Product appearance inspection equipment and inspection method

Abstract

The present invention discloses a product appearance inspection device and inspection method, comprising a conveying mechanism and a base; a position acquisition device and a shape magnification device located above the conveying mechanism are provided in the base; a first camera and a second camera are provided on the top of the base corresponding to the position acquisition device and the shape magnification device, respectively; a limit assembly for cooperating with the shape magnification device is also provided in the base; the device realizes rapid and continuous inspection of product appearance, shortens inspection time, improves inspection efficiency on the production line, and helps reduce production costs compared to traditional point-by-point measurement or complex optical scanning methods.

Description

Technical Field

[0001] The present invention relates to the field of testing technology, and in particular to a product appearance testing device and a testing method. Background Art

[0002] In the field of lithium-ion battery technology, battery safety and stability are crucial considerations. Lithium-ion batteries are typically packaged in aluminum-plastic film, typically no thicker than 0.1 mm. While lightweight and portable, this material is relatively insulated and susceptible to damage from external factors. Especially when used under harsh conditions such as overcharging, impact, and high temperatures, the electrolyte within the battery may decompose, releasing gases that can cause bulges in the aluminum-plastic film, forming bumps on the battery surface and potentially leading to battery failure. If these defects are not discovered and addressed promptly, they can not only shorten the battery's lifespan but also potentially lead to safety incidents, posing a potential threat to users.

[0003] Existing lithium-ion battery surface inspection methods have certain limitations in practical applications. First, the uneven texture of aluminum-plastic film packaging, coupled with its severe surface reflectivity, makes it difficult to detect surface defects using image recognition technology. This results in low recognition accuracy, time-consuming inspection, and low inspection efficiency. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a product appearance detection device and detection method to achieve rapid and continuous detection of product appearance.

[0005] To achieve the above-mentioned objectives, the specific solution of the present invention is as follows: a product appearance inspection device, comprising a conveying mechanism and a base; a position acquisition device and a shape magnification device located above the conveying mechanism are provided in the base; a first camera and a second camera are provided on the top of the base corresponding to the position acquisition device and the shape magnification device, respectively; a limit assembly for cooperating with the shape magnification device is also provided in the base.

[0006] The present invention further provides a position acquisition device including a first acquisition roller; the roller surface of the first acquisition roller is evenly distributed with first receiving grooves along the circumferential direction; a first flexible deformation portion is provided at the opening position of the first receiving groove; the first flexible deformation portion and the first receiving groove enclose a first cavity filled with magnetorheological fluid; a coil winding is also provided in the first cavity.

[0007] The present invention further provides that the shape magnification device includes a second collecting roller; the roller surface of the second collecting roller is uniformly provided with second accommodating grooves along the circumferential direction; a second flexible deformation portion is provided at the opening position of the second accommodating groove; the outer surface of the second flexible deformation portion protrudes from the roller surface of the second collecting roller; the second flexible deformation portion and the second accommodating groove enclose a second cavity to form; an air pumping mechanism is provided in the second cavity; the air pumping mechanism is used to pump air and exhaust the second cavity.

[0008] The present invention further provides that the limiting assembly includes a limiting support and a swinging member; one end of the swinging member is hinged to the limiting support, and the other end of the swinging member is connected to a locking block; the inner side wall portion of the limiting support is provided with a gear ring structure for driving the air pumping mechanism to pump air; the limiting support is provided with a limiting arc groove; the gear ring structure and the limiting arc groove are arranged in sequence along the rotation direction of the second collecting roller; the locking block is slidably connected to the limiting slide groove; a coil spring is connected between the swinging member and the limiting support; the coil spring causes the swinging member to swing to the side close to the gear ring structure.

[0009] The present invention further provides that the air pumping mechanism includes a pump body, a piston movably arranged in the pump body and an adjusting rod rotatably arranged through the pump body; the piston is movably sleeved on the outer wall of the adjusting rod; the end of the adjusting rod passing through the pump body is provided with a gear that can engage with the ring gear structure for transmission; the side of the gear facing away from the pump body is provided with spline teeth that can cooperate with the locking block; a return spring is connected between the piston and the pump body; the outer wall of the adjusting rod is provided with a spiral groove extending along its axial direction; the piston is provided with a pin; and the pin is movably embedded in the spiral groove.

