bucket closing speed, and even the need for secondary digging, thus impacting operational efficiency. When more hydraulic power is applied, travel power is evenly distributed between the front and rear wheels, resulting in insufficient traction on the front wheels and excessive traction on the rear wheels, causing slippage. The drive power is not fully utilized. Meanwhile, during the bucket-collecting process, regardless of the hydraulic power distribution, the travel power is evenly distributed between the front and rear wheels. This power distribution mode is not well adapted to the loader's bucket-collecting operation, and the fuel consumption is also relatively high, resulting in low overall productivity.

[0003] Therefore, achieving efficient digging and bucket collection and reducing power waste currently relies entirely on the operator's experience. While operator experience can improve power utilization, it is not the optimal solution. A key challenge in the industry is to automatically and precisely distribute engine power dynamically to the load during loading operations, thereby reducing unnecessary power consumption. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides an automatic bucket-collecting control method and system for loaders.

[0005] To achieve the above objectives, the present invention employs an automatic bucket-collecting control system for a loader, comprising a handle, a drive assembly, a controller, a power supply, a sensor for detecting the bucket angle, a tipping cylinder, a main valve, an electric pump, a first solenoid valve and a control cylinder for controlling the displacement of the electric pump, a second solenoid valve for controlling the pilot oil circuit, and a third solenoid valve and a sixth solenoid valve for controlling the opening degree of the main valve core.

[0006] One outlet of the electric pump is connected to the P port of the main valve, the A port of the main valve is connected to the G1 port of the tipping cylinder, and the G2 port of the tipping cylinder is connected to the B port of the main valve; another outlet of the electric pump is connected to the V1 port of the second solenoid valve, the X1 port of the second solenoid valve is simultaneously connected to the Q2 port of the third solenoid valve and the Q1 port of the sixth solenoid valve, the S2 port of the third solenoid valve is connected to the U2 port of the main valve, and the S1 port of the sixth solenoid valve is connected to the U1 port of the main valve; another outlet of the electric pump is connected to the H port of the first solenoid valve, the K port of the first solenoid valve is connected to the M port of the control cylinder, and the L port of the first solenoid valve is connected to the N port of the control cylinder.

[0007] The controller is connected to the handle, drive assembly, sensor for detecting bucket angle, power supply and each solenoid valve.

[0008] As improvements, the oil tank, second relief valve, and third relief valve are also included;

[0009] The T port of the main valve is connected to the oil tank, the G1 port of the tipping cylinder is connected to the oil tank through the third overflow valve, and the G2 port of the tipping cylinder is connected to the oil tank through the second overflow valve.

[0010] The W1 port of the second solenoid valve, the R2 port of the third solenoid valve, and the R1 port of the sixth solenoid valve are all connected to the oil tank.

[0011] As an improvement, a fourth solenoid valve and a fifth solenoid valve are also included;

[0012] The A port of the main valve is connected to the C port of the fifth solenoid valve, the D port of the fifth solenoid valve is connected to the G1 port of the tipping cylinder, the B port of the main valve is connected to the E port of the fourth solenoid valve, and the F port of the fourth solenoid valve is connected to the G2 port of the tipping cylinder.

[0013] As an improvement, the b1 terminal of the first solenoid valve, the b2 terminal of the second solenoid valve, the b3 terminal of the third solenoid valve, the b4 terminal of the fourth solenoid valve, the b5 terminal of the fifth solenoid valve, the b6 terminal of the sixth solenoid valve, and the b7 terminal of the first solenoid valve are respectively connected to the a1 terminal, a2 terminal, a3 terminal, a4 terminal, a5 terminal, a6 terminal, and a7 terminal of the controller.

[0014] As improvements, pressure reducing valves and pilot-operated relief valves are also included;

[0015] A pressure reducing valve is connected in series between the electric pump and the second solenoid valve, and the outlet of the pressure reducing valve is connected to both the pilot relief valve and the V1 port of the second solenoid valve. The outlet of the pilot relief valve is connected to the oil tank.

