Sanitation vehicle barrel holding mechanical arm self-balancing hydraulic control system and sanitation vehicle

Abstract

The invention discloses a sanitation vehicle barrel holding mechanical arm self-balancing hydraulic control system which comprises a rack and a telescopic arm, and the hydraulic control system is connected with the telescopic arm. The telescopic arm comprises a pull arm, a rocker arm and a lifting arm, the end of the lifting arm is connected with a can holding mechanism, and by the adoption of the self-balancing hydraulic control system for the can holding mechanical arm of the sanitation vehicle, the garbage can can be prevented from being excessively inclined in the lifting process.

Description

Technical Field

[0001] This invention belongs to the field of sanitation equipment technology. Specifically, this invention relates to a self-balancing hydraulic control system for a sanitation vehicle's bucket-holding robotic arm. Background Technology

[0002] A garbage bin-grabbing robotic arm is a device installed on sanitation vehicles for grabbing, lifting, and dumping garbage bins. It typically consists of a pull arm, a rocker arm, and a lifting arm. During the lifting action, the movement speed between the drive cylinders of the rocker arm and the lifting arm needs to be adjusted in real time to keep the garbage bin level and prevent excessive tilting that could lead to secondary pollution. Currently, most garbage bin-grabbing robotic arms on the market use a servo motor drive + vision control method. While this method meets the operational requirements, the motors are large, the implementation is complex, and the operating and maintenance costs are high, making it unsuitable for installation on sanitation vehicles.

[0003] Utility model patent CN219175107U, published on June 13, 2023, discloses a sweeping robotic arm and sanitation vehicle for use in sanitation vehicles. The arm includes a brush disc, the top surface of which is fixedly mounted to the bottom surface of a first fixed plate by screws. A hexagonal sleeve is fixedly connected to the top surface of the first fixed plate, and a hexagonal rod is slidably connected inside the hexagonal sleeve. Springs are fitted onto the side walls of the hexagonal sleeve and the hexagonal rod. A second fixed plate is fixedly connected to the top surface of the hexagonal rod, and a support arm is fixedly mounted to the top surface of the second fixed plate by screws. The arm is designed to automatically retract and extend by installing a hexagonal sleeve, hexagonal rod, and spring between the brush disc and the support arm. However, this sweeping robotic arm for sanitation vehicles does not solve the aforementioned technical problems. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a self-balancing hydraulic control system for the garbage bin-holding robotic arm of a sanitation vehicle to prevent excessive tilting of the garbage bin during the lifting process.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The self-balancing hydraulic control system of the sanitation vehicle's bucket-holding robotic arm includes a frame and a telescopic arm, with the hydraulic control system connected to the telescopic arm; the telescopic arm includes a pull arm, a rocker arm, and a lifting arm, with a bucket-holding mechanism connected to the end of the lifting arm.

[0006] The rocker arm is located above the frame, and the top of the pull arm is located on one side of the rocker arm; both ends of the pull arm are movably connected to the frame and the rocker arm, and the middle of the rocker arm is hinged to the top of the lifting arm; the hydraulic system includes a bucket-holding cylinder, a balance cylinder, a lifting cylinder, and an extension cylinder; the extension cylinder is located between the frame and the pull arm, the cylinder body of the extension cylinder is located at one end of the frame, and the end of the piston rod of the extension cylinder is hinged to the top of the rocker arm; the lifting cylinder is located between the frame and the lifting arm, the cylinder body of the lifting cylinder is located in the middle of the frame, and the end of the piston rod of the lifting cylinder is hinged to the top of the lifting arm; a mounting plate is connected to the bottom end of the lifting arm, the cylinder body of the balance cylinder is hinged to the other end of the rocker arm, and the end of the piston rod of the balance cylinder is hinged to the top of the mounting plate.

[0007] The barrel-holding mechanism includes two grippers, with toothed plates fixedly connected to the ends of the two grippers, and the toothed plates meshing; a mounting frame is provided above the grippers, and the toothed plates are rotatably connected to the mounting frame, and the cylinder body of the barrel-holding cylinder is hinged to the mounting frame.

