A packaging box printing surface defect detection device

Abstract

This invention discloses a packaging box printing surface defect detection device, belonging to the field of printing surface physical performance testing technology. It includes a gantry inspection frame, with bidirectional centering reset units fixedly installed at the middle positions of both sides of the inner wall of the open end of the gantry inspection frame. A first detection unit and a second detection unit, positioned one above the other, are assembled through these bidirectional centering reset units. The bidirectional centering reset units ensure that the first and second detection units always maintain a centered, close-fitting movement to clamp the packaging box panel. Through dynamic torsion detection, the physical integrity of the packaging box printing surface coating is detected online under simulated bending conditions. This differs from existing technologies that rely on static optical measurements and cannot capture cracking defects in the coating during subsequent molding processes. The device uses a detection camera and lightbox inside a high-transparency cylinder to observe the coating in real time during the torsion process.

Description

Technical Field

[0001] This invention relates to the field of physical performance testing technology for printed surfaces, and more specifically, to a device for detecting defects in the printed surfaces of packaging boxes. Background Technology

[0002] On existing packaging box production lines, online inspection equipment based on the printed surface of packaging boxes has become a standard configuration. Its technical essence is non-contact measurement and analysis of the optical properties of material surfaces. By collecting the reflected light signal of the sample surface under flat printing conditions and comparing it with standard images at the pixel level, it can identify appearance defects such as color and stains, and achieve rapid and automated screening of the static optical properties of materials.

[0003] However, for packaging materials with functional coatings such as scratch-off paint, the key to quality lies not only in their static appearance but also in the physical integrity of the coating during subsequent bending and forming processes. Current online inspection methods often employ bottom-transmitted light illumination and top imaging, indirectly judging coating coverage based on the uniformity of light transmission. However, this method can only detect overall coating thickness variations and cannot provide real-time feedback on issues such as insufficient coating cohesion and weak adhesion to the substrate. If such problems are not detected, they will manifest as coating cracking or peeling when the material is subjected to bending stress, leading to a large number of potentially defective products entering subsequent forming processes.

[0004] To address the aforementioned issues, existing technologies have attempted to introduce offline sampling for bending tests or to add simple mechanical pre-bending stations to the production line. However, offline sampling disrupts the production cycle and lacks representativeness, while mechanical pre-bending stations and light transmission detection stations are difficult to combine. Therefore, only result-based judgments can be made, and it is impossible to dynamically observe defects on the printed surface of the packaging box during the bending process. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a packaging box printing surface defect detection device, which aims to solve the above-mentioned technical problems.

[0006] To solve the above problems, the present invention adopts the following technical solution.

[0007] A packaging box printing surface defect detection device includes a gantry inspection frame. A bidirectional centering reset unit is fixedly installed at the middle position of both sides of the inner wall of the opening end of the gantry inspection frame. A first detection unit and a second detection unit are assembled through the bidirectional centering reset unit. The bidirectional centering reset unit ensures that the first detection unit and the second detection unit always have a centering and close-fitting movement tendency to clamp the packaging box panel.

[0008] The gantry inspection frame is equipped with independent inspection modules on both sides. Each inspection module includes a lateral rocker arm bracket located in the middle of the outer wall of the gantry inspection frame. Each lateral rocker arm bracket rotates up and down to drive the packaging box panel held by the first inspection unit and the second inspection unit to rotate dynamically.

[0009] The first detection unit includes a first high-transparency cylinder and a detection camera inside the first high-transparency cylinder, and the second detection unit includes a second high-transparency cylinder and a detection light box inside the second high-transparency cylinder. Together with the two side inspection modules, they drive the packaging box panel to perform physical performance testing of the coating surface during dynamic twisting.

[0010] As a further aspect of the present invention: the inspection module includes a collar frame movably installed on the top of the gantry inspection frame. Servo telescopic rods are fixedly connected to the sides of the collar frame. U-shaped traction brackets are movably installed on the telescopic ends of the servo telescopic rods. The opening size of the U-shaped traction bracket is the same as the opening size of the gantry inspection frame. Elastic centering and abutting modules are configured on both sides of the opening end of the U-shaped traction bracket. Each elastic centering and abutting module includes a bidirectional frame bracket. Hollow frames are opened on both sides of the bidirectional frame bracket, and several limiting rods are fixedly connected to each hollow frame.

[0011] As a further aspect of the present invention: the elastic centering and abutting module further includes a reset spring sleeve sleeved on each limiting rod. The reset spring sleeves in the two-way bidirectional frame brackets on both sides extend toward the midpoint of the two-way frame brackets, and a reset plate slidably sleeved on the limiting rod is fixedly installed on the extended end. A track drive sleeve is fixedly installed on one reset plate, and several driven sleeves are movably installed on the other reset plate. Several drive sleeves meshing with each other are fixedly installed on the output end of the track drive sleeve. The drive sleeve and the driven sleeve are all cavities with cotton tubes on their outer surfaces and openings for leakage holes, and a reverse suction fan is arranged in each cavity.

[0012] As a further aspect of the present invention: two sets of parallel hinged sleeves are fixedly connected at the midpoint of the outer side of the gantry inspection frame, and hinged sleeves are respectively hinged on the front and rear sides of the gantry inspection frame through the hinged sleeves. A first servo motor is fixedly installed on the side of each hinged sleeve. A lateral rocker arm bracket is fixedly connected to the surface of each first servo motor. A threaded rod that is integrally housed inside the lateral rocker arm bracket is fixedly installed on the output end of each first servo motor, and a nut slider that is slidably sleeved inside the lateral rocker arm bracket is engaged on each threaded rod. The two sides of the U-shaped traction bracket are movably connected to the nut slider to support the lateral rocker arm brackets on both sides through the servo telescopic rod.

[0013] As a further embodiment of the present invention: a rejection track is fixedly installed at the bottom of the gantry inspection frame; the overall structure of the bidirectional centering reset unit is the same as the centering tension structure composed of a bidirectional sleeve bracket, a limiting rod, a reset spring sleeve, and a reset plate in the elastic centering contact module; the first inspection unit and the second inspection unit are contacted by centering tension; and a detection feedback screen is also fixedly installed at the top side of the gantry inspection frame.

