Visual inspection device for surface defects of plastic bottles

Abstract

This device for visually inspecting surface defects in plastic bottles relates to the field of material inspection technology using optical methods. It includes a conveying mechanism, a lateral clamping mechanism, a visual inspection module, and a rejection mechanism. By incorporating a sliding suction cup assembly within the suction hole, the repulsive force between a first and second magnet allows the vacuum suction cup to automatically adjust its height according to the bottle's bottom shape (e.g., flat, convex, or sloping), conforming to irregular surfaces and forming an effective seal. This solves the problem of traditional fixed planar suction holes being unable to accommodate irregularly shaped bottle bottoms, ensuring that plastic bottles do not tip over or shift due to inertia during high-speed transport, thus improving the stability and accuracy of the inspection process.

Description

Technical Field

[0001] This invention relates to the field of material inspection technology using optical means, and specifically to a visual inspection device for plastic bottles. Background Technology

[0002] In existing technologies, surface defects, flaws, and stains (such as scratches, bubbles, and deformation) on plastic bottles are typically detected quickly using visual inspection. However, the high speed of the conveyor belt used to transport the bottles can easily cause them to tip over. To address this issue, traditional solutions use multiple vacuum suction holes on the bottom of the conveyor belt to adhere to the bottle bottoms for stable transport. However, the bottom shapes of different types of plastic bottles vary significantly, and traditional vacuum suction holes have a fixed planar structure, which can only accommodate flat bottle bottoms and cannot flexibly switch suction modes, making it difficult for the same inspection equipment to meet diverse product requirements. When the bottle bottom is uneven, sloping, or curved (such as the flat bottom of mineral water bottles or the convex bottom of carbonated beverage bottles), the planar suction holes cannot effectively fit the bottle bottom and cannot form an effective seal with the curved surface, resulting in insufficient suction force. Especially during high-speed transport, bottles with irregularly shaped bottoms are prone to tipping or shifting due to inertia, leading to low inspection stability. Summary of the Invention

[0003] In view of this, the present invention provides a visual inspection device for surface defects of plastic bottles, which can better adapt to irregular bottle bottoms, and the plastic bottles are less likely to tip over or shift due to inertia during high-speed transportation, resulting in higher inspection stability.

[0004] To achieve the above objectives, the present invention provides the following technical solutions.

[0005] A visual inspection device for surface defects on plastic bottles, including:

[0006] The conveying mechanism includes a feeding belt conveyor and a detection belt conveyor, wherein the surface of the detection belt conveyor is provided with a plurality of adsorption holes spaced apart along its length.

[0007] The lateral clamping mechanism includes a feeding clamping mechanism connected to the feeding belt conveyor and a discharging clamping mechanism connected to the detection belt conveyor. Both of them are equipped with a spacing adjustment component and symmetrically arranged clamping belt conveyors.

[0008] The vision inspection module includes industrial cameras respectively positioned above and below the feeding clamping mechanism, and multiple side-view industrial cameras arranged around the inspection belt conveyor line;

[0009] The rejection mechanism includes an air jet device and a waste bottle collection box;

[0010] The inspection belt conveyor line is also equipped with a vacuum assembly and multiple suction cup assemblies. Each suction cup corresponds to a suction hole. The vacuum assembly includes:

[0011] Vacuum pump;

[0012] The suction cup assembly includes:

[0013] A suction cup mounting base is installed inside the suction hole, and its interior has a first cavity that is connected to a vacuum pump.

[0014] The connecting tube is slidably fitted coaxially with the suction cup mounting base. Its lower end is located in the first cavity and a first magnet is fixedly sleeved thereon. The connecting tube has a first air passage inside, and the first air passage is connected to the first cavity.

[0015] A vacuum suction cup is fixedly installed at the top of the connecting tube and is connected to the first air passage;

[0016] A reset spring is sleeved on the connecting tube and connected to the upper wall of the first cavity and the top surface of the first magnet, respectively.

[0017] The detection belt conveyor is equipped with a second magnet that repels the first magnet, and the position of the second magnet corresponds to the movement trajectory of the first magnet.

[0018] By incorporating a sliding suction cup assembly within the suction hole, the repulsive force between the first and second magnets allows the vacuum suction cup to automatically adjust its height according to the bottle bottom shape (e.g., flat, convex, or sloping), conforming to irregular surfaces and forming an effective seal. This solves the problem of traditional fixed-plane suction holes being unable to adapt to irregularly shaped bottle bottoms. Through a return spring cooperating with the magnets, the suction cup assembly slides upwards to conform to the bottle bottom as it passes the second magnet. After leaving the second magnet, the spring pull tightens the vacuum suction cup, ensuring that the plastic bottle does not tip over or shift due to inertia during high-speed transport, thus improving the stability and accuracy of the inspection process.

