A packaging machine matching appearance detection device

Abstract

This invention relates to the field of industrial visual inspection technology, specifically to an appearance inspection device for packaging machines. The device includes a frame, a conveying mechanism, an image acquisition unit, an adaptive negative pressure flattening mechanism, and a controller. The flattening mechanism consists of a matrix of micro-movable adsorption plungers. The plungers are supported at the bottom by elastic elements and have adsorption holes and flexible sealing rings at the top. The base contains multiple independent negative pressure compartments, each equipped with a pressure sensor and a control valve. The controller executes a compartmentalized control strategy based on pressure feedback, maintaining adsorption in well-sealed areas and applying pulse adsorption to leaking areas, thereby adaptively flattening the packaging bag. Simultaneously, the device integrates a multi-view camera and a special lighting system, which can trigger imaging after reaching a stable state to complete comprehensive defect detection.

Description

Technical Field

[0001] This invention relates to the field of industrial visual inspection technology, specifically to an appearance inspection device for packaging machines. Background Technology

[0002] Packaging machines are equipped with appearance inspection devices that can automatically identify and reject product appearance defects, which is crucial for ensuring product quality and improving production efficiency.

[0003] For example, Chinese invention patent CN116626041A discloses a packaging machine-compatible appearance quality inspection device. This device uses a rubber extrusion plate to drive the rotating cylindrical item to be inspected, thereby causing the other rubber extrusion plate and disc to rotate along with the cylindrical item. This facilitates the rotation of the cylindrical item, enabling multi-angle scanning and reducing the difficulty of flipping it over, thus improving the convenience of appearance inspection. However, this device generally suffers from insufficient adaptability when dealing with flexible packaging bags. Because packaging bags are prone to random wrinkles during transport, and different products vary in size, material, and inflation status, traditional rigid positioning mechanisms often cause bag deformation or indentations. Platforms using ordinary negative pressure adsorption are prone to insufficient adsorption due to localized air leakage when dealing with packaging bags with uneven surfaces, causing the bag to shake during imaging. This makes it difficult to maintain production efficiency while ensuring inspection reliability.

[0004] Therefore, it is necessary to develop an appearance inspection device to be used with packaging machines to solve the above problems. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] An appearance inspection device for a packaging machine includes a frame, a conveying mechanism and an image acquisition unit mounted on the frame, and also includes an adaptive negative pressure flattening mechanism and a controller; the conveying mechanism is a conveyor.

[0007] The adaptive negative pressure flattening mechanism includes an adsorption matrix unit located in front of the image acquisition unit. The adsorption matrix unit is composed of M×N independent adsorption plungers that move slightly in the vertical direction, arranged in a matrix.

[0008] Each of the adsorption plungers has a negative pressure flow channel inside, an adsorption hole communicating with the negative pressure flow channel and a flexible sealing ring surrounding the adsorption hole on its top surface, and its bottom is supported on the base by an elastic element.

[0009] The base has K mutually isolated negative pressure partition chambers; each negative pressure partition chamber is connected to the main negative pressure pipeline through a partition control valve, and the main negative pressure pipeline is connected to the negative pressure generator; each negative pressure partition chamber is connected to and corresponds to an adsorption plunger array in a specific area;

[0010] Each of the negative pressure partition chambers is equipped with a pressure sensor for detecting the internal air pressure;

[0011] The controller is electrically connected to the negative pressure generator, image acquisition unit, transmission mechanism, zone control valves, and pressure sensors.

[0012] Preferably, the controller is configured to execute the following flattening logic:

[0013] After the packaging bag to be tested is in place, start the negative pressure generator and open all the zone control valves;

[0014] The air pressure sensor monitors the air pressure value in each negative pressure zone chamber in real time;

[0015] When the air pressure value of a certain negative pressure zone reaches the first preset vacuum threshold within a preset time, it is determined that the zone has achieved good sealing, and its zone control valve is kept open.

[0016] When the air pressure value of a certain negative pressure zone chamber fails to reach the first preset vacuum threshold, it is determined that there is a serious leak in that zone. The controller then periodically opens and closes the zone control valve of that zone to generate pulsed adsorption force, causing the adsorption plunger in that area to adjust its posture, remove foreign objects, and attempt to establish a seal.

