A loader automatic bucket collection operation control system

Abstract

The present invention proposes a loader automatic bucket retracting operation control system. In contrast to the existing manual control of bucket retracting, the driver simultaneously manipulates the handle and the throttle to control bucket retracting and driving. When the load pressure is very large, excessive flow will produce additional overflow, resulting in useless power consumption; since the driving power changes with the progress of the excavation operation, simply stepping on the throttle will cause the bucket retracting action to be weak. The present invention realizes walking control through a controller, and controls the opening of the main valve linearly controlled by the electric control pump, the pilot solenoid valve, the left solenoid valve and the right solenoid valve by controlling the handle angle, thereby controlling the extension or retraction speed of the bucket cylinder. The bucket retracting angle is monitored in real time by a sensor, and then when the load pressure decreases, the output of the driving power is increased, and when the bucket retracting angle exceeds a certain value, the output of the driving power is stopped until the bucket is retracted. The bucket retracting operation is more efficient, the degree of automation is higher, and the overall productivity is higher.

Description

Technical Field

[0001] The invention relates to an automatic bucket-collecting operation control system for a loader, and in particular to an operation control system for automatically controlling the loader to collect the bucket while walking after shoveling materials. Background Art

[0002] The prior art uses manual control to retract the bucket. The driver manipulates the handle and the throttle at the same time. The handle controls the retracting bucket, and the throttle controls the driving. Since it all depends on the driver's experience, when the handle is manipulated to retract the bucket inward, the displacement of the hydraulic system fluctuates. That is, when the load pressure is very high, even if a large flow rate is given, it will only produce additional overflow, and will not have a substantial effect on the excavation, so it is useless power consumption; when the driver steps on the accelerator, the engine speed also fluctuates. Since the driving power changes with the progress of the excavation operation, simply stepping on the accelerator will cause the bucket retracting action to be weak. At the same time, when walking and retracting the bucket are carried out at the same time, the engine speed fluctuates. The fluctuation of the speed will cause the effective output power to decrease, and the flow rate will drop significantly, the bucket retracting speed will be significantly slowed down, and the shoveling efficiency will be low. At the same time, operating the handle for 8 hours a day will easily fatigue the hands and arms. In the case of arm cramps and hand fatigue, continuing to operate the vehicle will result in lower shoveling efficiency. Summary of the invention

[0003] The present invention provides an automatic bucket collection operation control system that does not require manual operation, and belongs to automatic driving and automatic shoveling, thereby solving the above problems.

[0004] The present invention provides a loader automatic bucket collection operation control system, which is mainly composed of a main oil circuit, a control oil circuit, a controller 6, a handle 1 and a power supply 5.

[0005] The main oil circuit is composed of an electronically controlled pump 19, a main valve 11, a left stop valve 14L, a right stop valve 14R, a bucket cylinder 15 and an oil tank 7, wherein the main valve 11 is a three-position four-way hydraulically controlled spring-reset proportional valve; the left stop valve 14L and the right stop valve 14R are hydraulically controlled spring-reset proportional valves at both ends;

[0006] The hydraulic oil is connected to the main valve 11P port through the electronically controlled pump 19, the main valve 11A1 port is connected to the B1 port of the left stop valve 14L, the E1 port of the left stop valve 14L is connected to the G1 port of the bucket cylinder 15; the G2 port of the bucket cylinder 15 is connected to the E2 port of the right stop valve 14R, the B2 port of the right stop valve 14R is connected to the A2 port of the main valve 11, and the T port of the main valve 11 is connected to the oil tank 7;

[0007] The control oil circuit is mainly composed of an accumulator 16, a pilot solenoid valve 17, a left solenoid valve 12L, a right solenoid valve 12R, a left hydraulic control valve 13L and a right hydraulic control valve 13R; wherein the left solenoid valve 12L and the right solenoid valve 12R are both two-position three-way hydraulically controlled spring-reset solenoid valves; the pilot solenoid valve 17 is a two-position three-way spring-reset solenoid valve; the left hydraulic control valve 13L and the right hydraulic control valve 13R are proportional valves with hydraulically controlled spring resets at both ends;

