An automatic ground opening paperboard mechanism and a control method thereof

Abstract

The present application relates to the technical field of ground paperboard, and in particular to an automatic ground paperboard opening mechanism, which comprises: a servo motor driving a forward and reverse screw rod to realize synchronous and opposite or opposite movements of left and right paws, compact structure, simple control, and pre-opening and secondary shaping of the inner folding angle of the ground paperboard, ensuring that the folding angle is opened in place; combining a pneumatic cylinder and a vacuum chuck to realize accurate grabbing and releasing of the ground paperboard, a vacuum generator cooperating with a solenoid valve to realize vacuum breaking of the chuck by blowing, improving the stability of the board releasing; a laser range finder positioning is used for accurate positioning and triggering of the ground paperboard, improving the taking and placing accuracy; real-time sensing and adaptive processing of the abnormal state of the ground paperboard, with online detection, intelligent judgment and automatic correction ability, through the introduction of closed-loop feedback control based on laser ranging, realizing quality pre-inspection, fault self-diagnosis and early warning, adaptive operation, and improving process reliability.

Description

Technical Field

[0001] This invention relates to the field of paperboard cutting technology, and in particular to an automatic paperboard cutting mechanism and its control method. Background Technology

[0002] Traditional handling of floor linerboard relies on manual handling and opening of inner folds, resulting in low efficiency, high cost, and poor consistency. Existing automated equipment is complex in structure, expensive, and lacks compatibility, making it difficult to adapt to multi-variety production. Furthermore, current automated floor linerboard handling equipment mostly uses pre-programmed sequential control, lacking the ability to perceive and respond to the real-time status of the workpiece (floor linerboard). For example, it cannot detect and handle "double-sheet" problems caused by static electricity or hydraulic pressure adhesion, nor can it identify warping and unevenness caused by storage deformation. These problems can range from minor issues like material jams and machine stoppages to major issues like packaging quality defects, still requiring manual intervention and impacting the overall efficiency and reliability of automation.

[0003] In view of this, we propose an automatic cardboard opening mechanism and its control method to solve the existing problems. Summary of the Invention

[0004] The purpose of this invention is to provide an automatic cardboard opening mechanism and its control method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an automatic floorboard opening mechanism, comprising a robotic arm connecting flange, a left claw assembly, a right claw assembly, a floorboard opening power assembly and a positive and negative lead screw assembly for driving the claw assembly to move in opposite directions, and a suction cup assembly for picking up the floorboards; further comprising a laser rangefinder and a control system; the laser rangefinder is disposed on the mechanism and is used to measure the height information of the floorboard surface before picking up the floorboards; the control system is signal-connected to the laser rangefinder, the floorboard opening power assembly, and the suction cup assembly;

[0006] The control system is configured to: receive height information measured by a laser rangefinder; determine whether the status of the flooring is abnormal based on the height information, including multiple sheets of adhesion indicated by height abnormality, or flatness abnormality indicated by height distribution; and when the status is determined to be abnormal, trigger a control command corresponding to the abnormal status, including at least one of executing an alarm, pausing operation, triggering a correction procedure, or marking the flooring as a defective product.

[0007] Furthermore, the correction procedure includes: controlling the suction cup assembly to perform multiple suction and release actions, and / or controlling the floorboard opening power assembly to drive the claw assembly to pry the floorboards to attempt to separate the adhered floorboards.

[0008] Furthermore, when it is determined that the flooring board has an abnormal flatness, the control system is further configured to: differentiate the adsorption force or adsorption sequence of different suction cups in the suction cup assembly to adapt to the shape of the warped flooring board.

[0009] Furthermore, the laser rangefinder is also used to measure the height information of the edge of the floorboard after the claw assembly opens the inner corner of the floorboard to determine whether the corner is opened in place; the control system is further configured to: if it is determined that the corner is not opened in place, control the floorboard opening power assembly to drive the claw assembly to open or adjust it again.

[0010] Furthermore, the power assembly of the cardboard includes a servo motor, a reducer, and a synchronous belt transmission mechanism, and the positive and negative lead screw assembly is connected to the output shaft of the servo motor via a synchronous belt.

