A pallet - breaking robot clamping device and method

Abstract

The present invention discloses a clamping device for a pallet - dismantling robot, which comprises a device main body. The device main body includes a frame, a control mechanism installed above the frame, and multiple groups of clamping components symmetrically arranged at both ends of the frame. A distance sensor is provided at the lower end of the frame, and the control mechanism is electrically connected to the clamping components and the distance sensor respectively. The present invention also provides a method for clamping a pallet - dismantling robot. First, determine the position where the robotic arm moves to each time and the required clamping pressure P according to the stacking form of the goods to be unstacked and the weight of the goods. Then, according to the above conditions, the robotic arm reaches the specified position to clamp the fertilizer bag. During the clamping process, each jaw moves independently, and the fitting force is kept consistent, and the magnitude of the force is controlled by the pressure P. During the lifting process, by distributing the clamping force between the jaws, it is ensured that the goods bag is lifted horizontally. Through the above design, the present invention can cope with various bulk - filled goods bags with irregular shapes and position deviations, and dynamically control the claw force during pallet - dismantling to achieve efficient and stable grasping of goods.

Description

Technical Field

[0001] The present invention relates to the technical field of pallet - breaking in warehousing logistics, and in particular to a clamping device and method for a pallet - breaking robot. Background Art

[0002] In most current factory productions, it has become normal for incoming materials to be stacked in pallet form. Generally, pallet - breaking is completed by palletizing robots, and palletizing robots have become essential mechanical equipment in most factories. However, when disassembling goods, the stability of palletizing robots still needs to be improved, especially when dealing with goods that are difficult to clamp.

[0003] To improve transportation efficiency, bagged powder products such as fertilizer bags are usually stacked very densely. When a palletizing robot disassembles fertilizer bags, it is very likely to face special situations such as toxic products or irregular filling. It is difficult for the gripper of the pallet - breaking robot to adopt a bending design. Therefore, compared with picking goods from a conveyor belt, the difficulty level increases. Moreover, after the traditional clamping mechanism receives a determined instruction, it clamps the goods with symmetrically moving grippers, unable to ensure whether the grippers are aligned with the fertilizer bags. At the same time, if the filling objects in the bag are irregular, resulting in a change in the bag's shape, the gripper shape cannot match well, which will also cause the palletizing robot to be unable to pick up the goods and unable to ensure that the goods do not fall during the lifting and transportation process.

[0004] Although the prior art such as CN111498483A discloses a method for adjusting the gripper of a palletizing robot, it cannot feedback the clamping state, cannot adjust each gripper individually. At the same time, its structure of installing multiple parts such as servo motors, sprockets, and sleeves at the gripper part is not only difficult to install and layout, but also the complex connection process of its grippers will inevitably bring a high failure rate.

[0005] The prior art such as CN108910518A discloses a gripper for a palletizing robot that can adjust the claw teeth. Although it uses a telescopic driving part to adjust the size of the grasping target, it must be actively adjusted and cannot change in real - time according to production at any time. Moreover, its claw teeth can only rotate axially symmetrically and cannot cope with asymmetric complex shapes.

[0006] The problems encountered by the clamping mechanism of the palletizing robot when clamping the above - mentioned loose fertilizer bags will, at the least, affect the production efficiency of the factory, and at the worst, lead to safety accidents. Therefore, the stability of the palletizing robot is of crucial importance. Summary of the Invention

[0007] In order to solve the technical defects proposed in the above - mentioned background art, the purpose of the present invention is to provide a clamping device and method for a pallet - breaking robot, which can cope with goods in different situations through distributed grippers, and at the same time improve the quality and efficiency of the clamping equipment.

[0008] The present invention adopts the following technical solution: A clamping device for a pallet - unstacking robot, including a device main body. The device main body includes a frame, a control mechanism installed above the frame, and multiple groups of clamping components symmetrically arranged at both ends of the frame. A distance sensor is provided at the lower end of the frame, and the control mechanism is electrically connected to the clamping components and the distance sensor respectively.

[0009] By adopting the above - mentioned technical solution, the control mechanism and the distance sensor are used in cooperation to control the clamping components to perform pallet - unstacking work. Each group of jaw components can work independently to handle goods in different situations, and at the same time, the quality and efficiency of the clamping equipment are improved.

[0010] Further, the control mechanism includes a central controller, a reversing valve for controlling the tightening and loosening of the jaws, and an interlocking valve for maintaining the clamping pressure. The central controller is respectively connected to the reversing valve and the interlocking valve. The central controller is connected to the distance sensor, and the interlocking valve is connected to each group of clamping components.