[0017] Preferably, the controller is further configured to: when at least P of the negative pressure partition chambers reach a second preset vacuum threshold, the second preset vacuum threshold is lower than the first preset vacuum threshold, and P≤K, that is, to trigger the image acquisition unit to perform image acquisition.

[0018] Preferably, the adsorption matrix unit is driven by a lifting drive device, which is a telescopic cylinder, to perform lifting and lowering movements; the controller is configured to: before starting the negative pressure generator, control the lifting drive device to lower the adsorption matrix unit to a preset height, so that the top surfaces of all adsorption plungers make initial contact and pre-position with the surface of the packaging bag.

[0019] Preferably, the cross-section of the flexible sealing ring is wavy.

[0020] Preferably, the negative pressure partition chamber is further connected to a positive pressure pipeline, and the positive pressure pipeline is connected to a positive pressure generator and its on / off is controlled by a positive pressure control valve; the controller is configured to: after the image acquisition is completed, close all partition control valves, and open the positive pressure control valve to inject a short pulse positive pressure into the main negative pressure pipeline to purge dust or debris that may block the adsorption holes.

[0021] Preferably, the image acquisition unit includes a main camera arranged vertically downward and at least one auxiliary camera arranged at an inclined angle; the image acquisition unit further includes a lighting system supporting the cameras, and the lighting system at least includes a first light source for providing front lighting for the main camera and a second light source for providing low-angle grazing lighting for the auxiliary camera.

[0022] Preferably, the controller is configured to execute the following image acquisition control logic:

[0023] Trigger the image acquisition unit to perform image acquisition based on the stable signal of the adaptive negative pressure flattening mechanism;

[0024] Perform real-time quality analysis on the acquired images;

[0025] If the image quality analysis fails, control the conveying mechanism to convey in the reverse direction, and then the adaptive negative pressure flattening mechanism adjusts the working parameters and triggers the image acquisition unit to perform reshooting.

[0026] Preferably, the controller is further configured to: perform fusion processing on the image data acquired by the main camera and the auxiliary camera, and determine whether the product is qualified based on the processing result; and control the subsequent rejection device to perform rejection actions.

[0027] Advantages of the present invention:

[0028] The present invention realizes the adaptive and non-destructive flattening of flexible packaging bags through a matrix unit composed of independently micro-movable adsorption plungers, in cooperation with an intelligent control logic system based on partition air pressure feedback. The device can actively conform to irregular surfaces and effectively process local wrinkles through pulsed adsorption, greatly improving the flattening success rate and efficiency. The multi-view cameras cooperate with special lighting to achieve full coverage detection of two-dimensional and three-dimensional defects of the packaging bag. The unique positive pressure self-cleaning mechanism ensures the reliability of long-term operation. High-precision and high-stability appearance detection is achieved. Description of the Drawings

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] in:

[0031] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2 This is a schematic diagram of the adaptive negative pressure flattening mechanism;

[0033] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0034] Figure 4 for Figure 2 Enlarged view of point B in the middle;

[0035] Figure 5 for Figure 2 Enlarged view of point C in the middle;

[0036] Figure 6 This is a schematic diagram of the adsorption matrix unit.

[0037] Figure 7 for Figure 6 Enlarged view of point D;

[0038] In the picture:

[0039] 1. Frame; 2. Conveying mechanism;

[0040] 3. Image acquisition unit; 31. Main camera; 32. Auxiliary camera; 33. Illumination system; 331. First light source; 332. Second light source;

[0041] 4. Adaptive negative pressure flattening mechanism; 41. Adsorption matrix unit; 411. Adsorption plunger; 412. Negative pressure flow channel; 413. Adsorption hole; 414. Flexible sealing ring; 415. Elastic element; 416. Base; 417. Negative pressure partitioning chamber; 42. Negative pressure generator; 43. Lifting drive device; 44. Partition control valve; 45. Main negative pressure pipeline; 46. Air pressure sensor; 47. Positive pressure pipeline; 48. Positive pressure generator; 49. Positive pressure control valve;

[0042] 5. Controller; 99. Packaging bag. Detailed Implementation

[0043] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0044] Example:

[0045] like Figures 1-7 As shown, an appearance inspection device for a packaging machine includes a frame 1, a conveying mechanism 2 and an image acquisition unit 3 mounted on the frame 1, and also includes an adaptive negative pressure flattening mechanism 4 and a controller 5.