[0008] The hydraulic system also includes a hydraulic oil tank, an oil pump, and multiple electro-hydraulic proportional multi-way valves; the oil pump is connected to a load-sensitive valve, the load-sensitive valve is also connected to an overflow valve, and there are four electro-hydraulic proportional multi-way valves, which are respectively connected to a bucket-holding cylinder, a balance cylinder, a lifting cylinder, and an extension cylinder, and each electro-hydraulic proportional multi-way valve is connected to a pressure compensation valve.

[0009] The barrel-holding cylinder, balancing cylinder, lifting cylinder, and extension cylinder are all equipped with a balancing valve.

[0010] Displacement sensors are installed in the extension cylinder, balance cylinder, and lifting cylinder.

[0011] The bottom of the mounting plate is connected to an electric guide rail, which is horizontally arranged, and the mounting bracket is connected to the electric guide rail.

[0012] The mounting plate is triangular in shape.

[0013] The frame has a bent structure, and a base plate is provided at the bottom of the frame.

[0014] Sanitation vehicles, including the aforementioned sanitation vehicle bucket-holding robotic arm self-balancing hydraulic control system.

[0015] The technical advantages of this invention are as follows: The self-balancing hydraulic control system for the garbage bin-holding robotic arm of this invention uses hydraulic drive instead of the traditional servo motor drive + vision control method, reducing the implementation difficulty of the robotic arm control system, making it suitable for installation on sanitation vehicles, and reducing usage costs. During the movement of the robotic arm, each cylinder feeds back the piston rod displacement to the on-board controller in real time. The controller then adjusts the control current of the proportional valve group of each cylinder in real time, realizing the coordinated action between different cylinders and automatically adjusting the posture of the garbage bin, thus solving the problem of excessive tilting of the garbage bin during the lifting process of the garbage bin-holding robotic arm. Attached Figure Description

[0016] This manual includes the following figures, which illustrate the following: Figure 1 This is a schematic diagram of the structure of the bucket-carrying robotic arm of the present invention; Figure 2 This is a schematic diagram of the hydraulic control system of the bucket-carrying robotic arm of the present invention; Figure 3 This is a schematic diagram of the internal structure of the hydraulic cylinder of the present invention; Figure 4 This is a schematic diagram of the gripper structure of the present invention.

[0017] The components in the diagram are labeled as follows: 1. Frame; 2. Pulling arm; 3. Rocker arm; 4. Lifting arm; 5. Support arm; 6. Bucket gripping cylinder; 7. Balancing cylinder; 8. Lifting cylinder; 9. Extending cylinder; 10. Gripper; 11. Hydraulic oil tank; 12. Oil pump; 13. Electro-hydraulic proportional multi-way valve; 14. Pressure compensation valve; 15. Load-sensitive valve; 16. Relief valve; 17. Secondary pressure limiting valve; 18. Shuttle valve; 19. Level gauge; 20. Air filter; 21. Return oil filter; 22. Balancing valve; 23. Displacement sensor; 24. Mounting plate; 25. Electric guide rail; 26. Mounting bracket; 27. Toothed plate; 28. Base plate. Detailed Implementation

[0018] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention, and to facilitate its implementation.

[0019] The self-balancing hydraulic control system of the sanitation vehicle's bucket-holding robotic arm includes a frame 1 and a telescopic arm, with the hydraulic control system connected to the telescopic arm; the telescopic arm includes a pull arm 2, a rocker arm 3 and a lifting arm 4, with a bucket-holding mechanism connected to the end of the lifting arm 4.