[0011] Furthermore, the suction cup assembly includes a cylinder mounting plate, a dual-axis cylinder, a suction cup and a suction cup mounting bracket, and a vacuum generator and solenoid valve assembly to provide controllable negative and positive pressure for the suction cup.

[0012] A control method for an automatic floor-opening paperboard mechanism, comprising the following steps:

[0013] Positioning steps: Move the mechanism above the floorboard hopper;

[0014] Inspection steps: Measure the height of the floorboards using a laser rangefinder;

[0015] Judgment steps: Determine the status of the floorboards based on height information;

[0016] First execution branch: If the status is normal, then execute the following actions in sequence: pre-opening the pawl, picking up the floor board, transporting, opening the pawl again, and releasing the floor board;

[0017] Second execution branch: If the state is abnormal, the exception handler is triggered.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This invention uses a servo motor to drive forward and reverse lead screws, enabling synchronous opposite or backward movement of the left and right claws. It features a compact structure, simple control, and achieves pre-opening and secondary shaping of the inner folds of the floorboard, ensuring the folds are fully open. A cylinder and vacuum suction cups are combined to achieve precise gripping and release of the floorboard. A vacuum generator, in conjunction with a solenoid valve, blows air into the suction cups to break the vacuum, improving the stability of the floorboard placement. A laser rangefinder is used for precise positioning and triggering of the floorboard, improving pick-and-place accuracy. It senses and adaptively handles abnormal states of the floorboard in real time, possessing online detection, intelligent judgment, and automatic correction capabilities. By introducing closed-loop feedback control based on laser ranging, it achieves quality pre-inspection, fault self-diagnosis and early warning, adaptive operation, and improves process reliability. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an automatic cardboard opening mechanism according to the present invention;

[0021] Figure 2 This is a flowchart illustrating a control method for an automatic cardboard opening mechanism according to the present invention.

[0022] In the diagram: 1. Left claw assembly; 2. Floor plank power assembly; 3. Positive and negative lead screw assembly; 4. Linear guide rail assembly; 5. Vacuum generator; 6. Laser rangefinder; 7. Robot arm connecting flange; 8. Right claw assembly; 9. Solenoid valve assembly; 10. Suction cup assembly. Detailed Implementation

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Example 1

[0024] like Figure 1 As shown, an automatic floorboard opening mechanism includes a left claw assembly 1, a floorboard opening power assembly 2, a forward and reverse lead screw assembly 3, a linear guide rail assembly 4, a vacuum generator 5, a laser rangefinder 6, a robotic arm connecting flange 7, a right claw assembly 8, a solenoid valve assembly 9, and a suction cup assembly 10. Its main functions are: to remove the floorboard from the cover board hopper, automatically open the four corners of the floorboard, and finally place the floorboard on the designated roller pallet, completing the automatic floorboard picking and placing processes.

[0025] The left claw assembly 1 mainly consists of a sliding plate, a lead screw nut seat, and claws; the paperboard opening power assembly 2 mainly consists of a servo motor, a reducer, a motor support, a synchronous belt, a synchronous pulley, a protective cover, and a synchronous belt tensioning plate; the vacuum generator 5 provides vacuum negative pressure for the gripper suction cup; the right claw assembly 8 mainly consists of a sliding plate, a lead screw nut seat, and claws; the suction cup assembly 10 mainly consists of a cylinder fixing plate, a cylinder, a suction cup, and a suction cup fixing bracket.

[0026] The automatic board-opening mechanism is mounted on the end of a multi-axis robot or gantry robot via a connecting flange 7. The left and right claw assemblies 1 and 8 are symmetrically mounted on the left-hand and right-hand threaded sections of the forward and reverse lead screw assembly 3 via lead screw nut seats. The forward and reverse lead screw assembly 3 is connected to the servo motor in the board-opening power assembly 2 via a synchronous belt drive, enabling the servo motor to drive the left and right claw assemblies to perform precise opposite or reverse movements when rotating forward or backward.