[0019] Furthermore, the suction cup assembly also includes a movable ball head assembly, which includes:

[0020] The ball head mounting ring is fixedly sleeved on the inner wall of the adsorption hole, and two fixing rings are spaced apart on its inner side, forming a mounting cavity with the two fixing rings enclosing it.

[0021] The universal ball joint is located in the mounting cavity and rotates with the mounting cavity. The universal ball joint has a through stepped hole inside. The suction cup mounting seat is coaxially fixed in the stepped hole. The connecting tube slides with the inner wall of the stepped hole. The top surface of the suction cup mounting seat, the outer periphery of the connecting tube, and the inner wall of the stepped hole enclose to form a second cavity.

[0022] The universal ball joint can rotate within the mounting cavity, allowing the suction cup mount and vacuum suction cup to dynamically adjust to the angle of the bottle bottom curvature, achieving adaptive fitting within the rotation range (such as tangential fitting of curved bottle bottoms), further enhancing compatibility with irregular bottle bottoms.

[0023] Furthermore, the suction cup mounting base is provided with a second air passage connecting the first cavity and the second cavity, the universal ball joint is provided with a pin hole and a third air passage connecting the outside and the second cavity, and the movable ball joint assembly also includes a locking assembly, which includes:

[0024] A fixed expansion sleeve is fixed to the upper wall of the second cavity and connected to the connecting pipe, and it has a through hole communicating with the third air passage.

[0025] An expansion sleeve piston is located in the second cavity and is slidably sleeved with the connecting pipe. Its inner side matches the shape of the fixed expansion sleeve so that when the expansion sleeve piston moves away from the fixed expansion sleeve, it drives the fixed expansion sleeve to clamp and lock the connecting pipe.

[0026] A piston spring is located in the second cavity and is sleeved with the connecting tube. Its two ends are respectively connected to the top surface of the expansion sleeve piston and the suction cup mounting seat to provide elastic force to the expansion sleeve piston in the direction of fixing the expansion sleeve.

[0027] A retaining ring is fixed in the mounting cavity and sleeved on the outer periphery of the universal ball joint, and its inner surface is provided with multiple retaining blocks;

[0028] The locking pin slides coaxially with the pin hole. Its top is provided with a protrusion that engages with the locking block, and its bottom is provided with a driving slope. In the initial state, the driving slope extends into the second cavity and corresponds to the movement trajectory of the expansion sleeve piston.

[0029] A pin spring is located inside the pin hole and is sleeved with the locking pin. Its two ends are respectively connected to the inner wall of the pin hole and the locking pin to provide elastic force to the locking pin pointing towards the second cavity.

[0030] The locking assembly, through the cooperation of the expansion sleeve piston and the fixed expansion sleeve, uses air pressure to drive the expansion sleeve piston away from the fixed expansion sleeve after the vacuum suction cup is adjusted to fit the bottom of the bottle. This causes the fixed expansion sleeve to tightly grip and lock the connecting tube, preventing displacement of the vacuum suction cup and connecting tube due to vibration or airflow disturbance during high-speed transport, thus ensuring stable adsorption. Simultaneously, as the expansion sleeve piston moves away from the fixed expansion sleeve, it pushes the locking pin out through the driving inclined surface. The protrusion of the locking pin engages with the locking block of the fixed retaining ring to lock the universal ball joint.

[0031] Furthermore, the vacuum assembly also includes:

[0032] The suction cup belt is driven by the drive source of the detection belt conveyor line and moves synchronously with the detection belt conveyor line. Its surface is provided with multiple connection holes at intervals along the length direction. Each connection hole corresponds to a suction cup assembly, and the connection hole is connected to the corresponding first cavity through a flexible tube.

[0033] The air extraction chamber is located inside the detection belt conveyor and is surrounded by the suction cup belt. The air extraction chamber is connected to the vacuum pump. The upper surface of the air extraction chamber has an opening along the moving direction of the suction cup belt. The suction cup belt is embedded in the opening and slides in cooperation with the opening.

[0034] The suction cup belt moves synchronously with the detection belt conveyor line. A flexible hose connects the first chamber of the suction cup assembly to the vacuum chamber, avoiding the hose twisting or breakage problems caused by belt movement in traditional fixed pipelines. This ensures stable vacuum pressure transmission and improves the reliability of the vacuum system. The opening of the vacuum chamber slides with the suction cup belt, allowing only the suction cup assembly within the detection area to connect to the vacuum pump, achieving zoned vacuum and reducing unnecessary energy consumption by the vacuum pump. Simultaneously, integrating the vacuum assembly inside the belt reduces external piping, lowers equipment maintenance complexity, and improves the overall structural compactness and space utilization.