[0014] As a further aspect of the present invention: the first detection unit includes a first positioning sleeve fixedly installed on the upper tension end of the bidirectional centering reset unit. A first bearing sleeve is fixedly installed on the side of the first positioning sleeve facing the opening end of the gantry detection frame, and a first high-penetration cylinder is fixedly installed through the first bearing sleeve. Both the first bearing sleeve and the first high-penetration cylinder are annular. A monitoring component is fixedly installed in one side of the first positioning sleeve. A first linear motor is fixedly installed on the side end of the monitoring component, which is parallel to the inside of the first high-penetration cylinder. A detection camera is fixedly installed on the output end of the first linear motor, and the detection end of the detection camera is vertically facing directly downward.

[0015] As a further aspect of the present invention: the second detection unit includes a second positioning sleeve fixedly installed on the lower tension end of the bidirectional centering reset unit. A second bearing sleeve is fixedly installed on the side of the second positioning sleeve facing the opening end of the gantry detection frame, and a second high-penetration cylinder is fixedly installed through the second bearing sleeve. The second high-penetration cylinder and the second bearing sleeve are also annular. A second servo motor is fixedly installed in one side of the second positioning sleeve, and an extension support rod is fixedly installed in the other side of the second positioning sleeve. The output end of the second servo motor and the extension support rod are both inserted parallel to each other into the interior of the second high-penetration cylinder.

[0016] As a further aspect of the present invention: a rotating sleeve is fixedly installed on the output end of the second servo motor that penetrates into the second high-permeability cylinder. The rotating sleeve is fixedly connected to the inner wall of the side end of the second high-permeability cylinder to actively control the rotation of the second high-permeability cylinder. A crossbeam support frame is fixedly installed on one side of the extension rod that penetrates into the second high-permeability cylinder. A detection light box is fixedly installed on the upper side of the crossbeam support frame. The detection end of the detection light box is vertically facing upwards. A second linear motor is fixedly installed on the lower side of the crossbeam support frame. A third detection unit is configured on the output end of the second linear motor.

[0017] As a further aspect of the present invention: the third detection unit includes a fitting sleeve block, on the outer side of which a circular guide rail frame is fixedly mounted as an integral part of the crossbeam support frame, an inner circular sleeve frame is movably mounted on the side of the circular guide rail frame, a toothed collar is fixedly mounted on the circular edge of the inner circular sleeve frame, a third servo motor is fixedly mounted on the bottom of the fitting sleeve block, a gear disk is fixedly mounted on the output end of the third servo motor, and the gear disk meshes with the teeth of the toothed collar to drive the inner circular sleeve frame to rotate along the circular edge of the circular guide rail frame.

[0018] As a further aspect of the present invention: the third detection unit further includes a Hall magnetic block fixedly installed on the outer ring edge of the embedded circular ring frame. The Hall magnetic block is integrally attached to the inner wall of the second high-transparency cylinder, and an arc-shaped magnetic block is adsorbed and installed on the outer wall of the second high-transparency cylinder at a position corresponding to the Hall magnetic block. A battery block is installed at the inner center of the arc-shaped magnetic block, and a high-brightness LED bead is assembled on the surface of the battery block. A high-transparency hemispherical cavity cover that is integrally covered outside the high-brightness LED bead is fixedly installed on the surface of the arc-shaped magnetic block.

[0019] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects:

[0020] (1) This solution achieves online detection of the physical integrity of the coating on the printed surface of the packaging box under simulated bending conditions through dynamic torsion detection. Unlike existing technologies that rely on static optical measurement and cannot capture cracking defects in the coating during subsequent molding processes, this solution uses a bidirectional centering reset unit to keep the upper and lower detection units always centered and close together, adaptively clamping panels of different sizes. Combined with the detection camera and light box inside the high-transparency cylinder, the coating is observed in real time during the torsion process, overcoming the limitation of only being able to perform static appearance screening. This solution enables online identification of potential defects such as insufficient coating cohesion, preventing defective products from flowing into subsequent processes.

[0021] (2) Through a magnetic control mechanism, a local pressure point is formed in the high-transparency hemispherical cavity cover, simulating the point stress in actual use. This induces the development of micro-defects in the coating without mechanical contact, allowing for microscopic scanning of the coating area and identification of subtle issues such as uneven particle coverage. Compared to existing light transmission detection methods that can only determine overall thickness differences, this method dynamically exposes physical defects in the coating through the synergistic effect of light pressure and bending stress, thus improving the sensitivity and reliability of the detection. Attached Figure Description

[0022] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the invention and, together with the specification, further serve to explain the principles of the invention and enable those skilled in the art to practice and use the invention.

[0023] Figure 1This is a schematic diagram of the operation of the present invention in its production state;

[0024] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 3 This is a partial structural schematic diagram of the gantry inspection frame of the present invention;

[0026] Figure 4 This is a schematic diagram of the inspection module of the present invention;

[0027] Figure 5 for Figure 4 Enlarged structural diagram at point A;

[0028] Figure 6 This is a schematic diagram of the first detection unit of the present invention in a semi-sectional state;

[0029] Figure 7 This is a schematic diagram of the half-section structure of the second detection unit of the present invention;

[0030] Figure 8 This is a schematic diagram of the structure of the third detection unit in the split state of the present invention;

[0031] Figure 9 This is a schematic diagram of the high-transparency hemispherical cavity cover of the present invention in a half-section state;

[0032] Figure 10 This is a schematic diagram of the structure for detecting the flattening of the printed surface of the packaging box according to the present invention;

[0033] Figure 11 This is a schematic diagram of the structure for detecting the bending of the printed surface of the packaging box according to the present invention.

