Visual inspection device for surface defects of plastic bottle caps
By projecting from the inside of the bottle cap to the outside, combined with a variety of detection heads and equipment, the problem of difficulty in identifying the edge defects of the bottle cap is solved in the prior art, and efficient detection of the sides of the bottle cap is achieved.
Patent Information
- Application Number
- CN202411531402.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-01-07
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The existing visual inspection system is difficult to identify the edge defects of plastic bottle caps, mainly because the contrast between the projection background and the defects is not obvious enough, resulting in poor recognition effect.
By projecting from the inside of the bottle cap to the outside, by installing a cap top detection belt machine, an in-cap detection belt machine, a first visual detection head, a second visual detection head and a detection box, combined with a negative pressure hole, a detection disk, and a lamp source and the third visual detection head to realize defect detection on the side of the bottle cap.
Continuous defect detection of the inside, top and sides of the bottle cap is realized, and defects on the sides of the bottle cap are quickly identified, with excellent and accurate detection results.
Smart Images
Figure CN119259480A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of bottle cap detection, and in particular to a visual detection device for surface defects of plastic bottle caps. Background Art
[0002] Plastic bottle caps are a common packaging form for bottles, cans, and barrels, and are particularly widely used in the beverage, chemical, and pharmaceutical fields. Plastic bottle caps are produced using injection molding machines. Affected by temperature and pressure, some of the bottle caps will have surface defects after molding. In order to ensure the quality of the bottle caps, the molded bottle caps will be inspected. Currently, visual inspection systems are commonly used to identify defective bottle caps.
[0003] However, the existing visual inspection system has certain problems. The conventional imaging method is to shoot an image from top to bottom. The image taken in this way can usually better identify whether there are defects inside the bottle cap, but it cannot identify whether there are defects on the edge of the bottle cap. The side view is used for shooting. Since the projected background is usually on the inner wall of the bottle cap or the bottom near the edge, and these areas are mainly made of the same material as the side, there is not enough contrast between the defect and the background, and the recognition effect is poor. Summary of the invention
[0004] In view of the above problems, the present invention provides a visual inspection device for surface defects of plastic bottle caps, which can continuously complete the defect inspection process of the inside, top and side of the bottle cap, and adopts the method of projecting from the inside of the bottle cap to the outside to quickly identify the defects on the side of the bottle cap, and the inspection effect is excellent and accurate.
[0005] To solve the above problems, the technical solution adopted by the present invention is:
[0006] A visual inspection device for surface defects of plastic bottle caps comprises an inspection channel, wherein the front end of the inspection channel is connected to a feed belt conveyor, a transversely arranged inner-cap inspection belt conveyor is installed in the inspection channel, a cap top inspection belt conveyor is installed in the inspection channel between the feed belt conveyor and the inner-cap inspection belt conveyor, the cap top inspection belt conveyor can be raised and lowered, and a plurality of negative pressure holes for adsorbing bottle caps are arranged at intervals on the surface, a first visual inspection head is installed in the inspection channel below the cap top inspection belt conveyor, a second visual inspection head is installed in the inspection channel above the inner-cap inspection belt conveyor, an inspection box is installed in the rear end of the inspection channel, and the tail end of the inner-cap inspection belt conveyor extends to the inspection box A discharging belt conveyor is installed at the rear end of the detection box, and a detection disk is installed in the detection box between the detection belt conveyor inside the cover and the discharging belt conveyor. A plurality of bottle cap grooves adapted to bottle caps are provided on the circumference of the detection disk, and a circumferential side wall of the detection disk is provided with a material port connected with the plurality of bottle cap grooves in a one-to-one correspondence. A loading position, a detection position and a discharging position are respectively provided on the front, right and rear sides of the detection disk, a liftable turntable is installed on the inner bottom of the bottle cap groove, a resistance disk for pressing against the bottle cap mouth is installed above the detection position, a light source is installed at the bottom center of the resistance disk, and a third visual detection head for photographing the inner wall of the detection position corresponding to the detection position of the detection box is also installed above the detection position.
[0007] Preferably, a sealing plate attached to the inner surface of the belt is installed in the cover top detection belt conveyor, and a negative pressure groove connected to multiple negative pressure holes is provided at the bottom of the sealing plate. The negative pressure groove is externally connected to a negative pressure pump, and the negative pressure groove extends from the discharge end of the feed belt conveyor to the feed end of the cover inner detection belt conveyor.