[0010] The present invention further comprises a piston which separates the pump body into a first air cavity and a second air cavity; an air inlet valve and an air exhaust valve are provided at a position of the pump body corresponding to the first air cavity; the second air cavity is connected to the outside atmosphere; and a return spring is provided in the first air cavity.

[0011] The present invention further comprises a spraying device located between the position acquisition device and the shape magnification device and used for spraying paint onto the surface of the product to be inspected, and a removing device located between the spraying device and the shape magnification device and used for removing the paint on the shape magnification device; the removing device comprises two rollers and a removing belt wound around the two rollers; the removing belt covers a portion of the roller surface of the second acquisition roller.

[0012] Furthermore, the present invention provides that the position acquisition device and the shape magnification device are both in transmission connection with the transmission mechanism;

[0013] The transmission mechanism is a transmission belt structure; pulleys are provided on both sides of the transmission belt structure, both sides of the position acquisition device and both sides of the shape magnification device; tensioning shafts are provided on both inner side walls of the base; the same transmission belt is wound around the tensioning shaft and each pulley on the same side.

[0014] Furthermore, the present invention provides guide strips on both sides of the conveyor belt structure at positions corresponding to the position collection device and the shape magnification device.

[0015] The present invention also provides a detection method based on the above-mentioned product appearance detection device, which specifically includes the following steps:

[0016] Step S100: The position acquisition device acquires convex defects and / or concave defects on the inspection surface to obtain defect position information; the first camera photographs the defect position information acquired by the position acquisition device to obtain a first inspection image;

[0017] Step S200: The shape magnifying device collects the shape of the convex defects and / or concave defects on the inspection surface to obtain defect shape information, and cooperates with the limit assembly to magnify the defect shape information. The second camera takes a picture of the defect shape information to obtain a second inspection image.

[0018] Step S300: performing position and shape recognition on the first detection image and the second detection image to determine whether there are convex defects or concave defects, as well as the position and shape of the defects;

[0019] If the number and size of any of the detected defects exceeds the preset threshold limit, the product appearance is judged to be unqualified.

[0020] The beneficial effects of the present invention are as follows: the present invention drives the product to be inspected to pass through the position acquisition device and the shape magnification device in sequence by arranging a conveying mechanism, so that the product is inspected in sequence by the position acquisition device and the shape magnification device, thereby realizing rapid and continuous inspection of the product appearance. Compared with traditional point-by-point measurement or complex optical scanning methods, the present invention shortens the inspection time, improves the inspection efficiency on the production line, and helps to reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 is a cross-sectional view of the present invention;

[0023] Figure 3 It is a partial structural schematic diagram of the present invention;

[0024] Figure 4 It is a structural schematic diagram of the position acquisition device of the present invention;

[0025] Figure 5 is a schematic cross-sectional view of a position acquisition device of the present invention;

[0026] Figure 6 It is a structural schematic diagram of the shape magnification device of the present invention;

[0027] Figure 7 is a schematic cross-sectional view of the shape magnification device of the present invention;

[0028] Figure 8 It is a structural schematic diagram of the air pumping mechanism of the present invention;

[0029] Figure 9 It is a cross-sectional schematic diagram of the air pumping mechanism of the present invention;

[0030] Figure 10 It is a structural schematic diagram of the limit assembly of the present invention;

[0031] Explanation of the accompanying drawings: 1. bottom plate; 2. conveying mechanism; 21. guide bar; 3. base; 41. first collecting roller; 42. first flexible deformation part; 43. first cavity; 44. coil winding; 51. second collecting roller; 52. second flexible deformation part; 53. second cavity; 54. air pumping mechanism; 541. pump body; 542. piston; 543. adjusting rod; 5431. spiral groove; 544. gear; 5441. spline tooth; 545. return spring; 546. intake valve; 547. exhaust valve; 6. first camera; 7. second camera; 81. limit support; 811. gear ring structure; 812. limit arc groove; 82. swinging member; 83. locking block; 91. spraying device; 921. roller shaft; 922. material removal belt; 101. pulley; 102. transmission belt. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of implementation of the present invention is not limited thereto.