[0027] The linear guide assembly 4 ensures that the left and right pawl assemblies slide smoothly without deviation. The suction cup assembly 10 is installed in the middle of the mechanism, and its dual-axis cylinder can drive the suction cup to perform vertical lifting and lowering movements. The vacuum generator 5 and the solenoid valve assembly 9 are connected to the suction cup through air pipes to provide and cut off the vacuum negative pressure, and can realize vacuum breaking by blowing air. The laser rangefinder 6 is preferably fixedly installed on the mechanism frame, and its measuring beam is pointed at the area to be measured on the floorboard.

[0028] The working principle of an automatic cardboard opening mechanism based on Embodiment 1 is as follows:

[0029] The cardboard opening mechanism is delivered to a safe position above the cardboard hopper by a multi-axis robot (or multi-axis gantry robot). Upon arrival, the laser rangefinder 6 senses the material and triggers a secondary positioning signal for the cardboard. The servo motor of the cardboard opening power unit 2 reverses, driving the forward and reverse lead screw assembly 3 to reverse, causing the left claw assembly 1 and right claw assembly 8 to move in opposite directions. The claws of the left and right claw assemblies automatically open under the motor's drive, pre-opening the inner fold of the cardboard and performing secondary shaping. Once the claws are in position, an automatic cardboard gripping signal is triggered. The dual-axis cylinders of the two-sided suction cup assembly 10 extend, driving the suction cups downwards. Simultaneously, the vacuum generator 5 activates, and the suction cups hold the cardboard. After completing the automatic cardboard retrieval action, an automatic cardboard transport signal is triggered by the multi-axis robot (or multi-axis gantry robot). The cardboard opening mechanism is then delivered to a safe position above an empty pallet by the multi-axis robot (or multi-axis gantry robot), triggering a secondary cardboard opening signal. The cardboard opening mechanism then moves... The servo motor of the force component 2 rotates forward, driving the forward and reverse lead screw assembly 3 to rotate forward, causing the left pawl assembly 1 and the right pawl assembly 8 to move in opposite directions. The pawls of the left and right pawl assemblies automatically close under the drive of the motor. After they reach their positions, the servo motor reverses, driving the forward and reverse lead screw assembly 3 to rotate in reverse, causing the left pawl assembly 1 and the right pawl assembly 8 to move in opposite directions. The pawls of the left and right pawl assemblies automatically open under the drive of the motor, opening the inner fold of the floorboard for the second time. After the pawls reach their positions, the automatic floorboard release signal is triggered. The servo motor of the floorboard opening power component 2 rotates forward, driving the forward and reverse lead screw assembly 3 to rotate forward, causing the left pawl assembly 1 and the right pawl assembly 8 to move in opposite directions. The pawls of the left and right pawl assemblies automatically close under the drive of the motor. After the left and right pawls are closed, the dual-axis cylinders of the suction cup assembly 10 on both sides retract, causing the suction cups to move upward. At the same time, the vacuum generator 5 is turned off and blows air to break the vacuum, and the floorboard is lowered, completing the automatic floorboard release process. All actions of the automatic floorboard opening process are completed, and the cycle continues.

[0030] Therefore, this equipment not only realizes the replacement of traditional manual handling of floor lining boards with mechanical automation, but also realizes the replacement of traditional manual opening of the inner corners of floor lining boards with mechanical automation. It is also highly compatible, and the entire equipment can be compatible with a variety of products according to needs. Moreover, it is highly competitive in the market, greatly reduces equipment costs, and simplifies the structure.

[0031] Therefore, an automatic floor cardboard opening mechanism is an automated device that enables a robotic arm to automatically open the inner corner of the floor cardboard. It has many advantages, such as versatility in picking and placing products, lightweight structure, convenient assembly process, and low manufacturing cost. It is the first innovative application in the packaging industry. It is suitable for automated devices that automatically open the inner corner of the floor cardboard of bagged products in the daily consumer goods industry. It is especially suitable for the automatic packaging process of plastic packaging for household paper products (such as handkerchiefs, facial tissues, toilet paper, bottom drawer toilet paper, etc.). Example 2

[0032] The laser rangefinder 6 is mounted on the mechanism and is used to measure the height information of the floorboard surface before picking up the floorboard; the control system is connected to the laser rangefinder 6, the floorboard opening power assembly 2 and the suction cup assembly 10.