[0016] As an improvement, a throttle valve and a first relief valve are also included;

[0017] The J port of the first solenoid valve is connected to the oil tank through a throttle valve, and the H port of the first solenoid valve is connected to the oil tank through a first relief valve.

[0018] As an improvement, the drive assembly is provided with four, each drive assembly including a motor assembly and a tire, the motor assembly and the tire being mechanically connected through a reduction gear.

[0019] As an improvement, the controller is connected to the handle via a CAN bus, the controller is connected to the drive assembly via a cable and CAN communication, the controller is connected to the sensor via a signal line, and the controller is connected to the power supply via a cable and CAN communication.

[0020] In addition, the present invention also provides an automatic bucket-folding control method for a loader, which uses the aforementioned automatic bucket-folding control system to determine the distribution of the bucket-folding hydraulic system and the travel power of the front and rear wheels based on the bucket's angle range:

[0021] When the bucket is in the first zone, the full power load of the bucket retraction hydraulic system is allocated first, and the remaining power is allocated to the front wheel travel. No power is allocated to the rear wheel travel, and the sum of the bucket retraction hydraulic power and the front wheel travel power is equal to the total power that the engine or power supply can output.

[0022] When the bucket is in the second zone, priority is given to allocating and ensuring the power load demand of the bucket retraction hydraulic system. The remaining power is allocated to ensure the full-load operation of the front wheel travel power first, and then the remaining power is allocated to the rear wheel travel.

[0023] When the bucket is in the third zone, power is distributed only to the hydraulic system, and power distribution to the travel system is stopped.

[0024] As an improvement, the bucket angle θ ≤ 5° in the first interval, the bucket angle 5 < θ ≤ 15° in the second interval, and the bucket angle 15° < θ in the third interval.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. More energy-efficient: The controller monitors the pressure and flow signals of the electronically controlled pump in real time. Based on the bucket's retraction angle range and the load pressure and pump displacement, it prioritizes the power demand of the hydraulic system, and then ensures the power of the front wheels. When the angle is large, it completely stops the drive power output, avoiding power waste caused by manual control. For example, the power of rear wheel slippage will increase the additional fuel consumption, or excessive overflow of the hydraulic system will cause the power to be excessively distributed to the hydraulic system, resulting in weak travel and a low fill rate. The power overflow of the system will also increase the additional fuel consumption. Therefore, the energy-saving effect of this invention is significant.

[0027] 2. Higher degree of automation and more intelligent loading: The controller dynamically allocates hydraulic and travel power based on changes in system adaptive load pressure. It also adjusts the flow rate of the tipping cylinder and the bucket-closing speed by regulating the signals of the solenoid valves. Furthermore, by distributing travel power differently to the front and rear wheel motors, energy allocation is more conducive to digging and filling. Compared to manual operation, this invention offers a higher degree of automation and intelligence, more precise control, and better alignment with the loading process, facilitating the development of future autonomous driving technologies.

[0028] 3. Higher Efficiency: During manual operation, the driver cannot perceive the precise changes in the bucket angle, which inevitably leads to premature or delayed throttle input. This results in insufficient driving power output, rear wheel slippage, or excessive speed, making it difficult to perform digging and resulting in low overall operating efficiency. However, the control system of this invention can accurately detect changes in the bucket angle, and the output of driving power will adjust accordingly to advance the material or stop outputting power, thereby improving the overall efficiency of loading. Attached Figure Description

[0029] Figure 1 This is a control principle diagram of the present invention;

[0030] Figure 2 This is a schematic diagram illustrating the principle of the tipping cylinder extension action of the present invention;

[0031] Figure 3 This is a schematic diagram of the loader operation according to the present invention;

[0032] Figure 4 This is a schematic diagram of the loader bucket of the present invention;

[0033] Figure 5 This is a schematic diagram of the process of the present invention;