[0033] like Figures 1 to 10 As shown, the product appearance inspection device described in this embodiment specifically includes a base plate 1, a conveying mechanism 2 installed on the base plate 1, and a base 3; the conveying mechanism 2 is used to convey the product to be inspected so that the product to be inspected passes under the position acquisition device and the shape magnification device in sequence; the base 3 is provided with a position acquisition device and a shape magnification device located above the conveying mechanism 2; a first camera 6 and a second camera 7 are provided on the top of the base 3 corresponding to the position acquisition device and the shape magnification device, respectively; and the base 3 is also provided with a limit assembly for cooperating with the shape magnification device.

[0034] Specifically, this embodiment is described using the inspection of the appearance of lithium-ion batteries as an example. When the product appearance inspection device of this embodiment is actually used, the lithium-ion batteries to be inspected are placed on the conveying mechanism 2 at equal intervals with the inspection surface facing upward. The conveying mechanism 2 drives the lithium-ion batteries to be inspected to move sequentially to the bottom of the position acquisition device. The position acquisition device collects the raised defects and / or recessed defects on the inspection surface of the lithium-ion battery to obtain defect location information; the first camera 6 takes a picture of the defect location information collected by the position acquisition device to obtain a first inspection image;

[0035] After the defect position information is collected, the lithium-ion battery is conveyed to the bottom of the shape magnification device. The shape magnification device collects the shape of the raised defects and / or recessed defects on the inspection surface of the lithium-ion battery to obtain defect shape information. The shape magnification device then cooperates with the limit assembly to magnify the defect shape information. The second camera 7 takes a picture of the defect shape information after the magnification process to obtain a second inspection image.

[0036] Then, the control unit performs position and shape recognition on the first detection image and the second detection image to determine whether there are convex defects, concave defects, and the positions and shapes of the defects;

[0037] If the number and size of any of the detected defects exceed the preset threshold, the appearance of the lithium-ion battery is judged to be unqualified and the lithium-ion battery is determined to be defective;

[0038] If no defects are detected, or the number and size of the detected defects do not exceed the preset threshold, the lithium-ion battery is judged to have a qualified appearance and is determined to be a good product.

[0039] In this embodiment, a conveying mechanism 2 is provided to drive the product to be inspected to pass through the position acquisition device and the shape magnification device in sequence, so that the product is inspected in sequence by the position acquisition device and the shape magnification device, thereby realizing rapid and continuous inspection of the product appearance. Compared with traditional point-by-point measurement or complex optical scanning methods, this method shortens the inspection time, improves the inspection efficiency on the production line, and helps to reduce production costs.

[0040] like Figures 1 to 5 As shown, in some embodiments of the product appearance inspection device described in this embodiment, the position acquisition device includes a first acquisition roller 41; the roller surface of the first acquisition roller 41 is uniformly distributed with first receiving grooves along the circumference; a first flexible deformable portion 42 is provided at the opening of the first receiving groove; the first flexible deformable portion 42 and the first receiving groove enclose a first cavity 43 filled with magnetorheological fluid; and a coil winding 44 is further provided within the first cavity 43. Preferably, the first flexible deformable portion 42 is made of rubber or silicone.