[0011] By adopting the above - mentioned technical solution, the central controller controls the operation of the entire clamping device of the pallet - unstacking robot, ensuring the stable operation of the device.

[0012] Further, the clamping component includes a jaw for clamping or relaxing the goods, a hydraulic cylinder for pushing the jaw to move, and a switching valve for cutting off the flow rate of hydraulic oil. The jaw is connected to the hydraulic cylinder, the hydraulic cylinder is connected to the switching valve, and the switching valve is connected to the interlocking valve.

[0013] By adopting the above - mentioned technical solution, the switching valve is connected to the control mechanism, and the control mechanism controls the opening and closing of the switching valve to further control the operation of the clamping components.

[0014] Further, the control mechanism is also provided with an adjusting component for adjusting the flow rate of hydraulic oil. The adjusting component is respectively connected to the central controller and the reversing valve.

[0015] By adopting the above - mentioned technical solution, the overflow valve plays a certain protective role and adjusts the flow rate supplied by the hydraulic pump.

[0016] A clamping method for a pallet - unstacking robot, applicable to the above - mentioned clamping device for a pallet - unstacking robot. Each jaw is independently controlled by a hydraulic cylinder, and the force is adjusted by pressure. During the clamping process, the jaws can run asynchronously to adapt to the shapes of various goods bags. During the lifting process, the force of each jaw can be distributed to ensure the horizontal lifting of the goods, achieving efficient and stable clamping. The method includes the following steps:

[0017] S1: After the goods are received in the factory, determine the weight G of each bag of goods, and place the goods in a stacked form in the unstacking area for unstacking;

[0018] S2: Determine the lower jaw coordinate A according to the stacking form of the goods to be disassembled, and calculate the clamping pressure P required for a single jaw according to the weight of the goods:

[0019] Calculate the pressure P: P = G / (FNS)

[0020] In the formula, G represents the gravity of the goods, F represents the friction coefficient, N represents the number of jaws, and S represents the cross-sectional area of the hydraulic cylinder.

[0021] S3: The robotic arm of the palletizing robot moves to and aligns with the goods bag, and the jaws move downward to reach the coordinate A. At this time, the jaws have been inserted into the gap of the goods bag;

[0022] S4: Switch the directional control valve to the right position to control the hydraulic cylinder to contract;

[0023] S5: The jaws contract and clamp the goods together with the hydraulic cylinder push rod. If the same clamping force is reached and the pressure reaches the set value P, jump to S8; otherwise, go to the next step;

[0024] S6: The inlet oil circuits of each stage of the hydraulic cylinder share the same oil supply. According to the principle of minimum resistance, the pressure of each cylinder is distributed so that the jaws that are not in contact continue to contract. Finally, the overall contraction is completed, and the jaws clamp the goods at this time;

[0025] S7: Switch the directional control valve to the middle position, and the interlocking valve keeps the clamping force unchanged and lifts the goods;

[0026] S8: Set the requirement for clamping stability according to the type of goods. Set the front and rear tilt angles within the range not greater than X0 for this time. When the goods are lifted off the ground, two distance sensors located at the front and rear of the lower end of the rack measure the front and rear distances a and b, and calculate the required additional pressure P 增 , and thus control the working conditions of each gripper. The calculation process is as follows:

[0027] First calculate X = tan^(-1)((a - b) / l),

[0028] When X < X0, go to S10,

[0029] When X > X0, P 增 = (X - X0) × 4%

[0030] As Figure 3 shown in the formula, a represents the vertical distance from the front rack to the goods, b is the vertical distance from the rear rack to the goods, and l represents the horizontal distance between the front and rear jaws.

[0031] S9: When X is greater than 0, it means tilting forward. The switching valve closes the rear hydraulic cylinder, and the front part of the hydraulic cylinder continues to work to clamp the goods, and the pressure increases by P 增When X is less than 0, it indicates tilting backward. The electromagnetic switch valve closes the front hydraulic cylinder, and the front part of the hydraulic cylinder continues to work to clamp the goods, and the pressure increases by P. 增 ;

[0032] S10: Lift the goods to the conveyor belt or the destination, and the directional valve switches to the left side to lower the goods;

[0033] S11: Determine whether the current palletizing is completed. If not, update the coordinate A, jump to S4, and if so, the robotic arm moves above the next piece of goods for the next round of clamping;

[0034] S12: End the current process.

