Machine vision detection device and method for shafts

Abstract

The present application relates to the field of shaft detection, in particular to a kind of machine vision detection device and method for shaft. Including circulating conveyor belt, feeding station, detection station and discharging station, the circulating conveyor belt is equipped with several bearing plates, multiple placing grooves are set up on each bearing plate, the detection station is equipped with industrial camera and jacking frame, the middle region of the bearing plate is hollow structure that can be passed by the jacking frame, roller group assembly is installed on the jacking frame, including the fixed roller and the movable roller staggered arrangement along the direction of shaft body arrangement.The shaft body is lifted off the bearing plate to the state of suspension by jacking frame, the shaft body is clamped and rotated by the fixed roller and the movable roller, at this time, top camera and lateral camera complete full-surface dead angle-free coverage in the single rotation of shaft body, effectively solve the problem of blind area and low efficiency in the detection of micro band section shaft parts.

Description

Technical Field

[0001] This invention relates to the field of shaft inspection, and more specifically to a machine vision inspection device and method for shafts. Background Technology

[0002] In the field of precision manufacturing, flat micro shafts are generally 30–40 mm in length, <5 mm in diameter, and have a cut at one end. They are widely used in products such as micro motors, connectors, and medical devices. Their surface integrity and geometric accuracy directly affect assembly performance and service life.

[0003] However, existing machine vision inspection equipment mostly uses single-axis robotic arms for gripping or vibratory feeders for material feeding combined with fixed camera imaging, which has significant shortcomings: On the one hand, the loading and unloading process is prone to scratches on the shaft surface due to metal-to-metal contact, and it is difficult to ensure that the flat surfaces of all shafts face in the same direction, leading to missed inspections in critical areas. On the other hand, traditional inspection mechanisms usually inspect a single axis, making it difficult to achieve multi-axis parallel inspection, resulting in low efficiency. Furthermore, within the limited workstation, the ends of the shaft are often obstructed by fixtures, making it impossible to obtain complete imaging of the end face and flat transition area, creating blind spots in the inspection.

[0004] Therefore, there is a need for a machine vision inspection device for shafts that can achieve non-destructive directional transport of flat micro shafts, multi-axis synchronous inspection, and full-surface blind-zone-free inspection, so as to balance inspection accuracy, production efficiency and surface protection. Summary of the Invention

[0005] To address the problems existing in the prior art, a machine vision inspection device for shafts is provided. The shaft is lifted off the support plate by a lifting frame and suspended in the air. The shaft is then clamped and rotated by a fixed roller and a moving roller. At this time, the top camera and the side camera complete the full surface coverage without blind spots within a single rotation of the shaft, effectively solving the problems of blind spots and low efficiency in the inspection of miniature shaft parts with facets.

[0006] To address the problems of existing technologies, this invention provides a machine vision inspection device for shafts, comprising a circulating conveyor belt with several bearing plates evenly spaced along the conveying direction. Each bearing plate has multiple placement slots evenly spaced along the conveying direction for horizontally supporting shafts with cross-sections. A loading station is located at the beginning of the circulating conveyor belt for loading the shafts to be inspected into the placement slots. An inspection station is located in the middle of the circulating conveyor belt for performing full-surface visual inspection of the shafts. An unloading station is located at the end of the circulating conveyor belt for classifying and outputting the inspected shafts. The inspection station is equipped with industrial cameras located above and on both sides of the shafts for... The shaft is fully imaged during rotation. The inspection station is also equipped with a vertically lifting frame located below the circulating conveyor belt. The middle area of ​​the support plate has a hollow structure that allows the lifting frame to pass through. When the lifting frame rises through the support plate, the shaft is lifted away from the support plate and is in a suspended state. The lifting frame is equipped with a roller assembly, including fixed rollers and moving rollers arranged alternately along the shaft's direction. The axes of the fixed rollers and the moving rollers are parallel to the extension direction of the placement groove. A rolling support position is formed between every two adjacent fixed rollers and moving rollers. The lifting frame is equipped with a rotary driver for each moving roller, which drives the shaft to rotate around its own axis when the shaft is suspended.

[0007] Preferably, both the fixed roller and the moving roller rotatably connected to the lifting frame are rubber rollers. The rubber roller includes a metal roller core and an elastic material layer covering the outer periphery of the metal roller core. The elastic material layer is used to prevent damage to the surface of the shaft during rotation.