[0035] Furthermore, the conveying mechanism also includes an upper clamping assembly, which comprises a mounting column and a clamping belt conveyor. The clamping belt conveyor is located directly above the second magnet and is slidably connected to the mounting column to allow for height adjustment. The clamping belt conveyor moves synchronously with the detection belt conveyor. The synchronous movement of the clamping belt conveyor and the detection belt conveyor in the upper clamping assembly allows for the adjustment of the height to accommodate plastic bottles of different heights. Combined with the lateral clamping mechanism, this forms a four-way constraint in all directions (up, down, left, and right), preventing the plastic bottles from being lifted by the suction cup assembly and improving the stability of the conveying process.

[0036] Furthermore, the pressing belt conveyor has an internal inflation chamber, and its surface has multiple through inflation holes at intervals. The inflation chamber communicates with these inflation holes. The upper pressing assembly also includes an air pump, which is connected to the inflation chamber, allowing the chamber to blow air outwards through the inflation holes. The inflation holes of the pressing belt conveyor blow air into the plastic bottle, increasing the internal pressure and making the bottle less prone to denting.

[0037] Furthermore, the surface of the compression belt conveyor is covered with a sponge layer. The sponge layer can increase the contact area and friction between the compression belt and the bottle mouth, while also acting as a buffer layer to prevent scratches on the bottle mouth caused by rigid contact. In addition, the porous structure of the sponge diffuses and buffers the ejected high-pressure airflow, preventing excessive wind force from blowing plastic bottles that are not clamped by the vacuum suction cups out of place.

[0038] Furthermore, the vacuum suction cup is an accordion-style suction cup. The pleated structure of the accordion-style vacuum suction cup allows it to elastically deform in the axial and radial directions, enabling it to closely fit complex bottle bottom structures such as deep concave or convex points (e.g., the annular convex bottom of carbonated beverage bottles). Compared to traditional flat suction cups, it can significantly increase the effective adsorption area, improve vacuum sealing performance, and ensure stable fixation of irregularly shaped bottle bottoms during high-speed movement. Attached Figure Description

[0039] Figure 1 This is a three-dimensional structural diagram of the visual inspection device for surface defects of plastic bottles according to the present invention.

[0040] Figure 2 This is a partial cross-sectional view of the visual inspection device for surface defects of plastic bottles according to the present invention.

[0041] Figure 3 for Figure 2 Enlarged diagram of point A in the middle.

[0042] Figure 4 This is an exploded view of the suction cup assembly.

[0043] Figure 5 This is a cross-sectional view of the suction cup assembly.

[0044] Figure 6 This is a three-dimensional partial cross-sectional view of the visual inspection device for surface defects of plastic bottles according to the present invention.

[0045] Figure 7 An exploded view of an inspection belt conveyor line.

[0046] The reference numerals in the figures include:

[0047] Detection belt conveyor 1, suction hole 11, baffle 12, support plate 13;

[0048] Suction cup assembly 2, suction cup mounting base 21, first cavity 211, second air channel 212, connecting pipe 22, first magnet 221, first air channel 222, return spring 223, vacuum suction cup 23;

[0049] 3. Universal ball joint; 31. Ball joint mounting ring; 32. Fixing ring; 34. Second cavity; 35. Pin hole; 36. Third air passage; 37. Counterweight.

[0050] Fixed expansion sleeve 4, expansion sleeve piston 41, piston spring 42, fixed retaining ring 43, retaining block 431, locking pin 44, driving inclined surface 441, pin spring 442, protrusion 443, through hole 45;

[0051] Suction cup belt 5, connecting hole 51, hose 52, suction chamber 53, opening 531, vacuum pump connection port 532, second magnet 54;

[0052] Mounting column 6, pressing belt conveyor line 61, air chamber 611, air pump connection port 6111, air hole 612, sponge covering layer 613;

[0053] Base 7, feeding belt conveyor 71, guide plate 711, feeding clamping mechanism 72, unloading clamping mechanism 73, spacing adjustment component 74, clamping belt conveyor 75, vision inspection module 76, jetting device 77, waste bottle collection box 78.

[0054] 8. Plastic bottles. Detailed Implementation

[0055] The invention will be described in detail below with reference to specific embodiments.