[0035] By adopting the above technical solutions, each jaw is independently controlled by each cylinder. When the incoming material is not centered, the jaws can contract accordingly, and the goods can be grabbed without horizontally moving the goods, and various shaped goods can also be clamped, further improving the clamping stability. The maximum pressure value is set at the relief valve, and the pressure magnitude is used as the judgment condition for whether the clamping is good. When the goods bag is lifted off the ground, if one end becomes loose, the distance sensor feeds back at this time, and the force of each jaw is redistributed. When additional pressure is added to the loose end, the tilting of the goods will no longer increase, fundamentally solving various problems that may occur during clamping.

[0036] In summary, the beneficial effects of the present invention are: determining the position where the robotic arm moves each time and the required clamping pressure P according to the stacking form of the pallets to be unstacked and the weight of the goods, and then the robotic arm reaches the specified position to clamp the fertilizer bag according to the above conditions. During the clamping process, each jaw moves independently, and the fitting force remains consistent, and the magnitude of the force is controlled by the pressure P. During the lifting process, the clamping force between each jaw is distributed to ensure that the goods bag is lifted horizontally, and it can handle various irregularly shaped and position-deviated bulk-filled goods bags. During palletizing, the force of the claws is dynamically controlled to achieve efficient and stable grasping of the goods.

[0037] The above description is only an overview of the technical solution of the present invention. In order to be able to more clearly understand the technical means of the present invention, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given and described in detail in conjunction with the accompanying drawings as follows. Description of the Drawings

[0038] Figure 1 is the flowchart of the solution of an embodiment of a clamping device and method of a palletizing robot of the present invention;

[0039] Figure 2 is the front view of an embodiment of a clamping device and method of a palletizing robot of the present invention;

[0040] Figure 3This is an illustrative diagram of an embodiment of the clamping device and method of a depalletizing robot according to the present invention.

[0041] Explanation of the reference numerals in the figure: 1, device main body; 2, frame; 3, control mechanism; 31, central controller; 4, clamping assembly; 41, jaw; 42, hydraulic cylinder; 5, distance sensor. Detailed implementation manners

[0042] In order to make the content of the present invention easier to be clearly understood, the present invention will be further described below according to specific embodiments in conjunction with the accompanying drawings.

[0043] It should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc. used in this article is based on the orientation or positional relationship shown in the accompanying 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 cannot be understood as a limitation to the present invention. Unless otherwise specified, the meaning of "a plurality" is two or more.

[0044] Unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" 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, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0045] As Figures 1 to 3 shown, a clamping device for a depalletizing robot includes a device main body 1. The device main body 1 includes a frame 2, a control mechanism 3 installed above the frame 2, and multiple groups of clamping assemblies 4 symmetrically arranged at both ends of the frame 2. An ultrasonic distance sensor 5 is provided at the lower end of the frame 2, with a voltage of 3 - 5.5V, a millimeter-level precision selected, and an affordable price. The two sides inside the frame 2 are symmetrical, and drill holes are provided to supply oil paths for the clamping assemblies 4. The clamping assemblies 4 are arranged symmetrically and evenly. Two distance sensors 5 are provided at one end of the frame 2 facing the goods, respectively measuring the distances from the goods below them. The control mechanism 3 is electrically connected to the clamping assemblies 4 and the distance sensors 5 respectively. The control mechanism 3 and the distance sensors 5 cooperate to control the clamping assemblies 4 to perform depalletizing work. Each clamping assembly 4 can work independently to handle goods in different situations, improving the quality and efficiency of the clamping equipment.

[0046] The control mechanism 3 includes a central controller 31, a reversing valve for controlling the tightening and loosening of the gripper 41, and an interlocking valve for maintaining the clamping pressure. The central controller 31 is respectively connected to the reversing valve and the interlocking valve. The hydraulic oil first reaches the reversing valve through the oil supply line, then reaches the interlocking valve through the oil line between the reversing valves, and then reaches each clamping assembly 4 from the interlocking valve. The central controller 31 is connected to the distance sensor 5, and the interlocking valve is connected to each clamping assembly 4. After receiving the measurement data from the distance sensor 5, the central controller 31 issues an instruction according to the data to adjust the clamping assembly 4, thereby controlling the operation of the entire palletizing robot clamping device and ensuring the stable operation of the device.