[0034] Figure Labels

[0035] 1. Gantry inspection frame; 2. Track removal;

[0036] 3. Inspection module; 31. Collar frame; 32. Servo telescopic rod; 33. U-shaped traction bracket; 34. Lateral rocker arm bracket; 35. Hinge sleeve; 36. First servo motor; 37. Threaded rod; 38. Nut slider;

[0037] 4. Hinged socket;

[0038] 5. Flexible centering and contacting module; 51. Two-way sleeve bracket; 52. Limiting rod; 53. Return spring sleeve; 54. Returning plate; 55. Track drive sleeve; 56. Drive sleeve; 57. Driven sleeve;

[0039] 6. Bidirectional centering reset unit;

[0040] 7. First detection unit; 71. First positioning sleeve; 72. First bearing sleeve; 73. First high-transparency cylinder; 74. Monitoring component; 75. First linear motor; 76. Detection camera;

[0041] 8. Second detection unit; 81. Second positioning sleeve; 82. Second bearing sleeve; 83. Second high-transparency cylinder; 84. Second servo motor; 85. Rotating sleeve; 86. Extension support rod; 87. Crossbeam support frame; 88. Detection light box; 89. Second linear motor.

[0042] 9. Detection feedback screen;

[0043] 10. Third detection unit; 101. Fitting sleeve block; 102. Circular guide rail frame; 103. Third servo motor; 104. Gear disk; 105. Embedded circular sleeve frame; 106. Toothed collar; 107. Hall magnetic block; 108. Arc-shaped magnetic block; 109. Battery block; 1010. High-transparency hemispherical cavity cover; 1011. High-brightness LED bead.

[0044] As shown in the figure, specific structures and devices are marked in the figure to clearly illustrate the structure of the embodiments of the present invention. However, this is only for illustrative purposes and is not intended to limit the present invention to this specific structure, device and environment. Those skilled in the art can adjust or modify these devices and environments according to specific needs. Detailed Implementation

[0045] The following is a detailed description of a packaging box printing surface defect detection device provided by the present invention, with reference to the accompanying drawings and specific embodiments. It should be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0046] like Figures 1 to 11 As shown, this embodiment of the invention provides a packaging box printing surface defect detection device, including a gantry inspection frame 1. A bidirectional centering reset unit 6 is fixedly installed at the middle position of both sides of the inner wall of the opening end of the gantry inspection frame 1. A first detection unit 7 and a second detection unit 8 are assembled through the bidirectional centering reset unit 6. The bidirectional centering reset unit 6 ensures that the first detection unit 7 and the second detection unit 8 always have a centering and close-fitting movement tendency to clamp the packaging box panel.

[0047] The gantry inspection frame 1 is equipped with independent inspection modules 3 on both sides. Each inspection module 3 includes a lateral rocker arm bracket 34 located in the middle of the outer wall of the gantry inspection frame 1. Each lateral rocker arm bracket 34 rotates up and down to drive the packaging box panel held by the first inspection unit 7 and the second inspection unit 8 to rotate dynamically.

[0048] The first detection unit 7 includes a first high-transparency cylinder 73 and a detection camera 76 inside the first high-transparency cylinder 73. The second detection unit 8 includes a second high-transparency cylinder 83 and a detection light box 88 inside the second high-transparency cylinder 83. Together with the two side inspection modules 3, the packaging box panel is driven to perform physical performance testing of the coating surface during dynamic twisting.

[0049] To address the problem that existing technologies cannot detect physical integrity defects of functional coatings during bending in real time and dynamically on packaging box production lines, the above-mentioned technical solution is adopted. This solution mainly consists of a gantry inspection frame 1, a delivery module 3, a bidirectional centering reset unit 6, a first inspection unit 7, and a second inspection unit 8. The gantry inspection frame 1 serves as the support frame of the equipment. Its open end is used for feeding and inspecting packaging box panels. Bidirectional centering reset units 6 are fixedly installed at the middle positions on both sides of the inner wall of the open end of the gantry inspection frame 1. The bidirectional centering reset unit 6 is a mechanical reset mechanism, providing bidirectional elastic reset force. This ensures that the first inspection unit 7 and the second inspection unit 8 assembled on it always have a tendency to move towards the center, ensuring that the equipment can automatically adapt to packaging box panels of different sizes while also stably serving as a fulcrum for subsequent bending of the packaging box panels, thus improving inspection efficiency. The delivery module 3, configured on both sides of the gantry inspection frame 1, includes a lateral rocker arm bracket 34 located at the middle position of the outer wall of the gantry inspection frame 1. The lateral rocker arm bracket 34 can rotate up and down, and its angle can be adjusted according to the detection, conveying, or rejection states during operation to adapt to different work requirements. The first detection unit 7 and the second detection unit 8 are assembled in an up-down manner through the bidirectional centering reset unit 6 to form a clamping area. The first detection unit 7 includes a first high-transparency cylinder 73 and a detection camera 76 inside it, while the second detection unit 8 includes a second high-transparency cylinder 83 and a detection light box 88 inside it. Both the first high-transparency cylinder 73 and the second high-transparency cylinder 83 are made of high-transparency materials, including but not limited to optical plastics in the prior art, to ensure that light and image transmission are distortion-free. The detection camera 76 is fixed inside the first high-transparency cylinder 73 to capture images of the printed surface of the packaging box, while the detection light box 88 is fixed inside the second high-transparency cylinder 83 to provide uniform illumination and assist the camera in detecting surface defects. The first detection unit 7 and the second detection unit 8 are arranged in a symmetrical layout and combined with a high-transparency cylinder design. This not only enables simultaneous double-sided supplementary lighting detection of the packaging box panel, but also simulates the bending conditions in the actual subsequent packaging process through a dynamic torsion process. Compared with the light transmission detection in the prior art, it can observe the coating cracking or peeling in real time during the torsion process, thereby detecting physical performance defects such as insufficient coating cohesion.