[0041] Specifically, when the lithium-ion battery to be inspected moves to the bottom of the first collecting roller 41, the convex defect on the inspection surface will push up the first flexible deformation part 42, so that a first groove corresponding to the convex defect is formed on the first flexible deformation part 42, and the concave defect on the inspection surface is filled by the first flexible deformation part 42 under the action of the magnetorheological fluid, so that the first flexible deformation part 42 forms a first boss corresponding to the concave defect, while the defect-free part on the inspection surface is in contact with the plane of the inspection surface. At the same time, when the first flexible deformation part 42 contacts the inspection surface, The coil winding 44 in the first cavity 43 is energized and generates a magnetic field, so that the magnetorheological fluid in the first cavity 43 is arranged along the direction of the magnetic field to form a stable structure, so that the magnetorheological fluid hardens from liquid to solid, so that the first flexible deformation part 42 remains in the deformed shape, thereby obtaining the defect position information; after completion, the first collection roller 41 drives the first flexible deformation part 42 with the obtained defect position information to rotate to the position corresponding to the first camera 6, and the first camera 6 takes a picture of the first flexible deformation part 42 with the obtained defect position information, thereby obtaining a first detection image.

[0042] like Figure 2 、 Figure 3 、 Figure 6 and Figure 7 As shown, in some embodiments of the product appearance inspection device described in this embodiment, the shape magnification device includes a second collection roller 51; the roller surface of the second collection roller 51 is uniformly distributed with second receiving grooves along the circumference; a second flexible deformable portion 52 is provided at the opening of the second receiving groove; the outer surface of the second flexible deformable portion 52 protrudes from the roller surface of the second collection roller 51; the second flexible deformable portion 52 and the second receiving groove enclose a second cavity 53; a pumping mechanism 54 is provided in the second cavity 53; the pumping mechanism 54 is used to pump and exhaust air in the second cavity 53. Preferably, the second flexible deformable portion 52 is made of rubber or silicone.

[0043] Specifically, when the lithium-ion battery to be inspected moves to the bottom of the second collecting roller 51, the second flexible deformation part 52 on the second collecting roller 51 contacts the inspection surface, and the convex defect on the inspection surface will push up the second flexible deformation part 52, so that the first shape information corresponding to the convex defect is formed on the second flexible deformation part 52, and the concave defect on the inspection surface is filled by the second flexible deformation part 52 under the deformation action of the second flexible deformation part 52, so that the second flexible deformation part 52 forms the second shape information corresponding to the concave defect; then the air pumping mechanism 54 pumps air into the second cavity 53 under the drive of the limiting component, so that the air pressure in the second cavity 53 increases, and the second flexible deformation part 52 expands, so that the first shape information and the second shape information are amplified, and then the second collecting roller 51 drives the second flexible deformation part 52 with the first shape information and the second shape information collected to rotate to the bottom of the second camera 7, and the second camera 7 takes pictures of the amplified first shape information and the second shape information on the second flexible deformation part 52 to judge the shape and size of the defect on the inspection surface by the amplified first shape information and the second shape information.

[0044] like Figure 2 and Figure 3 As shown, in the product appearance inspection equipment described in this embodiment, in some embodiments, the base 3 is further provided with a spraying device 91 located between the position acquisition device and the shape magnification device and used to spray paint onto the surface of the product to be inspected, and a removing device located between the spraying device 91 and the shape magnification device and used to remove the paint on the shape magnification device; the removing device includes two rollers 921 and a removing belt 922 wound around the two rollers 921; the removing belt 922 covers a portion of the roller surface of the second acquisition roller 51.

[0045] It should be noted that the spraying device 91 is a prior art and adopts an existing paint spraying device 91. Specifically, after the defect position information is collected, the lithium-ion battery is conveyed to the bottom of the spraying device 91. The spraying device 91 sprays paint onto the detection surface. After the spraying is completed, the lithium-ion battery is conveyed to the bottom of the shape magnification device. The second flexible deformation portion 52 of the second collection roller 51 contacts the detection surface, and the paint on the detection surface is transferred to the second flexible deformation portion 52. At this time, if there is a defect on the detection surface, the defect will cause a difference in the color distribution on the second flexible deformation portion 52, thereby forming the first shape information and the second shape information. When the second camera 7 takes a picture of the second flexible deformation portion 52 that has collected the first shape information and the second shape information, the shape outline of the defect can be identified by light transmittance and pigment distribution, thereby judging the shape and size of the defect.