[0008] The W1 port of the pilot solenoid valve 17 is connected to the electronically controlled pump 19, and the X1 port is connected to the oil tank 7; the accumulator 16 is connected to the W1 port of the pilot relief valve 17, and the V1 port of the pilot solenoid valve 17 is simultaneously connected to the Q1 port of the left solenoid valve 12L and the Q2 port of the right solenoid valve 12R; the N1 port and the S1 port of the left solenoid valve 12L are interconnected; the S1 port of the left solenoid valve 12L is simultaneously connected to the U1 port of the main valve 11 and the L1 port of the left hydraulic control valve 13L, the K1 port of the left hydraulic control valve 13L is connected to the E1 port of the left stop valve 14L, the H1 port of the left hydraulic control valve 13L is connected to the F1 port of the left stop valve 14L, and the J1 port of the left hydraulic control valve 13L is connected to the M 1 port is interconnected and connected to the oil tank 7 at the same time; the E1 port of the left stop valve 14L is connected to the D1 port, and the B1 port of the left stop valve 14L is connected to the C1 port; the N2 port and the S2 port of the right solenoid valve 12R are interconnected; the S2 port of the right solenoid valve 12R is simultaneously connected to the U2 port of the main valve 11 and the L2 port of the right hydraulic control valve 13R, the K2 port of the right hydraulic control valve 13R is connected to the E2 port of the left stop valve 14L, the H2 port of the right hydraulic control valve 13R is connected to the F2 port of the right stop valve 14R, the J2 port and the M2 port of the right hydraulic control valve 13R are interconnected and connected to the oil tank 7 at the same time; the E2 port of the right stop valve 14R is connected to the D2 port, and the B2 port of the right stop valve 14R is connected to the C2 port;

[0009] There are four drive assemblies, each of which includes a motor assembly and a tire. The motor assembly and the tire are mechanically connected through a reduction mechanism. The handle 1 is connected to the controller 6 by a CAN bus. The sensor 4 is connected to the controller 6 by a signal line. The bucket retraction angle of the bucket is monitored in real time by the sensor 4. The power supply 5 is connected to the controller 6 by a cable and a CAN communication connection. The controller 6 is connected to the four drive assemblies by a cable and a CAN communication connection. The left solenoid valve 12L, the right solenoid valve 12R, the pilot solenoid valve 17, the electronically controlled pump 19 and the controller 6 are all connected by a signal line.

[0010] Preferably, the system further comprises a left overflow valve 10L and a right overflow valve 10R, and the G1 port of the tipping cylinder 15 returns to the oil tank 7 through the left overflow valve 10L; the G2 port of the tipping cylinder 15 returns to the oil tank 7 through the right overflow valve 10R.

[0011] Preferably, the system further comprises a pressure reducing valve 9 and a pilot relief valve 18 . The pressure reducing valve 9 is arranged between the electronically controlled pump 19 and the W1 port of the pilot solenoid valve 17 . The outlet of the pressure reducing valve 9 is connected to the oil tank 7 through the pilot relief valve 18 .

[0012] The control method of the loader automatic bucket collection operation control system of the present invention comprises the following steps:

[0013] 1) When the controller 6 controls the four drive assemblies to drive the whole machine to the front of the material, the whole machine is controlled to push the material with the maximum driving force until the speed of the drive assembly is 0, and then the driving is stopped. The controller 6 controls the handle 1 to rotate to the left by an angle, and the controller 6 outputs a voltage signal to the right solenoid valve 12R and the pilot solenoid valve 17, and the voltage value corresponds to the handle angle. At this time, the V1 port and the W1 port of the pilot solenoid valve 17 are connected, and the N2 port and the Q2 port of the right solenoid valve 12R are connected;

[0014] 2) When the pressure of the electric control pump or the large chamber of the bucket cylinder is high, the controller 6 automatically controls the angle of the handle 1 to be lowered according to the load pressure of the shovel, thereby reducing the voltage value signal input to the pilot solenoid valve 17 and the right solenoid valve 12R, thereby controlling the flow of the main valve 11 to the large chamber of the bucket cylinder 15 to reduce the extension speed of the bucket cylinder 15, and at the same time outputs power and torque to the drive system according to the change of the bucket retraction angle, so as to achieve the goal of pushing the material forward while retracting the bucket;

[0015] 3) When the bucket retracting angle exceeds 20°, the drive power output will automatically stop and only the bucket retracting action will be performed until the bucket is completed.

