A steel strip visual surface inspection apparatus

Abstract

The present application relates to the technical field of visual detection, and discloses a steel strip visual surface detection device, which comprises a workbench. In the detection process, when the CCD camera moves horizontally, the light supplement lamp irradiates at a normal light angle perpendicular to the surface of the steel strip. This mode can highlight the flatness defects, reduce the interference of reflection, and is suitable for detecting surface relief defects. When the camera reaches the left and right limit positions and returns, the mechanical structure linkage makes the reflection cover rotate, the light supplement lamp switches to an inclined side light angle, the shadow contrast of edge concave-convex defects is enhanced, and the recognition accuracy of microscopic defects is improved. The intelligent switching of the normal light and the side light is realized through the cooperation of mechanical structures such as the top rod, the ball, and the compression spring. The light irradiation angle can be automatically adjusted according to the camera position without electronic sensors, the system structure is simplified, the cost is reduced, and the reliability is improved.

Description

Technical Field

[0001] This invention belongs to the field of visual inspection technology, and more specifically, relates to a visual surface inspection device for steel strips. Background Technology

[0002] In the steel strip production process, accurate detection of surface defects (such as cracks, rust spots, scratches, pitting, wavy lines, etc.) is a key step in ensuring product quality.

[0003] Existing visual inspection systems generally employ fixed-angle illumination, making it difficult to simultaneously meet the detection needs of different types of defects. While direct illumination perpendicular to the steel strip surface helps detect flatness defects such as wavy lines, it easily misses microscopic defects like scratches and pitting due to insufficient shadow contrast. Side illumination at an angle, while enhancing the three-dimensionality of uneven defects, amplifies surface reflection interference, affecting the accuracy of flatness defect identification. This makes it impossible for a single illumination mode to comprehensively detect multiple types of defects. Solving this problem often requires manually switching illumination angles or using multiple light source systems, which not only reduces inspection efficiency but also significantly increases costs. Therefore, this invention is proposed. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0005] A visual surface inspection device for steel strips includes a worktable.

[0006] The workbench is equipped with a conveyor belt body for conveying steel belts.

[0007] The workbench is equipped with a vertically sliding pressure plate used to press the steel strip flat.

[0008] A friction wheel and an adjusting roller are rotatably mounted on the pressure plate. The friction wheel and the adjusting roller are connected to each other through a transmission assembly. The lower surface of the friction wheel is in contact with the steel belt, and a cylindrical cam groove is provided on the adjusting roller. A connecting cover is engaged on the cylindrical cam groove, and a CCD camera with a built-in image sensor is connected to the bottom of the connecting cover.

[0009] A reflector is rotatably mounted on the outside of the CCD camera. A push plate is mounted on the outer wall of the reflector, and the push plate corresponds to the push rods mounted at both ends of the pressure plate. The push plate is used to push the reflector to deflect at an angle. A fill light is rotatably mounted inside the reflector, and a rocker arm is mounted at the center of rotation of the fill light. A horizontally movable top rod is slidably mounted on the rocker arm, and the end of the top rod corresponds to several pairs of protrusions on the side wall of the connecting cover.

[0010] The worktable is equipped with four support legs at its bottom, and each of the four support legs has a reinforcing rib. The heights between adjacent reinforcing ribs are different. A controller is installed inside the worktable and is connected to a CCD camera.

[0011] In a preferred embodiment of the present invention, a cover is installed on the surface of the workbench, and an opening is provided on the cover, which corresponds to the conveyor belt body. A slide rail is installed on the side wall of the cover, and a cover plate is slidably disposed on the slide rail. The cover plate is used to block the opening. A positioning plate is also installed on the side wall of the cover plate, and the positioning plate is connected to the cover by bolts.

[0012] In a preferred embodiment of the present invention, an electric push rod body is installed on the inner side wall of the cover, a synchronization plate is installed at the output end of the electric push rod body, four connecting frames are installed around the synchronization plate, the bottom of the four connecting frames are connected to the side wall of the pressure plate, and the pressure plate is in the shape of a U-shape. A pair of extrusion rollers are installed at the bottom of the pressure plate, the lowest point of the extrusion rollers corresponds to the lowest point of the friction wheel, and the rotation direction of the extrusion rollers and the friction wheel is the same as the conveying direction of the conveyor belt body.

