Dumper lifting system with automatic unloading mode and control method thereof

Abstract

The dumper lifting system with the automatic discharging mode comprises a hydraulic oil tank, a lifting pump, a lifting proportional valve and a lifting oil cylinder and further comprises a controller, the input end of the controller is connected with a lifting angle sensor, a mode selection module, a lifting control module and a safety belt module, the lifting angle sensor is connected with the lifting oil cylinder, and the mode selection module is connected with the lifting control module. The mode selection module is a manual mode selection module and an automatic mode selection module, the output end of the controller is connected with a lifting proportional valve, a brake control module and a warning indicator, and the brake control module is connected with a vehicle brake. Through cooperative use of the mode selection module and the lifting control module, the manual operation mode and the automatic operation mode are completed, the automatic discharging mode of lifting discharging-top-reaching keeping-container falling is achieved, in the automatic discharging process, the safety of the system is monitored in real time, the mode can be switched to the manual mode at any time according to the actual situation, and the safety of the system is guaranteed. And the use safety of the system is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of construction machinery, and particularly to a lifting system of a dump truck with an automatic unloading mode and its control method. Background Art

[0002] The lifting system of a dump truck, that is, the unloading system, is a key function of a dump truck and also a basic function of a mining dump truck. With the progress of technology and the improvement of living standards, there are more and more diverse requirements for the lifting function of mining dump trucks. The main requirements are reflected in easier operation and safer use.

[0003] The lifting system of traditional dump trucks usually relies on manual operation. The driver needs to control the lifting, holding, and lowering actions of the cargo box throughout the process, which is cumbersome and inefficient. In addition, manual operation has safety hazards. For example, if the operation is improper during the unloading process, it may cause the cargo box to be overloaded or out of control. Although there are some automated improvement solutions in the prior art, the following problems generally exist: 1. The switching between the automatic mode and the manual mode is not convenient, and there is a lack of intuitive status feedback; 2. The safety detection functions (such as the status of the seat belt and the position of the operation handle) are not fully integrated; 3. There is a lack of precise closed-loop control during the lifting / lowering process of the cargo box, which is likely to cause the action to exceed the limit or impact.

[0004] Therefore, there is an urgent need for a lifting system of a dump truck that can balance automated operation, safety, and operation flexibility. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a lifting system of a dump truck with an automatic unloading mode and its control method, which has a simple structure and good effects.

[0006] The present invention is implemented as follows: A lifting system of a dump truck with an automatic unloading mode includes a lifting pump. One end of the lifting pump is connected to a hydraulic oil tank, and the other end of the lifting pump is connected to a lifting cylinder through a lifting proportional valve. It also includes a controller. The input end of the controller is connected to a lifting angle sensor, a mode selection module, a lifting control module, and a seat belt module. The lifting angle sensor is connected to the lifting cylinder. The mode selection module is a selection module for two modes: manual and automatic. The output end of the controller is connected to a lifting proportional valve, a braking control module, and a warning device. The braking control module is connected to a vehicle brake.

[0007] Furthermore, the lifting proportional valve is an electronically controlled proportional valve, and the electronically controlled end of the lifting proportional valve is connected to the controller.

[0008] The lift proportional valve has a spool with at least three positions: lift, hold, and float. The lift proportional valve is in the hold position by default. The lift control module has at least three positions: lift, hold, and float. The working positions of the lift control module correspond to those of the lift proportional valve. The lift control module is in the hold position by default.

[0009] The mode selection module is a self - reset button with a light, providing two operating modes for the vehicle: manual mode and automatic mode.

[0010] The lift control module is a four - position handle with a base. The lift and lower positions of the handle cannot be locked, and the handle is locked in the hold and float positions through slots.

[0011] In the lift control module, there is a track connecting the handle between the slot in the lift position and the slot in the hold position, and there is also a track connecting the handle between the slot in the lower position and the slot in the float position.