[0008] Preferably, a first cylinder is installed at the bottom of the detection channel, a bracket is fixedly installed at the telescopic end of the first cylinder, and the cover top detection belt conveyor is fixedly installed on the bracket.
[0009] Preferably, the first visual inspection head, the second visual inspection head and the third visual inspection head are all cameras, and the first visual inspection head, the second visual inspection head and the third visual inspection head are electrically connected to an image analysis inspection device.
[0010] Preferably, a driving shaft for driving the detection disk to rotate is installed at the bottom of the detection box.
[0011] Preferably, the diameter of the bottle cap groove, the diameter of the turntable, the diameter of the abutment plate and the width of the material opening are all consistent with the bottle cap, and the depth of the bottle cap groove is smaller than the depth of the bottle cap.
[0012] Preferably, a second cylinder is installed at the inner top of the detection box corresponding to the detection position, the resistance plate is rotatably connected to the telescopic end of the second cylinder, the light source is installed at the telescopic end of the second cylinder, a motor is fixedly installed on the telescopic section of the second cylinder, a gear is fixedly installed at the output end of the motor, and a gear ring meshing with the gear is fixed on the top of the resistance plate.
[0013] Preferably, a plurality of circular cavities corresponding one-to-one to a plurality of bottle cap grooves are provided in the bottom of the detection disk, a push rod is elastically connected to the circular cavity through a spring, the upper end of the push rod extends into the bottle cap groove and is rotatably connected to the turntable, a plurality of conductive heads electrically connected one-to-one to a plurality of springs are installed at the bottom of the detection disk, an annular guide rail is fixed below the detection disk in the detection box, the plurality of conductive heads are in contact with the annular guide rail, and a conductive plate is connected in series at the annular guide rail corresponding to the discharge position.
[0014] Preferably, a blowing position is provided between the loading position and the detection position, the detection box is provided with an arc-shaped blowing pipe at the blowing position, and the detection box is provided with a blowing head at the discharge position, and the blowing head is higher than the notch of the bottle cap groove.
[0015] Preferably, a material removal air duct is installed on one side of the discharging belt conveyor.
[0016] The beneficial effects of the present invention are:
[0017] 1. By installing the cap top detection belt conveyor, the cap inner detection belt conveyor, the first visual inspection head and the second visual inspection head, the formed bottle caps are transported to the inspection channel at intervals with the cap opening facing upwards through the feed belt conveyor. The first cylinder is started intermittently, and the cap top detection belt conveyor is driven to rise and fall reciprocatingly through the bracket. The lowering makes the feed end belt of the cap top detection belt conveyor stick to the cap opening of the bottle cap at the discharge end of the feed belt conveyor. At this time, the negative pressure hole at the feed end is transferred to the negative pressure groove, and the cap opening is in a closed state against the belt, thereby generating negative pressure to adsorb the bottle cap, so that the cap top is transported downwards, and the first visual inspection head completes the detection of cap top defects, and the bottle cap continues to move to the discharge end. At this time, the negative pressure hole is separated from the negative pressure groove area, the negative pressure disappears, and the bottle cap falls on the cap inner detection belt conveyor with the cap opening facing upwards. The second visual inspection head completes the detection process of the internal defects of the bottle cap.
[0018] 2. By installing the inspection box, inspection plate, contact plate, light source and the third visual inspection head, the bottle caps after the inner cap inspection are put into the inspection box, the driving shaft drives the inspection plate to rotate intermittently, the bottle caps are sent upward into the material port at the loading position, and then turned to the blowing position, the bottle caps are completely blown into the bottle cap groove through the arc-shaped air blowing pipe, and then turned to the inspection position, the second cylinder is started to drive the contact plate to move down, press against the cap mouth of the bottle cap, press the bottle cap between the contact plate and the turntable, start the motor, and drive the contact plate to rotate through the gear and the ring gear, so as to drive the bottle cap to rotate. At this time, the light source is located inside the bottle cap, and the light source radiates light all around. The light is evenly projected on the inner side wall of the bottle cap in the circumferential direction. If there is a notch defect, the light can be projected out of the notch onto the inner wall of the inspection box at the inspection position. The projection area is photographed by the third visual inspection head, and the defect can be detected by analyzing the image, completing the inspection process of the circumferential side wall defect of the bottle cap, and the inspection effect is excellent and accurate.