[0046] After the second camera 7 completes taking the photo, the second collecting roller 51 drives the second flexible deformation part 52 that has collected the first shape information and the second shape information to rotate until it contacts the removal belt 922. The removal belt 922 rotates under the drive of the second collecting roller 51, thereby removing the pigment on the second flexible deformation part 52, so that the second flexible deformation part 52 can perform defect shape detection on the inspection surface of the next lithium-ion battery.

[0047] like Figure 2 、 Figure 3 and Figure 10 As shown, in the product appearance inspection equipment described in this embodiment, in some embodiments, the limit assembly includes a limit support 81 and a swinging member 82; the limit support 81 is fixedly mounted on the base plate 1; one end of the swinging member 82 is hinged to the limit support 81, and the other end of the swinging member 82 is connected to a locking block 83; the inner side wall portion of the limit support 81 is provided with a gear ring structure 811 for driving the air pumping mechanism 54 to pump air; the limit support 81 is provided with a limit arc groove 812; the gear ring structure 811 and the limit arc groove 812 are arranged in sequence along the rotation direction of the second collecting roller 51; the locking block 83 is slidably connected to the limit slide groove; a coil spring (not shown in the figure) is connected between the swinging member 82 and the limit support 81; the coil spring causes the swinging member 82 to swing to the side close to the gear ring structure 811.

[0048] Specifically, the two ends of the coil spring are fixedly connected to the swing member 82 and the limit support 81 respectively; the swing member 82 is plate-shaped; after the second flexible deformation part 52 collects the shape information, the second collection roller 51 drives the second flexible deformation part 52 to rotate, so that the corresponding pumping mechanism 54 cooperates with the ring gear structure 811, and the ring gear structure 811 drives the pumping mechanism 54 to pump air into the second cavity 53, increasing the air pressure in the second cavity 53, so that the second flexible deformation part 52 expands and deforms, thereby being able to amplify the first shape information and the second shape information; after the ring gear structure 811 is disengaged from the pumping mechanism 54, the pumping mechanism 54 cooperates with the locking block 83, and the locking block 83 maintains the air pressure in the second cavity 53, and the locking block 83 drives the swing member 82 to swing synchronously, and the coil spring stores energy, thereby keeping the second flexible deformation part 52 in the expanded state, so that the second camera 7 can take a picture of the second flexible deformation part 52 to identify the shape and size of the defect;

[0049] After the second camera 7 takes a picture, as the second collecting roller 51 rotates, the locking block 83 disengages from the air pumping mechanism 54. At this time, the air pumping mechanism 54 is released, so that the second cavity 53 is exhausted and the air pressure is reduced, so that the second flexible deformation part 52 is restored. At the same time, the coil spring releases the stored energy, driving the swing member 82 to drive the locking block 83 to swing in the opposite direction to return to the initial position, waiting to cooperate with the next air pumping mechanism 54; the restored second flexible deformation part 52 rotates to contact the removal belt 922, thereby removing the pigment on the second flexible deformation part 52 for the next lithium-ion battery test.

[0050] like Figures 7 to 9 As shown, in the product appearance inspection equipment described in this embodiment, in some embodiments, the air pumping mechanism 54 includes a pump body 541, a piston 542 movably arranged in the pump body 541 and an adjusting rod 543 rotatably passed through the pump body 541; the piston 542 is movably sleeved on the outer wall of the adjusting rod 543; the end of the adjusting rod 543 passing through the outside of the pump body 541 is provided with a gear 544 that can engage with the ring gear structure 811 for transmission; the side of the gear 544 facing away from the pump body 541 is provided with spline teeth 5441 that can cooperate with the locking block 83; a return spring 545 is connected between the piston 542 and the pump body 541; the outer wall of the adjusting rod 543 is provided with a spiral groove 5431 extending along its axial direction; the piston 542 is provided with a pin; the pin is movably embedded in the spiral groove 5431. In the product appearance inspection equipment described in this embodiment, in some embodiments, the piston 542 separates the pump body 541 into a first air cavity and a second air cavity; an intake valve 546 and an exhaust valve 547 are provided at the position of the pump body 541 corresponding to the first air cavity; the second air cavity is connected to the outside atmosphere; and a return spring 545 is provided in the first air cavity.