[0050] like Figures 1 to 11As shown, the inspection module 3 includes a collar frame 31 movably installed on the top of the gantry inspection frame 1. Servo telescopic rods 32 are fixedly connected to the sides of the collar frame 31. U-shaped traction brackets 33 are movably installed on the telescopic ends of the servo telescopic rods 32. The opening end size of the U-shaped traction bracket 33 is the same as the opening end size of the gantry inspection frame 1. Elastic centering and abutting modules 5 are arranged on both sides of the opening end of the U-shaped traction bracket 33. Each elastic centering and abutting module 5 includes a bidirectional frame bracket 51. Hollow frames are opened on both sides of the bidirectional frame bracket 51, and several limiting rods 52 are fixedly connected to each hollow frame.

[0051] The inspection module 3 is an independent structure located on both sides of the gantry inspection frame 1. Each inspection module 3 operates and is independently controlled, used for adjustment and conveying during the inspection of packaging box panels. The collar frame 31 is connected to the top of the gantry inspection frame 1 through a movable installation method, allowing the collar frame 31 to rotate according to inspection requirements, thereby adapting to different working states. The servo telescopic rod 32 is a drive device capable of CNC telescopic extension and retraction in the prior art. Its extension and retraction stroke is adjusted by electrical signals to achieve fine-tuning of the overall position of the inspection module 3, ensuring the stability of power transmission. The U-shaped traction bracket 33 is connected to the telescopic end of the servo telescopic rod 32 through a movable installation method such as bearings, allowing the U-shaped traction bracket 33 to swing to adapt to the entry and exit of packaging box panels. Furthermore, the opening size of the U-shaped traction bracket 33 is the same as the opening size of the gantry inspection frame 1, ensuring that the U-shaped traction bracket 33 can be aligned with the inspection area of ​​the gantry inspection frame 1, avoiding offset and jamming during panel conveying.

[0052] like Figures 1 to 11 As shown, the elastic centering and abutting module 5 also includes a reset spring sleeve 53 sleeved on each limiting rod 52. The reset spring sleeves 53 in the two-way bidirectional frame brackets 51 on both sides extend toward the midpoint of the two-way frame brackets 51, and a reset plate 54 slidably sleeved on the limiting rod 52 is fixedly installed on the extended end. A track drive sleeve 55 is fixedly installed on one reset plate 54, and several driven sleeves 57 are movably installed on the other reset plate 54. Several drive sleeves 56 that mesh with each other are fixedly installed on the output end of the track drive sleeve 55. The drive sleeves 56 and driven sleeves 57 are all cavities with cotton tubes on their outer surfaces and openings for leakage holes. A reverse suction fan is arranged in each cavity.

[0053] like Figures 1 to 11As shown, two sets of parallel hinged sleeves 4 are fixedly connected at the midpoint of the outer side of the gantry inspection frame 1. Hinged sleeves 35 are respectively hinged to the front and rear sides of the gantry inspection frame 1 through the hinged sleeves 4. A first servo motor 36 is fixedly installed on the side of each hinged sleeve 35. A lateral rocker arm bracket 34 is fixedly connected to the surface of each first servo motor 36. A threaded rod 37, which is integrally housed inside the lateral rocker arm bracket 34, is fixedly installed on the output end of each first servo motor 36. A nut slider 38, which is slidably sleeved inside the lateral rocker arm bracket 34, is engaged on each threaded rod 37. The two sides of the U-shaped traction bracket 33 are movably connected to the nut slider 38 so as to support the lateral rocker arm brackets 34 on both sides through the servo telescopic rod 32.

[0054] The hinged sleeve 4 serves as a fixed connection point, and hinged sleeves 35 are hinged to the front and rear sides of the gantry inspection frame 1 through the hinged sleeve 4, allowing the hinged sleeves 35 to adapt to the swing of the lateral rocker arm bracket 34 within a certain range. The first servo motor 36 configured on the side of the hinged sleeve 35 is a programmable control drive device in the prior art, used to provide power output. The lateral rocker arm bracket 34 is integrated with the first servo motor 36 through a fixed connection to form an integral swing unit. The nut slider 38 and the threaded rod 37 are engaged by threads. When the first servo motor 36 drives the threaded rod 37 to rotate, the nut slider 38 slides linearly along the threaded rod 37. In actual operation, by controlling the clockwise and counterclockwise rotation of the threaded rod 37, the nut slider 38 is controlled to slide linearly to different positions to adapt to different tilt states of the lateral rocker arm bracket 34. Since the U-shaped traction bracket 33 is movably connected to the nut slider 38 on both sides, the lateral rocker arm brackets 34 on both sides can be supported by the servo telescopic rod 32. The servo telescopic rod 32 can adjust the position of the U-shaped traction bracket 33 by telescopic movement, thereby controlling the rotation of the lateral rocker arm bracket 34.

[0055] In the specific working process, the packaging box panel to be inspected is sent into the inspection area of ​​the gantry inspection frame 1. At this time, the inspection modules 3 on both sides of the gantry inspection frame 1 are in a ready position. Through the servo extension and retraction control of the servo telescopic rod 32, using the principle of oblique lifting, and in conjunction with the hinged state of the hinge sleeves 35 and the hinged sleeve heads 4 on both sides, the outer U-shaped traction bracket 33 and the lateral rocker arm brackets 34 on both sides of the U-shaped traction bracket 33 are adjusted to a horizontal position. After the lateral rocker arm brackets 34 are adjusted to a horizontal position, the output thread of the first servo motor 36 is synchronously controlled. The rod 37 rotates synchronously, driving the nut slider 38 facing the side of the packaging box panel to be inspected to the outermost position of the lateral rocker arm bracket 34, so as to enter the state of preparing to receive the packaging box panel to be inspected. Meanwhile, the nut slider 38 of the inspection module 3 on the other side is driven to the position close to the gantry inspection frame 1, so as to enter the state of preparing to receive the packaging box panel to be inspected after being processed by the first inspection unit 7 and the second inspection unit 8. In this state, the packaging box panel to be inspected can be stably and horizontally transported by the flush cooperation of the two inspection modules 3. Furthermore, during subsequent inspection, by simultaneously controlling the servo telescopic rods 32 on both sides of the inspection module 3 to retract synchronously, the U-shaped traction brackets 33 on both sides can be pulled upward and centered around the gantry inspection frame 1 as the central axis. This causes the flexible coated packaging box panel, which is held by the elastic centering and abutting module 5, to form a U-shaped opening with the opening facing upward. Alternatively, the servo telescopic rods 32 on both sides of the inspection module 3 can be simultaneously extended synchronously, causing the flexible coated packaging box panel, which is held by the elastic centering and abutting module 5, to form a U-shaped opening with the opening facing downward. The extension and retraction states of the servo telescopic rods 32 on both sides of the inspection module 3 can also be independently controlled, causing the flexible coated packaging box panel, which is held by the elastic centering and abutting module 5, to form an irregular curved shape to fully expose whether the coverage of the particles to be scraped on the special coating surface is uniform.