[0046] The adaptive negative pressure flattening mechanism 4 includes an adsorption matrix unit 41 located in front of the image acquisition unit 3. The adsorption matrix unit 41 is composed of M×N independent adsorption plungers 411 that move slightly in the vertical direction arranged in a matrix.

[0047] Each adsorption plunger 411 has a negative pressure flow channel 412 inside, and its top surface has an adsorption hole 413 communicating with the negative pressure flow channel 412 and a flexible sealing ring 414 surrounding the adsorption hole 413. Its bottom is supported on the base 416 by an elastic element 415.

[0048] The base 416 has K mutually isolated negative pressure partition chambers 417 inside; each negative pressure partition chamber 417 is connected to the main negative pressure pipeline 45 through a partition control valve 44, and the main negative pressure pipeline 45 is connected to the negative pressure generator 42; each negative pressure partition chamber 417 is connected to and corresponds to a specific area of ​​adsorption plunger 411 group;

[0049] Each negative pressure compartment 417 is equipped with a pressure sensor 46 for detecting the internal air pressure;

[0050] The controller 5 is electrically connected to the negative pressure generator 42, the image acquisition unit 3, the transmission mechanism 2, the zone control valves 44, and the pressure sensors 46.

[0051] Specifically, the adsorption matrix unit 41 is driven by a lifting drive device 43 to perform lifting and lowering movements; the controller 5 is configured to: before starting the negative pressure generator 42, control the lifting drive device 43 to drive the adsorption matrix unit 41 to descend to a preset height, so that the top surfaces of all adsorption plungers 411 make initial contact and pre-position with the surface of the packaging bag 99.

[0052] Specifically, the cross-section of the flexible sealing ring 414 is wavy.

[0053] The core innovation of this invention lies in the adaptive negative pressure flattening mechanism 4. This mechanism is located in front of the image acquisition unit 3, and its actuating component is an adsorption matrix unit 41 composed of M rows × N columns of adsorption plungers 411. Each adsorption plunger 411 is an independent micro-motion unit: it has a negative pressure flow channel 412 machined inside, an adsorption hole 413 at its top and a flexible sealing ring 414 surrounding it, and its bottom is supported on a base 416 by an elastic element 415 (such as a precision spring). This design allows each plunger to independently rise and fall within a small range in the vertical direction.

[0054] The base 416 is not a hollow cavity, but is divided into K isolated negative pressure partition chambers 417. Each negative pressure partition chamber 417 is connected to the main negative pressure pipeline 45 through a dedicated partition control valve 44, and the negative pressure is ultimately provided by the negative pressure generator 42. Each negative pressure partition chamber 417 is responsible for supplying gas to a specific area of ​​the adsorption plunger 411 array. At the same time, a pressure sensor 46 is installed inside each negative pressure partition chamber 417 to monitor the vacuum level of that area in real time.

[0055] When the device is started, the controller 5 first controls the lifting drive device 43 to move, driving the entire adsorption matrix unit 41 to descend a preset height. This action ensures that the top surfaces of all adsorption plungers 411 make initial contact with the surface of the packaging bag 99 to be inspected. Since each plunger is independently micro-moving, they can passively adapt to the irregular three-dimensional contour of the packaging bag 99 surface, ensuring that most of the flexible sealing rings 414 can achieve initial contact with the bag surface. The flexible sealing ring 414 adopts a wave-shaped cross-section design. Compared with conventional O-rings, the wave-shaped structure can produce a larger deformation under the same pressure, thus better compensating for surface unevenness. It is more friendly to soft or easily scratched packaging materials, effectively establishing an initial seal and preventing damage. This achieves the technical effect of non-destructive, adaptive pre-positioning of flexible packaging bags 99 with unknown and irregular contours, improving the quality of subsequent image acquisition.