[0051] Specifically, when the second collecting roller 51 rotates, the gear 544 meshes with the ring gear structure 811 for transmission. The ring gear structure 811 drives the gear 544 to rotate, and the gear 544 drives the adjusting rod 543 to rotate. The adjusting rod 543 cooperates with the spiral groove 5431 through the bayonet pin, driving the piston 542 to slide. The return spring 545 is compressed, causing the effective volume of the first air cavity to decrease and the effective volume of the second air cavity to increase. The exhaust valve 547 opens, allowing the gas in the first air cavity to enter the second cavity 53, thereby increasing the air pressure in the second cavity 53 and causing the second flexible deformation portion 52 to expand and deform.

[0052] After the ring gear structure 811 and the gear 544 are disengaged, the spline teeth 5441 mesh with the locking block 83. Since the gear 544 no longer rotates, the second collecting roller 51 drives the gear 544 to perform a circular motion. At this time, the locking block 83 locks the gear 544 through the spline teeth 5441, so that the piston 542 remains in position, thereby maintaining the air pressure in the second chamber 53, so that the second camera 7 can take pictures and recognize the amplified first and second shape information.

[0053] As the second collecting roller 51 rotates, the locking block 83 is restricted by the limiting arc groove 812 and cannot continue to move with the gear 544. The gear 544 disengages from the locking block 83, and the gear 544 is no longer restricted by the locking block 83. The return spring 545 pushes the piston 542 to slide and reset, and the piston 542 drives the adjusting rod 543 to rotate, thereby increasing the effective volume of the first air cavity and reducing the effective volume of the second air cavity, so that the air inlet valve 546 opens, and the gas in the second cavity 53 enters the first air cavity, realizing the exhaust of the second cavity 53, so that the second flexible deformation part 52 recovers its deformation.

[0054] like Figures 1 to 3 As shown, in the product appearance inspection equipment described in this embodiment, in some embodiments, the position acquisition device and the shape magnification device are both transmission-connected to the transmission mechanism 2; such a setting makes the structural manufacturing cost lower, does not require multiple power sources, and makes the transmission mechanism 2 more consistent with the position acquisition device and the shape magnification device.

[0055] In this embodiment, Figures 1 to 3 As shown, the transmission mechanism 2 is a transmission belt structure; pulleys 101 are provided on both sides of the transmission belt 102 structure, both sides of the position acquisition device and both sides of the shape magnification device; tensioning shafts are provided on both inner side walls of the base 3; the same transmission belt 102 is wound around the tensioning shaft and each pulley 101 on the same side; specifically, both ends of the first collection roller 41 and both ends of the second collection roller 51 are connected to the pulley 101. When the transmission belt 102 structure is working, the transmission belt 102 structure drives the pulley 101 to rotate. Through the transmission of the transmission belt 102 and the pulley 101, the first collection roller 41 and the second collection roller 51 are synchronously driven to rotate, and the tensioning shaft tensions the transmission belt 102 to ensure the transmission stability of the transmission belt 102.

[0056] like Figure 3 As shown, in some embodiments of the product appearance inspection device described in this embodiment, guide bars 21 are provided on both sides of the conveyor belt structure at locations corresponding to the position acquisition device and shape magnification device. In this embodiment, the guide bars 21 are provided to centrally guide the lithium-ion battery, ensuring sufficient contact between the position acquisition device and the shape magnification device with the inspection surface, thereby providing more accurate inspection results.

[0057] The above description is only a preferred embodiment of the present invention. Therefore, any equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the patent application of the present invention are included in the protection scope of the patent application of the present invention.