[0034] In the diagram: 1. Handle, 2. Front drive assembly, 2L. Left front drive assembly, 2R. Right front drive assembly, 3. Controller, 4. Power supply, 5. Sensor, 6. Rear drive assembly, 6L. Left rear drive assembly, 6R. Right rear drive assembly, 7. Control cylinder, 8. First relief valve, 9. First solenoid valve, 10. Second solenoid valve, 11. Third solenoid valve, 12. Fourth solenoid valve, 13. Second relief valve, 14. Bucket cylinder, 15. Third relief valve, 16. Fifth solenoid valve, 17. Main valve, 18. Sixth solenoid valve, 19. Pressure reducing valve, 20. Pilot relief valve, 21. Electric pump, 22. Oil tank, 23. Throttle valve, 24. Tire, 25. Bucket. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below. However, it should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0037] like Figure 1 As shown, an automatic bucket-tipping control system for a loader includes a handle 1, a drive assembly, a sensor 5 for detecting the bucket angle, a controller 3, a power supply 4, an electric pump 21, a main valve 17, a tipping cylinder 14, a first solenoid valve 9 and a control cylinder 7 for controlling the displacement of the electric pump 21, a second solenoid valve 10 for controlling the pilot oil circuit, a third solenoid valve 11 and a sixth solenoid valve 18 for controlling the opening of the main valve core;

[0038] One outlet of the electric pump 21 is connected to the P port of the main valve 17, the A port of the main valve 17 is connected to the G1 port of the tipping cylinder 14, and the G2 port of the tipping cylinder 14 is connected to the B port of the main valve 17.

[0039] The outlet of the electric pump 21 is connected to the V1 port of the second solenoid valve 10. The X1 port of the second solenoid valve 10 is connected to both the Q2 port of the third solenoid valve 11 and the Q1 port of the sixth solenoid valve 18. The S2 port of the third solenoid valve 11 is connected to the U2 port of the main valve 17, and the S1 port of the sixth solenoid valve 18 is connected to the U1 port of the main valve 17.

[0040] The outlet of the electric pump 21 is connected to the H port of the first solenoid valve 9, the K port of the first solenoid valve 9 is connected to the M port of the control cylinder 7, and the L port of the first solenoid valve 9 is connected to the N port of the control cylinder 7.

[0041] The handle 1 is connected to the controller 3 via a CAN bus. The controller 3 is connected to the drive assembly via a cable and a CAN communication connection. The sensor 5 is connected to the controller 3 via a signal line. The power supply 4 is connected to the controller 3 via a cable and a CAN communication connection. The controller 3 is connected to each solenoid valve via a signal line.

[0042] As an improvement to the embodiment, the loader automatic bucket retraction control system also includes an oil tank 22, a second overflow valve 13, and a third overflow valve 15;

[0043] The T port of the main valve 17 is connected to the oil tank 22. The G1 port of the tipping cylinder 14 is connected to the oil tank 22 via the third overflow valve 15. The G2 port of the tipping cylinder 14 is connected to the oil tank 22 via the second overflow valve 13. The W1 port of the second solenoid valve 10, the R2 port of the third solenoid valve 11, and the R1 port of the sixth solenoid valve 18 are all connected to the oil tank 22.

[0044] As an improvement to the embodiment, it also includes a fourth solenoid valve 12 and a fifth solenoid valve 16; the A port of the main valve 17 is connected to the C port of the fifth solenoid valve 16, the D port of the fifth solenoid valve 16 is connected to the G1 port of the tipping cylinder 14, the B port of the main valve 17 is connected to the E port of the fourth solenoid valve 12, and the F port of the fourth solenoid valve 12 is connected to the G2 port of the tipping cylinder 14.

[0045] As a further improvement to the embodiment, the b1 terminal of the first solenoid valve 9, the b2 terminal of the second solenoid valve 10, the b3 terminal of the third solenoid valve 11, the b4 terminal of the fourth solenoid valve 12, the b5 terminal of the fifth solenoid valve 16, the b6 terminal of the sixth solenoid valve 18, and the b7 terminal of the first solenoid valve 9 are respectively connected to the a1 terminal, a2 terminal, a3 terminal, a4 terminal, a5 terminal, a6 terminal, and a7 terminal of the controller 3.