[0008] Preferably, the inspection station is provided with a workbench for installing an industrial camera and a lifting frame, and the workbench is provided with a lifting driver for driving the lifting frame to rise and fall.

[0009] Preferably, the industrial camera located above the shaft is a top camera, used to photograph the shaft surface vertically downwards, and the industrial cameras located on both sides of the shaft are side cameras, used to photograph the shaft end face from a horizontal direction.

[0010] Preferably, the workbench is provided with a top bracket for mounting the top camera and a side bracket for mounting the side camera. Each side bracket is provided with a position sensor along the shooting direction, and each side of the support plate is provided with a corresponding sensing point for detecting the position of the shaft.

[0011] Preferably, two inner push plates are symmetrically arranged on the worktable. The inner push plates are arranged perpendicular to the conveying direction and are used to center and reset the shaft to be returned to the placement slot.

[0012] Preferably, the worktable is provided with a guide rail for each inner push plate, the inner push plate is slidably disposed on the guide rail along the conveying direction, the worktable is provided with a first electric push rod for driving the guide rail to push towards the bearing plate, and the guide rail is provided with a second electric push rod for driving the inner push plate to push along the conveying direction.

[0013] Preferably, the loading station is equipped with a box to be tested and a loading robot, and the unloading station is equipped with a defective box, a qualified box and an unloading robot. The unloading robot has a gripping and turning head that is linked to an industrial camera, which is used to uniformly swing the cross-section of the qualified product shaft towards a preset direction and then place it into the qualified product box.

[0014] Preferably, the test box, defective product box and qualified product box are each provided with a plurality of slots arranged in a matrix, the slots being spaced apart to accommodate the faceted shaft and to isolate them from each other.

[0015] The present invention also provides a machine vision inspection method for shafts, comprising the following steps: S1. At the loading station, the cut-faced shaft is loaded into the bearing plate placement slot and transported to the inspection station until the sensing point triggers the position sensor to confirm that the shaft is in place. S2. The lifting frame rises, lifting the shaft away from the bearing plate to a suspended state, and the rotary drive is started to drive the shaft to rotate 360°. S3. The top camera and the side camera simultaneously acquire images of the entire surface of the shaft to complete defect identification and classification; S4. The lifting frame descends, and the shaft falls back into the placement slot. The unloading robot sorts the products into qualified or defective boxes according to the inspection results, and the qualified products are oriented and placed with cross-sections.

[0016] The advantages of this application compared to the prior art are: 1. This invention uses a position sensor triggered by a sensing point to stop the circulating conveyor belt. At this time, the control system initiates the lifting action of the lifting frame. The lifting frame lifts the shaft off the support plate to a suspended state, eliminating obstruction from the placement slot. It also uses rubber rollers to flexibly clamp the shaft and the drive rollers to rotate it at a uniform speed through friction, avoiding surface damage.

[0017] During this process, the top camera vertically images the surface of the shaft, while the side cameras horizontally image the end face. Within a single rotation, the entire surface is covered without any blind spots, effectively solving the problems of blind spots, scratches, and low efficiency in the inspection of miniature shaft parts with facets.

[0018] 2. The present invention uses a second electric push rod to push the inner push plate out of the imaging area along the conveying direction before detection, thus avoiding obstruction.

[0019] During testing, the inner push plate is moved to the opposite side to serve as a high-contrast background plate, thereby improving the imaging quality of the end face.

[0020] After inspection, both inner push plates are moved laterally to the sides of the support plate under the second electric push rod. Then, the two first electric push rods simultaneously drive the corresponding inner push plates to advance towards the support plate, precisely centering and resetting the shaft that has shifted due to rotation. This ensures interference-free visual inspection of the entire surface and clear images, while also guaranteeing accurate positioning of the shaft after it enters the slot, effectively solving the imaging problems caused by inspection obstruction and cluttered backgrounds.

[0021] 3. In this invention, a loading robot precisely picks up materials from the test box in the matrix slot and places them in the placement slot of the carrier plate. After inspection, the unloading robot automatically sorts the materials according to the judgment results of the vision system. Defective products are directly placed into the defective product box, while qualified products are dynamically adjusted in posture according to the cross-sectional angle data by the gripping and turning head and uniformly placed into the corresponding slot of the qualified product box.