[0047] The clamping assembly 4 includes a gripper 41 for clamping or relaxing the goods, a hydraulic cylinder 42 for pushing the gripper 41 to move, and a switching valve for cutting off the hydraulic oil flow. In this embodiment, the hydraulic cylinder 42 adopts a YGX series micro hydraulic cylinder 42, and the maximum single rod can use a pressure of 7 MPa. A thrust of more than 3000 N is sufficient for grasping the goods. Each inlet and outlet of the hydraulic cylinder 42 are respectively interconnected. The end of the push rod of the hydraulic cylinder 42 is connected to the gripper 41. The gripper 41 relies on the action of the hydraulic cylinder 42 to complete the clamping of the goods. The other end of the hydraulic cylinder 42 is connected to the switching valve, and the switching valve is connected to the interlocking valve. During operation, the hydraulic oil reaches the open switching valve through the interlocking valve, thereby promoting the operation of the cylinder and driving the gripper 41 to work.

[0048] The control mechanism 3 is also provided with an adjustment assembly for adjusting the size of the hydraulic oil flow. The adjustment assembly includes an overflow valve and a hydraulic pump. The overflow valve is connected to the central controller 31, and the central controller 31 controls the opening and closing of the overflow valve. The hydraulic pump is connected to the reversing valve to supply hydraulic oil to the reversing valve. The overflow valve has a certain protective effect, controlling the hydraulic pump and thus adjusting the size of the flow supplied by the hydraulic pump.

[0049] A palletizing robot clamping method is applicable to the above-mentioned palletizing robot clamping device. Each gripper 41 is independently controlled by a hydraulic cylinder 42, and the force is adjusted by pressure. During the clamping process, the grippers 41 can operate asynchronously to adapt to the shapes of various goods bags. During the lifting process, the force of each gripper 41 can be distributed to ensure the horizontal lifting of the goods, realizing efficient and stable clamping. In this embodiment, the following steps are included:

[0050] S1: The factory purchases palletized compound fertilizer in bags, determines the weight G of each bag of goods. The fertilizer bags are in a 40 kg specification and are stacked in a 2 + 3 stacking form, and the goods are placed in the palletizing area for palletizing;

[0051] S2: Determine the first fertilizer bag to be disassembled according to the 2 + 3 stacking form, and the pressure P is calculated and set to 0.13 MPa;

[0052] S3: The robotic arm of the palletizing robot moves to the cargo bag and aligns with the first fertilizer bag. The gripper 41 moves downward with the robotic arm and reaches the coordinate A(0, 0, 1700). At this time, the gripper 41 has been inserted into the gap of the cargo bag.

[0053] S4: The directional control valve switches to the right position to control the hydraulic cylinder 42 to contract.

[0054] S5: The gripper 41 contracts and tightens the cargo together with the push rod of the hydraulic cylinder 42. When the edge of the fertilizer bag is irregular, the inlet oil circuits of all levels of the hydraulic cylinder 42 share the same oil. According to the principle of minimum resistance, after the two end hydraulic cylinders 42 stop, the middle hydraulic cylinder 42 continues to contract, so that the gripper 41 that is not in contact continues to contract. Finally, the overall contraction is completed, and the gripper 41 tightens the cargo at this time.

[0055] S7: The directional control valve switches to the middle position, and the interlocking valve keeps the clamping force unchanged and lifts the cargo.

[0056] S8: When the cargo is lifted off the ground, the two front and rear distance sensors 5 on the frame 2 send back the distance information a and b to the central controller 31. It is calculated that X = 5°, and X0 is set to 0°. At this time, the additional pressure required is P 增 = 20%;

[0057] S9: If X is a positive value, it means tilting forward. The inlet oil circuits of some hydraulic cylinders 42 are closed after the switching valve is closed, and the relief valve is adjusted to increase the oil pressure by 20%, and the cargo is continuously lifted.

[0058] S10: When reaching the destination, the directional control valve switches to the left side to put down the cargo, and the number of unstacking is incremented by one. At this time, if the unstacking is not completed, the coordinate A is updated to (600, 0, 1700), and it returns to S3 to clamp the next cargo bag. When all the clamping is completed, this process ends.

[0059] The principle of the embodiment of the present application is as follows: The control mechanism 3 is respectively electrically connected to the clamping assembly 4 and the distance sensor 5. The switching valve 43 cooperates with the distance sensor 5. Each gripper 41 is independently controlled by each cylinder. When the incoming material is misaligned, the gripper 41 can perform corresponding contractions, and it can grip goods of various shapes. The maximum pressure value is set at the relief valve, and the pressure magnitude is used as the judgment condition for whether the goods are clamped well. During the process of lifting the cargo bag off the ground, if one end becomes loose, the distance sensor 5 gives feedback, and the force of each claw is redistributed. When additional pressure is added to the loose end, the tilting of the cargo will no longer increase.