[0046] As an improvement to the embodiment, it also includes a pressure reducing valve 19 and a pilot relief valve 20;

[0047] A pressure reducing valve 19 is connected in series between the electric pump 21 and the second solenoid valve 10. The outlet of the pressure reducing valve 19 is connected to both the pilot relief valve 20 and the V1 port of the second solenoid valve 10. The outlet of the pilot relief valve 20 is connected to the oil tank 22.

[0048] As an improvement to the embodiment, it also includes a throttle valve 23 and a first relief valve 8. The J port of the first solenoid valve 9 is connected to the oil tank 22 through the throttle valve 23, and the H port of the first solenoid valve 9 is connected to the oil tank 22 through the first relief valve 8.

[0049] As an improvement to the embodiment, the drive assembly includes two front drive assemblies 2 and two rear drive assemblies 6. The two front drive assemblies 2 are divided into a left front drive assembly 2L and a right front drive assembly 2R. The two rear drive assemblies 6 are divided into a left rear drive assembly 6L and a right rear drive assembly 6R. Each drive assembly includes a motor assembly and a tire 24. The motor assembly and the tire 24 are mechanically connected through a reduction mechanism.

[0050] The loader automatic bucket-collecting control system of the present invention specifically includes:

[0051] 1. Hydraulic connection:

[0052] Main oil circuit: Hydraulic oil is connected to the P port of the main valve 17 via the electric control pump 21. The A port of the main valve 17 is connected to the C port of the fifth solenoid valve 16. The D port of the fifth solenoid valve 16 is connected to the G1 port of the tipping cylinder 14. The G2 port of the tipping cylinder 14 is connected to the F port of the fourth solenoid valve 12. The E port of the fourth solenoid valve 12 is connected to the B port of the main valve 17. The T port of the main valve 17 is connected to the oil tank 22. Another path from the G1 port of the tipping cylinder 14 returns to the oil tank 22 through the third relief valve 15. Another path from the G2 port of the tipping cylinder 14 returns to the oil tank 22 through the second relief valve 13.

[0053] Pilot control oil circuit: The outlet of the electronically controlled pump 21 is connected to the pressure reducing valve 19. The outlet of the pressure reducing valve 19 is simultaneously connected to the pilot relief valve 20 and the V1 port of the second solenoid valve 10. The X1 port of the second solenoid valve 10 is simultaneously connected to the Q2 port of the third solenoid valve 11 and the Q1 port of the sixth solenoid valve 18. The outlet of the pilot relief valve 20, the W1 port of the second solenoid valve 10, the R2 port of the third solenoid valve 11, and the R1 port of the sixth solenoid valve 18 are simultaneously connected to the oil tank 22. The S2 port of the third solenoid valve 11 is connected to the U2 port of the main valve 17, and the S1 port of the sixth solenoid valve 18 is connected to the U1 port of the main valve 17.

[0054] Pump displacement control oil circuit: The outlet of the electric pump 21 is connected to the H port of the first solenoid valve 9 and the first relief valve 8. The K port of the first solenoid valve 9 is connected to the M port of the control cylinder 7. The L port of the first solenoid valve 9 is connected to the N port of the control cylinder 7. The J port of the first solenoid valve 9 is connected to the oil tank 22 via the throttle valve 23. The outlet of the first relief valve 8 is connected to the oil tank 22.

[0055] 2. Electrical connections:

[0056] Handle 1 is connected to controller 3 via CAN bus. Controller 3 is connected to the four drive assemblies via cables and CAN communication. Sensor 5 is connected to controller 3 via signal line. Power supply 4 is connected to controller 3 via cables and CAN communication.

[0057] Among them, the current value output by the controller 3 to the fourth solenoid valve 12 and the fifth solenoid valve 16 is a constant value greater than 0 or 0, which is a switching signal; while the current value output to the other solenoid valves is a variable linear value or 0, which is an analog signal; the sensor 5 is used to detect the bucket angle signal of the bucket 25 in real time and send it to the controller 3.