[0056] Combination Figures 1-3 The visual inspection device for surface defects of plastic bottles in this embodiment includes a base 7, a conveying mechanism, a lateral clamping mechanism, a visual inspection module 76, and a rejection mechanism. All of the above mechanisms and modules are fixedly mounted on the base 7. The conveying mechanism includes a feeding belt conveyor 71 and a detection belt conveyor 1. The surface of the detection belt conveyor 1 is provided with multiple suction holes 11 spaced apart along its length. The feeding belt conveyor 71 is provided with a guide plate 711. The lateral clamping mechanism includes a feeding clamping mechanism 72 connected to the feeding belt conveyor 71 and a discharging clamping mechanism 73 connected to the detection belt conveyor 1. Both are provided with a spacing adjustment component 74 and symmetrically arranged clamping belt conveyors 75. The visual inspection module 76 includes industrial cameras respectively positioned above and below the feeding clamping mechanism 72, and four side-view industrial cameras arranged around the detection belt conveyor 1. The rejection mechanism includes an air jet device 77 and a waste bottle collection frame 78. All of the above are prior art and will not be described in detail here. The plastic bottle 8 is first conveyed to the feeding clamping mechanism 72 by the feeding belt conveyor 71. The clamping belt conveyor 75 of the feeding clamping mechanism 72 clamps the plastic bottle 8 and continues to convey it downstream. The plastic bottle 8 is suspended in the air and passes through industrial cameras arranged vertically to detect the bottle mouth end face and bottle bottom. Then it is conveyed by the detection belt conveyor 1 through the side-viewing industrial camera to detect the four sides of the plastic bottle 8. The unqualified plastic bottle 8 will be blown into the waste bottle collection box 78 when passing through the jet device 77. The qualified plastic bottle 8 is conveyed into the unloading clamping mechanism 73 and finally sent out of this detection device.

[0057] like Figure 2-3 As shown, the inspection belt conveyor line 1 is equipped with a vacuum pumping assembly and multiple suction cup assemblies 2. Each suction cup assembly 2 corresponds one-to-one with an adsorption hole 11. The vacuum pumping assembly includes a vacuum pump (not shown in the figure). Specifically, as... Figure 7 As shown, the inspection belt conveyor 1 includes two baffles 12 and support plates 13. The two baffles 12 are respectively located on both sides of the inspection belt conveyor 1, forming a sealed cavity inside the inspection belt conveyor 1. One of the baffles 12 is provided with a vacuum pump connection port 532, through which the vacuum pump is connected to the interior of the inspection belt conveyor 1. The two support plates 13 are respectively fixedly connected to the two baffles 12 and located below the upper belt of the inspection belt conveyor 1 to provide support for the upper belt of the inspection belt conveyor 1. A gap is left between the two support plates 13. Figure 3As shown, the suction cup assembly 2 includes a suction cup mounting base 21, a connecting tube 22, a vacuum suction cup 23, and a return spring 223. The suction cup mounting base 21 is installed inside the suction hole 11. The suction cup mounting base 21 has a first cavity 211 inside, which is connected to the inside of the detection belt conveyor line 1 via a flexible hose 52, thereby connecting to the vacuum pump. Figure 5 The connecting tube 22 and the suction cup mounting base 21 are coaxially and slidably fitted. The lower end of the connecting tube 22 is located inside the first cavity 211 and a first magnet 221 is fixedly sleeved thereon. The first magnet 221 does not contact the inner wall of the first cavity 211 to leave a gap for ventilation. Figure 5 The connecting pipe 22 has a first air passage 222 inside, which communicates with the first cavity 211. A vacuum suction cup 23 is fixedly installed at the top of the connecting pipe 22 and communicates with the first air passage 222. A return spring 223 is sleeved on the connecting pipe 22 and connected to the upper wall of the first cavity 211 and the top surface of the first magnet 221, respectively. The detection belt conveyor 1 has a second magnet 54 inside that repels the first magnet 221, and the position of the second magnet 54 corresponds to the movement trajectory of the first magnet 221.

[0058] Combination Figures 1-2 The rear end of the feeding clamping mechanism 72 extends into the front end of the inspection belt conveyor 1 to form an overlapping area, ensuring that the plastic bottle 8 is continuously clamped during the vacuum suction cup 23's suction process, preventing the plastic bottle 8 from tipping over before being properly clamped. During the conveying process of the inspection belt conveyor 1, the vacuum pump drives the vacuum suction cup 23 to draw in air, combined with... Figure 6 When the suction cup assembly 2 passes the second magnet 54, under the mutual repulsion of the first magnet 221 and the second magnet 54, the connecting tube 22 slides upward, causing the vacuum suction cup 23 to extend out of the suction hole 11. This allows the vacuum suction cup 23 to adaptively conform to and firmly adhere to the uneven bottom surface of the plastic bottle 8, enhancing the suction force. When the plastic bottle 8 moves out of the area of ​​the second magnet 54, the connecting tube 22 slides downward under the action of the return spring 223 and gravity, causing the vacuum suction cup 23 to tighten the plastic bottle 8, thereby better securing the plastic bottle 8.