[0012] A control method for a dump truck lift system with an automatic unloading mode includes the following steps: Manual mode: S1. Place the handle of the lift control module in the lift or lower position. S2. After the controller receives the lift or lower position signal from the lift control module, it first detects the lift angle of the cargo box through the lift angle sensor. S3. If the lift angle of the cargo box has not reached the maximum or minimum lift angle, the controller sends a signal to make the proportional lift valve enter the lift or lower position, causing the lift pump to operate. S4. If the controller detects that the lift angle of the cargo box reaches the maximum or minimum lift angle, the controller turns off the electrical signal of the proportional lift valve, making the proportional lift valve in the hold position. Automatic mode: T1. Press the self - reset button of the mode selection module, and the controller turns on the green button light of the mode selection module and makes it blink. T2. The controller detects whether the handle of the lift control module is in the hold position and simultaneously detects the status of the seat belt through the seat belt module. T3. If the handle of the lift control module is in the hold position and the signal from the seat belt module indicates that the seat belt latch is inserted, the controller sets the green button light of the mode selection module to be constantly on and enters the automatic mode. T4. Place the handle of the lift control module in the lift position and release it. T5. When the controller detects through the lifting angle sensor that the lifting angle of the cargo box has not reached the maximum lifting angle, the controller sends a signal to make the proportional lifting valve enter the lifting position, causing the lifting pump to act and the cargo box to start lifting for unloading operations; T6. When the controller detects through the lifting angle sensor that the cargo box has reached the maximum lifting angle, the controller will turn off the electrical signal of the proportional lifting valve and make the proportional lifting valve stay in the holding position for a period of time; T7. The controller adjusts the electrical signal of the proportional lifting valve to make it in the lowering position, and the lifting pump acts; T8. When the controller detects through the lifting angle sensor that the cargo box has reached the minimum lifting angle, the controller will turn off the electrical signal of the proportional lifting valve and make the proportional lifting valve stay in the holding position; T9. After the automatic operation is completed, the controller will switch the green button light of the mode selection module to the flashing state and control the buzzer to emit a beeping sound to remind the user to take over in time; T10. The controller turns off the green button light of the selection module to complete the exit from the automatic mode.

[0013] In the manual mode, when the handle is released at the lifting position of the lifting control module, the handle will stay at the holding position of the lifting control module. When the handle is released at the lowering position of the lifting control module, the handle will stay at the floating position of the lifting control module.

[0014] In step S4, if the controller detects that the lifting angle of the cargo box is close to the minimum lifting angle, the controller will adjust the electrical signal of the proportional lifting valve to make the proportional lifting valve in the floating position, and the cargo box will slowly fall under the action of gravity.

[0015] In step T2, if the handle of the lifting control module is not in the holding position or the signal of the seat belt module indicates that the seat belt latch is in the pulled-out state, the controller will issue a risk reminder, prompting the user to put the handle of the lifting control module into the holding position or prompting the user to fasten the seat belt, and turn off the green light of the mode selection module. At the same time, the controller will turn off the electrical signal of the proportional lifting valve to make the proportional lifting valve stay in the holding position.

[0016] During the execution of the automatic mode, if there are signal changes in the lifting control module, switching of the mode selection button, pulling out of the seat belt latch, and the lifting process exceeding the set time limit, the controller will exit the automatic mode and return to the manual mode for the user to take over at any time.

[0017] In the automatic mode, when the controller detects through the lifting angle sensor that the cargo box starts to lift from the minimum lifting angle, timing starts. When the timing exceeds the set time limit, the controller will execute the exit procedure of the automatic mode.

[0018] In the automatic mode, when the controller detects that the user has opened the seat belt through the seat belt module, it will exit the automatic operation and apply braking to the vehicle brake through the braking control module.

[0019] The present invention has the following advantages: The tipping system of the dump truck with an automatic unloading mode and its control method of the present invention, through the combined use of the mode selection module and the lifting control module, complete two operation modes of manual and automatic, realize the automatic unloading mode of lifting and unloading - holding at the top - the cargo box falling back, and during the automatic unloading process, the safety of the system is monitored in real time, and it can be switched to the manual mode at any time according to the actual situation, ensuring the safety of system use. At the same time, the user can also take over at any time according to needs. While improving the safety during the use of the equipment, it reduces the operation difficulty of the lifting system and improves the operation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings, as a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation to the present invention. Obviously, the drawings in the following description are only some embodiments, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0021] In the drawings: Figure 1 is the hydraulic schematic diagram of the present invention; Figure 2 is the hydraulic schematic diagram of another embodiment of the present invention.

[0022] In the figure: 1, hydraulic oil tank; 2, lifting pump; 3, lifting proportional valve; 4, lifting cylinder; 5, lifting angle sensor; 6, braking control module; 7, vehicle brake; 8, controller; 9, mode selection module; 10, lifting control module; 11, warning device; 12, seat belt module.