[0022] All three types of material boxes adopt an interval matrix slot design to achieve single-slot isolation storage of shafts, effectively preventing mutual collisions and surface scratches during transportation and storage, and ensuring high reliability of loading and unloading. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural schematic diagram of a machine vision inspection device for shafts according to the present invention.

[0024] Figure 2 This is a top view of a machine vision inspection device for shafts according to the present invention.

[0025] Figure 3 This is a three-dimensional structural diagram of a circulating conveyor belt and inspection station for a machine vision inspection device for shafts according to the present invention.

[0026] Figure 4 This is a partial three-dimensional structural cross-sectional view of the circulating conveyor belt and inspection station of a machine vision inspection device for shafts according to the present invention.

[0027] Figure 5 This is a plan view of the top camera and side camera of a machine vision inspection device for shafts according to the present invention.

[0028] Figure 6 This is a three-dimensional structural diagram of the push plate and the support plate of a machine vision inspection device for shafts according to the present invention.

[0029] Figure 7 This is a three-dimensional structural diagram of an internal push plate of a machine vision inspection device for shafts according to the present invention, which is laterally moved between a lateral camera and a support plate.

[0030] Figure 8 This is a schematic diagram of a machine vision inspection device for shafts according to the present invention, showing the shaft being held in the center by two inner push plates.

[0031] Figure 9 This is a schematic diagram of the state of a shaft in a machine vision inspection device for shafts according to the present invention, from a supported state to a suspended state on a support plate.

[0032] Figure 10 This is an exploded three-dimensional structural diagram of the lifting frame and bearing plate of a machine vision inspection device for shafts according to the present invention.

[0033] Figure 11 This is a three-dimensional structural cross-sectional view of a lifting frame for a machine vision inspection device for shafts according to the present invention.

[0034] Figure 12 This is a planar sectional view of a lifting frame for a machine vision inspection device for shafts according to the present invention.

[0035] The diagram is labeled as follows: 1. Circulating conveyor belt; 11. Bearing plate; 111. Placement trough; 112. Sensor point; 12. Shaft; 121. Cross-section; 2. Loading station; 21. Box to be tested; 22. Loading robot; 3. Testing station; 31. Lifting frame; 32. Roller assembly; 321. Fixed roller; 3211. Metal roller core; 3212. Elastic material layer; 322. Moving roller; 323. Miniature rotary motor; 324. Drive roller; 33. Worktable; 331. Lifting 3311. Driver; 3312. Fixed block; 3313. Movable block; 3314. Fixed electromagnet; 3315. Movable electromagnet; 3316. Return spring; 3317. Guide rod; 4. Unloading station; 41. Defective product box; 42. Qualified product box; 43. Unloading robot; 5. Top camera; 51. Top bracket; 6. Side camera; 61. Side bracket; 62. Position sensor; 7. Inner push plate; 71. Guide rail; 72. First electric push rod; 73. Second electric push rod. Detailed Implementation

[0036] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0037] See Figures 1 to 5As shown, a machine vision inspection device for shafts includes a circulating conveyor belt 1 with several support plates 11 evenly spaced along the conveying direction. Each support plate 11 has multiple placement slots 111 evenly spaced along the conveying direction for horizontally supporting shafts 12 with a cross-section 121. A loading station 2, located at the beginning of the circulating conveyor belt 1, is used to load the shafts to be inspected into the placement slots 111. An inspection station 3, located in the middle of the circulating conveyor belt 1, is used to perform full-surface visual inspection of the shafts 12. An unloading station 4, located at the end of the circulating conveyor belt 1, is used to classify and output the inspected shafts. The inspection station 3 is equipped with industrial cameras located above and on both sides of the shafts 12 for full-coverage imaging during the rotation of the shafts 12. The inspection station 3 is also equipped with a vertically lifting frame 31 located below the circulating conveyor belt 1. The middle area of ​​the support plate 11 has a hollow structure that allows the lifting frame 31 to pass through. When the lifting frame 31 rises through the support plate 11, the shaft 12 is lifted away from the support plate 11 and is in a suspended state. A roller assembly 32 is installed on the lifting frame 31, including fixed rollers 321 and moving rollers 322 arranged alternately along the arrangement direction of the shaft 12. The axes of the fixed rollers 321 and the moving rollers 322 are parallel to the extension direction of the placement groove 111, and a rolling support position is formed between every two adjacent fixed rollers 321 and moving rollers 322. A rotary driver is provided on the lifting frame 31 for each moving roller 322, which drives the shaft 12 to rotate around its own axis when the shaft 12 is in a suspended state.