[0056] The flexible centering and abutting module 5 has the same function as the bidirectional centering and reset unit 6, used for centering and clamping. The reset spring sleeve 53 is an elastic element in the prior art, sleeved outside the limiting rod 52, to provide reset force. The reset spring sleeves 53 in the bidirectional sleeve brackets 51 on both sides extend towards the midpoint of the bidirectional sleeve brackets 51, ensuring that the reset force always points in the center direction, so that the module can automatically return to its original position when subjected to external force. The reset plate 54 is slidably sleeved on the limiting rod 52, allowing it to slide freely on the limiting rod 52, while being pushed by the reset spring sleeve 53. For a single inspection module 3, a track drive sleeve 55 is fixedly installed on one side of the reset plate 54. The track drive sleeve 55 is a device with a built-in motor and synchronous drive through track power transmission in the prior art, fixed on the reset plate 54, to drive the drive sleeve 56 to rotate. The rotation of the drive sleeve 56 can cooperate with the driven sleeve 57 to rotate into the panel to be inspected. Both the driving sleeve 56 and the driven sleeve 57 are hollow structures with cotton tubes on their outer surfaces and perforations. Each cavity is equipped with a reverse suction fan. The cotton tube material provides flexibility, and the perforation design allows airflow. The reverse suction fan generates negative pressure in the cavity, thereby enabling the packaging box panel to adsorb dust on its surface during the process of being rotated in by the driving sleeve 56, reducing debris interference in the coating area.

[0057] like Figures 1 to 11 As shown, the bottom of the gantry inspection frame 1 is fixedly installed with a rejection track 2. The overall structure of the bidirectional centering reset unit 6 is the same as the centering tension structure in the elastic centering contact module 5, which consists of a bidirectional sleeve bracket 51, a limiting rod 52, a reset spring sleeve 53, and a reset plate 54. The first detection unit 7 and the second detection unit 8 are contacted by centering tension. A detection feedback screen 9 is also fixedly installed at the top side of the gantry inspection frame 1.

[0058] The rejection conveyor 2, configured as a transport mechanism, is fixedly installed on the bottom base frame of the gantry inspection frame 1. Its position allows it to receive and transfer packaging box panels identified as defective. The entire system consists of a motor-driven conveyor chain, enabling continuous or intermittent operation. It is used to quickly remove non-conforming panels from the inspection area, preventing them from flowing into subsequent processes. Its integration into the bottom of the equipment saves space while ensuring the smooth operation of the production line. The inspection feedback screen 9 is a standard human-machine interface screen found on existing production lines. It is fixedly installed on the top side of the gantry inspection frame 1, allowing operators to monitor the inspection status in real time. It displays image data captured by the inspection camera 76, defect analysis results, equipment operating parameters, and rejection instructions.

[0059] During the inspection process, if the inspection feedback screen 9 displays a defect in the resilient packaging box panel, such as coating cracking or peeling, the equipment will initiate a rejection procedure, achieved through the coordinated action of the delivery module 3 and the rejection track 2. The delivery module 3, used to transport the packaging box panel, is pulled upwards by the retraction of its servo telescopic rod 32, causing the U-shaped traction bracket 33 and the lateral rocker arm bracket 34 to rotate around the hinge point of the hinge sleeve 4 and the hinge sleeve 35. This tilts the delivery module 3 from a horizontal position toward the rejection track 2 at the bottom of the gantry inspection frame 1, ensuring that the panel transport path points toward the rejection track 2. After the delivery module 3 is tilted and positioned, its elastically centered abutment module 5's track drive disc 55 is controlled to reverse drive. The track drive disc 55, through the meshing transmission of the drive sleeve 56 and the driven sleeve 57 on the output end, drives the clamped panel back in the opposite direction, i.e., toward the rejection track 2. Due to the tilted posture of the inspection module 3, the reverse-feedback panel slides onto the surface of the rejection track 2, which then starts to transport the panel to the waste area or a designated collection point to complete the rejection operation. Throughout the process, the detection feedback screen 9 updates the rejection status in real time to ensure the traceability of the action.

[0060] like Figures 1 to 11 As shown, the first detection unit 7 includes a first positioning sleeve 71 fixedly installed on the upper tension end of the bidirectional centering reset unit 6. A first bearing sleeve 72 is fixedly installed on the side of the first positioning sleeve 71 facing the opening end of the gantry detection frame 1, and a first high-penetration cylinder 73 is fixedly installed through the first bearing sleeve 72. Both the first bearing sleeve 72 and the first high-penetration cylinder 73 are annular. A monitoring component 74 is fixedly installed in one side of the first positioning sleeve 71. A first linear motor 75 is fixedly installed on the side end of the monitoring component 74, which is parallel to the inside of the first high-penetration cylinder 73. A detection camera 76 is fixedly installed on the output end of the first linear motor 75, and the detection end of the detection camera 76 is vertically facing directly downward.