[0013] In a preferred embodiment of the present invention, the transmission assembly includes a drive gear and a transmission gear that mesh with each other. A positioning shaft is mounted on the rotation center of the drive gear, and a gear shaft is mounted on the rotation center of the transmission gear. The gear shaft and the rotation center of the adjusting roller are interconnected, and the positioning shaft is interconnected with the rotation center of the friction wheel. A positioning frame is rotatably mounted on the side wall of the positioning shaft and the gear shaft, and the positioning frame is mounted on the pressure plate. A protective cover is mounted on the side wall of the positioning frame, and the protective cover covers the outer side wall of the drive gear and the transmission gear.

[0014] In a preferred embodiment of the present invention, a limiting frame is installed on the side wall of the positioning frame, and the limiting frame is arched. The limiting frame moves through the protective cover. A limiting rod is installed on the limiting frame, and a slider is slidably arranged on the limiting rod. The top of the slider engages with a cylindrical cam groove. A positioning rod is installed at the bottom of the slider, and the positioning rod is connected to the connecting cover. The reflector is rotatably connected to the positioning rod.

[0015] In a preferred embodiment of the present invention, a fixing seat is installed at the end of the push rod, the fixing seat is installed on the pressure plate, and the push rod and the push plate are located on the same plane.

[0016] In a preferred embodiment of the present invention, a guide seat is welded to the side wall of the reflector, a synchronous shaft is rotatably mounted on the guide seat, a supplementary light is mounted at one end of the synchronous shaft, the beam of the supplementary light is downward, and the synchronous shaft is connected to the rotation center of the rocker arm.

[0017] In a preferred embodiment of the present invention, the side wall of the connecting cover is provided with an inner groove, and a plurality of protrusions are installed on the inner groove. A ball is installed at the end of the top rod, and the ball fits against the inner side wall of the inner groove. Slide rods are installed at both ends of the top rod, and a strip groove is provided on the rocker arm. The slide rod is slidably disposed in the strip groove.

[0018] In a preferred embodiment of the present invention, a guide rod is movably inserted into the top rod, the end of the guide rod is connected to the inner wall of the reflector, and a compression spring is sleeved on the guide rod. One end of the compression spring is engaged with the inner wall of the reflector, and the other end of the compression spring is engaged with the end face of the top rod.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] In this invention, during the inspection process, when the CCD camera moves horizontally, the supplementary light illuminates the steel strip surface at a direct angle perpendicular to the surface. This mode highlights flatness defects, reduces reflection interference, and is suitable for detecting surface undulation defects. When the camera reaches its left or right limit and returns, a mechanical structure rotates the reflector, switching the supplementary light to an oblique side angle. This enhances the shadow contrast of edge-protruding defects and improves the accuracy of micro-defect identification. Furthermore, the intelligent switching between direct and side lighting is achieved through a mechanical structure involving a push rod, ball bearings, and compression springs. This eliminates the need for electronic sensors, automatically adjusting the illumination angle based on the camera position, simplifying the system structure, reducing costs, and improving reliability. The specific embodiments of this invention will be described in further detail below with reference to the accompanying drawings. Attached Figure Description

[0021] In the attached diagram:

[0022] Figure 1 A three-dimensional structural diagram of a visual surface inspection device for steel strips;

[0023] Figure 2 A cross-sectional view of the cover of a steel strip visual surface inspection device;

[0024] Figure 3 A partial structure of a visual surface inspection device for steel strips Figure 1 ;

[0025] Figure 4 A visual surface inspection device for steel strip Figure 3 Bottom view;

[0026] Figure 5 A partial structure of a visual surface inspection device for steel strips Figure 2 ;

[0027] Figure 6 A partial structure of a visual surface inspection device for steel strips Figure 3 ;

[0028] Figure 7 A cross-section of the reflector of a steel strip visual surface inspection device. Figure 1 ;

[0029] Figure 8 A visual surface inspection device for steel strip Figure 7 Enlarged view of point A in the middle;

[0030] Figure 9 A cross-section of the reflector of a steel strip visual surface inspection device. Figure 2 .

[0031] In the picture:

[0032] 1. Workbench; 11. Support leg; 111. Reinforcing rib; 12. Conveyor belt body; 13. Cover; 131. Through-hole; 132. Cover plate; 133. Slide rail; 134. Positioning plate;

[0033] 2. Pressure plate; 21. Extrusion roller; 22. Electric push rod body; 221. Synchronizing plate; 222. Connecting frame;

[0034] 3. Friction wheel; 31. Positioning frame; 311. Positioning shaft; 312. Protective cover; 32. Drive gear; 321. Transmission gear; 322. Gear shaft; 33. Adjusting roller; 331. Cylindrical cam groove; 332. Slider; 333. Limiting rod; 334. Limiting frame; 34. CCD camera; 341. Connecting cover; 342. Positioning rod;

[0035] 4. Reflector; 41. Push plate; 411. Push rod; 412. Fixing base; 42. Fill light; 421. Guide seat; 43. Rocker arm; 431. Synchronous shaft; 432. Strip groove; 44. Top rod; 441. Ball bearing; 442. Inner groove; 443. Protrusion; 444. Slide rod; 45. Guide rod; 451. Compression spring. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention.