[0059] By setting a sliding vacuum suction cup 23 inside the adsorption hole 11, the repulsive force between the first magnet 221 and the second magnet 54 allows the vacuum suction cup 23 to automatically adjust its height according to the shape of the bottle bottom (such as flat bottom, convex bottom, or slope), conforming to irregular surfaces and forming an effective seal. This solves the problem that traditional fixed flat adsorption holes 11 cannot adapt to irregular bottle bottoms. Through the cooperation of the return spring 223 and the magnet, the suction cup assembly 2 slides upwards to conform to the bottle bottom when passing the second magnet 54. After leaving the second magnet 54, the vacuum suction cup 23 is tightened by the spring force, ensuring that the plastic bottle 8 does not tip over or shift due to inertia during high-speed transport. This improves the stability during the inspection process, prevents the plastic bottle 8 from shaking or shifting, and allows the vision inspection module 76 to clearly acquire surface images, reducing inspection errors caused by positional deviations and thus improving the accuracy of defect identification.

[0060] Because the bottom of the plastic bottle 8 may have sloped or curved surfaces, if the vacuum suction cup 23 can only maintain a straight up-and-down motion, it may not be able to fully adapt to the shape of the bottle bottom. Combined with... Figures 4-5 The suction cup assembly 2 also includes a movable ball joint assembly, which includes a ball joint mounting ring 31 and a universal ball joint 3. The ball joint mounting ring 31 is fixedly sleeved on the inner wall of the suction hole 11, and two fixing rings 32 are spaced apart on its inner side. The ball joint mounting ring 31 and the two fixing rings 32 together form a mounting cavity (not shown in the figure). The universal ball joint 3 is disposed in the mounting cavity and rotates with the mounting cavity to form a ball joint. The universal ball joint 3 has a through stepped hole inside, and the suction cup mounting seat 21 is coaxially fixed in the stepped hole. The bottom of the suction cup mounting seat 21 is provided with a counterweight 37 so that the universal ball joint 3 is initially held in the center position (the stepped hole is axially upward). The connecting tube 22 slides with the inner wall of the stepped hole. The top surface of the suction cup mounting seat 21, the outer periphery of the connecting tube 22, and the inner wall of the stepped hole form a second cavity 34.

[0061] When the vacuum suction cup 23 adheres to the inclined or curved surface of the bottle bottom, the universal ball head 3 can rotate within the mounting cavity. This allows the suction cup mounting base 21, connecting tube 22, vacuum suction cup 23, and universal ball head 3 to dynamically adjust together with the bottle bottom angle, achieving adaptive fitting within the rotation range (such as tangential fitting for curved bottle bottoms), further enhancing the adaptability to irregular bottle bottoms. When the vacuum suction cup 23 stops adhering to the inclined or curved surface, the universal ball head 3 returns to the center position under the action of the counterweight 37.

[0062] During high-speed transport, the connecting pipe 22 may shift due to vibration or airflow disturbance, causing the plastic bottle 8 to shake and reducing the detection quality. Combined with... Figure 4 and Figure 5The suction cup mounting base 21 is provided with a second air passage 212 connecting the first cavity 211 and the second cavity 34. The universal ball joint 3 is provided with a pin hole 35 and a third air passage 36 connecting the outside and the second cavity 34. The movable ball joint assembly also includes a locking assembly, which includes a fixed expansion sleeve 4, an expansion sleeve piston 41, a piston spring 42, a fixed retaining ring 43, a locking pin 44, and a pin spring 442. The fixed expansion sleeve 4 is fixed to the upper wall of the second cavity 34 and sleeved with the connecting pipe 22. The bottom of the fixed expansion sleeve 4 is provided with a through hole 45 communicating with the third air passage 36. The expansion sleeve piston 41 is located inside the second cavity 34 and slidably sleeved with the connecting pipe 22. Its inner side matches the shape of the outer side of the fixed expansion sleeve 4 and is inclined, so that when the expansion sleeve piston 41 moves away from the fixed expansion sleeve 4, it can drive the fixed expansion sleeve 4 to grip and lock the connecting pipe 22. This is the working principle of the expansion sleeve, which is existing technology and will not be described in detail here. A piston spring 42 is located inside the second cavity 34 and sleeved with the connecting pipe 22. Its two ends are connected to the top surfaces of the expansion sleeve piston 41 and the suction cup mounting base 21, respectively, to provide a spring force to the expansion sleeve piston 41 pointing towards the fixed expansion sleeve 4. A retaining ring 43 is fixed inside the mounting cavity and sleeved on the outer periphery of the universal ball joint 3. Its inner surface has multiple retaining blocks 431. A locking pin 44 is coaxially and slidably engaged with a pin hole 35. Its top has a protrusion 443 that engages with the retaining blocks 431, and its bottom has a driving inclined surface 441. In the initial state, the driving inclined surface 441 extends into the second cavity 34. A pin spring 442 is located inside the pin hole 35 and sleeved with the locking pin 44. Its two ends are connected to the inner wall of the pin hole 35 and the locking pin 44, respectively, to provide a spring force to the locking pin 44 pointing towards the second cavity 34.