[0016] 4) When the bucket is closed, the controller controls the handle angle to 0° and outputs a 0 voltage signal to the electronically controlled pump 19. The displacement of the electronically controlled pump 19 becomes 0, so it runs idle without displacement output. At the same time, it outputs a 0 voltage signal to the pilot solenoid valve 17 and the right solenoid valve 12R, and the pilot solenoid valve 17 and the right solenoid valve 12R are automatically reset.

[0017] Beneficial effects of the present invention:

[0018] 1. More energy-saving: The controller detects the pressure and flow signals of the electronically controlled pump in real time. When the load pressure is high, it automatically outputs a signal to reduce the displacement of the electronically controlled pump, thereby reducing the system flow and slowing down the extension speed of the bucket cylinder. This can avoid the power loss caused by increasing the flow rate during manual operation, and has a significant energy-saving effect.

[0019] 2. Higher degree of automation: Since the controller can dynamically adjust the signals of the electronically controlled pump and the solenoid valve according to the pressure requirements of the load in real time, and then adjust the system flow and output power, and can also adjust the travel output power according to the bucket retraction angle, compared with manual operation, it has a higher degree of automation and more precise control.

[0020] 3. More efficient: Since manual operation depends entirely on the driver's experience, and the driver cannot perceive the precise changes in the bucket retraction angle, it is inevitable that the accelerator pedal will be stepped on early or late, resulting in the output of driving power, but the vehicle is unable to move or the rear wheels slip or the vehicle moves too fast, resulting in the need for secondary shoveling or digging powerlessness, etc., and the overall operating efficiency is low. The automatic bucket retraction operation control system of the present invention can accurately perceive the changes in the bucket retraction angle, and the output of the walking power will make timely changes to push the material forward or stop the output power according to the angle change, thereby improving the overall shoveling efficiency.

[0021] 4. It liberates the driver, and there is no arm muscle cramp caused by fatigue of hands and arms due to long-term operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the control principle diagram of the present invention; Figure 1 Middle: 1. Handle; 2. Front drive assembly (2L is the left front drive assembly, 2R is the right front drive assembly); 3. Rear drive assembly (3L is the left rear drive assembly, 3R is the right rear drive assembly); 4. Sensor; 5. Power supply; 6. Controller; 7. Fuel tank; 8. Motor; 9. Pressure reducing valve; 10. Overflow valve (10R. Right overflow valve, 10L. Left overflow valve); 11. Main valve; 12. Solenoid valve (12R. Right solenoid valve, 12L. Left solenoid valve); 13. Hydraulic control valve (13R. Right hydraulic control valve, 13L. Left hydraulic control valve); 14. Stop valve (14R. Right stop valve, 14L. Left stop valve); 15. Tipping cylinder; 16. Accumulator; 17. Pilot solenoid valve; 18. Pilot overflow valve; 19. Electronically controlled pump;

[0023] Figure 2 This is a schematic diagram of the tipping cylinder extending action of the present invention; DETAILED DESCRIPTION

[0024] The system is mainly composed of the main oil circuit, control oil circuit, controller 6, handle 1 and power supply 5. The hydraulic connection parts are as follows:

[0025] Main oil circuit: The hydraulic oil is connected to the main valve 11P port through the electronically controlled pump 19, the main valve 11A1 port is connected to the B1 port of the left stop valve 14L, the E1 port of the left stop valve 14L is connected to the G1 port of the bucket cylinder 15; the G2 port of the bucket cylinder 15 is connected to the E2 port of the right stop valve 14R, the B2 port of the right stop valve 14R is connected to the A2 port of the main valve 11, the T port of the main valve 11 is connected to the oil tank 7, the G1 port of the bucket cylinder 15 returns to the oil tank 7 through the left relief valve 10L in another way; the G2 port of the bucket cylinder 15 returns to the oil tank 7 through the right relief valve 10R in another way.