[0058] The automatic bucket collection operation control principle of this invention:

[0059] like Figure 2 , Figure 3 and Figure 4As shown, when controller 3 controls the four drive assemblies to drive the machine to the material, it controls the machine to push the material with maximum driving force until the speed of the front drive assembly 2 reaches 0, at which point the drive stops. Simultaneously, controller 3 controls handle 1 to rotate to the left by an angle. Controller 3 outputs current signals to terminal b7 of the first solenoid valve 9, terminal b2 of the second solenoid valve 10, and terminal b6 of the sixth solenoid valve 18, with the current value corresponding to (approximately proportional to) the angle of handle 1. It also outputs constant current signals to terminal b4 of the fourth solenoid valve 12 and terminal b5 of the fifth solenoid valve 16. At this time:

[0060] Pump displacement control oil circuit:

[0061] When the H and K ports of the first solenoid valve 9 are connected, and the J and L ports are connected, hydraulic oil enters the small chamber of the control cylinder 7 through the electric pump 21, the H and K ports of the first solenoid valve 9, and the M port of the control cylinder 7, pushing the piston rod to the right, increasing the tilt angle of the pump swashplate, and thus the pump outputs a displacement corresponding to the angle of the handle 1. The hydraulic oil in the large chamber of the control cylinder 7 returns through the N, L, and J ports and the throttle valve 23. When the angle of the handle 1 is larger, the valve core opening of the first solenoid valve 9 is larger, and the pump displacement is larger.

[0062] Pilot control oil circuit:

[0063] The V1 and X1 ports of the second solenoid valve 10 are connected, and the S1 and Q1 ports of the sixth solenoid valve 18 are connected. Pilot oil flows through the electronically controlled pump 21, the pressure reducing valve 19, the V1 and X1 ports of the second solenoid valve 10, and the Q1 and S1 ports of the sixth solenoid valve 18 to the U1 port of the main valve 17, pushing the valve core of the main valve 17 to the right, connecting the P and A ports, and the B and T ports of the main valve 17. The control oil at the other end of the main valve 17 returns to the oil tank 22 through the U2 port, the S2 port and R2 port of the third solenoid valve 11. When the angle of the handle 1 is larger, the current value at the b2 terminal of the second solenoid valve 10 and the b6 terminal of the sixth solenoid valve 18 is larger, the flow rate through the V1 and X1 ports of the second solenoid valve 10 and the Q1 and S1 ports of the sixth solenoid valve 18 is larger, and the rightward displacement of the valve core of the main valve 17 is larger.

[0064] Main oil circuit:

[0065] The F and E ports of the fourth solenoid valve 12 are fully connected, the D and C ports of the fifth solenoid valve 16 are fully connected, the P and A ports of the main valve 17 are connected, and the B and T ports are connected. The hydraulic oil flows through the electric control pump 21, the P and A ports of the main valve 17, the C and D ports of the fifth solenoid valve 16, and the G1 port of the tipping cylinder 14 to the large chamber of the tipping cylinder 14, pushing the piston rod of the tipping cylinder 14 to extend to the right. The small chamber of the tipping cylinder returns oil through the G2 port, the F and E ports of the fourth solenoid valve 12, and the B and T ports of the main valve 17, thereby realizing the bucket-retracting action.

[0066] Among them, the pressure reducing valve 19 mainly ensures that the pilot pressure meets the requirements of the pilot oil circuit; here it is a fixed value pressure reducing valve, that is, the pressure of the pilot oil circuit is a constant value, preferably, the pilot pressure is 2MPa.

[0067] The pilot relief valve 20 is used to ensure that the maximum value of the pilot pressure does not exceed the set value; preferably, the maximum pilot pressure is 2.5 MPa.

[0068] The first relief valve 8 is used to ensure that the maximum pressure of the electric pump 21 does not exceed the set value, preferably 35 MPa.

[0069] The second overflow valve 13 and the third overflow valve 15 are used to ensure that the pressure in the small chamber and the large chamber of the tipping cylinder does not exceed the set value; preferably, the set value is 30MPa.