[0056] Specifically, controller 5 is configured to execute the following flattening logic:

[0057] After the packaging bags 99 to be tested are in place, start the negative pressure generator 42 and open all the zone control valves 44;

[0058] The air pressure sensor 46 monitors the air pressure value in each negative pressure zone chamber 417 in real time;

[0059] When the air pressure value of a certain negative pressure partition chamber 417 reaches the first preset vacuum threshold within a preset time, it is determined that the partition has achieved good sealing, and its partition control valve 44 is kept open.

[0060] When the air pressure value of a certain negative pressure zone 417 fails to reach the first preset vacuum threshold, it is determined that there is a serious leak in the zone. Then the controller 5 periodically switches the zone control valve 44 of the zone to generate pulsed adsorption force, causing the adsorption plunger 411 in the area to adjust its posture, remove foreign objects, and attempt to establish a seal.

[0061] Specifically, the controller 5 is also configured to: when at least P of the air pressure values ​​in all negative pressure partition cavities 417 reach the second preset vacuum threshold, the second preset vacuum threshold is lower than the first preset vacuum threshold, and P≤K, that is, to trigger the image acquisition unit 3 to perform image acquisition.

[0062] After the adsorption matrix unit 41 and the packaging bag 99 have completed initial contact and pre-positioning, the controller 5 initiates the flattening logic. It first activates the negative pressure generator 42 and opens all the zone control valves 44, so that negative pressure is applied to the entire adsorption matrix unit 41.

[0063] Subsequently, controller 5 monitors the air pressure values ​​in each negative pressure zone chamber 417 in real time through each air pressure sensor 46. The control logic of the system is as follows:

[0064] For a certain zone, if its air pressure value can quickly reach the first preset vacuum threshold (a higher vacuum degree) within a preset time, the controller 5 determines that the zone is well sealed and the packaging bag 99 has been perfectly flattened in the area. Therefore, it keeps its zone control valve 44 open to maintain the flatness of the area with a stable strong adsorption force.

[0065] Conversely, if the air pressure in a certain zone consistently fails to reach the first preset threshold, the controller 5 determines that there is a serious leak in that area due to wrinkles or foreign objects. In this case, the controller 5 will not abandon the area but will activate the pulse adsorption mode, that is, periodically and rapidly opening and closing the zone control valve 44 of that zone. This high-frequency on-off negative pressure generates strong pulsed adsorption forces, which can effectively and repeatedly tap the local area of ​​the packaging bag 99, causing wrinkles to be flattened or small foreign objects to be shaken off, increasing the probability of establishing an effective seal.

[0066] To balance detection accuracy and production efficiency, controller 5 is configured not to wait for all K partitions to achieve perfect sealing (first preset threshold). As long as P partitions (P≤K) reach a slightly lower but sufficient second preset vacuum threshold to ensure image clarity, controller 5 can trigger image acquisition unit 3 to take pictures.

[0067] Specifically, the negative pressure partition chamber 417 is also connected to a positive pressure pipeline 47, which is connected to a positive pressure generator 48 and controlled by a positive pressure control valve 49. The controller 5 is configured to close all partition control valves 44 and open the positive pressure control valve 49 to inject a brief pulse of positive pressure into the main negative pressure pipeline 45 after image acquisition is completed, so as to blow away dust or debris that may be blocked in the adsorption hole 413.

[0068] To ensure long-term operational reliability, this device also integrates a self-cleaning function. After image acquisition, the controller 5 first closes all main negative pressure pipelines 45, cutting off the negative pressure. Then, it opens the positive pressure control valve 49, and the positive pressure generator 48 injects a brief pulse of positive pressure (compressed air) into the negative pressure partition chamber 417 through the positive pressure pipeline 47. This positive airflow flows in the opposite direction through the negative pressure channel 412 and is ejected from the adsorption hole 413, effectively blowing away dust, debris, and other foreign matter accumulated or blocked in the adsorption hole 413. This avoids a decrease or failure of adsorption force due to blockage of the adsorption hole 413, ensuring the continuity and stability of the production process and reducing the frequency and cost of equipment maintenance.

[0069] Specifically, the image acquisition unit 3 includes a main camera 31 set vertically downward and at least one auxiliary camera 32 set at an angle; the image acquisition unit 3 also includes an illumination system 33 that is compatible with the camera, the illumination system 33 includes at least a first light source 331 for providing front illumination to the main camera 31 and a second light source 332 for providing low-angle grazing illumination to the auxiliary camera 32.