[0026] Control oil circuit: another route of the outlet of the electronically controlled pump 19 is connected to the pressure reducing valve 9, the outlet of the pressure reducing valve 9 is simultaneously connected to the pilot relief valve 18, the accumulator 16 and the W1 port of the pilot solenoid valve 17, the V1 port of the pilot solenoid valve 17 is simultaneously connected to the Q1 port of the left solenoid valve 12L and the Q2 port of the right solenoid valve 12R, the X1 port of the pilot relief valve 17, the R1 port of the left solenoid valve 12L and the R2 port of the right solenoid valve 12R are simultaneously connected to the oil tank 7;

[0027] The N1 port and the S1 port of the left solenoid valve 12L are interconnected; the S1 port of the left solenoid valve 12L is simultaneously connected to the U1 port of the main valve 11 and the L1 port of the left hydraulic control valve 13L, the K1 port of the left hydraulic control valve 13L is connected to the E1 port of the left stop valve 14L, the H1 port of the left hydraulic control valve 13L is connected to the F1 port of the left stop valve 14L, the J1 port and the M1 port of the left hydraulic control valve 13L are interconnected and simultaneously connected to the oil tank 7; the E1 port of the left stop valve 14L is connected to the D1 port, and the B1 port of the left stop valve 14L is connected to the C1 port;

[0028] The N2 port and the S2 port of the right solenoid valve 12R are interconnected; the S2 port of the right solenoid valve 12R is simultaneously connected to the U2 port of the main valve 11 and the L2 port of the right hydraulic control valve 13R, the K2 port of the right hydraulic control valve 13R is connected to the E2 port of the left stop valve 14L, the H2 port of the right hydraulic control valve 13R is connected to the F2 port of the right stop valve 14R, the J2 port and the M2 port of the right hydraulic control valve 13R are interconnected and simultaneously connected to the oil tank 7; the E2 port of the right stop valve 14R is connected to the D2 port, and the B2 port of the right stop valve 14R is connected to the C2 port;

[0029] Electrical connection: The handle 1 is connected to the controller 6 by CAN bus, the controller 6 is connected to the four drive assemblies by cables and CAN communication, the sensor 4 is connected to the controller 6 by signal lines, and the bucket retraction angle is monitored in real time by the sensor 4, the power supply 5 is connected to the controller 6 by cables and CAN communication, and the left solenoid valve 12L, the right solenoid valve 12R, the pilot solenoid valve 17, the electronically controlled pump 19 and the controller 6 are all connected by signal lines.

[0030] Each drive assembly includes a motor assembly and a tire, and the motor assembly and the tire are mechanically connected through a reduction mechanism.

[0031] The control principle of automatic bucket collection operation is as follows:

[0032] 1) Start collecting buckets

[0033] When the controller 6 controls the four drive assemblies to drive the whole machine to the front of the material, the whole machine is controlled to push the material with the maximum driving force until the speed of the drive assembly is 0, then the drive is stopped, and the handle is controlled to rotate to the left by an angle. The controller 6 outputs a voltage signal to the right solenoid valve 12R and the pilot solenoid valve 17, and the voltage value corresponds to the handle angle (approximately proportional). At this time, the V1 port and the W1 port of the pilot solenoid valve 17 are connected, and the N2 port and the Q2 port of the right solenoid valve 12R are connected.

[0034] Among them, the large-cavity control oil circuit of the tipping cylinder 15: the pilot oil passes through the electronically controlled pump 19, the pressure reducing valve 9, the W1 port and the V1 port of the pilot solenoid valve 17, the Q2 port and the N2 port of the right solenoid valve, one way through the L2 port of the right hydraulic control valve 13R to push the right hydraulic control valve 13R to the left position, and the other way through the U2 port of the main valve 11 to push the main valve 11 to the right position. The main oil circuit passes through the electronically controlled pump 19, the P port and the A2 port of the main valve 11, and enters the B2 port and the C2 port of the right stop valve 14R. At this time, the pressure at port C2 increases, pushing the right stop valve 14R to the left, connecting ports B2 and E2, and the main oil circuit continues to pass through ports B2 and E2 of the right stop valve 14R, and enters the large chamber of the bucket cylinder 15 through port G2 of the bucket cylinder 15. The control oil source of the right stop valve 14R returns to the oil tank 7 through port F2, ports H2 and J2 of the right hydraulic control valve 13R; the oil source of the right hydraulic control valve 13R returns to the oil tank 7 through port M2.