Claims

1. A product appearance inspection device, characterized in that: The device comprises a transmission mechanism and a base; the base is provided with a position acquisition device and a shape magnification device located above the transmission mechanism; a first camera and a second camera are provided on the top of the base corresponding to the position acquisition device and the shape magnification device, respectively; and the base is also provided with a limit assembly for cooperating with the shape magnification device. The position acquisition device includes a first acquisition roller; the roller surface of the first acquisition roller is uniformly distributed with first receiving grooves along the circumference; a first flexible deformation portion is provided at the opening of the first receiving groove; the first flexible deformation portion and the first receiving groove enclose a first cavity filled with magnetorheological fluid; a coil winding is also provided in the first cavity; The shape magnifying device includes a second collecting roller; the roller surface of the second collecting roller is uniformly distributed with second receiving grooves along the circumference; a second flexible deformation portion is provided at the opening of the second receiving groove; the outer surface of the second flexible deformation portion protrudes from the roller surface of the second collecting roller; the second flexible deformation portion and the second receiving groove enclose a second cavity; an air pumping mechanism is provided in the second cavity; the air pumping mechanism is used to pump air into and out of the second cavity; The base is also provided with a spraying device located between the position acquisition device and the shape magnifying device and used to spray paint onto the surface of the product to be tested, and a removing device located between the spraying device and the shape magnifying device and used to remove the paint on the shape magnifying device; The material removal device comprises two roller shafts and a material removal belt wound around the two roller shafts; the material removal belt covers a part of the roller surface of the second collecting roller.

2. A product appearance inspection device according to claim 1, characterized in that: The limiting assembly includes a limiting support and a swinging member; one end of the swinging member is hinged on the limiting support, and the other end of the swinging member is connected to a locking block; the inner side wall of the limiting support is provided with a gear ring structure for driving the air pumping mechanism to pump air; the limiting support is provided with a limiting arc groove; the gear ring structure and the limiting arc groove are arranged in sequence along the rotation direction of the second collecting roller; the locking block is slidably connected to the limiting slide groove; a coil spring is connected between the swinging member and the limiting support; the coil spring causes the swinging member to swing to the side close to the gear ring structure.

3. The product appearance inspection device according to claim 2, characterized in that: The air pumping mechanism includes a pump body, a piston movably arranged in the pump body and an adjusting rod rotatably arranged through the pump body; the piston is movably sleeved on the outer wall of the adjusting rod; the end of the adjusting rod passing through the pump body is provided with a gear that can engage with the ring gear structure for transmission; the side of the gear facing away from the pump body is provided with spline teeth that can cooperate with the locking block; a return spring is connected between the piston and the pump body; the outer wall of the adjusting rod is provided with a spiral groove extending along its axial direction; the piston is provided with a bayonet; the bayonet is movably embedded in the spiral groove.

4. The product appearance inspection device according to claim 3, characterized in that: The piston divides the pump body into a first air cavity and a second air cavity; an air inlet valve and an air exhaust valve are provided at a position of the pump body corresponding to the first air cavity; the second air cavity is connected to the outside atmosphere; and a return spring is provided in the first air cavity.

5. The product appearance inspection device according to any one of claims 1 to 4, characterized in that: The position acquisition device and the shape magnification device are both transmission-connected to the transmission mechanism; The transmission mechanism is a transmission belt structure; pulleys are provided on both sides of the transmission belt structure, both sides of the position acquisition device and both sides of the shape magnification device; tensioning shafts are provided on both inner side walls of the base; the same transmission belt is wound around the tensioning shaft and each pulley on the same side.

6. The product appearance inspection device according to claim 5, characterized in that: Guide strips are provided on both sides of the conveyor belt structure at positions corresponding to the position collection device and the shape magnification device.

7. A detection method based on the product appearance detection device according to any one of claims 1 to 6, characterized in that: The steps include: S100: The position acquisition device acquires convex defects and / or concave defects on the inspection surface to obtain defect position information; the first camera photographs the defect position information acquired by the position acquisition device to obtain a first inspection image; S200: The shape magnifying device collects the shape of the convex defect and / or concave defect on the inspection surface to obtain defect shape information, and cooperates with the limiting component to magnify the defect shape information. The second camera takes a picture of the defect shape information to obtain a second inspection image; S300: Performing position and shape recognition on the first detection image and the second detection image to determine whether there are convex defects or concave defects, as well as the positions and shapes of the defects; If the number and size of any of the detected defects exceeds the preset threshold limit, the product appearance is judged to be unqualified.

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