[0063] When the vacuum suction cup 23 extends out of the suction hole 11 and adheres to the bottom of the plastic bottle 8, the vacuum pump draws air out, and the air in the vacuum suction cup 23 and the first air channel 222 is extracted, causing the vacuum suction cup 23 to adhere tightly to the bottom of the bottle. The air in the first cavity 211 and the second cavity 34 is extracted through the gap between the first magnet 221 and the first cavity 211, causing the expansion sleeve piston 41 to move away from the fixed expansion sleeve 4 under the action of internal negative pressure and external atmospheric pressure (external air enters the second cavity 34 through the third air channel 36 and the through hole 45), thereby driving the fixed expansion sleeve 4 to grip the locking connecting tube 22. At the same time as the expansion sleeve piston 41 moves away from the fixed expansion sleeve 4, the expansion sleeve piston 41 contacts the driving inclined surface 441 and pushes the locking pin 44 out of the pin hole 35, so that the protrusion 443 of the locking pin 44 engages with the locking block 431 to lock the universal ball head 3. When the vacuum suction cup 23 stops adsorbing the bottom of the bottle, the expansion sleeve piston 41 approaches the fixed expansion sleeve 4 under the action of the piston spring 42, unlocking it and allowing the suction cup to fall back naturally with the reset spring 223. The pin spring 442 pushes the locking pin 44 to retract into the pin hole 35, unlocking the universal ball head 3.

[0064] The locking assembly, through the cooperation of the expansion sleeve piston 41 and the fixed expansion sleeve 4, after the vacuum suction cup 23 is adjusted to the position of adhering to the bottom of the bottle, uses air pressure to drive the expansion sleeve piston 41 away from the fixed expansion sleeve 4, so that the fixed expansion sleeve 4 tightly grips and locks the connecting tube 22. At the same time, as the expansion sleeve piston 41 moves away from the fixed expansion sleeve 4, the expansion sleeve piston 41 pushes the locking pin 44 out through the driving inclined surface 441. The protrusion 443 of the locking pin 44 engages with the locking block 431 of the fixed retaining ring 43 to lock the universal ball head 3, preventing the vacuum suction cup 23 and the connecting tube 22 from shifting due to vibration or airflow disturbance during high-speed transport, and ensuring that the connecting tube 22 remains stable during adsorption.

[0065] Since the plastic bottles 8 are only conveyed via the upper surface of the detection belt conveyor 1, if the suction cup assembly 2, which operates on other surfaces, continues to suck air even when it is not needed to hold the plastic bottles 8, it will significantly increase the unnecessary energy consumption of the vacuum pump. Combined with... Figure 2 and Figure 6 , Figure 7 The vacuum assembly also includes a suction cup belt 5 and a vacuum chamber 53. The suction cup belt 5 is driven by the drive source of the detection belt conveyor 1 and moves synchronously with the detection belt conveyor 1. Multiple connection holes 51 are spaced apart along its length on its surface. Each connection hole 51 corresponds to a suction cup assembly 2, and the connection holes 51 are connected to the corresponding first cavity 211 via flexible hoses 52. The vacuum chamber 53 is located inside the detection belt conveyor 1 and is surrounded by the suction cup belt 5. Two baffles 12 are fixedly connected to both sides of the vacuum chamber 53. The vacuum chamber 53 is connected to a vacuum pump via a vacuum pump connection port 532. An opening 531 is provided on the upper surface of the vacuum chamber 53 along the moving direction of the suction cup belt 5. The suction cup belt 5 is embedded in the opening 531 and slides within it. When the vacuum pump is pumping air, the suction cup belt 5 is pressed against the upper surface of the pumping chamber 53 under the action of negative pressure to form a dynamic seal. After the suction cup assembly 2 enters the area of ​​the opening 531, the connecting hole 51 is connected to the opening 531, thereby connecting the pumping chamber 53 with the first chamber 211.