[0070] like Figure 4 , Figure 5 As shown, the present invention also provides an automatic bucket-folding control method for a loader, which employs the aforementioned automatic bucket-folding control system. This control method determines the distribution of the bucket-folding hydraulic system and the travel power of the front and rear wheels based on the bucket's angular range θ.

[0071] When the bucket 25's retraction angle θ ≤ 5° (i.e., in the first interval), the controller 3 prioritizes ensuring the power demand of the hydraulic system, allocating the remaining power of the engine or power supply 4 to the travel motor. Furthermore, when the main oil circuit pressure reaches or approaches its maximum and the pump displacement is also at its maximum, i.e., when the hydraulic power reaches its maximum limit, the remaining available power is allocated only to the front drive assembly 2, while no power is allocated to the rear drive assembly 6. At this time, the machine relies solely on the front axle to push the material forward while simultaneously performing high-power bucket retraction; the rear wheels, due to their small load, are either suspended or dragged by the front wheels, lacking active traction power. This interval primarily ensures that the bucket 25 can overcome a large load for bucket retraction, with traction and material pushing serving only as auxiliary. Therefore, in this interval, the main pump displacement reaches its maximum, the valve core opening of the main valve 17 is at its maximum, and the pressure and flow rate of the tipping cylinder 14 reach or approach their maximum. Prioritizing the maximum power requirement of the bucket, the power allocation is primarily focused on the bucket for excavating material. While the front wheels push the material forward, this helps to fill the bucket completely. As the angle increases, the hydraulic system pressure gradually decreases, reducing the bucket's power output. The drive power allocated to the front wheels gradually increases, resulting in a greater forward thrust and a higher filling rate. Specifically, controller 3 gradually increases the power allocated to the front drive assembly 2 as the bucket angle increases and the system pressure decreases. At this point, the sum of the hydraulic bucket power and the power of the front drive assembly 2 equals the total output power of the engine or power supply 4. Although the angle changes, the total power remains constant; the reduced hydraulic power increases the overall success rate of the front drive.

[0072] When the bucket angle of 25 is 5° < θ ≤ 15° (i.e., in the second range), controller 3 prioritizes ensuring the power demand of the hydraulic system, allocating the remaining power of the engine or power supply 4 to the travel motor. Due to the reduced system pressure (meaning the hydraulic power is not at its maximum), the power output from the engine or power supply 4 to the hydraulic system decreases, while the power to the drive system increases. Furthermore, the drive power prioritizes ensuring the full load power of the front wheels, supplying the remaining power to the rear wheels as needed, ensuring a certain traction force without rear wheel slippage. In other words, the prerequisite for allocating drive power to the rear wheels is that the front wheels are at full load and the rear wheels do not slip. As the bucket angle increases, the machine has greater thrust, further increasing the material filling rate. Since the bucket angle exceeds 5° and the pressure gradually decreases, the power allocated by controller 3 to the front drive assembly 2 gradually increases to the maximum power (or torque) of the front axle motor. When the angle further increases, controller 3 maintains the maximum power (or torque) output of the front wheels, and then determines whether and how much power to allocate based on the rear wheel slippage. When the rear wheels are not slipping, the sum of hydraulic power, front drive power, and rear drive power equals the total power that the engine or power source can output. When the rear wheels slip, no power is allocated to the rear wheels. At this time, the engine or power source 4 has surplus power, which can reduce fuel consumption.

[0073] When the bucket retraction angle is 15° < θ (i.e., in the third interval, and θ ≤ 45°), controller 3 only outputs power to meet the hydraulic system's requirements, and does not output power to the travel drive. That is, the bucket retraction is performed while the entire machine is stopped, until the bucket retraction action is completed. The material in this interval is basically full, and the drive to push material stops as the goal is to retract the bucket to the correct position.