[0033] The control system is configured to: receive height information measured by the laser rangefinder 6; determine whether the status of the flooring is abnormal based on the height information, the abnormal status including multiple sheets of adhesion indicated by height abnormality, or flatness abnormality indicated by height distribution; when the status is determined to be abnormal, trigger a control command corresponding to the abnormal status, the control command including at least one of executing an alarm, pausing operation, triggering a correction program, or marking the flooring as a defective product.

[0034] The suction cup assembly 10 is controlled to perform multiple suction and release actions, and / or the floorboard opening power assembly 2 is controlled to drive the claw assembly to pry the floorboards in an attempt to separate the adhered floorboards.

[0035] When the floorboard is determined to have an abnormal flatness, the control system is further configured to: differentiate the adsorption force or adsorption sequence of different suction cups in the suction cup assembly 10 to adapt to the shape of the warped floorboard.

[0036] The laser rangefinder 6 is also used to measure the height information of the edge of the floorboard after the claw assembly opens the inner corner of the floorboard to determine whether the corner is opened in place; the control system is further configured to: if it is determined that the corner is not opened in place, control the floorboard opening power assembly 2 to drive the claw assembly to open or adjust it again.

[0037] like Figure 2 As shown, a control method for an automatic cardboard opening mechanism includes the following steps:

[0038] Positioning steps: Move the mechanism above the floorboard hopper;

[0039] Inspection steps: Measure the height of the floorboards using a laser rangefinder 6;

[0040] Judgment steps: Determine the status of the floorboards based on height information;

[0041] First execution branch: If the status is normal, then execute the following actions in sequence: pre-opening the pawl, picking up the floor board, transporting, opening the pawl again, and releasing the floor board;

[0042] Second execution branch: If the state is abnormal, the exception handler is triggered.

[0043] The working principle of the control method for an automatic cardboard opening mechanism based on Embodiment 2 is as follows:

[0044] A control system centered on a programmable logic controller (PLC) or robot controller. This control system communicates with the following components via industrial fieldbuses (such as EtherCAT, Profinet) or I / O modules: the servo driver of the cardboard power assembly 2 receives pulse / direction signals or bus commands from the control system to control the start, stop, direction, speed, and position of the servo motor; the solenoid valve assembly 9 receives digital output signals from the control system to control the on / off state of the vacuum generator 5 and to blow air to break the vacuum; the laser rangefinder 6 transmits measured height data to the control system in real time via analog inputs (such as 4-20mA, 0-10V) or digital communication interfaces (such as RS485, Ethernet); and the audible and visual alarm receives signals from the control system and issues a warning when an anomaly is detected.

[0045] During the positioning and detection steps, the multi-axis robot moves the mechanism to a safe position above the floor linerboard hopper. Once in position, the control system activates the laser rangefinder 6. The laser rangefinder performs at least three spot measurements or one linear scan at different locations on the surface of the floor linerboard at the top of the hopper to acquire a set of height data.

[0046] In the decision-making step, the control system processes and judges the height data: calculating the average height H. avg and height standard deviation H std (Used to characterize flatness). For double-sheet adhesion judgment: H avg Compare with the preset nominal thickness T of a single sheet of flooring; set a safety factor k (e.g., k=1.5), if H avg If the value is greater than k*T, it is determined to be an abnormality of multiple adhesions. For warpage determination: H... std Compare with the preset flatness threshold δ; if H std If the value is greater than δ, it is determined that the cardboard in that location has warping and abnormal flatness.

[0047] If H avg ≤k*T and H std If the value is less than or equal to δ, then it is considered to be in a normal state.