[0038] Work process: The shaft 12 with the cut surface 121 to be tested is first loaded into the bearing plate 11 on the circulating conveyor belt 1 at the loading station 2.

[0039] Subsequently, the circulating conveyor belt 1 smoothly transports the bearing plate 11 to the testing station 3 according to the rhythm.

[0040] When the support plate 11 is located at the inspection station 3, the lifting frame 31 located below the circulating conveyor belt 1 begins to move vertically upward. The lifting frame 31 passes through the hollow structure in the middle of the support plate 11, simultaneously lifting all the shafts 12 placed in the placement groove 111 away from the bottom of the groove, so that the whole is in a completely suspended state. At this time, there is no obstruction at both ends and on the outer surface of the shafts 12, creating ideal conditions for full-surface imaging.

[0041] In the suspended state, the roller assembly 32 on the lifting frame 31 functions. Fixed rollers 321 and moving rollers 322, arranged alternately along the direction of the shaft 12, clamp each shaft 12 from both sides. The fixed rollers 321 remain stationary to provide supporting reaction force, while each moving roller 322 is driven by an independent rotary actuator, causing the shaft 12 to rotate uniformly and continuously around its own axis via friction transmission.

[0042] During the rotation of shaft 12, the industrial camera is activated simultaneously to clearly capture the cut surface 121, the outer circular surface, and the two end faces. The three-view collaboration achieves full surface coverage without blind spots within the time it takes for shaft 12 to complete one full rotation.

[0043] The vision system processes multi-view images in real time and identifies defects such as scratches, dents, dimensional deviations, or incorrect angles of the cut surface through algorithms. It then outputs the pass or fail judgment result for each shaft 12 in real time, providing a basis for material unloading and sorting.

[0044] After the inspection is completed, the lifting driver 331 resets, the lifting frame 31 descends smoothly, and the shaft 12 falls back into the original placement slot 111. The circulating conveyor belt 1 then continues to run, sending the bearing plate 11 to the unloading station 4.

[0045] At unloading station 4, sorting is performed according to the classification instructions, and qualified products and defective products are placed separately.

[0046] The entire process achieves full-coverage imaging of shaft 12, improving the detection efficiency, accuracy and consistency of miniature shaft-type parts with cross-sections 121.

[0047] See Figures 9 to 12 As shown, the fixed roller 321 and the moving roller 322, which are rotatably connected to the lifting frame 31, are both rubber rollers. The rubber roller includes a metal roller core 3211 and an elastic material layer 3212 covering the outer periphery of the metal roller core 3211. The elastic material layer 3212 is used to avoid damage to the surface of the shaft 12 during rotation.

[0048] The rotary driver includes a miniature rotary motor 323 and a drive roller 324 connected to its motor output end. The outer periphery of the drive roller 324 abuts against the outer periphery of the corresponding moving roller 322, and drives the moving roller 322 to rotate through friction transmission.

[0049] After the shaft 12 is lifted to a suspended state, the fixed roller 321 and the moving roller 322 on the lifting frame 31 flexibly clamp the shaft 12 from both sides. The fixed roller 321 and the moving roller 322 are both rubber rollers, which provide sufficient support while avoiding indentations or scratches on the surface of the precision shaft 12.

[0050] When the micro rotary motor 323 is started, the outer periphery of the drive roller 324 comes into close contact with the outer periphery of the moving roller 322. The rotational motion is transmitted to the moving roller 322 by the friction between the two. The moving roller 322 rotates accordingly and drives the shaft 12 to rotate around its own axis at a uniform speed and smoothly through the friction between its elastic material layer 3212 and the surface of the shaft 12. This achieves a low-wear and high-synchronization driving effect, providing stable and reliable rotation conditions for the subsequent full-surface imaging of the industrial camera.