[0070] The image acquisition unit 3 of this device is specially optimized to capture comprehensive information. It includes a vertically downward-facing main camera 31 for frontal acquisition of defects such as printing and stains on the main surface of the packaging bag 99. Simultaneously, it is equipped with at least one auxiliary camera 32 positioned at an angle, specifically for acquiring three-dimensional images of the edges, seals, and other areas of the packaging bag 99. The lighting system 33 is designed in conjunction with the cameras: a first light source 331 (such as a ring-shaped shadowless lamp) provides uniform frontal illumination to the main camera 31, highlighting two-dimensional features; a second light source 332 (such as a strip light) provides low-angle grazing illumination to the auxiliary camera 32, greatly enhancing the shadow contrast of three-dimensional morphological defects such as scratches, seal wrinkles, and dents. This multi-view camera and multi-mode lighting scheme constitutes a three-dimensional visual capture network, achieving full coverage and high-contrast acquisition of two-dimensional and three-dimensional appearance defects of the packaging bag 99.

[0071] Specifically, controller 5 is configured to execute the following image acquisition control logic:

[0072] The image acquisition unit 3 is triggered to acquire images based on the stable signal of the adaptive negative pressure flattening mechanism 4;

[0073] Perform real-time quality analysis on the acquired images;

[0074] If the image quality analysis fails, the control conveyor 2 reverses the transmission, and then the adaptive negative pressure flattening mechanism 4 adjusts the working parameters and triggers the image acquisition unit 3 to retake the image.

[0075] The controller 5 triggers image capture based on a stable signal from the adaptive negative pressure flattening mechanism 4 (i.e., P zones meet the standard). This ensures that the packaging bag 99 is flattened as much as possible at the moment of image capture, preventing wrinkles from obstructing the view. After image capture, the controller 5 immediately performs real-time quality analysis on the acquired image (e.g., sharpness and brightness assessment). If the analysis finds the image quality to be substandard, the controller 5 will not simply classify the product as defective, but will initiate a correction process: it first controls the conveyor mechanism 2 to briefly reverse the transport, separating and repositioning the packaging bag 99 from the adsorption matrix unit 41; then it adjusts the operating parameters of the adaptive negative pressure flattening mechanism 4 (e.g., increasing the pulse adsorption duration or negative pressure intensity); and finally, it triggers image capture again. This automatic correction of accidental shooting errors significantly reduces the misjudgment rate caused by instantaneous system fluctuations, improving the accuracy and reliability of detection.

[0076] Specifically, the controller 5 is also configured to: perform fusion processing on the image data acquired by the main camera 31 and the auxiliary camera 32, and determine whether the product is qualified based on the processing results; and control the subsequent rejection equipment to perform rejection actions.

[0077] During the image processing and decision-making stage, controller 5 fuses the multi-view image data acquired by main camera 31 and auxiliary camera 32. Through image stitching and registration algorithms, a complete image containing information about the main surface and side edges of the packaging bag 99 is generated. This image is then precisely compared with a pre-stored standard template image to determine defects. Once a defective product is identified, controller 5 sends a command to the downstream rejection equipment on the production line to accurately remove it.

[0078] The workflow is as follows:

[0079] The conveying mechanism 2 of this device transports the packaging bag 99 to be inspected to the inspection station. When the packaging bag 99 reaches the predetermined position in front of the image acquisition unit 3, the conveying mechanism 2 stops.

[0080] Subsequently, the controller 5 issues a command to activate the lifting drive device 43. The lifting drive device 43 drives the entire adsorption matrix unit 41, as a rigid whole, to move downwards by a preset height. This downward movement causes the top surface of the adsorption plunger 411 in the matrix to contact the surface of the packaging bag 99. Since the bottom of each adsorption plunger 411 is supported by an independent elastic element 415, they can independently move up and down according to the three-dimensional contour of the packaging bag 99 surface, thus passively adapting to its irregular shape. During this process, the wavy cross-section flexible sealing ring 414 at the top of the adsorption plunger 411 undergoes elastic deformation, forming a preliminary and good sealing contact with the surface of the packaging bag 99. This achieves adaptive pre-positioning of the flexible packaging bag 99, avoiding damage to the packaging bag 99 or inaccurate positioning caused by forced pulling.