[0048] If double-sheet adhesion is detected, the control system immediately pauses the cycle and triggers an audible and visual alarm. Simultaneously, an automatic correction program is initiated: the suction cup assembly 10 executes three cycles of "cylinder extension → vacuum activation (adsorption) → hold for 0.5 seconds → vacuum deactivation and air blowing (release) → cylinder retraction," attempting to separate the adhered cardboard using airflow impact and mechanical vibration. After correction, the system is re-detected. If three consecutive correction attempts fail, the alarm remains active, awaiting manual intervention.

[0049] If warping is detected, the control system internally marks the cardboard as "defective." The process continues, but in subsequent placements, the robot will move it to the waste bin instead of the target pallet. As an enhancement, the control system can perform adaptive adsorption: based on height data, it identifies the highest and lowest points of warping and, through independent control of solenoid valves, extends the vacuum opening time or increases the vacuum level of the suction cup located at the lowest point to ensure reliable gripping.

[0050] The optional laser rangefinder is the Keyence IL-300, which boasts a measurement accuracy of ±0.1% and a response time of 1ms, making it suitable for the high-speed, high-precision measurement scenarios required for this application. The nominal thickness of a single sheet of flooring is set to 1.2mm, based on commonly used materials. The safety factor k is set to 1.5, meaning that when the average height H is detected... avg When the thickness exceeds 1.8mm, it is judged as double-sheet adhesion; the flatness threshold δ is set to 0.3mm, that is, when the standard deviation of the local cardboard surface height data exceeds 0.3mm, it is judged as warped and uneven.

[0051] A method for detecting double-sheet adhesion during the paperboard hopper unloading process includes the following steps:

[0052] A1. Establishing a baseline: When the cardboard stack in the silo is in its initial state, obtain the average initial height of its top surface using a laser rangefinder;

[0053] A2. Pre-retrieving measurement: Before each retrieving action, the average real-time height of the top surface of the current cardboard stack is measured using a laser rangefinder;

[0054] A3. Calculate apparent thickness: Calculate the difference between the average height before this material handling and the average height recorded after the previous material handling, and use this difference as the apparent thickness H of the cardboard to be handled this time. avg ;

[0055] A4. Dynamic threshold comparison: The apparent thickness H... avg Compare with a dynamically updated single-sheet cardboard thickness reference value T;

[0056] A5. Adhesion determination: If H avg If the thickness exceeds the product of the dynamic thickness reference value T and a preset coefficient k, it is determined that the cardboard to be picked up has stuck together.

[0057] A6. Data Update: If it is determined that no adhesion has occurred and the material handling operation has been successfully completed, then update the current H data. avg Historical data sequences are incorporated, and the dynamic thickness reference value T is updated.

[0058] The dynamic thickness reference value T is calculated by statistically processing the apparent thickness values ​​corresponding to N successful material take-offs in the past. The statistical processing includes calculating the arithmetic mean, median, or average value after removing the maximum and minimum values.

[0059] The preset coefficient k is a dynamically adjusted value, which is automatically adjusted according to the dispersion parameter of historical apparent thickness data. When the dispersion is lower than the first threshold, the value of k is reduced to improve detection sensitivity; when the dispersion is higher than the second threshold, the value of k is increased to enhance system robustness.

[0060] Between steps A2 and A3, there is also a step: during the material handling mechanism's material handling action, continuously acquire the height change data of the top of the cardboard stack at a sampling rate higher than the frequency of the material handling mechanism's action, and generate a height drop curve; the judgment condition of step A5 further includes: analyzing the shape or drop time of the height drop curve, and if it does not match the preset single cardboard material handling characteristic curve, then strengthen the adhesion judgment.

[0061] A method for evaluating surface flatness based on laser ranging includes the following steps:

[0062] B1: Use a laser rangefinder to measure multiple points on the surface to be measured and obtain a set of height measurement data;

[0063] B2: Based on height measurement data, calculate multiple evaluation parameters to characterize surface flatness. These multiple evaluation parameters include at least: statistical parameters reflecting data dispersion and geometric morphological parameters reflecting overall morphological characteristics.