[0035] The small chamber control oil circuit part of the tipping cylinder 15: Since the left solenoid valve 12L loses power and does not receive the voltage signal from the controller 6, the N1 port and the R1 port of the left solenoid valve 12L remain connected, and the left control oil source of the main valve 11 returns oil through the U1 port, the S1 port, the N1 port and the R1 port of the left solenoid valve 12L.

[0036] The L1 port of the left hydraulic control valve 13L is connected to the S1 port of the left solenoid valve 12L, and the N1 port of the left solenoid valve 12L is interconnected with the S1 port. Therefore, the L1 port of the left hydraulic control valve 13L realizes oil return. At this time, the left hydraulic control valve 13L remains in the left position, and the oil sources of the J1 port and the M1 port of the left hydraulic control valve realize oil return. Since the pressure of the E1 port of the left stop valve 14L is relatively high at this time, the pressure oil source from the E1 port pushes the left stop valve 14L to the right position through the D1 port, and the E1 port and the B1 port are connected at this time. The oil source of the small chamber of the bucket cylinder 15 returns oil through the G1 port, the E1 port of the left stop valve 14L, the B1 port, the A1 port and the T port of the main valve 11; it should be noted that the left oil source of the left stop valve 14L returns to the E1 port through the F1 port, the H1 port and the K1 port of the left hydraulic control valve, and realizes differential oil return through the E1 port and the B1 port.

[0037] The oil source of the pilot solenoid valve 17 returns to the oil through the X1 port; the oil source of the K2 port of the right hydraulic control valve 13R is maintained at the pressure value of the main oil circuit.

[0038] Pressure reducing valve 9: mainly realizes the pilot pressure to meet the requirements of solenoid valve and hydraulic control valve;

[0039] Pilot relief valve 18: ensure that the maximum value of the pilot pressure does not exceed the set value;

[0040] Accumulator 16: Reduces fluctuations in pilot pressure and absorbs pressure shocks.

[0041] Right relief valve 10R and left relief valve 10L: ensure that the pressure in the large chamber and small chamber of the bucket cylinder 15 does not exceed the set value;

[0042] 2) When the pressure of the large chamber of the electronically controlled pump and the bucket cylinder is high (it is generally believed in the art that the pressure of the large chamber of the electronically controlled pump and the bucket cylinder is high when it reaches 30Mpa, which is also equivalent to the pressure when the overflow valve is opened in the present invention), the controller 6 automatically controls the angle of the handle 1 according to the load pressure of the shovel, thereby reducing the voltage value signal input to the pilot solenoid valve 17 and the right solenoid valve 12R, thereby controlling the flow of the main valve 11 to the large chamber of the bucket cylinder 15 to reduce, so as to control the extension speed of the bucket cylinder 15, and at the same time, according to the change of the bucket retraction angle, output power and torque to the drive system to achieve forward pushing and retracting the bucket. The transient overflow phenomenon when retracting the bucket can be avoided, and the power can be fully utilized at the same time, and the power reduced by the hydraulic pressure can be supplemented to the walking system, so as to achieve full utilization of power in the same time, that is, the average power utilization rate per unit time is high. In this way, the efficiency of the comprehensive shoveling process is higher, the energy utilization is more sufficient, and the energy loss is smaller.

[0043] In order to realize proportional control, that is, the angle of the handle is approximately proportional to the flow rate output by the main valve 11. The pilot solenoid valve, the left solenoid valve, the right solenoid valve, the left hydraulic control valve, the right hydraulic control valve and the main valve 11 are all proportional valves.

[0044] Among them: the left solenoid valve and the right solenoid valve are both two-position three-way hydraulically controlled spring-reset solenoid valves; the pilot solenoid valve is a two-position three-way solenoid valve with spring reset; the main valve 11 is a three-position four-way hydraulically controlled spring-reset proportional valve. The left hydraulically controlled valve and the right hydraulically controlled valve are proportional valves with hydraulically controlled spring reset at both ends. The left stop valve 14L and the right stop valve 14R are proportional valves with hydraulically controlled spring reset at both ends.

[0045] 3) When the bucket retracting angle exceeds 20°, the drive power output will automatically stop and only the bucket retracting action will be performed until the bucket is completed.