[0019] 3. By installing the turntable, spring, push rod, conductive head, circular guide rail, conductive plate and blowing head, the turntable is always located at the inner bottom of the bottle cap slot when the bottle cap slot rotates through the loading position, blowing position and detection position. When it rotates to the discharge position, the conductive head contacts the conductive plate, the conductive plate is connected to an external power supply, the spring is energized and contracts, and then the turntable is driven upward through the push rod to push the bottle cap to the slot position. The blowing head can blow air to blow the bottle cap onto the discharge belt conveyor, and the defective bottle cap can be blown away through the ejection air duct to realize the material separation process. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a structural schematic diagram of the present invention;
[0021] Figure 2 A top view of the cover top detection belt conveyor proposed by the present invention;
[0022] Figure 3 A top view of a cross-sectional view of the detection box proposed by the present invention;
[0023] Figure 4 A side sectional view of the detection box proposed by the present invention;
[0024] Figure 5 for Figure 4 A schematic diagram of the structure enlargement at point A;
[0025] Figure 6 This is a schematic diagram of the plate structure proposed by the present invention;
[0026] Figure 7 This is a top view of the annular guide rail proposed by the present invention.
[0027] In the figure: 1 detection channel, 2 feeding belt conveyor, 3 cover top detection belt conveyor, 4 negative pressure hole, 5 sealing plate, 6 negative pressure groove, 7 first visual inspection head, 8 bracket, 9 first cylinder, 10 second visual inspection head, 11 cover inner detection belt conveyor, 12 inspection box, 13 material removal air duct, 14 discharging belt conveyor, 15 loading position, 16 blowing position, 17 inspection position, 18 discharging position, 19 arc blowing pipe, 20 blowing head, 21 material port, 22 bottle cap groove, 23 driving shaft, 24 annular guide rail, 25 inspection disk, 26 third visual inspection head, 27 second cylinder, 28 resistance disk, 29 light source, 30 turntable, 31 resistance rod, 32 spring, 33 circular cavity, 34 conductive head, 35 gear ring, 36 motor, 37 gear, 38 conductive plate. DETAILED DESCRIPTION
[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.
[0029] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.
[0030] Reference Figure 1-7 A visual inspection device for surface defects of plastic bottle caps comprises an inspection channel 1, a feeding belt conveyor 2 is connected to the front end of the inspection channel 1, a transversely arranged inner-cap inspection belt conveyor 11 is installed in the inspection channel 1, a cap top inspection belt conveyor 3 is installed between the feeding belt conveyor 2 and the inner-cap inspection belt conveyor 11 in the inspection channel 1, the cap top inspection belt conveyor 3 can be raised and lowered, and a plurality of negative pressure holes 4 for adsorbing bottle caps are arranged at intervals on the surface, a first visual inspection head 7 is installed below the cap top inspection belt conveyor 3 in the inspection channel 1, and a second visual inspection head 10 is installed above the inner-cap inspection belt conveyor 11 in the inspection channel 1, the inspection of the cap top defects is completed by photographing with the first visual inspection head 7, and the inspection process of the internal defects of the bottle cap is completed by photographing with the second visual inspection head 10.
[0031] Furthermore, a sealing plate 5 attached to the inner surface of the belt is installed in the cap top detection belt conveyor 3, and a negative pressure groove 6 connected to multiple negative pressure holes 4 is provided at the bottom of the sealing plate 5. The negative pressure groove 6 is externally connected to a negative pressure pump, and the negative pressure groove 6 extends from the discharge end of the feed belt conveyor 2 to the feed end of the cap inner detection belt conveyor 11. A first cylinder 9 is installed at the bottom of the detection channel 1, and a bracket 8 is fixedly installed at the telescopic end of the first cylinder 9. The cap top detection belt conveyor 3 is fixedly installed on the bracket 8. The first cylinder 9 is started intermittently, and the cap top detection belt conveyor 3 is driven to reciprocate and rise and fall through the bracket 8. The descent makes the feeding end belt of the cap top detection belt conveyor 3 stick to the bottle cap cover at the discharge end of the feed belt conveyor 2. At this time, the negative pressure hole 4 at the feeding end is turned to the negative pressure groove 6, and the cover mouth is in a closed state against the belt, thereby generating negative pressure to adsorb the bottle cap and transport the top of the cap downward.