[0064] B3: By comprehensively analyzing the results of multiple evaluation parameters, the flatness grade or warping probability of the surface to be tested is determined.

[0065] Statistical parameters include at least one of standard deviation and range; geometric parameters include at least one of flatness error of a plane fitted by least squares method and local curvature calculated based on a measurement lattice.

[0066] The multi-point measurement in step B1 is performed according to a pre-designed measurement point array that covers the main areas of the surface to be measured. The measurement point array includes at least the four corners and the center area of ​​the surface to be measured. The measurement point array is a grid-like array or an adaptively refined array.

[0067] In step B3, the comprehensive analysis is performed by comparing each evaluation parameter with a preset threshold and making a judgment based on predetermined decision rules; the decision rules include multi-parameter weighted scoring rules or logical judgment tree rules.

[0068] After step B3, a three-dimensional topographic map or a two-dimensional contour map of the surface to be measured is generated based on the height measurement data, and then visualized.

[0069] The above specific embodiments are merely several preferred embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. An automatic ground paperboard opening mechanism, comprising a mechanical hand connecting flange (7), a left pushing claw assembly (1), a right pushing claw assembly (8), a ground paperboard opening power assembly (2) and a forward and reverse screw assembly (3) for driving the pushing claw assemblies to move towards or away from each other, and a suction cup assembly (10) for sucking the ground paperboard, characterized in that: The laser range finder (6) is arranged on the mechanism and is used to measure the height information of the ground paperboard surface before the ground paperboard is sucked; The control system is configured to receive the height information measured by the laser range finder (6), judge whether the state of the ground paperboard is abnormal based on the height information, and the abnormal state includes multiple adhesions indicated by the height abnormality or flatness abnormalities indicated by the height distribution; when it is determined that the state is abnormal, a control instruction corresponding to the abnormal state is triggered, and the control instruction includes at least one of executing an alarm, pausing running, triggering a correction program, or marking the ground paperboard as a defective product; The control system is configured to control the ground paperboard power component (2) to drive the pawl component to move the ground paperboard in order to attempt to separate the adhesion of the ground paperboard; the laser range finder (6) is also used to measure the height information of the edge of the ground paperboard after the pawl component opens the inside corner of the ground paperboard, in order to judge whether the corner is opened to the right position; the control system is configured to control the ground paperboard power component (2) to drive the pawl component to open again or adjust if it is determined that the corner is not opened to the right position.

2. An automatic opening ground paperboard mechanism according to claim 1, characterized in that The correction program includes controlling the suction cup assembly (10) to perform multiple suction and release actions.

3. An automatic opening ground paperboard mechanism according to claim 1, characterized in that, When it is determined that the ground paperboard has flatness abnormalities, the control system is configured to differentially control the suction force or suction timing of different suction cups in the suction cup assembly (10) to adapt to the shape of the warped ground paperboard.

4. An automatic opening ground paperboard mechanism according to claim 1, characterized in that: The ground paperboard power component (2) includes a servo motor, a speed reducer, and a synchronous belt transmission mechanism, and the positive and negative screw rod assembly (3) is connected with the output shaft of the servo motor through the synchronous belt.

5. An automatic opening ground paperboard mechanism according to claim 1, characterized in that: The suction cup assembly (10) includes a cylinder fixing plate, a double-shaft cylinder, a suction cup, and a suction cup fixing support, and the vacuum generator (5) and the electromagnetic valve assembly (9) provide controllable negative pressure and positive pressure for the suction cup.

6. A control method for an automatic ground board opening mechanism according to any one of claims 1 to 5, characterized by The method comprises the following steps: Positioning step: moving the mechanism above the ground paperboard stock bin; Detection step: measuring the height information of the ground paperboard by the laser range finder (6); Judgment step: judging the state of the ground paperboard based on the height information; First execution branch: if the state is normal, sequentially execute the actions of pawl pre-opening, sucking the ground paperboard, carrying, pawl secondary opening, and releasing the ground paperboard; Second execution branch: if the state is abnormal, trigger an abnormal handling program.

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