[0046] 4) When the bucket is closed, the controller controls the handle angle to 0° and outputs a 0 voltage signal to the electronically controlled pump 19, and the displacement of the electronically controlled pump 19 becomes 0, so it runs idle without displacement output; at the same time, it outputs a 0 voltage signal to the pilot solenoid valve 17 and the right solenoid valve 12R, and the pilot solenoid valve 17 and the right solenoid valve 12R automatically reset. At this time, the V1 port and the X1 port of the pilot solenoid valve 17 are connected, and the N2 port and the R2 port of the right solenoid valve 12R are connected, and the pilot oil is cut off and maintained under the action of the accumulator 16;

[0047] The control oil source of the main valve 11 returns oil through the U2 port, the N2 port and the R2 port of the right solenoid valve 12R. The main valve 11 automatically resets under the action of its own spring, and the P port and A2 port of the main valve 11 are cut off, and the T port and A1 port are cut off;

[0048] The L2 port of the right hydraulic control valve 13R returns oil via the N2 port and R2 port of the right solenoid valve 12R, and the right hydraulic control valve 13R automatically resets under the action of its own spring, that is, the H2 port and J2 port of the right hydraulic control valve 13R are cut off, and the H2 port and K2 port are connected. The pressure oil from the large chamber of the bucket cylinder 15 passes through the G2 port, the E2 port of the right stop valve 14R, the K2 port and H2 port of the right hydraulic control valve 13R, and the F2 port of the right stop valve 14R. Under the action of the spring and the pressure oil from the F2 port, the right stop valve 14R is reset, and the E2 port and B2 port of the right stop valve 14R are cut off. Therefore, the large chamber of the bucket cylinder 15 is locked by the right stop valve 14R and maintained at the current position.

[0049] Similarly, the pressure oil source from the small chamber of the bucket cylinder 15 passes through the G1 port, E1 port, K1 port and H1 port of the left hydraulic control valve 13L, through the F1 port of the left stop valve 14L, and together with the spring of the left stop valve 14L, the valve core of the left stop valve 14L is reset, and the E1 port and B1 port of the left stop valve 14L are cut off, and the small chamber of the bucket cylinder 15 is locked by the left stop valve 14L and maintained at the current position.

[0050] Since the left solenoid valve 12L has been de-energized and has not received any voltage signal from the controller 6, the N1 port and the R1 port of the left solenoid valve 12L remain connected and oil return is achieved. The left control oil source of the main valve 11 returns oil through the U1 port, the S1 port, the N1 port and the R1 port of the left solenoid valve 12L.

[0051] The L1 port of the left hydraulic control valve 13L is connected to S1, so the L1 port realizes oil return, the left hydraulic control valve 13L is kept in the left position, and the oil source of the left hydraulic control valve 13L realizes oil return through the J1 port and the M1 port.

[0052] In the bucket tipping operation corresponding to the bucket collecting operation, the valve core of the main valve 11 moves to the left, and the principle is the same as that of moving to the right.

[0053] The output energy of walking power comes from a power source, which can be a lithium battery, a hydrogen fuel cell, etc., or a power grid.

[0054] The hydraulic pump is mechanically connected to the motor, and the energy of the motor can also come from the power supply. The power input of the motor is output by controlling the power supply through the controller. The motor of the present invention can be a permanent magnet synchronous motor, or an AC asynchronous motor, etc.