[0023] It should be noted that these drawings and text descriptions are not intended to limit the scope of the concept of the present invention in any way, but to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0025] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0026] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] Such as Figures 1 to 2The tipping truck lifting system with an automatic unloading mode shown in the figure includes a lifting pump 2. One end of the lifting pump 2 is connected to a hydraulic oil tank 1, and the other end of the lifting pump 2 is connected to a lifting cylinder 4 through a lifting proportional valve 3. It also includes a controller 8. The input end of the controller 8 is connected to a lifting angle sensor 5, a mode selection module 9, a lifting control module 10, and a seat belt module 12. The lifting angle sensor 5 is connected to the lifting cylinder 4. The mode selection module 9 is a selection module for two modes: manual and automatic. The output end of the controller 8 is connected to a lifting proportional valve 3, a braking control module 6, and a warning device 11. The braking control module 6 is connected to a vehicle brake 7. The tipping truck lifting system with an automatic unloading mode of the present invention includes a hydraulic system and a control system. The hydraulic system includes a hydraulic oil tank, a lifting pump, a lifting proportional valve, and a lifting cylinder. The control system includes a controller, a lifting angle sensor, a mode selection module, a lifting control module, a braking control module, a vehicle brake, a warning device, and a seat belt module. During use, the lifting angle sensor, the mode selection module, the lifting control module, and the seat belt module serve as input modules to input signals to the controller. The controller makes a judgment based on the input signals and outputs signals for controlling the lifting proportional valve, the braking control module, and the warning device, causing the lifting proportional valve to act to control the operation of the lifting cylinder. At the same time, the braking control module and the warning device are made to react as needed to remind the operator of the working state and ensure the safe operation of the system. Among them, the lifting cylinder can be a single-acting cylinder or a double-acting cylinder, and the number of lifting cylinders can be one or multiple. When the lifting pressure acts on the large chamber of the lifting cylinder, it pushes the lifting cylinder to extend, realizing the lifting of the cargo box and completing the unloading. The lifting angle sensor is used to detect the lifting angle of the cargo box relative to the vehicle frame. The controller stores the maximum and minimum lifting angles of the vehicle and uses the value detected by the lifting angle sensor as one of the bases for continuous operation under automatic vehicle operation. The braking control module receives signals from the controller and applies and releases braking force to the wheel brakes according to the control signals, providing braking force for the vehicle through the vehicle brake. The controller can work in manual mode or automatic mode. When the controller determines that the automatic operation is completed or there is a risk based on the received signals, it will automatically switch to manual mode to reduce the operation risk. The warning device provides a reminder signal for the vehicle. When the vehicle is about to exit the automatic mode, the controller will issue a reminder through the warning device. The warning device can be a beeping buzzer, a lighting indicator, or other warning devices that emit sound and light simultaneously. The seat belt module is used to detect the situation of the user wearing the seat belt and provide the state of the seat belt to the controller; when the seat belt latch is in the pulled-out or inserted state, the controller will receive different signals through the seat belt module; the signal of the seat belt module is one of the bases for the vehicle to operate in the automatic operation mode. When the controller detects through the seat belt module that the seat belt latch is in the pulled-out state, it will not enter the automatic mode or switch from the automatic mode to the manual mode.The lift system of a dump truck with an automatic unloading mode according to the present invention completes two working modes, namely automatic and manual, through the coordinated use of a hydraulic system and a control system. In the automatic mode, it can be switched to the manual mode according to the actual situation to ensure the safety of use.

[0028] As Figures 1 to 2 shown in the lift system of a dump truck with an automatic unloading mode, the lift proportional valve 4 is an electrically controlled proportional valve, and the electrically controlled end of the lift proportional valve 4 is connected to the controller 8. The lift proportional valve of the present invention is an electrically controlled proportional valve, and the electrically controlled end of the electrically controlled proportional valve is connected to the controller. The electrical signal sent by the controller can control the opening degree of the valve core at a certain position to limit the flow capacity of the valve core at this position, so as to control the action speed of the lift cylinder. In addition, the lift proportional valve has at least three positions of the valve core, namely lift, hold, and float. A lowering position can be added according to the working conditions. When the lift proportional valve loses the electrical signal, the valve core stays at the hold position under the action of the spring. When the valve core is in the hold position, all the oil ports of the lift cylinder are blocked, and the cargo box is in a locked state and cannot move; when the valve core is in the lift position, the lift pump supplies oil to the large chamber of the lift cylinder through the lift proportional valve, pushing the cylinder out to achieve the dumping of materials; when the valve core is in the float position, all the cavities in the lift cylinder are connected to the fuel tank through the valve core; when the valve core is in the lowering position, the lift pump supplies oil to the small chamber of the lift cylinder through the lift proportional valve, pushing the cylinder to retract and pulling the cargo box to fall.