[0061] The first positioning sleeve 71, serving as the basic support structure of the first detection unit 7, is fixedly installed on the upper tension end of the bidirectional centering reset unit 6. It is cylindrical in shape, with the side of the first positioning sleeve 71 facing the opening of the gantry inspection frame 1 designed as an open end to facilitate alignment of the detection components with the packaging box panel. A first bearing sleeve 72, an annular structure with an integrated rolling bearing, is fixedly installed on the side of the first positioning sleeve 71 facing the opening of the gantry inspection frame 1, providing rotational support for the first high-transparency cylinder 73. The first high-transparency cylinder 73 is made of a high-transparency material to ensure distortion-free light transmission. Because the first high-transparency cylinder 73 is connected via a bearing in the first bearing sleeve 72, it can rotate freely relative to the first positioning sleeve 71, allowing it to adjust its position vertically during detection and to rotate with the incoming detection panel. The first linear motor 75 is a linear drive device in the prior art, which can control the linear displacement of its output end through electrical signals. The installation direction of the first linear motor 75 is parallel to the axis of the first high-transparency cylinder 73 to ensure that the movement trajectory does not deviate from the detection area. A monitoring component 74 is fixedly installed in the first positioning sleeve 71 on one side. The monitoring component 74 is a conventional module that works with the detection end in the prior art, including sensors, control circuits or data processors, used to monitor the working status of the detection camera 76. The first linear motor 75 is fixedly installed on the monitoring component 74 and forms a rigid connection with the first positioning sleeve 71 on one side. During the rotation of the first high-transparency cylinder 73 following the rotating detection panel, the detection angle between the monitoring component 74 and the detection camera 76 can also be kept stable. The configured detection camera 76 is a high-resolution industrial camera in the prior art, used to capture images of the printed surface of the packaging box. Driven by the first linear motor 75, the detection camera 76 can move parallel inside the first high-transparency cylinder 73 to adjust the focus or scan different areas, thereby adapting to the bending or twisting state of the panel.

[0062] like Figures 1 to 11 As shown, the second detection unit 8 includes a second positioning sleeve 81 fixedly installed on the lower tension end of the bidirectional centering reset unit 6. A second bearing sleeve 82 is fixedly installed on the side of the second positioning sleeve 81 facing the opening end of the gantry detection frame 1, and a second high-penetration cylinder 83 is fixedly installed through the second bearing sleeve 82. The second high-penetration cylinder 83 and the second bearing sleeve 82 are also annular. A second servo motor 84 is fixedly installed in one side of the second positioning sleeve 81, and an extension rod 86 is fixedly installed in the other side of the second positioning sleeve 81. The output end of the second servo motor 84 and the extension rod 86 are both inserted parallel into the interior of the second high-penetration cylinder 83.

[0063] The second detection unit 8 is fixedly mounted on the lower tension end of the bidirectional centering reset unit 6. Through the elastic reset force of the bidirectional centering reset unit 6, the second detection unit 8 maintains a tendency to move towards the center, thus working in conjunction with the upper first detection unit 7 to clamp the packaging box panel. The second positioning sleeve 81, as a basic support component, is directly fixed to the lower tension end of the bidirectional centering reset unit 6 to ensure overall stability. A second high-transparency cylinder 83 is fixedly mounted via a second bearing sleeve 82. The second high-transparency cylinder 83 is also annular and made of a high-transparency material to ensure that light transmission is distortion-free or scattering-free, thereby providing uniform illumination for detection. A second servo motor 84 is fixedly mounted in one side of the second positioning sleeve 81. This servo motor 84 is used to actively control the movement of the second high-transparency cylinder 83. An extension support rod 86 is fixedly mounted in the other side of the second positioning sleeve 81. The extension support rod 86, as a rigid support element, is symmetrically arranged with the second servo motor 84 to ensure structural balance and provide a foundation for components such as the detection light box 88.

[0064] like Figures 1 to 11 As shown, a rotating sleeve 85 is fixedly installed on the output end of the second servo motor 84, which is inserted into the second high-permeability cylinder 83. The rotating sleeve 85 is fixedly connected to the inner wall of the side end of the second high-permeability cylinder 83 to actively control the rotation of the second high-permeability cylinder 83. A crossbeam support frame 87 is fixedly installed on one side of the extension rod 86, which is inserted into the second high-permeability cylinder 83. A detection light box 88 is fixedly installed on the upper side of the crossbeam support frame 87. The detection end of the detection light box 88 is vertically facing upward. A second linear motor 89 is fixedly installed on the lower side of the crossbeam support frame 87. A third detection unit 10 is configured on the output end of the second linear motor 89.

[0065] The second servo motor 84, via a rotating bracket 85, actively controls the rotation of the second high-transparency cylinder 83 to stably connect to the packaged box panel that has been transferred in, cooperating with the driven first detection unit 7 for conveying and detection. The configured detection light box 88 provides high-brightness low-light to illuminate one end of the coating for light transmission detection.

[0066] like Figures 1 to 11As shown, the third detection unit 10 includes a fitting sleeve block 101. A circular guide rail frame 102, which is integrally fitted outside the crossbeam support frame 87, is fixedly installed on the outer side of the fitting sleeve block 101. An embedded circular sleeve frame 105 is movably installed on the side of the circular guide rail frame 102. A toothed collar 106 is fixedly installed on the circular edge of the embedded circular sleeve frame 105. A third servo motor 103 is fixedly installed at the bottom of the fitting sleeve block 101. A gear disk 104 is fixedly installed on the output end of the third servo motor 103. The gear disk 104 meshes with the teeth of the toothed collar 106 to drive the embedded circular sleeve frame 105 to rotate along the circular edge of the circular guide rail frame 102.

[0067] like Figures 1 to 11 As shown, the third detection unit 10 further includes a Hall magnetic block 107 fixedly installed on the outer ring edge of the inner ring sleeve 105. The Hall magnetic block 107 is integrally attached to the inner wall of the second high-transparency cylinder 83, and an arc-shaped magnetic block 108 is adsorbed and installed on the outer wall of the second high-transparency cylinder 83 at a position corresponding to the Hall magnetic block 107. A battery block 109 is installed at the inner center of the arc-shaped magnetic block 108. A high-brightness LED bead 1011 is assembled on the surface of the battery block 109. A high-transparency hemispherical cavity cover 1010 is fixedly installed on the surface of the arc-shaped magnetic block 108, which is integrally covered by the high-brightness LED bead 1011.