Claims

1. A control method for a loader automatic bucket collection control system, It is characterized in that The loader automatic bucket collection operation control system comprises a main oil circuit, a control oil circuit, a controller (6), a handle (1), a power supply (5) and four drive assemblies. The main oil circuit is composed of an electronically controlled pump (19), a main valve (11), a left stop valve (14L), a right stop valve (14R), a bucket cylinder (15) and an oil tank (7). The main valve (11) is a three-position four-way hydraulically controlled spring-reset proportional valve; the left stop valve (14L) and the right stop valve (14R) are hydraulically controlled spring-reset proportional valves at both ends. The hydraulic oil is connected to the P port of the main valve (11) through the electronically controlled pump (19); the A1 port of the main valve (11) is connected to the B1 port of the left stop valve (14L); the E1 port of the left stop valve (14L) is connected to the G1 port of the bucket cylinder (15); the G2 port of the bucket cylinder (15) is connected to the E2 port of the right stop valve (14R); the B2 port of the right stop valve (14R) is connected to the A2 port of the main valve (11); and the T port of the main valve (11) is connected to the oil tank (7); The control oil circuit is composed of an accumulator (16), a pilot solenoid valve (17), a left solenoid valve (12L), a right solenoid valve (12R), a left hydraulic control valve (13L) and a right hydraulic control valve (13R); wherein the left solenoid valve (12L) and the right solenoid valve (12R) are both two-position three-way hydraulically controlled spring-reset solenoid valves; the pilot solenoid valve (17) is a two-position three-way spring-reset solenoid valve; the left hydraulic control valve (13L) and the right hydraulic control valve (13R) are two-end hydraulically controlled spring-reset proportional valves; The W1 port of the pilot solenoid valve (17) is connected to the electric control pump (19), and the X1 port is connected to the oil tank (7); the accumulator (16) is connected to the W1 port of the pilot solenoid valve (17), and the V1 port of the pilot solenoid valve (17) is connected to the Q1 port of the left solenoid valve (12L) and the Q2 port of the right solenoid valve (12R); the N1 port and the S1 port of the left solenoid valve (12L) are interconnected; the S1 port of the left solenoid valve (12L) is connected to the U1 port of the main valve (11) and the L1 port of the left hydraulic control valve (13L); the K1 port of the left hydraulic control valve (13L) is connected to the E1 port of the left stop valve (14L); the H1 port of the left hydraulic control valve (13L) is connected to the F1 port of the left stop valve (14L); the J1 port of the left hydraulic control valve (13L) is connected to the The port M1 is interconnected with the oil tank (7); the port E1 of the left stop valve (14L) is connected to the port D1, and the port B1 of the left stop valve (14L) is connected to the port C1; the port N2 of the right solenoid valve (12R) is interconnected with the port S2; the port S2 of the right solenoid valve (12R) is simultaneously connected to the port U2 of the main valve (11) and the port L2 of the right hydraulic control valve (13R); the port K2 of the right hydraulic control valve (13R) is connected to the port E2 of the left stop valve (14L); the port H2 of the right hydraulic control valve (13R) is connected to the port F2 of the right stop valve (14R); the port J2 of the right hydraulic control valve (13R) is interconnected with the port M2 and is connected to the oil tank (7); the port E2 of the right stop valve (14R) is connected to the port D2, and the port B2 of the right stop valve (14R) is connected to the port C2; Four drive assemblies, each drive assembly includes a motor assembly and a tire, the motor assembly and the tire are mechanically connected through a reduction mechanism, the handle (1) and the controller (6) are connected through a CAN bus, the sensor (4) and the controller (6) are connected through a signal line, the bucket retraction angle of the bucket is monitored in real time through the sensor (4), the power supply (5) and the controller (6) are connected through a cable and a CAN communication connection, the controller (6) and the four drive assemblies are connected through a cable and a CAN communication connection, and the left solenoid valve (12L), the right solenoid valve (12R), the pilot solenoid valve (17), the electronically controlled pump (19) and the controller (6) are all connected through a signal line; The steps of the control method of the system are as follows: 1) When the controller (6) controls the four drive assemblies to drive the whole machine to move in front of the material, the whole machine is controlled to push the material with the maximum driving force until the speed of the drive assembly is 0, and then the driving is stopped. The controller (6) controls the handle (1) to rotate to the left by an angle. The controller (6) outputs a voltage signal to the right solenoid valve (12R) and the pilot solenoid valve (17), and the voltage value corresponds to the handle angle. At this time, the V1 port and the W1 port of the pilot solenoid valve (17) are connected, and the N2 port and the Q2 port of the right solenoid valve (12R) are connected; The large chamber control oil circuit of the tipping