[0032] A detection box 12 is installed in the rear end of the detection channel 1, the tail end of the inner-cover detection belt conveyor 11 extends to the front end of the detection box 12, and a discharging belt conveyor 14 is installed at the rear end of the detection box 12. A detection disk 25 is installed in the detection box 12 between the inner-cover detection belt conveyor 11 and the discharging belt conveyor 14. A plurality of bottle cap grooves 22 adapted for bottle caps are provided on the circumferential direction of the detection disk 25, and a material port 21 connected to the plurality of bottle cap grooves 22 in a one-to-one correspondence is provided on the circumferential side wall of the detection disk 25. A loading position 15, a detection position 17 and a discharging position 18 are respectively provided on the front side, the right side and the rear side of the detection disk 25. A driving shaft 23 for driving the detection disk 25 to rotate is installed at the bottom of the detection box 12. The driving shaft 23 drives the detection disk 25 to rotate intermittently, and passes through the loading position 15, the detection position 17 and the discharging position 18 in sequence.
[0033] Furthermore, the diameter of the bottle cap groove 22, the diameter of the turntable 30, the diameter of the abutment plate 28 and the width of the material port 21 are all consistent with the bottle cap, and the depth of the bottle cap groove 22 is less than the depth of the bottle cap, so that the side wall of the upper part of the bottle cap is higher than the bottle cap groove 22, which is convenient for the abutment plate 28 to press tightly and is conducive to projection.
[0034] A liftable turntable 30 is installed at the inner bottom of the bottle cap groove 22, and a plurality of circular cavities 33 corresponding to the plurality of bottle cap grooves 22 are provided in the bottom of the detection disk 25. A push rod 31 is elastically connected to the circular cavity 33 through a spring 32. The upper end of the push rod 31 extends into the bottle cap groove 22 and is rotatably connected to the turntable 30. A plurality of conductive heads 34 electrically connected to the plurality of springs 32 are installed at the bottom of the detection disk 25. An annular guide rail 24 is fixed below the detection disk 25 in the detection box 12, and the plurality of conductive heads 34 all contact the annular guide rail 24. A conductive plate 38 is connected in series at the annular guide rail 24 corresponding to the discharge position 18. When the detection disk 25 is rotated to the discharge position 18, the conductive head 34 contacts the conductive plate 38, and the conductive plate 38 is connected to an external power supply. The spring 32 is energized and contracted, and then the turntable 30 is driven to move upward through the push rod 31 to push the bottle cap to the notch position.
[0035] A disc 28 for pressing against the bottle cap opening is installed above the detection position 17, a light source 29 is installed at the bottom center of the disc 28, a third visual detection head 26 for photographing the inner wall of the detection position 17 corresponding to the detection box 12 is also installed above the detection position 17, a second cylinder 27 is installed on the inner top of the detection position 17 corresponding to the detection box 12, the disc 28 is rotatably connected to the telescopic end of the second cylinder 27, the light source 29 is installed at the telescopic end of the second cylinder 27, a motor 36 is fixedly installed on the telescopic section of the second cylinder 27, a gear 37 is fixedly installed at the output end of the motor 36, and a gear 37 is fixedly installed on the top of the disc 28. The gear ring 35 meshes with the gear 37, and starts the second cylinder 27 to drive the plate 28 to move downward, press against the cover of the bottle cap, and press the bottle cap between the plate 28 and the turntable 30. The motor 36 is started to drive the plate 28 to rotate through the gear 37 and the gear ring 35, and the bottle cap can be driven to rotate. At this time, the light source 29 is located inside the bottle cap, and the light source 29 emits light in all directions. The light is evenly projected on the inner wall of the bottle cap in the circumferential direction. If there is a notch defect, the light can be projected out of the notch and projected onto the inner wall of the detection box 12 at the detection position 17. The projection area is photographed by the third visual inspection head 26, and the defect can be detected by analyzing the image.
[0036] Furthermore, the first visual inspection head 7, the second visual inspection head 10 and the third visual inspection head 26 are all cameras, and the first visual inspection head 7, the second visual inspection head 10 and the third visual inspection head 26 are electrically connected to image analysis and detection equipment, which can quickly analyze and judge the taken pictures.