[0074] Among them, the second solenoid valve 10, the third solenoid valve 11 and the sixth solenoid valve 18 are all two-position three-way proportional solenoid valves; the fourth solenoid valve 12 and the fifth solenoid valve 16 are two-position two-way solenoid valves with spring return; the first solenoid valve 9 is a three-position four-way spring-return proportional solenoid valve; and the main valve 17 is a three-position four-way hydraulically controlled spring-return proportional valve.

[0075] When the bucket is fully collected, controller 3 controls handle 1 to a 0-degree angle. Simultaneously, controller 3 outputs a zero-current signal to terminal b7 of the first solenoid valve 9, terminal b2 of the second solenoid valve 10, and terminal b6 of the sixth solenoid valve 18; it also outputs a zero-current signal to terminals b4 of the fourth solenoid valve 12 and terminal b5 of the fifth solenoid valve 16; and outputs a current signal to terminal b1 of the first solenoid valve 9. At this time:

[0076] Pump displacement control oil circuit: The H and L ports of the first solenoid valve 9 are connected, and the J and K ports are connected; the hydraulic oil enters the large chamber of the control cylinder through the electric control pump 21, the H and L ports of the first solenoid valve 9, and the N port of the control cylinder 7, pushing the piston rod to the left, so that the tilt angle of the pump swashplate decreases until it is 0, thereby controlling the pump output displacement to 0. The hydraulic oil in the small chamber of the control cylinder 7 returns through the M port, K ​​port, J port and the throttle valve 23.

[0077] When the pump displacement is 0, the first solenoid valve 9 outputs a 0 current signal at terminal b1, and the solenoid valve is reset.

[0078] Pilot control oil circuit: The V1 port and W1 port of the second solenoid valve 10 are connected; the S1 port and R1 port of the sixth solenoid valve 18 are connected; the pilot oil returns through the electronically controlled pump 21, the pressure reducing valve 19, and the V1 port and W1 port of the second solenoid valve 10.

[0079] The pilot oil on the left side of the main valve 17 returns to the main valve via port U1, port S1 and port R1 of the sixth solenoid valve 18. The main valve core automatically resets until it is shut off at port P and port A, and port B and port T of the main valve 17.

[0080] Main oil circuit: The F and E ports of the fourth solenoid valve 12 are completely closed, and the D and C ports of the fifth solenoid valve 16 are completely closed, locking the piston rod of the tipping cylinder 14 in the current position.

[0081] This invention controls the main valve and the electric pump through multiple solenoid valves, thereby controlling the flow output of the tipping cylinder, resulting in higher efficiency, higher automation, and higher overall productivity in bucket collection operations.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An automatic bucket-collecting control system for a loader, characterized in that, Includes handle (1), drive assembly, controller (3), power supply (4), sensor (5) for detecting bucket angle, tipping cylinder (14), main valve (17), electric pump (21), first solenoid valve (9) and control cylinder (7) for controlling the displacement of electric pump (21), second solenoid valve (10) for controlling pilot oil circuit, third solenoid valve (11) and sixth solenoid valve (18) for controlling the valve core opening of main valve (17); One outlet of the electric pump (21) is connected to the P port of the main valve (17), the A port of the main valve (17) is connected to the G1 port of the tipping cylinder (14), and the G2 port of the tipping cylinder (14) is connected to the B port of the main valve (17); another outlet of the electric pump (21) is connected to the V1 port of the second solenoid valve (10), the X1 port of the second solenoid valve (10) is simultaneously connected to the Q2 port of the third solenoid valve (11) and the Q1 port of the sixth solenoid valve (18), the S2 port of the third solenoid valve (11) is connected to the U2 port of the main valve (17), and the S1 port of the sixth solenoid valve (18) is connected to the U1 port of the main valve (17); another outlet of the electric pump (21) is connected to the H port of the first solenoid valve (9), the K port of the first solenoid valve (9) is connected to the M port of the control cylinder (7), and the L port of the first solenoid valve (9) is connected to the N port of the control cylinder (7); The controller (3) is connected to the handle (1), the drive assembly, the sensor (5) for detecting the bucket angle, the power supply (4), and each solenoid valve respectively; The drive assembly is provided in four parts, each drive assembly includes a motor assembly and a tire (24), the motor assembly and the tire (24) are mechanically connected by a reduction mechanism; The loader automatic bucket retraction control method using the aforementioned loader automatic bucket retraction control system determines the distribution of the bucket retraction hydraulic system and the front and rear wheel travel power according to the angle range of the bucket (25): When the bucket (25) is in the first interval, the full power load of the bucket retraction hydraulic system is allocated first, the remaining power is allocated to the front wheel travel, and no power is allocated to the rear wheel travel. The sum of the bucket retraction hydraulic power and the front wheel travel power is equal to the total power that the engine or power supply can output. When the bucket (25) is in the second interval, the power load requirement of the bucket retraction hydraulic system is prioritized and ensured. The remaining power is prioritized to ensure the full load operation of the front wheel travel power, and then the remaining power is allocated to the rear wheel travel. When the bucket (25) is in the third zone, power distribution is only applied to the hydraulic system, and power distribution to the travel system is stopped; The bucket angle θ ≤ 5° in the first interval, the bucket angle 5 < θ ≤ 15° in the second interval, and the bucket angle 15° < θ in the third interval.