[0037] Example 1:

[0038] like Figures 1 to 9 As shown, a visual surface inspection device for steel strip includes a worktable 1.

[0039] The workbench 1 is equipped with a conveyor belt body 12 for conveying steel belts;

[0040] A vertically sliding pressure plate 2 is installed on the workbench 1 for pressing the steel strip flat;

[0041] Friction wheel 3 and adjusting roller 33 are rotatably mounted on pressure plate 2. Friction wheel 3 and adjusting roller 33 are connected to each other through transmission assembly. The lower surface of friction wheel 3 is in contact with steel belt. A cylindrical cam groove 331 is opened on adjusting roller 33. A connecting cover 341 is engaged on cylindrical cam groove 331. A CCD camera 34 with built-in image sensor is connected to the bottom of connecting cover 341.

[0042] A reflector 4 is rotatably mounted on the outside of the CCD camera 34. A push plate 41 is mounted on the outer wall of the reflector 4, and the push plate 41 corresponds to the push rods 411 mounted at both ends of the pressure plate 2. The push plate 41 is used to push the reflector 4 to deflect at an angle. A fill light 42 is rotatably mounted inside the reflector 4, and a rocker arm 43 is mounted at the rotation center of the fill light 42. A horizontally movable top rod 44 is slidably mounted on the rocker arm 43, and the end of the top rod 44 corresponds to several pairs of protrusions 443 provided on the side wall of the connecting cover 341.

[0043] The mechanical linkage design, which drives the adjusting roller 33 through the friction wheel 3 and controls the movement of the CCD camera 34 through the cylindrical cam groove 331, enables automated transverse scanning of the steel strip surface, avoiding manual intervention and improving detection efficiency and accuracy.

[0044] like Figures 1 to 9 As shown in the specific embodiment, the workbench 1 has four support legs 11 installed at its bottom, and reinforcing ribs 111 are installed on the four support legs 11. The heights between adjacent reinforcing ribs 111 are different, and a controller is installed inside the workbench 1, which is connected to the CCD camera 34. The non-equal height design of the support legs 11 and reinforcing ribs 111 enhances the stability of the device, adapts to different working conditions, and reduces damage caused by stress concentration. The controller and the CCD camera 34 work together to achieve real-time data processing, ensuring the timeliness and reliability of the detection results.

[0045] like Figures 1 to 9As shown, further, a cover 13 is installed on the surface of the workbench 1, and an opening 131 is provided on the cover 13. The opening 131 corresponds to the conveyor belt body 12. A slide rail 133 is installed on the side wall of the cover 13. A cover plate 132 is slidably arranged on the slide rail 133. The cover plate 132 is used to block the opening 131. A positioning plate 134 is also installed on the side wall of the cover plate 132, and the positioning plate 134 is connected to the cover 13 by bolts. The design of the cover 13 with the opening 131 can protect the detection device inside the workbench 1 from external dust and debris, ensuring stable operation of the equipment, and also leave a passage for the steel belt conveyor. The sliding structure of the slide rail 133 and the cover plate 132 allows the operator to quickly open or close the opening 131, which is convenient for equipment debugging, maintenance and steel belt loading and unloading. The combination of the positioning plate 134 and the bolts can firmly fix the cover plate 132, ensuring that the cover plate will not shake or shift during the operation of the device, which enhances the sealing and safety of the equipment, and also facilitates disassembly and maintenance.

[0046] Example 2:

[0047] The difference between the above embodiments and this embodiment is that: Figures 1 to 9 As shown, an electric push rod body 22 is installed on the inner wall of the cover 13. A synchronization plate 221 is installed at the output end of the electric push rod body 22. Four connecting brackets 222 are installed around the synchronization plate 221. The bottom of the four connecting brackets 222 is connected to the side wall of the pressure plate 2. The pressure plate 2 is U-shaped. A pair of extrusion rollers 21 are installed at the bottom of the pressure plate 2. The lowest point of the extrusion rollers 21 corresponds to the lowest point of the friction wheel 3. The rotation direction of the extrusion rollers 21 and the friction wheel 3 is the same as the conveying direction of the conveyor belt body 12. The electric push rod body 22 drives the pressure plate 2 to link the extrusion rollers 21 and the friction wheel 3, realizing the pre-flattening treatment of the steel belt surface, eliminating the interference of waveform wrinkles on the detection accuracy, and improving the image acquisition quality.