[0068] The third detection unit 10 is configured to perform local fine detection of the coating on the printed surface of the packaging box. It simulates local pressure points when the panel is stationary through magnetic control and non-contact transmission mechanism to enhance the detection accuracy of the uniformity of coating particle coverage. It is configured on the lower side of the second detection unit 8 and connected through the output end of the second linear motor 89. The fitting block 101 serves as a basic mounting component, and a circular guide rail frame 102, which is integrally fitted onto the outside of the crossbeam support frame 87, is fixedly mounted on its outer side. The circular guide rail frame 102 is a ring track structure that provides a circular motion path. An embedded circular sleeve frame 105 is movably mounted on the side of the circular guide rail frame 102. The embedded circular sleeve frame 105 can slide along the circular edge of the circular guide rail frame 102. A toothed collar 106 is fixedly mounted on its circular edge. The toothed collar 106 has a uniformly distributed tooth structure. A gear disk 104 is fixedly mounted on the output end of the third servo motor 103. The gear disk 104 meshes with the teeth of the toothed collar 106. When the third servo motor 103 is started, the gear disk 104 drives the toothed collar 106 to rotate, thereby causing the embedded circular sleeve frame 105 to rotate along the circumference of the circular guide rail frame 102. The Hall magnetic block 107 is integrally attached to the inner wall of the second high-transparency cylinder 83. Utilizing the Hall controllable magnetic field, an arc-shaped magnetic block 108 is adsorbed and installed on the outer wall of the second high-transparency cylinder 83 at a position corresponding to the Hall magnetic block 107. The arc-shaped magnetic block 108 is coupled to the Hall magnetic block 107 through magnetic attraction to achieve non-contact transmission. A battery block 109 is installed at the center of the arc-shaped magnetic block 108. The battery block 109 is an independent power source, and a high-brightness LED bead 1011 is assembled on its surface. The high-brightness LED bead 1011 can emit high-intensity light. The high-transparency hemispherical cavity cover 1010 is made of a high-transparency material, forming a hemispherical protrusion structure for transmitting light and simulating local pressure.

[0069] During the inspection process, after the inspection module 3 completes the dynamic torsion, fine inspection can be performed as needed. First, the packaging box panel is brought to a standstill in the inspection position. The third servo motor 103, through the meshing transmission of the gear disk 104 and the toothed collar 106, controls the inner circular ring frame 105 and the Hall magnetic block 107 to move along the circumference of the circular guide rail frame 102. The magnetic field change of the Hall magnetic block 107 drives the outer arc-shaped magnetic block 108 to move synchronously, positioning the high-transparency hemispherical cavity cover 1010 to the target area on the bottom surface of the panel. Light passes through the high-transparency hemispherical cavity cover 1010 to form a local light spot, and at the same time, the hemispherical structure produces a convex point effect, simulating the bending stress in actual use. The inspection camera 76 captures the microscopic reaction of the coating under light pressure in real time, and identifies defects such as uneven particle coverage, peeling, or cracks through image analysis, avoiding damage caused by mechanical contact, improving the sensitivity and reliability of the inspection, and is especially suitable for the quality inspection of special coatings on high-end tough packaging box surfaces in existing technologies.

[0070] The usage method provided by this invention is as follows:

[0071] In use, the invention firstly monitors the packaging box production line in real time based on the detection feedback screen 9, and the control device starts the detection process. The packaging box panel is sent into the opening end of the gantry inspection frame 1. The bidirectional centering reset unit 6, which is fixedly installed at the middle position of both sides of the inner wall of the opening end of the gantry inspection frame 1, uses its elastic reset force to make the first detection unit 7 assembled on the upper side and the second detection unit 8 assembled on the lower side always have a tendency to move towards the center, thereby automatically clamping the packaging box panel and transferring the panel through the outer inspection module 3 for transferring the packaging box panel.

[0072] Then, the servo telescopic rod 32 of the inspection module 3 retracts synchronously, pulling the U-shaped traction bracket 33 axially upward with the gantry inspection frame 1 as the center. This causes the packaging box panel, held by the elastically centered abutment module 5, to concave out into an upward-facing U-shape, simulating a bending condition. Simultaneously, the first inspection unit 7 and the second inspection unit 8 work together. The inspection camera 76, driven by the first linear motor 75, moves parallel inside the first high-transparency cylinder 73, adjusting its focus to capture images of the coating surface during the torsion process. The second high-transparency cylinder 83 of the second inspection unit 8 is connected to the second positioning sleeve 81 via the second bearing sleeve 82. The second servo motor 84 actively controls the rotation of the second high-transparency cylinder 83 via the rotating sleeve 85, maintaining synchronization with the panel. During the process, the inspection light box 88 is fixed to the upper side of the crossbeam support frame 87, providing uniform illumination to assist camera imaging.

[0073] During the torsion process, the coating exposes physical defects such as cracking or peeling under bending stress. The detection camera 76 captures image data in real time, which is processed by the monitoring component 74 and compared with standard images at the pixel level to simulate the identification of potential defects such as insufficient coating cohesion in actual molding conditions.