[0029] As Figures 1 to 2 shown in the lift system of a dump truck with an automatic unloading mode, the mode selection module 9 is a self-resetting button with a light, providing two operating modes for the vehicle, namely manual mode and automatic mode. The mode selection module of the present invention is used to switch between automatic and manual modes. Among them, the mode selection module is a self-resetting button with a light. The light of the button has three states: off, always on, and flashing. The light off indicates the manual mode, the light always on indicates the automatic mode, and the light flashing indicates entering or exiting the automatic mode. By default, the light is off. The user can select the required mode by pressing the mode selector, and the controller displays the change of the mode by controlling the change of the light. When in use, when the user presses the self-resetting button, the controller will perform a startup determination of the automatic mode and make the green button light of the mode selection module flash. If the controller determines that it cannot enter the automatic mode, the controller will turn off the green button light of the mode selection module and issue a corresponding risk prompt to the user. The user can eliminate the corresponding risk according to the prompt and then press the self-resetting button again to try to start the automatic mode; if the controller determines that it can enter the automatic mode, the controller will keep the green button light of the mode selection module always on to indicate entering the automatic mode.

[0030] As Figures 1 to 2The tipping truck lifting system with an automatic unloading mode as shown. The lifting control module of the present invention has at least three positions: lifting, holding, and floating, and a lowering position can be added according to the working conditions. Different positions emit different signals, and it is in the holding position by default. The lifting control module can automatically stay in the holding position and the floating position. When the lifting control module needs to stay in other positions, the user needs to continuously provide a holding force to the lifting control module. When the lifting control module loses the holding force from the lifting position, the control module will automatically switch to the holding position. When the lifting control module loses the holding force from the lowering position (if there is a lowering position), the control module will automatically switch to the floating position.

[0031] As Figures 1 to 2 The tipping truck lifting system with an automatic unloading mode as shown. The lifting control module 10 is a four-position handle with a base. The lifting position and the lowering position of the handle cannot be locked, and the handle is position-locked at the holding position and the floating position through a card slot. In the lifting control module 10, there is a track connecting the handle between the card slot at the lifting position and the card slot at the holding position, and there is a track connecting the handle between the card slot at the lowering position and the card slot at the floating position. The lifting control module of the present invention is a four-position handle with a base, which are respectively lifting, holding, floating, and lowering. The handle is in the holding position by default, and different positions output different signals. When the handle is in the holding position, no signal is emitted; the user sends a request to the controller through the handle of the lifting control module, and the controller judges the user's needs and makes corresponding actions according to the signal of the lifting control module. The handle base has a card slot at each of the holding position and the floating position, and the handle can be position-locked at the holding position and the floating position through the card slot. However, the handle cannot be locked at the lifting position and the lowering position. When the user releases the handle at the lifting position, the handle will slide into the card slot at the holding position and stay at the holding position. When the user releases the handle at the lowering position, the handle will slide into the card slot at the floating position and stay at the floating position.

[0032] The control method of the tipping truck lifting system with an automatic unloading mode includes a manual mode and an automatic mode. In the manual mode, the user sends a request by operating the lifting control module 10, and the controller 8 controls the proportional lifting valve 3 to perform corresponding actions according to the received request. In the automatic mode, the controller 8 first makes a determination. During the determination period, the light of the mode selection module 9 will flash. If the determination is successful, the controller 8 will set the light of the mode selection module 9 to be constantly on. If the determination fails, the controller 8 will turn off the light of the mode selection module 9 and prompt the corresponding risks. Specifically, it includes the following steps: Manual mode: A1. Holding state in manual mode When the handle of the lifting control module 10 enters the holding position from other positions, the control valve 8 will lose the signal from the lifting control module 10. After the controller 8 turns off the electrical signal of the proportional lifting valve 3, the proportional lifting valve 3 will be in the holding position under the action of the spring, thus realizing the position holding of the cargo box.