[0048] like Figures 1 to 9 As shown, in a specific embodiment, the transmission assembly includes a drive gear 32 and a transmission gear 321 that mesh with each other. A positioning shaft 311 is mounted at the rotation center of the drive gear 32, and a gear shaft 322 is mounted at the rotation center of the transmission gear 321. The gear shaft 322 and the adjusting roller 33 are interconnected at their rotation centers. The positioning shaft 311 is interconnected with the rotation center of the friction wheel 3. A positioning frame 31 is rotatably mounted on the sidewalls of the positioning shaft 311 and the gear shaft 322, and the positioning frame 31 is mounted on the pressure plate 2. A protective cover 312 is mounted on the sidewall of the positioning frame 31, covering the outer sidewalls of the drive gear 32 and the transmission gear 321. The gear transmission assembly composed of the drive gear 32 and the transmission gear 321 ensures precise matching of the rotational speeds of the friction wheel 3 and the adjusting roller 33, guaranteeing the regularity of the scanning trajectory of the CCD camera 34. The protective cover 312 prevents the gear assembly from being contaminated by impurities on the steel belt surface, extending the service life of the mechanical components.

[0049] like Figures 1 to 9 As shown, further, a limiting frame 334 is installed on the side wall of the positioning frame 31, and the limiting frame 334 is arched. The limiting frame 334 moves through the protective cover 312. A limiting rod 333 is installed on the limiting frame 334, and a slider 332 is slidably arranged on the limiting rod 333. The top of the slider 332 meshes with the cylindrical cam groove 331. A positioning rod 342 is installed at the bottom of the slider 332, and the positioning rod 342 is connected to the connecting cover 341. The reflector 4 is rotatably connected to the positioning rod 342. The push rod 411 and the push plate 41 arranged on the same plane ensure the stability of the angle adjustment of the reflector 4. The cooperation between the guide seat 421 and the synchronous shaft 431 realizes the precise transmission of the rotation action of the supplementary light 42, improving the reliability of the light angle switching.

[0050] Example 3:

[0051] The difference between the above embodiments and this embodiment is that: Figures 1 to 9 As shown, a fixed seat 412 is installed at the end of the push rod 411. The fixed seat 412 is installed on the pressure plate 2, and the push rod 411 and the push plate 41 are located on the same plane. A guide seat 421 is welded to the side wall of the reflector 4. A synchronous shaft 431 is rotatably installed on the guide seat 421. A supplementary light 42 is installed at one end of the synchronous shaft 431. The beam of the supplementary light 42 is downward. The synchronous shaft 431 is connected to the rotation center of the rocker arm 43.

[0052] like Figures 1 to 9 As shown, in a specific embodiment, the connecting cover 341 has an inner groove 442 on its side wall, and several pairs of protrusions 443 are installed on the inner groove 442. A ball bearing 441 is installed at the end of the top rod 44, and the ball bearing 441 fits against the inner side wall of the inner groove 442. Sliding rods 444 are installed at both ends of the top rod 44. A strip groove 432 is opened on the rocker arm 43, and the sliding rod 444 is slidably disposed in the strip groove 432. The sliding cooperation between the ball bearing 441 and the inner groove 442 reduces mechanical wear and extends the service life of the device. The structural design of the sliding rod 444 and the strip groove 432 converts the lateral movement of the top rod 44 into the swing of the rocker arm 43, realizing stepless adjustment of the angle of the supplementary light 42 to adapt to the lighting requirements of different detection positions.

[0053] like Figures 1 to 9 As shown, a guide rod 45 is further inserted and connected inside the top rod 44. The end of the guide rod 45 is connected to the inner wall of the reflector 4. A compression spring 451 is sleeved on the guide rod 45. One end of the compression spring 451 is engaged with the inner wall of the reflector 4, and the other end is engaged with the end face of the top rod 44. The guide rod 45 serves as a limit, and the compression spring 451 facilitates subsequent reset operations.