[0066] The suction cup belt 5 moves synchronously with the detection belt conveyor line 1. A flexible hose 52 connects the first chamber 211 of the suction cup assembly 2 to the vacuum chamber 53, avoiding the problems of hose 52 twisting or breaking caused by belt movement in traditional fixed pipelines. This ensures stable vacuum pressure transmission and improves the reliability of the vacuum system. The opening 531 of the vacuum chamber 53 slides with the suction cup belt 5, allowing only the suction cup assembly 2 within the detection area to connect to the vacuum pump, achieving zoned vacuum and reducing unnecessary energy consumption of the vacuum pump. Simultaneously, integrating the vacuum assembly inside the belt reduces external piping layout, lowers equipment maintenance complexity, and improves the overall structural compactness and space utilization.

[0067] To prevent deformation of the plastic bottle 8, the clamping force of the lateral clamping mechanism will not be too large. When the plastic bottle 8 is relatively light, the vacuum suction cup 23 and the connecting tube 22 may lift the plastic bottle 8 under the action of the magnet, causing it to tilt and potentially tip over. Figure 2 and Figure 6 The conveying mechanism also includes an upper clamping assembly, which comprises a mounting post 6 and a clamping belt conveyor 61. The clamping belt conveyor 61 is located directly above the second magnet 54. It is slidably connected to the mounting post 6 to adjust its height. The clamping belt conveyor 61 moves synchronously with the detection belt conveyor 1 to convey the plastic bottle 8. The contact surface of the clamping belt conveyor 61 has a certain degree of elasticity to flexibly contact the bottle opening of the plastic bottle 8. Before production, the height of the clamping belt conveyor 61 is adjusted according to the height of the plastic bottle 8, so that when the plastic bottle 8 enters the detection belt conveyor 1, its opening just makes slight contact with the clamping belt conveyor 61. Then, the clamping belt conveyor 61 and the detection belt conveyor 1 together convey the plastic bottle 8 downstream. By setting an adjustable-height clamping belt conveyor 61, combined with a lateral clamping mechanism, the plastic bottle 8 is constrained in four directions (up, down, left, and right), preventing it from being lifted by the suction cup assembly 2 and improving the stability of the conveying process.

[0068] For lightweight or thin plastic bottles 8, the combined pressure from the upper clamping assembly and the lateral clamping mechanism may cause the plastic bottle 8 to dent and deform. For example... Figure 6 As shown, based on the above embodiment, the pressing belt conveyor 61 further includes an inflation chamber 611 inside, and a plurality of through inflation holes 612 spaced apart on the surface of the pressing belt conveyor 61. The inflation chamber 611 communicates with the inflation holes 612. The upper pressing assembly also includes an air pump (not shown in the figure), which communicates with the inflation chamber 611 through an air pump connection port 6111. When the plastic bottle 8 enters the detection belt conveyor 1, its bottle mouth contacts the pressing belt conveyor 61. The air pump inflates the inflation chamber 611, causing the inflation holes 612 to blow air into the plastic bottle 8, thereby increasing the internal pressure of the plastic bottle 8 and making it less prone to denting.

[0069] like Figure 6 As shown, based on the above embodiment, the surface of the pressing belt conveyor 61 is further provided with a sponge covering layer 613. The sponge covering layer 613 can increase the contact area and friction between the pressing belt and the bottle mouth, and at the same time, it serves as a buffer layer to avoid scratches on the bottle mouth caused by rigid contact. In addition, the porous structure of the sponge diffuses and buffers the ejected high-pressure airflow, preventing the plastic bottle 8 that is not held by the vacuum suction cup 23 from being blown askew by excessive wind force.

[0070] like Figure 5As shown, based on the above embodiment, the vacuum suction cup 23 is further an accordion-type suction cup. The pleated structure of the accordion-type vacuum suction cup 23 allows it to undergo elastic deformation in the axial and radial directions, enabling it to fit more closely to complex bottle bottom structures such as deep concave or convex points (e.g., the annular convex bottom of a carbonated beverage bottle). Compared with traditional flat suction cups, it can significantly increase the effective adsorption area, improve vacuum sealing performance, and ensure stable fixation of irregularly shaped bottle bottoms during high-speed movement.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions created by the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions created by the present invention without departing from the essence and scope of the technical solutions created by the present invention.