2. The loader automatic bucket retraction control system according to claim 1, characterized in that, It also includes an oil tank (22), a second overflow valve (13) and a third overflow valve (15); The T port of the main valve (17) is connected to the oil tank (22), the other path of the G1 port of the tipping cylinder (14) is connected to the oil tank (22) through the third overflow valve (15), and the other path of the G2 port of the tipping cylinder (14) is connected to the oil tank through the second overflow valve (13). The W1 port of the second solenoid valve (10), the R2 port of the third solenoid valve (11), and the R1 port of the sixth solenoid valve (18) are all connected to the oil tank (22).

3. The loader automatic bucket retraction control system according to claim 1, characterized in that, It also includes a fourth solenoid valve (12) and a fifth solenoid valve (16). The A port of the main valve (17) is connected to the C port of the fifth solenoid valve (16), the D port of the fifth solenoid valve (16) is connected to the G1 port of the tipping cylinder (14), the B port of the main valve (17) is connected to the E port of the fourth solenoid valve (12), and the F port of the fourth solenoid valve (12) is connected to the G2 port of the tipping cylinder (14).

4. The loader automatic bucket retraction control system according to claim 3, characterized in that, The b1 terminal of the first solenoid valve (9), the b2 terminal of the second solenoid valve (10), the b3 terminal of the third solenoid valve (11), the b4 terminal of the fourth solenoid valve (12), the b5 terminal of the fifth solenoid valve (16), the b6 terminal of the sixth solenoid valve (18), and the b7 terminal of the first solenoid valve (9) are respectively connected to the a1 terminal, a2 terminal, a3 terminal, a4 terminal, a5 terminal, a6 terminal, and a7 terminal of the controller (3).

5. The loader automatic bucket retraction control system according to claim 1, characterized in that, It also includes a pressure reducing valve (19) and a pilot relief valve (20); A pressure reducing valve (19) is connected in series between the electric pump (21) and the second solenoid valve (10), and the outlet of the pressure reducing valve (19) is connected to both the pilot relief valve (20) and the V1 port of the second solenoid valve (10). The outlet of the pilot relief valve (20) is connected to the oil tank (22).

6. The loader automatic bucket-collecting control system according to claim 1, characterized in that, It also includes a throttle valve (23) and a first relief valve (8); The J port of the first solenoid valve (9) is connected to the oil tank (22) through the throttle valve (23), and the H port of the first solenoid valve (9) is connected to the oil tank (22) through the first overflow valve (8).

7. The loader automatic bucket retraction control system according to claim 1, characterized in that, The controller (3) is connected to the handle (1) via a CAN bus, the controller (3) is connected to the drive assembly via a cable and CAN communication, the controller (3) is connected to the sensor (5) via a signal line, and the controller (3) is connected to the power supply (4) via a cable and CAN communication.

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