[0037] A blowing position 16 is provided between the loading position 15 and the detection position 17, an arc-shaped air blowing pipe 19 is installed at the blowing position 16 of the detection box 12, and a blowing head 20 is installed at the discharging position 18 of the detection box 12. The blowing head 20 is higher than the notch of the bottle cap groove 22, and a material removal air duct 13 is installed on one side of the discharging belt conveyor 14. The blowing head 20 can blow air to blow the bottle caps onto the discharging belt conveyor 14, and the defective bottle caps can be blown away through the material removal air duct 13 to realize the material separation process.
[0038] The formed bottle caps are transported to the inspection channel 1 at intervals with the cover opening facing upwards by the feeding belt conveyor 2. The first cylinder 9 is started intermittently, and the cap top inspection belt conveyor 3 is driven to rise and fall reciprocally through the bracket 8. The lowering makes the feeding end belt of the cap top inspection belt conveyor 3 stick to the cap opening of the bottle cap at the discharging end of the feeding belt conveyor 2. At this time, the negative pressure hole 4 at the feeding end is turned to the negative pressure groove 6, and the cover opening is in a closed state against the belt, thereby generating negative pressure to adsorb the bottle cap and transport it downwards. The first visual inspection head 7 takes pictures to complete the inspection of the cap top defects, and the bottle cap continues to move to the discharging end. At this time, the negative pressure hole 4 is separated from the negative pressure groove 6 area, the negative pressure disappears, and the bottle cap falls on the inner cap inspection belt conveyor 11 with the cover opening facing upwards. The second visual inspection head 10 takes pictures to complete the inspection process of the internal defects of the bottle cap.
[0039] After the inner cap inspection is completed, the bottle cap enters the inspection box 12, and the driving shaft 23 drives the inspection disk 25 to rotate intermittently. The bottle cap is sent upward into the material port 21 at the loading position 15, and then turns to the blowing position 16. The bottle cap is completely blown into the bottle cap groove 22 through the arc-shaped air blowing pipe 19, and then turns to the inspection position 17. The second cylinder 27 is started to drive the plate 28 to move downward, press against the cap opening of the bottle cap, and press the bottle cap between the plate 28 and the turntable 30. The motor 36 is started, and the plate 28 is driven to rotate through the gear 37 and the ring gear 35, so as to drive the bottle cap to rotate. At this time, the light source 29 is located inside the bottle cap, and the light source 29 radiates light all around. The light is evenly projected on the inner side wall of the bottle cap in the circumferential direction. If there is a notch defect, the light can be projected out of the notch and projected on the inner wall of the inspection box 12 at the inspection position 17. The projection area is photographed by the third visual inspection head 26, and the defect can be detected by analyzing the image, thereby completing the inspection process of the circumferential side wall defect of the bottle cap, and the inspection effect is excellent and accurate.
[0040] When the bottle cap slot 22 rotates through the loading position 15, the blowing position 16 and the detecting position 17, the turntable 30 is always located at the inner bottom of the bottle cap slot 22. When it rotates to the discharging position 18, the conductive head 34 contacts the conductive plate 38, and the conductive plate 38 is connected to an external power supply. The spring 32 is energized and contracts, and then the turntable 30 is driven to move upward through the push rod 31, and the bottle cap is pushed to the slot position. The blowing head 20 blows air to blow the bottle cap onto the discharging belt conveyor 14, and the defective bottle cap can be blown away through the ejection air duct 13 to realize the material separation process.
[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A visual inspection device for surface defects of plastic bottle caps, comprising an inspection channel (1), characterized in that: The front end of the detection channel (1) is connected to a feeding belt conveyor (2), a transversely arranged inner-cap detection belt conveyor (11) is installed in the detection channel (1), a cap top detection belt conveyor (3) is installed in the detection channel (1) between the feeding belt conveyor (2) and the inner-cap detection belt conveyor (11), the cap top detection belt conveyor (3) can be raised and lowered, and a plurality of negative pressure holes (4) for adsorbing bottle caps are arranged at intervals on the surface, a first visual detection head (7) is installed in the detection channel (1) below the cap top detection belt conveyor (3), a second visual detection head (10) is installed in the detection channel (1) above the inner-cap detection belt conveyor (11), a detection box (12) is installed in the rear end of the detection channel (1), the tail end of the inner-cap detection belt conveyor (11) extends to the front end of the detection box (12), and a discharge belt conveyor (14) is installed at the rear end of the detection box (12) A detection disk (25) is installed in the detection box (12) between the inner detection belt conveyor (11) and the discharging belt conveyor (14), and a plurality of bottle cap grooves (22) adapted for bottle caps are arranged on the circumference of the detection disk (25). A material port (21) connected to the plurality of bottle cap grooves (22) in a one-to-one correspondence is arranged on the circumferential side wall of the detection disk (25). A loading position (15), a detection position (17) and a discharging position (18) are respectively arranged on the front side, the right side and the rear side of the detection disk (25). A liftable turntable (30) is installed on the inner bottom of the bottle cap groove (22), a contact disk (28) for contacting the bottle cap opening is installed above the detection position (17), a light source (29) is installed at the bottom center of the contact disk (28), and a third visual detection head (26) for photographing the inner wall of the detection position (17) corresponding to the detection position of the detection box (12) is also installed above the detection position (17).