[0074] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0075] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A defect detection device for printed surfaces of packaging boxes, comprising a gantry inspection frame, characterized in that: A bidirectional centering reset unit is fixedly installed at the middle position of both sides of the inner wall of the opening end of the gantry inspection frame. A first inspection unit and a second inspection unit are assembled through the bidirectional centering reset unit. The bidirectional centering reset unit ensures that the first inspection unit and the second inspection unit always have a centering and close-fitting movement tendency to hold the packaging box panel. The gantry inspection frame is equipped with independent inspection modules on both sides. Each inspection module includes a lateral rocker arm bracket located in the middle of the outer wall of the gantry inspection frame. Each lateral rocker arm bracket rotates up and down to drive the packaging box panel held by the first inspection unit and the second inspection unit to rotate dynamically. The first detection unit includes a first high-transparency cylinder and a detection camera inside the first high-transparency cylinder, and the second detection unit includes a second high-transparency cylinder and a detection light box inside the second high-transparency cylinder. Together with the two side inspection modules, the packaging box panel is driven to perform physical performance testing of the coating surface during dynamic twisting. The inspection module includes a collar frame movably installed on the top of the gantry inspection frame. Servo telescopic rods are fixedly connected to the sides of the collar frame. U-shaped traction brackets are movably installed on the telescopic ends of the servo telescopic rods. The opening end size of the U-shaped traction bracket is the same as the opening end size of the gantry inspection frame. Elastic centering and abutting modules are configured on both sides of the opening end of the U-shaped traction bracket. Each elastic centering and abutting module includes a bidirectional frame bracket. Hollow frames are opened on both sides of the bidirectional frame bracket, and several limiting rods are fixedly connected to each hollow frame. The elastic centering and abutting module also includes a reset spring sleeve sleeved on each limiting rod. The reset spring sleeves in the two-way bidirectional frame brackets on both sides extend toward the midpoint of the two-way frame brackets, and a reset plate that is slidably sleeved on the limiting rod is fixedly installed on the extended end. A track drive sleeve is fixedly installed on one reset plate, and several driven sleeves are movably installed on the other reset plate. Several drive sleeves that mesh with each other are fixedly installed on the output end of the track drive sleeve. The drive sleeve and the driven sleeve are all cavities with cotton tubes on their outer surfaces and openings for leakage holes. A reverse suction fan is configured in each cavity. The bottom of the gantry inspection frame is fixedly installed with a rejection track. The overall structure of the bidirectional centering reset unit is the same as the centering tension structure in the elastic centering contact module, which consists of a bidirectional sleeve bracket, a limiting rod, a reset spring sleeve, and a reset plate. The first and second inspection units are contacted by centering tension. A detection feedback screen is also fixedly installed at the top side of the gantry inspection frame.

2. The packaging box printing surface defect detection device according to claim 1, characterized in that, Two sets of parallel hinged heads are fixedly connected at the midpoint of the outer side of the gantry inspection frame. Hinged sleeves are hinged to the front and rear sides of the gantry inspection frame through the hinged heads. A first servo motor is fixedly installed on the side of each hinged sleeve. A lateral rocker arm bracket is fixedly connected to the surface of each first servo motor. A threaded rod that is integrally housed inside the lateral rocker arm bracket is fixedly installed on the output end of each first servo motor. A nut slider that is slidably sleeved inside the lateral rocker arm bracket is engaged on each threaded rod. The two sides of the U-shaped traction bracket are movably connected to the nut slider to support the lateral rocker arm brackets on both sides through the servo telescopic rod.

3. The packaging box printing surface defect detection device according to claim 2, characterized in that, The first detection unit includes a first positioning sleeve fixedly installed on the upper tension end of the bidirectional centering reset unit. A first bearing sleeve is fixedly installed on the side of the first positioning sleeve facing the opening end of the gantry detection frame, and a first high-penetration cylinder is fixedly installed through the first bearing sleeve. Both the first bearing sleeve and the first high-penetration cylinder are annular. A monitoring component is fixedly installed in one side of the first positioning sleeve. A first linear motor is fixedly installed on the side end of the monitoring component, parallel to the interior of the first high-penetration cylinder. A detection camera is fixedly installed on the output end of the first linear motor, and the detection end of the detection camera faces vertically downward.

4. The packaging box printing surface defect detection device according to claim 3, characterized in that, The second detection unit includes a second positioning sleeve fixedly installed on the lower tension end of the bidirectional centering reset unit. A second bearing sleeve is fixedly installed on the side of the second positioning sleeve facing the opening end of the gantry detection frame, and a second high-penetration cylinder is fixedly installed through the second bearing sleeve. The second high-penetration cylinder and the second bearing sleeve are also annular. A second servo motor is fixedly installed in one side of the second positioning sleeve, and an extension support rod is fixedly installed in the other side of the second positioning sleeve. The output end of the second servo motor and the extension support rod are both inserted parallel to each other into the interior of the second high-penetration cylinder.

5. The packaging box printing surface defect detection device according to claim 4, characterized in that, A rotating sleeve is fixedly installed on the output end of the second servo motor that penetrates into the second high-permeability cylinder. The rotating sleeve is fixedly connected to the inner wall of the side end of the second high-permeability cylinder to actively control the rotation of the second high-permeability cylinder. A crossbeam support frame is fixedly installed on one side of the extension rod that penetrates into the second high-permeability cylinder. A detection light box is fixedly installed on the upper side of the crossbeam support frame. The detection end of the detection light box faces vertically upward. A second linear motor is fixedly installed on the lower side of the crossbeam support frame. A third detection unit is configured on the output end of the second linear motor.

6. The packaging box printing surface defect detection device according to claim 5, characterized in that, The third detection unit includes a fitting sleeve block. A circular guide rail frame, which is integrally fitted onto the outside of the crossbeam support frame, is fixedly installed on the outer side of the fitting sleeve block. An embedded circular sleeve frame is movably installed on the side of the circular guide rail frame. A toothed collar is fixedly installed on the circular edge of the embedded circular sleeve frame. A third servo motor is fixedly installed at the bottom of the fitting sleeve block. A gear disk is fixedly installed on the output end of the third servo motor. The gear disk meshes with the teeth of the toothed collar to drive the embedded circular sleeve frame to rotate along the circular edge of the circular guide rail frame.

7. The packaging box printing surface defect detection device according to claim 6, characterized in that, The third detection unit also includes a Hall magnetic block fixedly installed on the outer ring edge of the embedded circular ring frame. The Hall magnetic block is integrally attached to the inner wall of the second high-transparency cylinder, and an arc-shaped magnetic block is adsorbed and installed on the outer wall of the second high-transparency cylinder at a position corresponding to the Hall magnetic block. A battery block is installed at the inner center of the arc-shaped magnetic block, and a high-brightness LED bead is assembled on the surface of the battery block. A high-transparency hemispherical cavity cover is fixedly installed on the surface of the arc-shaped magnetic block, which is integrally covered by the high-brightness LED bead.

Images