[0054] The implementation principle of the steel strip visual surface inspection device of the present invention is as follows:

[0055] When the steel belt is conveyed forward by the conveyor belt body 12 inside the workbench 1, the pressure plate 2 moves downward through the vertical sliding mechanism. The squeezing roller 21 at its bottom and the friction wheel 3 contact the steel belt in the same direction of rotation (consistent with the conveyor belt conveying direction). The squeezing roller 21 flattens the surface of the steel belt, while the friction wheel 3 rotates with the movement of the steel belt. This rotation drives the drive gear 32 inside the protective cover 312 to rotate via the positioning shaft 311. The drive gear 32 meshes with the transmission gear 321, causing the gear shaft 322 and the adjusting roller 33 to rotate.

[0056] The cylindrical cam groove 331 on the outer surface of the adjusting roller 33 engages with the top protrusion of the slider 332. As the adjusting roller 33 rotates, the contour of the cylindrical cam groove 331 drives the slider 332 to slide laterally along the horizontally set limiting rod 333 (the limiting rod 333 is fixed to the positioning frame 31 by the arched limiting frame 334, restricting the slider 332 to move only in the horizontal direction). The slider 332 drives the connecting cover 341 and the built-in CCD camera 34 to move horizontally synchronously through the positioning rod 342, realizing the line-by-line scanning detection of the steel strip surface in the transverse direction (perpendicular to the conveying direction).

[0057] As the CCD camera 34 moves with the connecting cover 341, its built-in image sensor continuously acquires images of the steel strip surface. These images are then processed in real time by a controller (such as an industrial computer), using algorithms such as edge detection and grayscale analysis to identify defects such as cracks, rust spots, scratches, pitting, and wavy patterns. The camera's horizontal movement trajectory precisely matches the contour of the cylindrical cam groove 331 of the adjusting roller 33, ensuring coverage of all areas in the width direction of the steel strip and avoiding missed detections.

[0058] During this process, the push rods 411 at both ends of the pressure plate 2 correspond to the push plate 41 on the outside of the reflector 4. When the CCD camera 34 slides along the horizontal limit rod 333 with the connecting cover 341 to the left / right limit position of the detection area, the end of the push rod 411 contacts the push plate 41 and applies a pushing force, forcing the push plate 41 to drive the reflector 4 to deflect around the positioning rod 342, thereby adjusting the direction of the supplementary light so that the light covers the edge of the detection area when the camera is at the limit position.

[0059] At the same time, as the CCD camera 34 moves, the reflector 4 on the CCD camera 34 begins to slide synchronously. At this time, the fill light is in a vertical downward state, illuminating at a positive angle (perpendicular to the steel strip surface) to highlight surface flatness defects (such as wavy shapes) and reduce reflection interference.

[0060] When the CCD camera 34 moves to the side wall, the push plate 41 on the reflector 4 is pressed by the push rod 411, which in turn causes the reflector 4 to rotate as a whole. At this time, the position of the supplementary light 42 changes synchronously, reducing the presence of shadows and making the detection more accurate.

[0061] Furthermore, when the reflector 4 rotates, the guide rod 45 on the reflector 4 drives the top rod 44 to rotate synchronously, and the ball 441 on the top rod 44 slides on the inner groove 442. When the protrusion 443 on the inner groove 442 slides, the top rod 44 slides outward as a whole. The top rod 44 slides on the guide rod 45 and drives the compression spring 451 to compress. The compression spring 451 facilitates the later reset.

[0062] As the push rod 44 slides outward, it drives the slide rod 444 to move synchronously. The slide rod 444 slides on the slot 432, eventually causing the rocker arm 43 with the slot 432 to slide. The rocker arm 43 then swings, driving the supplementary light 42 to rotate via the synchronous shaft 431. At this time, the supplementary light 42 changes angle and shines obliquely onto the steel strip. Therefore, during the later resetting process, the supplementary light is in an oblique state. The light is projected at a side angle, enhancing the shadow contrast of the uneven defects (such as scratches and pits) on the edge of the steel strip.

[0063] This dynamic adjustment mode of "in-process positive light detection and return light measurement detection" uses a purely mechanical combination of the protrusion and the top rod to automatically switch the illumination angle according to the camera's movement direction without the need for electronic sensors. When scanning the steel strip on one side, it uses side light to highlight microscopic concave and convex defects, and during the return, it uses positive light to balance and detect flatness, avoiding the limitations of single-angle illumination. This achieves full coverage and accurate detection of multiple types of defects on the steel strip surface, combining the advantages of both detection efficiency and imaging quality.