[0020] like Figure 1As shown, rocker arm 3 is located above frame 1, and top of pull arm 2 is located on one side of rocker arm 3; both ends of pull arm 2 are movably connected to frame 1 and rocker arm 3, and the middle of rocker arm 3 is hinged to the top of lifting arm 4; the hydraulic system includes bucket-holding cylinder 6, balance cylinder 7, lifting cylinder 8 and extension cylinder 9; extension cylinder 9 is located between frame 1 and pull arm 2, the cylinder body of extension cylinder 9 is located at one end of frame 1, and the piston rod end of extension cylinder 9 is hinged to the top of rocker arm 3; lifting cylinder 8 is located between frame 1 and lifting arm 4, the cylinder body of lifting cylinder 8 is located in the middle of frame 1, and the piston rod end of lifting cylinder 8 is hinged to the top of lifting arm 4; a mounting plate 24 is connected to the bottom of lifting arm 4, the cylinder body of balance cylinder 7 is hinged to the other end of rocker arm 3, and the piston rod end of balance cylinder 7 is hinged to the top of mounting plate 24. Driven by the aforementioned hydraulic cylinders, the telescopic arm can extend, grab the garbage bin, tilt, and return to its original position. If the garbage bin is far from the vehicle, the telescopic arm can grab it after extending. When the vehicle is moving, the hydraulic cylinders return to their original positions, and the telescopic arm is in a retracted state, occupying little space and not obstructing the vehicle's movement, thus reducing safety hazards. Two support arms 5 are hinged to the end of the frame 1. The tops of the two support arms 5 are respectively hinged to the pull arm 2 and the rocker arm 3. The support arms 5 support the movement of the pull arm 2 and the rocker arm 3, ensuring stable operation. When the telescopic arm is in operation, oil enters the rodless chamber of the extension cylinder 9, driving the pull arm 2 to move. The pull arm 2 drives the lifting arm 4 to move via the rocker arm 3. After the gripper 10 reaches the position of the garbage bin, the extension cylinder 9 stops moving. Oil enters the rodless chamber of the bin-holding cylinder 6, driving the gripper 10 to retract and perform the bin-holding action. Oil enters the rod chamber of the extension cylinder 9, driving the robotic arm and garbage bin to retract to the initial position. Then, oil enters the rod chamber of the lifting cylinder 8, driving the lifting arm 4 to rotate around its fulcrum, causing the garbage bin to move upward. At the same time, oil enters the rodless chamber of the balancing cylinder 7. The hydraulic control system adjusts the movement speed of the balancing cylinder 7 in real time according to the displacement of the lifting cylinder 8, so as to always keep the garbage bin from tilting excessively and causing leakage during the upward movement. After the lifting cylinder 8 retracts to the end, oil enters the rod chamber of the balancing cylinder 7, driving the garbage bin to tip over and unload. After unloading is completed, oil enters the rod chamber of the lifting cylinder 8, and the lifting arm 4 retracts to the initial state, completing the entire loading and unloading cycle.

[0021] like Figure 4 As shown, the bin-holding mechanism includes two grippers 10, with toothed plates 27 fixedly connected to the ends of the two grippers 10, and the toothed plates 27 meshing with each other. A mounting frame 26 is provided above the grippers 10, and the toothed plates 27 are rotatably connected to the mounting frame 26. The cylinder body of the bin-holding cylinder 6 is hinged to the mounting frame 26. The piston rod of the bin-holding cylinder 6 is eccentrically connected to one of the toothed plates 27. Driven by the bin-holding cylinder 6, it drives the relative movement of the two grippers 10, realizing the unfolding and clamping process of the garbage bin. At the same time, it realizes the bin-holding action by a single cylinder, reducing the size and number of parts, and reducing the structural complexity of the bin-holding mechanism.

[0022] like Figure 2 As shown, the hydraulic system also includes a hydraulic oil tank 11, an oil pump 12, and multiple electro-hydraulic proportional multi-way valves 13. The oil pump 12 is connected to a load-sensitive valve 15, which is also connected to an overflow valve 16. Four electro-hydraulic proportional multi-way valves 13 are provided and are respectively connected to the bucket-holding cylinder 6, the balance cylinder 7, the lifting cylinder 8, and the extension cylinder 9. Each electro-hydraulic proportional multi-way valve 13 is connected to a pressure compensation valve 14. The hydraulic oil tank 11 is also connected to a level gauge 19 and an air filter 20. The return oil filter 21 is also provided in the return oil pipeline of the hydraulic oil tank 11. The pressure compensation valve 14 ensures that the cylinder movement speed is not affected by load changes through a pressure compensation mechanism. The electro-hydraulic proportional multi-way valve 13 of the bucket-holding cylinder 6 is also connected to a secondary pressure limiting valve 17 to limit the maximum clamping force of the gripper 10 to prevent damage to the garbage can.