[0033] A2. Lifting state in manual mode 1. Put the handle of the lifting control module 10 into the lifting position; 2. After the controller 8 receives the lifting position signal from the lifting control module 10, it first detects the lifting angle of the cargo box through the lifting angle sensor 5; 3. If the lifting angle of the cargo box does not reach the maximum lifting angle, the controller sends a signal to make the proportional lifting valve 3 enter the lifting position, so that the pressure oil of the lifting pump 2 enters the large chamber of the lifting cylinder 4 through the lifting proportional valve 3, pushing the lifting cylinder 4 to extend, and the cargo box starts to rise and the unloading operation begins; 4. If the controller 8 detects that the lifting angle of the cargo box reaches the maximum lifting angle, the controller 8 will turn off the electrical signal of the proportional lifting valve 3 to make the proportional lifting valve 3 in the holding position.

[0034] Among them, when the user releases the handle at the lifting position of the lifting control module 10, the handle will stay at the holding position of the lifting control module 10, and the controller 8 will lose the electrical signal of the lifting control module 10, making the proportional lifting valve 3 in the holding position.

[0035] A3. Lowering state in manual mode 1. Put the handle of the lifting control module 10 into the lowering position; 2. After the controller 8 receives the lowering position signal from the lifting control module 10, it first detects the lifting angle of the cargo box through the lifting angle sensor 5; 3. If the lifting angle of the cargo box does not reach the minimum lifting angle, the controller sends a signal to make the proportional lifting valve 3 enter the lowering position, so that the pressure oil of the lifting pump 2 enters the small chamber of the lifting cylinder 4 through the lifting proportional valve 3, pushing the lifting cylinder 4 to retract, and the cargo box starts to fall and the falling operation begins; 4. If the controller 8 detects that the lifting angle of the cargo box is close to the minimum lifting angle, the controller 8 will adjust the electrical signal of the proportional lifting valve 3 to make the proportional lifting valve 3 in the floating position, and the cargo box will slowly fall under the action of gravity; 5. If the controller 8 detects that the lifting angle of the cargo box reaches the minimum lifting angle, the controller 8 will turn off the electrical signal of the proportional lifting valve 3 to make the proportional lifting valve 3 in the holding position.

[0036] Among them, when the user releases the handle at the lowering position of the lifting control module 10, the handle will stay at the floating position of the lifting control module 10. When the controller 8 receives the floating position signal of the lifting control module 10, the controller 8 will adjust the electrical signal of the proportional lifting valve 3 to make the proportional lifting valve 3 in the floating position.

[0037] Automatic mode: B1. Entering the automatic mode 1. Press the self-resetting button of the mode selection module 9, and the controller 8 turns on the green button light of the mode selection module 9 and makes it flash; 2. The controller 8 detects the handle position signal of the lifting control module 10; 3. If the handle of the lifting control module 10 is not in the holding position, the controller 8 will issue a risk reminder to prompt the user to put the handle of the lifting control module 10 into the holding position and turn off the green light of the mode selection module 9; at the same time, the controller 8 will turn off the electrical signal of the proportional lifting valve 3 to make the proportional lifting valve 3 in the holding position; 3. If the handle of the lifting control module 10 is in the holding position, the controller 8 will continue to make the green button light of the mode selection module 9 flash, and then detect the status of the seat belt through the seat belt module 12; 4. If the signal of the seat belt module 12 indicates that the seat belt latch is in the pulled-out state, the controller 8 will issue a risk reminder to prompt the user to fasten the seat belt and turn off the green light of the mode selection module 9; at the same time, the controller 8 will turn off the electrical signal of the proportional lifting valve 3 to make the proportional lifting valve 3 in the holding position; 5. If the signal of the seat belt module 12 indicates that the seat belt latch is in the inserted state, the controller 8 will set the green button light of the mode selection module 9 to be constantly on and enter the automatic mode.