[0081] After pre-positioning is completed, controller 5 initiates the flattening logic. It first turns on the negative pressure generator 42 and simultaneously opens all the zone control valves 44. The negative pressure flows through the main negative pressure pipeline 45, through each of the opened zone control valves 44, into the K negative pressure zone chambers 417 inside the base 416, and finally acts on the packaging bag 99 through the suction hole 413 via the negative pressure flow channel 412. At the same time, the air pressure sensor 46 in each negative pressure zone chamber 417 begins to monitor the changes in its internal vacuum level in real time.

[0082] Based on feedback data from the pressure sensor 46, the controller 5 executes a zone control strategy: for zones where the pressure value can quickly reach the first preset vacuum threshold (high standard) within a preset time, the controller 5 determines that the area has achieved perfect sealing and flattening, and keeps its zone control valve 44 open to maintain strong adsorption force; while for zones where the pressure value can never reach the first preset threshold, the controller 5 determines that there is a leak caused by stubborn wrinkles or foreign objects, and then activates the pulse adsorption mode, periodically and rapidly opening and closing the zone control valve 44 of that zone. This pulse adsorption generates a high-frequency "shaking" effect, which can effectively flatten local wrinkles or shake off small foreign objects.

[0083] To balance detection accuracy and production efficiency, controller 5 does not require all K zones to reach a perfect state. Once it detects that the air pressure values ​​of at least P zones (P≤K) have reached a slightly lower but sufficient second preset vacuum threshold to ensure image clarity, controller 5 determines that the packaging bag 99 has reached a detectable stable state.

[0084] After determining that a stable state has been reached (i.e., the state of maximum flattening), the packaging bag 99 is conveyed forward, and the controller 5 immediately sends a trigger command to the image acquisition unit 3. The main camera 31, in the vertical direction, receives uniform frontal illumination from the first light source 331, acquiring images of the main surface of the packaging bag 99; simultaneously, at least one auxiliary camera 32, in the tilted direction, receives low-angle grazing illumination from the second light source 332, acquiring images of the edges or sidewall areas of the packaging bag 99. This multi-view, multi-mode illumination design constitutes a three-dimensional visual capture network, capable of simultaneously and efficiently capturing two-dimensional problems such as surface stains and printing defects, as well as three-dimensional morphological defects such as scratches and edge wrinkles.

[0085] After image acquisition is complete, controller 5 first closes all zone control valves 44, cutting off the negative pressure. Then, it opens the positive pressure control valve 49, and a brief pulse of positive pressure is injected by the positive pressure generator 48 through the positive pressure pipeline 47. This positive airflow flows in the opposite direction through the negative pressure channel 412 and is ejected from the adsorption orifice 413. This effectively blows away dust or debris that may clog the adsorption orifice 413, ensuring the long-term reliability and stability of the adsorption system and significantly reducing maintenance requirements.

[0086] Subsequently, the adsorption matrix unit 41 rises and resets under the drive of the lifting drive device 43, and the conveying mechanism 2 restarts, sending the packaging bag 99 out of the inspection station. In the background, the controller 5 fuses the image data collected by the main camera 31 and the auxiliary camera 32 to generate a complete image containing information of the main surface and side edges, and compares it with a pre-stored standard template to determine whether the product is qualified. If it is determined to be a defective product, the controller 5 will issue an instruction to the subsequent rejection equipment to accurately remove the packaging bag 99 at an appropriate location on the production line.