[0023] like Figure 1 and Figure 2 As shown, the holding cylinder 6, balancing cylinder 7, lifting cylinder 8, and extending cylinder 9 are all equipped with a balancing valve 22. The balancing valve 22 is connected to the rod chamber and rodless chamber of each cylinder, ensuring that the cylinder is not affected by changes in load direction during movement. When lifting the trash can, it ensures that the cylinder is reliably locked, preventing the risk of the trash can falling due to accidental pipe burst.

[0024] like Figure 3 As shown, displacement sensors 23 are installed in the extension cylinder 9, the balancing cylinder 7, and the lifting cylinder 8. When the robotic arm cylinders perform their actions, the displacement sensors 23 in the three cylinders convert the displacement of the cylinders into electrical signals in real time and feed them back to the vehicle controller. The controller compares the current displacement of the cylinders with the set displacement and then adjusts the current by adjusting the load-sensitive proportional multi-way valve, thereby adjusting the cylinder flow rate and controlling the cylinder movement speed, thus automatically adjusting the posture of the trash can.

[0025] like Figure 4 As shown, an electric guide rail 25 is connected to the bottom of the mounting plate 24. The electric guide rail 25 is horizontally positioned, and the mounting frame 26 is connected to the electric guide rail 25. When the gripper 10 grabs the trash can, the relative positions of the two may differ, causing the gripper 10 to not grasp the trash can in the correct position, resulting in unstable gripping or trash leakage when dumping. The electric guide rail 25 drives the horizontal movement of the gripper 10, facilitating accurate gripping of the trash can and eliminating the need for vehicle repositioning and personnel to adjust the position of the trash can, thus improving operational convenience. Furthermore, when dumping trash, the gripper 10 moves horizontally above the trash can, preventing trash accumulation in certain areas of the trash can. The electric guide rail 25 has two tracks that support the movement of the mounting frame 26, improving the accuracy and stability of the gripper 10's movement direction.

[0026] like Figure 4As shown, the mounting plate 24 is triangular. The three ends of the mounting plate 24 serve as the connection ends of the balance cylinder 7, the lifting arm 4, and the electric guide rail 25, which helps to reduce the volume of the mounting plate 24.

[0027] like Figure 1 As shown, the frame 1 has a bent structure, and a base plate 28 is provided at the bottom of the frame 1. The base plate 28 increases the mounting area with the frame and improves the installation stability of the entire bucket-holding robotic arm.

[0028] Sanitation vehicles, including the aforementioned sanitation vehicle bucket-holding robotic arm self-balancing hydraulic control system.

[0029] The bucket-holding robotic arm is driven by a hydraulic control system, which includes the following components: extension cylinder 9, lifting cylinder 8, balance cylinder 7, bucket-holding cylinder 6, load-sensitive electro-proportional multi-way valve, balance valve 22, displacement sensor 23, oil pipes and connectors, etc. Its control principle is as follows: 1. Low-pressure standby: When the hydraulic pump 12 is started, and no current signal is supplied to the proportional solenoid of the electro-hydraulic proportional multi-way valve 13, all multi-way valves are in the neutral position. At this time, the cylinder does not move, and the output pressure of the pump 12 acts on the upper part of the spool of the load-sensitive valve 15. As the output pressure of the pump 12 gradually increases, the spool of the load-sensitive valve 15 begins to move downwards, and the passage of hydraulic oil to the oil tank is gradually opened until the output pressure of the pump 12 is balanced with the spring force at the bottom of the spool of the load-sensitive valve 15. At this time, the output pressure of the pump 12 no longer rises, realizing the low-pressure standby function of the hydraulic control system.