2. A visual inspection device for surface defects of plastic bottle caps according to claim 1, characterized in that: A sealing plate (5) attached to the inner surface of the belt is installed in the cover top detection belt conveyor (3), and a negative pressure groove (6) connected to a plurality of negative pressure holes (4) is provided at the bottom of the sealing plate (5). The negative pressure groove (6) is externally connected to a negative pressure pump, and the negative pressure groove (6) extends from the discharge end of the feed belt conveyor (2) to the feed end of the cover inner detection belt conveyor (11).
3. A visual inspection device for surface defects of plastic bottle caps according to claim 1, characterized in that: A first cylinder (9) is installed at the bottom of the detection channel (1), a bracket (8) is fixedly installed at the telescopic end of the first cylinder (9), and the cover top detection belt conveyor (3) is fixedly installed on the bracket (8).
4. A visual inspection device for surface defects of plastic bottle caps according to claim 1, characterized in that: The first visual inspection head (7), the second visual inspection head (10) and the third visual inspection head (26) are all cameras, and the first visual inspection head (7), the second visual inspection head (10) and the third visual inspection head (26) are electrically connected to an image analysis inspection device.
5. A visual inspection device for surface defects of plastic bottle caps according to claim 1, characterized in that: A driving shaft (23) for driving the detection disk (25) to rotate is installed at the bottom of the detection box (12).
6. A visual inspection device for surface defects of plastic bottle caps according to claim 1, characterized in that: The diameter of the bottle cap groove (22), the diameter of the rotating disk (30), the diameter of the abutting disk (28) and the width of the material opening (21) are all consistent with the bottle cap, and the depth of the bottle cap groove (22) is less than the depth of the bottle cap.
7. A visual inspection device for surface defects of plastic bottle caps according to claim 1, characterized in that: A second cylinder (27) is installed at the inner top of the detection box (12) corresponding to the detection position (17); the contact plate (28) is rotatably connected to the telescopic end of the second cylinder (27); the light source (29) is installed at the telescopic end of the second cylinder (27); a motor (36) is fixedly installed on the telescopic section of the second cylinder (27); a gear (37) is fixedly installed at the output end of the motor (36); and a gear ring (35) meshing with the gear (37) is fixedly installed on the top of the contact plate (28).
8. A visual inspection device for surface defects of plastic bottle caps according to claim 1, characterized in that: A plurality of circular cavities (33) corresponding to the plurality of bottle cap grooves (22) are provided in the bottom of the detection disk (25); a push rod (31) is elastically connected to the circular cavity (33) via a spring (32); the upper end of the push rod (31) extends into the bottle cap groove (22) and is rotatably connected to the turntable (30); a plurality of conductive heads (34) electrically connected to the plurality of springs (32) are installed at the bottom of the detection disk (25); an annular guide rail (24) is fixed below the detection disk (25) in the detection box (12); the plurality of conductive heads (34) are in contact with the annular guide rail (24); and a conductive plate (38) is connected in series to the annular guide rail (24) at a position corresponding to the discharge position (18).
9. A visual inspection device for surface defects of plastic bottle caps according to claim 1, characterized in that: A blowing position (16) is provided between the loading position (15) and the detection position (17); an arc-shaped air blowing pipe (19) is installed at the blowing position (16) of the detection box (12); and an air blowing head (20) is installed at the discharge position (18) of the detection box (12); the air blowing head (20) is higher than the notch of the bottle cap groove (22).
10. A visual inspection device for surface defects of plastic bottle caps according to claim 1, characterized in that: A material removal air duct (13) is installed on one side of the discharging belt conveyor (14).