[0051] See Figure 3, Figure 4 and Figures 9 to 12 As shown, the inspection station 3 is provided with a workbench 33 for installing an industrial camera and a lifting frame 31. The workbench 33 is provided with a lifting driver 331 for driving the lifting frame 31 to rise and fall.

[0052] The lifting driver 331 includes electromagnetic drive structures symmetrically arranged on both sides of the lifting frame 31. The electromagnetic drive structure includes a fixed block 3311 fixedly connected to the worktable 33, a movable block 3312 fixedly connected to the lifting frame 31, a fixed electromagnet 3313 mounted on the fixed block 3311, and a movable electromagnet 3314 mounted on the movable block 3312.

[0053] The movable block 3312 is located above the fixed block 3311. The fixed block 3311 is provided with a guide rod 3316 that extends vertically upward through the movable block 3312 and slides with it. A reset spring 3315 is provided between the fixed block 3311 and the movable block 3312 and sleeved on the guide rod 3316 to assist the lifting frame 31 in resetting and descending.

[0054] Once the support plate 11 carries the shaft 12 into position, the lifting driver 331 is activated, synchronously energizing the electromagnetic drive structures symmetrically arranged on both sides of the lifting frame 31. The fixed electromagnet 3313 on the fixed block 3311 and the movable electromagnet 3314 on the movable block 3312 generate a repulsive magnetic force, pushing the movable block 3312 upwards along the vertical guide rod 3316, thereby causing the lifting frame 31, which is fixed to it, to rise vertically. The guide rod 3316 passes through the movable block 3312 and slides with it, ensuring a smooth and unbiased lifting process.

[0055] After being lifted into position, the shaft 12 is lifted away from the placement slot 111 and enters a suspended state, which facilitates rotation and testing. After the test is completed, the fixed electromagnet 3313 and the movable electromagnet 3314 generate a magnetic attraction force, and with the assistance of the return spring 3315, the movable block 3312 slowly returns to its original position along the guide rod 3316, driving the lifting frame 31 to descend smoothly, so that the shaft 12 falls back into the placement slot 111 of the bearing plate 11, completing a complete lifting, testing, and reset cycle.

[0056] See Figures 3 to 5 As shown, the industrial camera located above the shaft 12 is a top camera 5, used to photograph the surface of the shaft 12 vertically downwards, and the industrial cameras located on both sides of the shaft 12 are side cameras 6, used to photograph the end face of the shaft 12 from a horizontal direction.

[0057] As the shaft 12 is lifted into the air and begins to rotate, the top camera 5 located directly above it captures the upper surface of the shaft 12 in real time from a vertically downward perspective, clearly capturing the outline of the cross-section 121 and the outer circular area.

[0058] Simultaneously, lateral cameras 6, positioned on the left and right sides of the shaft 12, align with the shaft 12 horizontally and simultaneously acquire complete images of its two end faces. Through the coordinated operation of the three industrial cameras, full surface coverage without blind spots is achieved within one rotation of the shaft 12 at a uniform speed, providing complete and high-resolution image data for subsequent defect identification.

[0059] See Figures 3 to 5 As shown, the workbench 33 is provided with a top bracket 51 for mounting the top camera 5 and a side bracket 61 for mounting the side camera 6. Each side bracket 61 is provided with a position sensor 62 along the shooting direction, and each side of the support plate 11 is provided with a corresponding sensing point 112 for detecting the position of the shaft 12.

[0060] On the workbench 33 of inspection station 3, the top camera 5 is securely mounted above the shaft 12 via the top bracket 51, ensuring that its optical axis is vertically downward and aligned with the inspection area. The side cameras 6 on both sides are fixed on the side brackets 61 located on the left and right sides of the shaft 12, respectively, so that their lenses are horizontally facing the end face of the shaft 12.

[0061] When the circulating conveyor belt 1 transports the carrier plate 11 to the inspection station 3, the preset sensing point 112 on the side of the carrier plate 11 enters the sensing range of the position sensor 62, triggering a positioning signal. After the control system receives this signal, it confirms that the shaft 12 has accurately stopped at the predetermined position for imaging and lifting, thereby synchronously starting subsequent actions such as the lifting frame 31 rising, the shaft 12 rotating, and the industrial camera acquiring images, ensuring that the entire inspection process is executed efficiently and reliably based on precise positioning.