[0038] In the automatic mode, after the controller receives the lifting signal of the lifting control module, it will control the signal of the lifting proportional valve to make the lifting cylinder complete the actions of "lifting the cargo box to the top, staying at the top, and lowering the cargo box back to the vehicle frame" in sequence, completing the automatic unloading operation, and then making the lifting proportional valve stay in the holding mode. The specific steps are as follows: B2. Operations in the automatic mode The user puts the handle of the lifting control module 10 into the lifting position and releases it. In this way, the controller 8 will detect a lifting signal; The controller 8 will first detect the lifting angle of the cargo box through the lifting angle sensor 5; If the controller 8 detects that the lifting angle of the cargo box reaches the maximum lifting angle, the controller 8 will turn off the electrical signal of the proportional lifting valve 3 to make the proportional lifting valve 3 in the holding position; 4. When the controller 8 detects through the lifting angle sensor 5 that the lifting angle of the cargo box has not reached the maximum lifting angle, the controller 8 sends a signal to make the proportional lifting valve 3 enter the lifting position, so that the pressure oil of the lifting pump 2 enters the large chamber of the lifting cylinder 4 through the lifting proportional valve 3, pushing the lifting cylinder 4 to extend, causing the cargo box to start lifting and starting the unloading operation; 5. When the controller 8 detects through the lifting angle sensor 5 that the cargo box has reached the maximum lifting angle, the controller 8 will turn off the electrical signal of the proportional lifting valve 3 and last for 3 seconds, making the proportional lifting valve 3 in the holding position and lasting for 3 seconds; the cargo box stays at the maximum lifting angle for more sufficient unloading; 6. The controller 8 adjusts the electrical signal of the proportional lifting valve 3 to make it in the lowering position. The pressure oil of the lifting pump 2 enters the small chamber of the lifting cylinder 4 through the lifting proportional valve 3, pushing the lifting cylinder 4 to retract, causing the cargo box to start falling until the controller 8 detects through the lifting angle sensor 5 that the cargo box has reached the minimum lifting angle; 7. When the controller 8 detects through the lifting angle sensor 5 that the cargo box has reached the minimum lifting angle, the controller 8 will turn off the electrical signal of the proportional lifting valve 3, making the proportional lifting valve 3 in the holding position.

[0039] B2. Exit in Automatic Mode 1. Turn off the electrical signal of the proportional lifting valve 3 to make the proportional lifting valve 3 in the holding position. At the same time, the controller 8 controls the buzzer 11 to emit a beep for 1 second to remind the user to take over in time; 2. The controller 8 turns off the green button light of the selection module 9 to complete the exit of the automatic mode.

[0040] Among them, during the execution of the automatic mode, there are various situations that will cause the program to exit the automatic mode and return to the manual mode, including signal changes in the lifting control module, switching the mode selection button, pulling out the seat belt latch, and the lifting process exceeding the set duration.

[0041] During the actions of the lifting cylinder to complete "lifting the cargo box to the top, staying at the top, and the cargo box falling back to the vehicle frame" in sequence, any signal change in the lifting control module will cause the controller to exit the automatic mode and return to the manual mode for the user to take over at any time. Specifically, in the automatic mode, when the controller 8 receives the first lifting signal from the lifting control module 10 and starts automatic unloading, until the process of the cargo box falling back to the vehicle frame is completed, the controller 8 continuously monitors any signal change in the lifting control module 10. Any signal change in the lifting control module 10 will cause the controller 8 to execute the exit program of the automatic mode.

[0042] In the automatic mode, when the user switches the mode selection button, the controller will exit the automatic mode and return to the manual mode for the user to take over at any time. Specifically, when the user switches the mode of the mode selection module 9 and the controller 8 detects a signal change in the mode selection module 9, the controller 8 will execute the exit procedure for the automatic mode.

[0043] In the automatic mode, the controller detects the duration from the minimum lifting angle to the maximum lifting angle of the cargo box through the lifting angle sensor. When the timing exceeds the set duration, the controller will exit the automatic mode. Then, the controller will give a risk reminder to the user, reminding the user that the lifting system efficiency is too low and suggesting the user to check the lifting system. Specifically, in the automatic mode, when the controller 8 detects the start of the unloading operation of the cargo box from the minimum lifting angle through the lifting angle sensor 5, the controller 8 starts timing. When the controller 8 detects that the cargo box reaches the maximum lifting angle through the lifting angle sensor 5, the timing is terminated. When the timing exceeds 40 seconds, the controller 8 will trigger the exit of the automatic mode.

[0044] In the automatic mode, when the controller detects that the user unfastens the seat belt through the seat belt module, it will exit the automatic operation and apply brakes to the vehicle brakes through the brake control module. Specifically, in the automatic mode, the controller continuously detects the state of the seat belt through the seat belt module 12. When it detects that the state of the seat belt module 12 changes to the seat belt latch being pulled out, the controller 8 will execute the exit procedure for the automatic mode. At the same time, the controller 8 will send a brake application signal to the brake control module 6 to make the vehicle brakes apply braking force. This exit mechanism can prevent the vehicle from suddenly moving when the user unfastens the seat belt and leaves the operation area during the operation of the automatic mode, and cannot effectively protect the user. At the same time, it can also prevent the user from not being able to return to the operation area in time to handle emergencies or unexpected events during the automatic operation process.