Claims

1. A visual inspection device for surface defects of plastic bottles, comprising: The conveying mechanism includes a feeding belt conveyor and a detection belt conveyor, wherein the surface of the detection belt conveyor is provided with a plurality of adsorption holes spaced apart along its length. The lateral clamping mechanism includes a feeding clamping mechanism connected to the feeding belt conveyor and a discharging clamping mechanism connected to the detection belt conveyor. Both of them are equipped with a spacing adjustment component and symmetrically arranged clamping belt conveyors. The vision inspection module includes industrial cameras respectively positioned above and below the feeding clamping mechanism, and multiple side-view industrial cameras arranged around the inspection belt conveyor line; The rejection mechanism includes an air jet device and a waste bottle collection box; The feature is that the detection belt conveyor line is further equipped with a vacuum pumping component and multiple suction cup components, with each suction cup component corresponding to a suction hole. The vacuum pumping component includes: Vacuum pump; The suction cup assembly includes: A suction cup mounting base is installed inside the suction hole, and its interior has a first cavity that is connected to a vacuum pump. The connecting tube is slidably fitted coaxially with the suction cup mounting base. Its lower end is located in the first cavity and a first magnet is fixedly sleeved thereon. The connecting tube has a first air passage inside, and the first air passage is connected to the first cavity. A vacuum suction cup is fixedly installed at the top of the connecting tube and is connected to the first air passage; A reset spring is sleeved on the connecting tube and connected to the upper wall of the first cavity and the top surface of the first magnet, respectively. The detection belt conveyor is equipped with a second magnet that repels the first magnet, and the position of the second magnet corresponds to the movement trajectory of the first magnet; The suction cup assembly also includes a movable ball head assembly, which includes: The ball head mounting ring is fixedly sleeved on the inner wall of the adsorption hole, and two fixing rings are spaced apart on its inner side, forming a mounting cavity with the two fixing rings enclosing it. The universal ball head is located in the mounting cavity and rotates with the mounting cavity. The universal ball head has a through stepped hole inside. The suction cup mounting seat is coaxially fixed in the stepped hole. The connecting tube slides with the inner wall of the stepped hole. The top surface of the suction cup mounting seat, the outer periphery of the connecting tube, and the inner wall of the stepped hole enclose to form a second cavity. The suction cup mounting base has a second air passage connecting the first cavity and the second cavity. The universal ball joint has a pin hole and a third air passage connecting the outside and the second cavity. The movable ball joint assembly also includes a locking assembly, which includes: A fixed expansion sleeve is fixed to the upper wall of the second cavity and connected to the connecting pipe, and it has a through hole communicating with the third air passage. An expansion sleeve piston is located in the second cavity and is slidably sleeved with the connecting pipe. Its inner side matches the shape of the fixed expansion sleeve so that when the expansion sleeve piston moves away from the fixed expansion sleeve, it drives the fixed expansion sleeve to clamp and lock the connecting pipe. A piston spring is located in the second cavity and is sleeved with the connecting tube. Its two ends are respectively connected to the top surface of the expansion sleeve piston and the suction cup mounting seat to provide elastic force to the expansion sleeve piston in the direction of fixing the expansion sleeve. A retaining ring is fixed in the mounting cavity and sleeved on the outer periphery of the universal ball joint, and its inner surface is provided with multiple retaining blocks; The locking pin slides coaxially with the pin hole. Its top is provided with a protrusion that engages with the locking block, and its bottom is provided with a driving slope. In the initial state, the driving slope extends into the second cavity and corresponds to the movement trajectory of the expansion sleeve piston. A pin spring is located inside the pin hole and is sleeved with the locking pin. Its two ends are respectively connected to the inner wall of the pin hole and the locking pin to provide elastic force to the locking pin pointing towards the second cavity.

2. The detection device as described in claim 1, characterized in that, The vacuum assembly also includes: The suction cup belt is driven by the drive source of the detection belt conveyor line and moves synchronously with the detection belt conveyor line. Its surface is provided with multiple connection holes at intervals along the length direction. Each connection hole corresponds to a suction cup assembly, and the connection hole is connected to the corresponding first cavity through a flexible tube. The air extraction chamber is located inside the detection belt conveyor and is surrounded by the suction cup belt. The air extraction chamber is connected to the vacuum pump. The upper surface of the air extraction chamber has an opening along the moving direction of the suction cup belt. The suction cup belt is embedded in the opening and slides in cooperation with the opening.

3. The detection device as described in claim 1, characterized in that, The conveying mechanism also includes an upper clamping assembly, which includes: Mounting column; The pressure belt conveyor is located directly above the second magnet and is slidably connected to the mounting column to adjust its height. The pressure belt conveyor moves synchronously with the detection belt conveyor.

4. The detection device as described in claim 3, characterized in that, The pressure belt conveyor has an internal inflation chamber, and its surface has multiple through-holes. The inflation chamber communicates with the inflation holes. The upper pressure assembly also includes: An air pump is connected to the inflation chamber so that the inflation chamber can blow air to the outside through the inflation hole.

5. The detection device as described in claim 4, characterized in that, The surface of the pressure belt conveyor is covered with a sponge layer.

6. The detection device as described in claim 1, characterized in that, The vacuum suction cup is an accordion-style suction cup.

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