[0087] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A surface inspection device for a packaging machine, comprising a frame (1), a conveying mechanism (2) mounted on the frame (1), and an image acquisition unit (3), characterized in that, It also includes an adaptive negative pressure flattening mechanism (4) and a controller (5); The adaptive negative pressure flattening mechanism (4) includes an adsorption matrix unit (41) located in front of the image acquisition unit (3). The adsorption matrix unit (41) is composed of M×N independent adsorption plungers (411) that move slightly in the vertical direction, arranged in a matrix. Each of the adsorption plungers (411) is provided with a negative pressure flow channel (412) inside, and its top surface is provided with an adsorption hole (413) communicating with the negative pressure flow channel (412) and a flexible sealing ring (414) surrounding the adsorption hole (413). Its bottom is supported on the base (416) by an elastic element (415). The base (416) is provided with K mutually isolated negative pressure partition chambers (417); each negative pressure partition chamber (417) is connected to the main negative pressure pipeline (45) through a partition control valve (44), and the main negative pressure pipeline (45) is connected to the negative pressure generator (42); each negative pressure partition chamber (417) is connected to and corresponds to a specific area of ​​the adsorption plunger (411) group; Each of the negative pressure partition chambers (417) is provided with a pressure sensor (46) for detecting the internal air pressure; The controller (5) is electrically connected to the negative pressure generator (42), the image acquisition unit (3), the transmission mechanism (2), the zone control valves (44), and the air pressure sensors (46); The controller (5) is configured to execute the following flattening logic: After the packaging bag (99) to be tested is in place, start the negative pressure generator (42) and open all the zone control valves (44); The air pressure sensor (46) monitors the air pressure value in each negative pressure zone chamber (417) in real time; When the air pressure value of a certain negative pressure partition chamber (417) reaches the first preset vacuum threshold within a preset time, it is determined that the partition has achieved good sealing, and its partition control valve (44) is kept open. When the air pressure value of a certain negative pressure partition chamber (417) fails to reach the first preset vacuum threshold, it is determined that there is a serious leak in the partition. Then the controller (5) periodically switches the partition control valve (44) of the partition to generate pulse adsorption force, causing the adsorption plunger (411) in the area to adjust its posture, remove foreign objects, and try to establish a seal. The controller (5) is also configured to: when at least P of the negative pressure partition chambers (417) reach the second preset vacuum threshold, the second preset vacuum threshold is lower than the first preset vacuum threshold, and P≤K, that is, to trigger the image acquisition unit (3) to perform image acquisition.

2. The appearance detection device supporting the packaging machine according to claim 1, wherein The adsorption matrix unit (41) is driven by a lifting drive device (43) to perform lifting and lowering movements. The controller (5) is configured to control the lifting drive device (43) to lower the adsorption matrix unit (41) by a preset height before starting the negative pressure generator (42), so that the top surface of all adsorption plungers (411) makes initial contact and pre-positioning with the surface of the packaging bag (99).

3. The appearance detection device supporting the packaging machine according to claim 1, wherein The cross-section of the flexible sealing ring (414) is wavy.

4. The appearance inspection device for the packaging machine according to claim 1, characterized in that, The negative pressure partition chamber (417) is also connected to a positive pressure pipeline (47), which is connected to a positive pressure generator (48) and controlled by a positive pressure control valve (49). The controller (5) is configured to close all partition control valves (44) and open the positive pressure control valve (49) to inject a brief pulse of positive pressure into the main negative pressure pipeline (45) after image acquisition is completed, so as to blow away dust or debris that may be blocked in the adsorption hole (413).

5. The appearance inspection device for packaging machines according to any one of claims 1 to 4, characterized in that, The image acquisition unit (3) includes a main camera (31) set vertically downward and at least one auxiliary camera (32) set at an angle; the image acquisition unit (3) also includes an illumination system (33) for the camera, the illumination system (33) including at least a first light source (331) for providing front illumination to the main camera (31) and a second light source (332) for providing low-angle grazing illumination to the auxiliary camera (32).

6. The appearance inspection device for packaging machines according to any one of claims 1 to 4, characterized in that, The controller (5) is configured to execute the following image acquisition control logic: The image acquisition unit (3) is triggered to acquire images based on the stable signal of the adaptive negative pressure flattening mechanism (4); Perform real-time quality analysis on the acquired images; If the image quality analysis fails, the control transmission mechanism (2) reverses the transmission, and then the adaptive negative pressure flattening mechanism (4) adjusts the working parameters and triggers the image acquisition unit (3) to retake the image.

7. The appearance inspection device for the packaging machine according to claim 5, characterized in that, The controller (5) is also configured to: perform fusion processing on the image data collected by the main camera (31) and the auxiliary camera (32), and determine whether the product is qualified based on the processing result; and control the subsequent rejection equipment to perform rejection actions.

Images