[0030] 2. Bin-clamping action: The hydraulic pump 12 is activated, gradually increasing the current of the proportional solenoid in the multi-way valve of the extension cylinder 9, activating the multi-way valve at position b. The piston rod extends, driving the gripper 10 to move towards the target trash can, and the displacement is transmitted to the vehicle controller via the displacement sensor 23. As the bin approaches, the current is manually reduced to decrease the speed of the extension cylinder 9 and prevent it from knocking over the bin. When the gripper 10 reaches the appropriate gripping position, the current of the proportional solenoid in the control valve of the extension cylinder 9 is closed, and the current of the proportional solenoid in the multi-way valve of the bin-clamping cylinder 6 is gradually increased, activating the multi-way valve at position b. The piston rod extends and begins to clamp the trash can. Simultaneously, the piston rod displacement signal is fed back to the vehicle controller. When the piston rod displacement reaches the set value, the vehicle controller sends a signal to close the current of the proportional solenoid in the multi-way valve, completing the bin-clamping action. The secondary pressure relief valve 17 controls the maximum clamping force to prevent damage to the trash can. Under the action of the balance valve 22, the bin-clamping cylinder 6 maintains the clamping force. Gradually increase the current of the proportional electromagnet of the multi-way valve in the extended cylinder 9, so that the multi-way valve a position is in working state, the piston rod retracts, and when the displacement reaches the value recorded by the vehicle sensor, the control current is automatically cut off, and the pull arm 2 returns to the initial state.

[0031] 3. Unloading Action: Start the hydraulic pump 12, gradually increasing the current of the proportional solenoid of the multi-way valve in the lifting cylinder 8, causing the multi-way valve (position b) to be in the working state. The piston rod extends, driving the garbage bin to rise. Simultaneously, the displacement sensor 23 inside the lifting cylinder 8 feeds back the piston rod displacement to the vehicle controller in real time. After receiving the piston rod displacement signal from the lifting cylinder 8, the controller, according to a pre-set proportional relationship, sets the current of the proportional solenoid of the multi-way valve in the balance cylinder 7, causing the multi-way valve (position b) to be in the working state. Hydraulic oil enters the rodless chamber of the balance cylinder 7, and the piston rod of the balance cylinder 7 gradually extends, keeping the garbage bin opening horizontal throughout the lifting process to prevent excessive tilting and leakage. After the garbage bin is lifted to the correct position, the displacement sensor 23 inside the lifting cylinder 8 transmits the displacement signal to the controller. The controller outputs a current signal, causing the multi-way valve (position a) of the balance cylinder 7 to be in the working state, allowing oil to enter the rod chamber and driving the garbage bin to complete the unloading action.

[0032] 4. Overpressure protection: When the system working pressure is too high and exceeds the set value of the relief valve 16, the relief valve 16 opens, and the pressurized oil returns to the oil tank through the relief valve 16, so the system pressure no longer rises, thus playing the function of hydraulic system overpressure protection.

[0033] The self-balancing hydraulic control system of this sanitation vehicle's bin-holding robotic arm has the following advantages: 1. High degree of automation: Real-time feedback detection of cylinder displacement allows for real-time adjustment of cylinder movement speed without human intervention. 2. Stable and reliable system: The load-sensitive system ensures that each cylinder operates independently or collaboratively without interference. The pressure compensation mechanism ensures that the cylinder movement speed is unaffected by load changes, being proportional only to the control current of the electro-hydraulic proportional multi-way valve 13, facilitating control. 3. High safety: The cylinder is equipped with a balance valve 22, ensuring that the cylinder is unaffected by changes in load direction during movement. Simultaneously, when lifting the garbage bin, the cylinder reliably locks, preventing the risk of the garbage bin falling due to accidental pipe bursts. 4. Significant cost advantage: Compared to the servo motor + vision control method, it can save approximately 30% in costs.

[0034] This self-balancing hydraulic control system for the garbage bin-holding robotic arm of a sanitation vehicle uses hydraulic drive instead of the traditional servo motor drive + vision control method. This reduces the implementation difficulty of the robotic arm control system, making it suitable for retrofitting into sanitation vehicles and reducing operating costs. During the movement of the robotic arm, each cylinder provides real-time feedback of piston rod displacement to the on-board controller. The controller then adjusts the control current of the proportional valve groups of each cylinder in real time, enabling coordinated actions between different cylinders and automatically adjusting the garbage bin's posture. This solves the problem of excessive tilting of the garbage bin during the lifting process.