Claims

1. A visual surface inspection device for steel strips, comprising a worktable, Its characteristics are: The workbench is equipped with a conveyor belt body for conveying steel belts. The workbench is equipped with a vertically sliding pressure plate used to press the steel strip flat. A friction wheel and an adjusting roller are rotatably mounted on the pressure plate. The friction wheel and the adjusting roller are connected to each other through a transmission assembly. The lower surface of the friction wheel is in contact with the steel belt, and a cylindrical cam groove is provided on the adjusting roller. A connecting cover is engaged on the cylindrical cam groove, and a CCD camera with a built-in image sensor is connected to the bottom of the connecting cover. A reflector is rotatably mounted on the outside of the CCD camera. A push plate is mounted on the outer wall of the reflector, and the push plate corresponds to the push rods mounted at both ends of the pressure plate. The push plate is used to push the reflector to deflect at an angle. A fill light is rotatably mounted inside the reflector, and a rocker arm is mounted at the rotation center of the fill light. A horizontally movable top rod is slidably mounted on the rocker arm, and the end of the top rod corresponds to several pairs of protrusions set on the side wall of the connecting cover. The transmission assembly includes a drive gear and a transmission gear that mesh with each other. A positioning shaft is mounted on the rotation center of the drive gear, and a gear shaft is mounted on the rotation center of the transmission gear. The gear shaft and the rotation center of the adjusting roller are connected to each other, and the positioning shaft is connected to the rotation center of the friction wheel. A positioning frame is rotatably mounted on the side wall of the positioning shaft and the gear shaft, and the positioning frame is mounted on the pressure plate. A protective cover is mounted on the side wall of the positioning frame, and the protective cover covers the outer side wall of the drive gear and the transmission gear. The positioning frame is equipped with a limiting frame on its side wall, and the limiting frame is arched. The limiting frame moves through the protective cover. A limiting rod is installed on the limiting frame, and a slider is slidably arranged on the limiting rod. The top of the slider engages with a cylindrical cam groove. A positioning rod is installed at the bottom of the slider, and the positioning rod is connected to the connecting cover. The reflector is rotatably connected to the positioning rod. A guide seat is welded to the side wall of the reflector, and a synchronous shaft is rotatably mounted on the guide seat. A supplementary light is mounted on one end of the synchronous shaft, and the beam of the supplementary light is downward. The synchronous shaft is connected to the rotation center of the rocker arm. The connecting cover has an inner groove on its side wall, and several pairs of protrusions are installed on the inner groove. A ball is installed at the end of the top rod, and the ball fits against the inner side wall of the inner groove. Slide rods are installed at both ends of the top rod. A strip groove is opened on the rocker arm, and the slide rod is slidably disposed in the strip groove. A guide rod is movably inserted into the top rod. The end of the guide rod is connected to the inner wall of the reflector. A compression spring is sleeved on the guide rod. One end of the compression spring is engaged with the inner wall of the reflector, and the other end of the compression spring is engaged with the end face of the top rod.

2. The visual surface inspection device for steel strip according to claim 1, characterized in that, The worktable is equipped with four support legs at its bottom, and each of the four support legs has a reinforcing rib. The heights between adjacent reinforcing ribs are different. A controller is installed inside the worktable and is connected to a CCD camera.

3. The visual surface inspection device for steel strip according to claim 1, characterized in that, The workbench surface is equipped with a cover, and the cover has an opening that corresponds to the conveyor belt body. A slide rail is installed on the side wall of the cover, and a cover plate is slidably mounted on the slide rail. The cover plate is used to block the opening. A positioning plate is also installed on the side wall of the cover plate, and the positioning plate is connected to the cover by bolts.

4. The visual surface inspection device for steel strip according to claim 3, characterized in that, An electric push rod body is installed on the inner side wall of the cover. A synchronization plate is installed at the output end of the electric push rod body. Four connecting frames are installed around the synchronization plate. The bottom of the four connecting frames is connected to the side wall of the pressure plate. The pressure plate is U-shaped. A pair of extrusion rollers are installed at the bottom of the pressure plate. The lowest point of the extrusion rollers corresponds to the lowest point of the friction wheel. The rotation direction of the extrusion rollers and the friction wheel is the same as the conveying direction of the conveyor belt body.

5. The visual surface inspection device for steel strip according to claim 1, characterized in that, The push rod is fitted with a fixed seat at its end, which is mounted on the pressure plate, and the push rod and the push plate are on the same plane.

Images