[0045] During the exit process of the automatic mode, the controller keeps the lift proportional valve in the holding position and exits the automatic mode with the lift proportional valve in the holding position. The proportional lift valve enters and exits the automatic mode in the holding position to ensure the equipment safety during the mode switching process.

[0046] The lifting system and its control method of the dump truck with an automatic unloading mode of the present invention are convenient to operate. The automatic unloading mode can be started with one key, reducing the manual operation intensity; the control is precise. Through the closed-loop control of the electro-hydraulic proportional valve and the angle sensor, the precise adjustment of the cargo box movement is realized; the safety is high. Multiple safety detections (seat belt, handle state, operation timeout) are integrated in the automatic mode, reducing the accident risk; the efficiency is higher. The automatic cyclic operation ensures sufficient unloading, and the top stay time can be adjusted to adapt to different material characteristics; the experience is good. The mode switching and status prompt (lights, beeps) are designed intuitively, improving the user experience.

[0047] In the specification provided herein, a large number of specific details are set forth. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0048] In addition, those skilled in the art will understand that although some of the embodiments described herein include certain features contained in other embodiments but not others, the combinations of the features of different embodiments are equally within the scope of the present invention and form different embodiments. For example, in the above embodiments, those skilled in the art can use them in a combined manner according to the known technical solutions and the technical problems to be solved by this application.

[0049] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed as above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art of this patent, without departing from the scope of the technical solution of the present invention, can make some changes or modifications to the above-mentioned technical content as equivalent embodiments of equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A dump truck lifting system with automatic unloading mode, characterized by: The invention comprises a lifting pump (2), one end of which is connected to a hydraulic oil tank (1), and the other end of which is connected to a lifting cylinder (4) via a lifting proportional valve (3). The invention also comprises a controller (8), an input end of which is connected to a lifting angle sensor (5), a mode selection module (9), a lifting control module (10) and a safety belt module (12), the lifting angle sensor (5) and the lifting cylinder (4) are connected together, the mode selection module (9) is a selection module for manual and automatic modes, and an output end of the controller (8) is connected to a lifting proportional valve (3), a brake control module (6) and a warning device (11), and the brake control module (6) is connected to a vehicle brake (7).

2. The dump truck lifting system with automatic unloading mode according to claim 1, characterized in that: The lifting proportional valve (4) is an electrically controlled proportional valve, and the electrically controlled end of the lifting proportional valve (4) is connected to a controller (8).

3. The dump truck lifting system with automatic unloading mode according to claim 1, characterized in that: The lifting proportional valve (4) has at least three valve core positions of lifting, holding and floating. The lifting proportional valve (4) is in the holding position in a default state. The lifting control module (10) has at least three positions of lifting, holding and floating. The working position of the lifting control module (10) corresponds to the working position of the lifting proportional valve (4). The lifting control module (10) is in the holding position in a default state.

4. The dump truck lifting system with automatic unloading mode according to claim 1, characterized in that: The mode selection module (9) is a self-reset button with a light, which provides two operating modes for the vehicle: a manual mode and an automatic mode.

5. The dump truck lifting system with automatic unloading mode according to claim 1, characterized in that: The lifting control module (10) is a four-position handle with a base; the lifting position and the lowering position of the handle cannot be locked; the handle is locked in position through a slot in the holding position and the floating position.

6. The dump truck lifting system with automatic unloading mode according to claim 5, characterized in that: In the lifting control module (10), a track connected to the handle is provided between the card slot at the lifting position and the card slot at the holding position, and a track connected to the handle is provided between the card slot at the lowering position and the card slot at the floating position.