[0062] See Figure 3 , Figure 4 and Figures 6 to 8 As shown, two inner push plates 7 are symmetrically arranged on the worktable 33. The inner push plates 7 are arranged perpendicular to the conveying direction and are used to center and reset the shaft to be returned to the placement slot 111.

[0063] After the shaft 12 completes inspection and descends with the lifting frame 31 back into the placement slot 111 of the support plate 11, it may experience lateral displacement due to rotation, making it unable to accurately enter the placement slot 111 upon return. At this time, the two inner push plates 7 move synchronously towards the center along a direction perpendicular to the conveying direction, gently pushing the shaft 12 from both sides until it is clamped in the center, smoothly pushing it back to the geometric center position of the placement slot 111. This centering and resetting action ensures that the shaft 12 maintains a stable posture during subsequent conveying.

[0064] See Figure 3 , Figure 4 and Figures 6 to 8As shown, the worktable 33 is provided with a guide rail 71 for each inner push plate 7. The inner push plate 7 is slidably disposed on the guide rail 71 along the conveying direction. The worktable 33 is provided with a first electric push rod 72 for driving the guide rail 71 to push towards the bearing plate 11. The guide rail 71 is provided with a second electric push rod 73 for driving the inner push plate 7 to push along the conveying direction.

[0065] Before the inspection begins, in order to prevent the inner push plate 7 from obstructing the view of the industrial camera, the second electric push rod 73 is activated first, driving the inner push plate 7 to slide backward along the conveying direction, so that the whole plate exits the inspection area.

[0066] After the shaft 12 completes its rotational imaging, the second electric push rod 73 reverses direction, pushing the inner push plate 7 back along the guide rail 71 to its initial lateral position on both sides of the support plate 11. Subsequently, the first electric push rod 72 activates, pushing the entire guide rail 71, along with the inner push plate 7, horizontally towards the center of the support plate 11 perpendicular to the conveying direction. This allows the inner push plate 7 to simultaneously abut against the shaft 12 from both sides, precisely centering it. This ensures unobstructed imaging and precise positioning of the shaft 12 after it enters the slot.

[0067] Furthermore, during the rotation detection of the shaft 12, when the lateral camera 6 on one side is imaging, the inner push plate 7 on the other side can be precisely moved to the opposite side of the lateral camera 6 by the second electric push rod 73, serving as a high-contrast background plate. Its surface is typically made of matte black or uniformly diffuse reflective material, effectively shielding the cluttered structure behind it and providing a stable and uniform imaging background for the end face and outer circular contour of the shaft 12, thereby improving the image edge clarity and the recognition accuracy of the visual algorithm.

[0068] See Figure 1 and Figure 2 As shown, the loading station 2 is equipped with a test box 21 and a loading robot 22, and the unloading station 4 is equipped with a defective box 41, a qualified box 42, and an unloading robot 43. The unloading robot 43 has a gripping and turning head that is linked with an industrial camera, which is used to uniformly swing the cut surface 121 of the qualified product shaft 12 to a preset direction and then place it into the qualified product box 42.

[0069] At loading station 2, loading robot 22 picks up shafts 12 with cut surfaces 121 one by one from the test box 21 and places them into the placement slot 111 of the carrier plate 11 of the circulating conveyor belt 1. After being conveyed, lifted, rotated and visually inspected, the shafts 12 are determined by the industrial camera system to be qualified or defective products.

[0070] Upon reaching the unloading station 4, the unloading robot 43 performs sorting operations based on the inspection results. For defective products, they are directly grabbed and placed into the defective product box 41. For qualified products, the gripping steering head first grasps the shaft 12, and then, based on the angle data of the cross-section 121 obtained by the industrial camera during the inspection stage, drives the steering head to rotate by a corresponding angle, precisely adjusting the cross-section 121 of the shaft 12 to a uniform preset direction. Subsequently, it is stably placed in the corresponding slot of the qualified product box 42, ensuring the consistency of the shaft 12's orientation in subsequent assembly or packaging processes.

[0071] See Figure 1 and Figure 2 As shown, the test box 21, the defective box 41 and the qualified box 42 are all provided with a number of slots arranged in a matrix. The slots are spaced apart to accommodate the shaft 12 with the cut surface 121 and are isolated from each other.