cylinder (15): the pilot oil passes through the electronically controlled pump (19), the pressure reducing valve (9), the W1 port and the V1 port of the pilot solenoid valve (17), the Q2 port and the N2 port of the right solenoid valve (12R), and one way passes through the L2 port of the right hydraulic control valve (13R) to push the right hydraulic control valve (13R) to the left position, and the other way passes through the U2 port of the main valve (11) to push the main valve (11) to the right position; the main oil circuit passes through the electronically controlled pump (19), the P port and the A2 port of the main valve (11), and enters the right stop valve (12R). At this time, the pressure at port C2 increases, pushing the right stop valve (14R) to the left, connecting ports B2 and E2, and the main oil circuit continues to flow through ports B2 and E2 of the right stop valve (14R), and enters the large chamber of the bucket cylinder (15) through port G2 of the bucket cylinder (15). The control oil source of the right stop valve (14R) returns to the oil tank (7) through port F2, ports H2 and J2 of the right hydraulic control valve (13R); the oil source of the right hydraulic control valve (13R) returns to the oil tank (7) through port M2. The small chamber control oil circuit of the tipping cylinder (15): since the left solenoid valve (12L) loses power and does not receive the voltage signal from the controller (6), the N1 port and the R1 port of the left solenoid valve (12L) remain connected, and the left control oil source of the main valve (11) returns oil via the U1 port, the S1 port, the N1 port and the R1 port of the left solenoid valve (12L); The L1 port of the left hydraulic control valve (13L) is connected to the S1 port of the left solenoid valve (12L). At the same time, the N1 port and the S1 port of the left solenoid valve (12L) communicate with each other. Therefore, the L1 port of the left hydraulic control valve (13L) realizes oil return. At this time, the left hydraulic control valve (13L) remains in the left position, and the oil sources of the J1 port and the M1 port of the left hydraulic control valve (13L) realize oil return. Since the pressure of the E1 port of the left check valve (14L) is relatively high at this time, the pressure oil source from the E1 port pushes the left check valve (14L) to the right position through the D1 port. At this time, the E1 port and the B1 port are connected. The oil source of the small chamber of the tipping cylinder (15) returns oil through the G1 port, the E1 port of the left check valve (14L), the B1 port, the A1 port, and the T port of the main valve (11). The oil source on the left side of the left check valve (14L) returns to the E1 port through the F1 port, the H1 port, and the K1 port of the left hydraulic control valve (13L), and realizes differential oil return through the E1 port and the B1 port. The oil source of the pilot solenoid valve (17) returns oil through the X1 port; the oil source of the K2 port of the right hydraulic control valve (13R) maintains the pressure value of the main oil circuit. 2) When the pressure of the electric control pump (19) or the large chamber of the tipping cylinder (15) is high, the controller (6) automatically controls the reduction of the angle of the handle (1) according to the load pressure during loading, thereby reducing the voltage signal input to the pilot solenoid valve (17) and the right solenoid valve (12R), thereby controlling the flow rate of the main valve (11) to the large chamber of the tipping cylinder (15) to decrease, so as to control the extending speed of the tipping cylinder (15). At the same time, according to the change of the tipping bucket closing angle, the power and torque are output to the drive system to realize pushing the material forward while closing the bucket. 3) When the closing angle exceeds 20°, the drive power output is automatically stopped, and only the closing action is performed until the closing is completed. 4) When the closing is completed, the controller controls the handle angle to 0°, and outputs a 0 voltage signal to the electric control pump (19). The displacement of the electric control pump (19) becomes 0, so it idles without displacement output. At the same time, a 0 voltage signal is output to the pilot solenoid valve (17) and the right solenoid valve (12R), and the pilot solenoid valve (17) and the right solenoid valve (12R) are automatically reset.

2. The control method of the automatic tipping bucket operation control system of the loader according to claim 1, characterized in that, The control system further includes a left relief valve (10L) and a right relief valve (10R). Another path of the G1 port of the tipping cylinder (15) returns to the fuel tank (7) through the left relief valve (10L); another path of the G2 port of the tipping cylinder (15) returns to the fuel tank (7) through the right relief valve (10R).

3. The control method of the automatic tipping bucket operation control system of the loader according to claim 2, characterized in that, The control system further includes a pressure reducing valve (9) and a pilot relief valve (18). The pressure reducing valve (9) is arranged between the electric control pump (19) and the W1 port of the pilot solenoid valve (17), and the outlet of the pressure reducing valve (9) is connected to the fuel tank (7) through the pilot relief valve (18).

Images