7. The control method of the dump truck lifting system with automatic unloading mode according to claim 1 is characterized in that: The steps include: Manual Mode: S1, placing the handle of the lifting control module (10) in a lifting or lowering position; S2, after receiving the lifting or lowering position signal from the lifting control module (10), the controller (8) first detects the lifting angle of the cargo box through the lifting angle sensor (5); S3, if the lifting angle of the cargo box does not reach the maximum or minimum lifting angle, the controller sends a signal to make the proportional lifting valve (3) enter the lifting or lowering position, so that the lifting pump (2) is activated; S4. If the controller (8) detects that the lifting angle of the cargo box reaches the maximum or minimum lifting angle, the controller (8) will turn off the electrical signal of the proportional lifting valve (3), so that the proportional lifting valve (3) is in the holding position; Automatic mode: T1, pressing the self-reset button of the mode selection module (9), the controller (8) turns on the green button light of the mode selection module (9) and makes it flash; T2, the controller (8) detects whether the handle of the lifting control module (10) is in the holding position, and at the same time detects the state of the seat belt through the seat belt module (12); T3. If the handle of the lift control module (10) is in the hold position and the signal of the seat belt module (12) indicates that the seat belt latch is in the inserted state, the controller (8) sets the green button light of the mode selection module (9) to be always on and enters the automatic mode; T4. Put the handle of the lifting control module (10) into the lifting position and release it; T5. When the controller (8) detects through the lifting angle sensor (5) that the lifting angle of the cargo box has not reached the maximum lifting angle, the controller (8) sends a signal to cause the proportional lifting valve (3) to enter the lifting position, so that the lifting pump (2) starts to lift the cargo box to perform unloading operations; T6. When the controller (8) detects through the lifting angle sensor (5) that the cargo box has reached the maximum lifting angle, the controller (8) will turn off the electrical signal of the proportional lifting valve (3) and keep the proportional lifting valve (3) in the holding position for a period of time; T7, the controller (8) adjusts the electrical signal of the proportional lift valve (3) so that it is in the descending position, and the lift pump (2) is activated; T8. When the controller (8) detects through the lifting angle sensor (5) that the cargo box has reached the minimum lifting angle, the controller (8) turns off the electrical signal of the proportional lifting valve (3), so that the proportional lifting valve (3) is in the holding position; T9, after the automatic operation is completed, the controller (8) switches the green button light of the mode selection module (9) to a flashing state, and controls the alarm (11) to emit a buzzer to remind the user to take over in time; T10. The controller (8) turns off the green button light of the selection module (9), completing the exit from the automatic mode.

8. The control method of the dump truck lifting system with automatic unloading mode according to claim 7, characterized in that: In the manual mode, when the handle is released at the lifting position of the lifting control module (10), the handle will stay at the holding position of the lifting control module (10), and when the handle is released at the lowering position of the lifting control module (10), the handle will stay at the floating position of the lifting control module (10).

9. The control method of the dump truck lifting system with automatic unloading mode according to claim 7, characterized in that: In step S4, if the controller (8) detects that the lifting angle of the cargo box is close to the minimum lifting angle, the controller (8) will adjust the electrical signal of the proportional lifting valve (3) so that the proportional lifting valve (3) is in a floating position, and the cargo box slowly falls under the action of gravity.

10. The control method of the dump truck lifting system with automatic unloading mode according to claim 7, characterized in that: In step T2, if the handle of the lift control module (10) is not in the holding position or the signal of the seat belt module (12) indicates that the seat belt latch is in the unplugged state, the controller (8) will issue a risk reminder to prompt the user to put the handle of the lift control module (10) into the holding position or to prompt the user to fasten the seat belt, and turn off the green light of the mode selection module (9). At the same time, the controller (8) will turn off the electrical signal of the proportional lift valve (3) to put the proportional lift valve (3) in the holding position.

11. The control method of the dump truck lifting system with automatic unloading mode according to claim 7, characterized in that: During the execution of the automatic mode, if the signal of the lifting control module changes, the mode selection button is switched, the seat belt latch is pulled out, or the lifting process exceeds the set time, the controller (8) will exit the automatic mode and return to the manual mode, so that the user can take over at any time.

12. The control method of the dump truck lifting system with automatic unloading mode according to claim 11, characterized in that: In the automatic mode, when the controller (8) detects through the lifting angle sensor (5) that the cargo box is lifted from the minimum lifting angle, the timing starts. When the timing exceeds the set time, the controller (8) will execute the exit procedure of the automatic mode.

13. The control method of the dump truck lifting system with automatic unloading mode according to claim 11, characterized in that: In the automatic mode, when the controller (8) detects through the seat belt module (12) that the user has opened the seat belt, the automatic operation will be terminated and the vehicle brake will be applied through the brake control module (6).

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