[0060] The embodiments of the specific implementation manners are all the preferred embodiments of the present application. The protection scope of the present application is not limited thereby. The same components are denoted by the same reference numerals. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A clamping method for a pallet - de - stacking robot, including a clamping device for a pallet - de - stacking robot. The device body of the clamping device for the pallet - de - stacking robot includes a frame (2), a control mechanism (3) installed above the frame (2), and multiple groups of clamping components (4) symmetrically arranged at both ends of the frame (2). A distance sensor (5) is provided at the lower end of the frame (2), and the control mechanism (3) is electrically connected to the clamping components (4) and the distance sensor (5) respectively; The clamping component (4) includes a jaw (41) for clamping or relaxing goods, a hydraulic cylinder (42) for pushing the jaw (41) to move, and a switching valve for cutting off the hydraulic oil flow. The jaw (41) is connected to the hydraulic cylinder (42), the hydraulic cylinder (42) is connected to the switching valve, and the switching valve is connected to an inter - locking valve; The control mechanism (3) includes a central controller (31), a reversing valve for controlling the tightening and loosening of the jaw (41), and an inter - locking valve for maintaining the clamping pressure. The central controller (31) is respectively connected to the reversing valve and the inter - locking valve. The central controller (31) is connected to the distance sensor (5), and the inter - locking valve is connected to each group of clamping components (4); The control mechanism (3) is also provided with an adjustment component for adjusting the size of the hydraulic oil flow. The adjustment component is respectively connected to the central controller (31) and the reversing valve; It is characterized in that: Each jaw (41) is independently controlled by the hydraulic cylinder (42), and the force is adjusted by pressure. During the clamping process, the jaws (41) run asynchronously to adapt to the shapes of various goods bags. During the lifting process, the force of each jaw (41) is distributed to ensure the horizontal lifting of goods, achieving efficient and stable clamping. The method includes the following steps: S1: After the goods are received in the factory, determine the weight G of each bag of goods, and place the goods in a stacked form in the pallet - de - stacking area for pallet - de - stacking; S2: Determine the coordinates A of the lower jaws according to the stacked form of the goods to be de - stacked, and calculate the required clamping pressure P for a single jaw (41) according to the weight of the goods: Calculate the pressure P: , In the formula, G represents the gravity of the goods, F represents the friction coefficient, N represents the number of jaws (41), and S represents the cross - sectional area of the hydraulic cylinder (42); S3: The robotic arm of the palletizing robot moves to and aligns with the goods bag, and the jaws (41) move downward to reach the coordinates A. At this time, the jaws (41) have been inserted into the gaps between the goods bags; S4: The reversing valve is switched to the right position to control the hydraulic cylinder (42) to contract; S5: The jaws (41) contract together with the push rod of the hydraulic cylinder (42) to clamp the goods. If the same clamping force is reached and the pressure reaches the set value P, jump to S8, otherwise go to the next step; S6: The inlet oil circuits of each level of hydraulic cylinder (42) share the same oil path. According to the principle of minimum resistance, the pressure of each cylinder is distributed so that the jaws (41) that are not in contact continue to contract. Finally, the overall contraction is completed, and the jaws (41) clamp the goods at this time; S7: The reversing valve is switched to the middle position, and the inter - locking valve maintains the clamping force unchanged to lift the goods; S8: Set the clamping stability requirement according to the type of goods. Set the forward and backward tilt angles within the range not greater than X0 this time. When lifting the goods off the ground, two distance sensors (5) located at the front and rear of the lower end of the rack (2) measure the front and rear distances a and b, and calculate the required increased pressure P 增 , so as to control the working conditions of each gripper. The calculation process is as follows: Calculate first , When reaches S10, When , , Wherein, a represents the vertical distance from the front rack (2) to the goods, and b represents the vertical distance from the rear rack (2) to the goods. represents the horizontal distance between the front and rear clamping jaws (41); S9: When X is greater than 0, it indicates a forward tilt. The switching valve closes the rear hydraulic cylinder (42), and the front part of the hydraulic cylinder (42) continues to work to clamp the goods, and the pressure increases by P increase; when X is less than 0, it indicates a backward tilt. The electromagnetic switching valve closes the front hydraulic cylinder (42), and the front part of the hydraulic cylinder (42) continues to work to clamp the goods, and the pressure increases by P increase; S10: Lift the goods to the conveyor belt or the destination, and the directional control valve switches to the left to lower the goods; S11: Determine whether the current palletizing is completed. If not, update the coordinate A, jump to S4, and if so, the robotic arm moves above the next good for the next round of clamping; S12: End the current process.

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