[0035] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A self-balancing hydraulic control system for a sanitation vehicle's bucket-holding robotic arm, comprising a frame (1) and a telescopic arm, characterized in that: The hydraulic control system is connected to the telescopic arm; the telescopic arm includes a pull arm (2), a rocker arm (3) and a lifting arm (4), and the end of the lifting arm (4) is connected to a bucket holding mechanism.

2. The self-balancing hydraulic control system for the sanitation vehicle bucket-holding robotic arm according to claim 1, characterized in that: The rocker arm (3) is located above the frame (1), and the top of the pull arm (2) is located on one side of the rocker arm (3); the two ends of the pull arm (2) are movably connected to the frame (1) and the rocker arm (3), and the middle part of the rocker arm (3) is hinged to the top of the lifting arm (4); the hydraulic system includes a bucket-holding cylinder (6), a balance cylinder (7), a lifting cylinder (8), and an extension cylinder (9); the extension cylinder (9) is located between the frame (1) and the pull arm (2), and the cylinder body of the extension cylinder (9) is located at one end of the frame (1). The piston rod end of the extended cylinder (9) is hinged to the top of the rocker arm (3); the lifting cylinder (8) is located between the frame (1) and the lifting arm (4), the cylinder body of the lifting cylinder (8) is located in the middle of the frame (1), and the piston rod end of the lifting cylinder (8) is hinged to the top of the lifting arm (4); the bottom end of the lifting arm (4) is connected to the mounting plate (24), the cylinder body of the balancing cylinder (7) is hinged to the other end of the rocker arm (3), and the piston rod end of the balancing cylinder (7) is hinged to the top of the mounting plate (24).

3. The self-balancing hydraulic control system for the sanitation vehicle bucket-holding robotic arm according to claim 2, characterized in that: The bucket-holding mechanism includes two grippers (10), and toothed plates (27) are fixedly connected to the ends of the two grippers (10), and the toothed plates (27) mesh with each other; a mounting frame (26) is provided above the grippers (10), and the toothed plates (27) are rotatably connected to the mounting frame (26), and the cylinder body of the bucket-holding cylinder (6) is hinged to the mounting frame (26).

4. The self-balancing hydraulic control system for the sanitation vehicle bucket-holding robotic arm according to claim 2 or 3, characterized in that: The hydraulic system also includes a hydraulic oil tank (11), an oil pump (12) and multiple electro-hydraulic proportional multi-way valves (13); the oil pump (12) is connected to a load-sensitive valve (15), the load-sensitive valve (15) is also connected to an overflow valve (16), the electro-hydraulic proportional multi-way valves (13) are provided with four valves and are respectively connected to a bucket-holding cylinder (6), a balance cylinder (7), a lifting cylinder (8) and an extension cylinder (9), and each electro-hydraulic proportional multi-way valve (13) is connected to a pressure compensation valve (14).

5. The self-balancing hydraulic control system for the sanitation vehicle bucket-holding robotic arm according to claim 4, characterized in that: The barrel-holding cylinder (6), the balancing cylinder (7), the lifting cylinder (8), and the extension cylinder (9) are all equipped with a balancing valve (22).

6. The self-balancing hydraulic control system for the sanitation vehicle bucket-holding robotic arm according to claim 5, characterized in that: Displacement sensors (23) are provided in the extension cylinder (9), balance cylinder (7) and lifting cylinder (8).

7. The self-balancing hydraulic control system for the sanitation vehicle bucket-holding robotic arm according to claim 2, characterized in that: The bottom end of the mounting plate (24) is connected to an electric guide rail (25), which is horizontally arranged, and the mounting bracket (26) is connected to the electric guide rail (25).

8. The self-balancing hydraulic control system for the sanitation vehicle bucket-holding robotic arm according to claim 7, characterized in that: The mounting plate (24) is triangular.

9. The self-balancing hydraulic control system for the sanitation vehicle bucket-holding robotic arm according to claim 1, characterized in that: The frame (1) has a bent structure, and the bottom of the frame (1) is provided with a base plate (28).

10. A sanitation vehicle, characterized in that: The self-balancing hydraulic control system for the sanitation vehicle bucket-holding robotic arm as described in any one of claims 1-9.

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