[0072] During the loading stage, the shafts 12 with cut surfaces 121 to be inspected are placed one by one into the slots of the inspection box 21. Each slot can only accommodate one shaft 12 to prevent them from colliding with each other.

[0073] After the inspection is completed, the unloading robot 43 places the qualified products and the defective products into the corresponding slots of the qualified product box 42 and the defective product box 41, respectively. The isolation of the slots ensures that each shaft 12 is separated from each other during storage and transportation, avoiding surface scratches, rolling deviation or confusion of the direction of the cut surface 121, thereby maintaining the consistency of the product status.

[0074] A machine vision inspection method for shafts, applied to the aforementioned machine vision inspection device for shafts, includes the following steps: S1. At the loading station 2, the shaft 12 with the cut surface 121 is loaded into the placement slot 111 of the bearing plate 11 and transported to the detection station 3 until the sensing point 112 triggers the position sensor 62 to confirm that the shaft 12 is in place. S2. The lifting frame 31 rises, lifting the shaft 12 away from the bearing plate 11 to a suspended state, and the rotary drive is started to drive the shaft 12 to rotate 360°. S3, top camera 5 and side camera 6 simultaneously acquire full surface images of shaft 12 to complete defect identification and classification; S4. The lifting frame 31 descends, and the shaft 12 falls back into the placement slot 111. The unloading robot 43 sorts the qualified products into the qualified product box 42 or the defective product box 41 according to the test results, and the qualified products are oriented by cutting the surface 121.

[0075] The present invention achieves precise positioning by using sensing point 112 in conjunction with position sensor 62, so that shaft 12 accurately enters the detection station 3. Then, the lifting frame 31 is triggered to lift shaft 12 away from bearing plate 11 to a suspended state, eliminating the obstruction of placement slot 111. The flexible clamping of rubber roller and friction transmission of drive roller 324 drive shaft 12 to rotate at a uniform speed, avoiding surface damage.

[0076] During this process, the top camera 5 takes vertical images, while the side cameras 6 on both sides create horizontal images, completing a full-surface, blind-angle-free inspection within a single rotation.

[0077] Before the test, the second electric push rod 73 pushes the inner push plate 7 out of the imaging area to prevent obstruction.

[0078] During testing, the inner push plate 7 can be moved to the opposite side as a high-contrast background plate to improve the image quality of the end face.

[0079] After testing, the inner push plate 7, with the cooperation of the two push rods, precisely centers and resets the offset shaft 12 to ensure stable subsequent conveying.

[0080] Simultaneously, the loading robot 22 retrieves materials from the matrix slot inspection box 21, and the unloading robot 43 automatically sorts them based on visual judgment results: qualified products are oriented and aligned into the box by the gripping steering head according to the angle data of the cross-section 121, while defective products are directly sorted. All three types of boxes adopt an interval matrix slot to achieve single-slot isolation storage, effectively avoiding collisions and scratches, and improving the imaging quality, sorting accuracy, and loading / unloading reliability of the inspection of miniature shaft parts with cross-section 121.

[0081] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A machine vision inspection device for shafts, characterized in that, include: A circulating conveyor belt has several bearing plates evenly spaced along the conveying direction. Each bearing plate has multiple placement slots evenly spaced along the conveying direction for horizontally supporting the belt cross-section shaft. The loading station is located at the beginning of the circulating conveyor belt and is used to load the shaft to be inspected into the placement groove. The inspection station is located in the middle of the circulating conveyor belt and is used for visual inspection of the entire surface of the shaft. The unloading station is located at the end of the circulating conveyor belt and is used to classify and output the shafts that have completed inspection. The inspection station is equipped with industrial cameras located above and on both sides of the shaft, which are used to perform full-coverage imaging of the shaft during its rotation. The testing station is also equipped with a lifting frame that can be vertically raised and lowered below the circulating conveyor belt. The middle area of ​​the bearing plate is a hollow structure that allows the lifting frame to pass through. When the lifting frame passes through the bearing plate and rises, the shaft is lifted away from the bearing plate and is in a suspended state. The lifting frame is equipped with a roller assembly, including fixed rollers and moving rollers arranged alternately along the shaft arrangement direction. The axes of the fixed rollers and the moving rollers are parallel to the extension direction of the placement groove, and a rolling support position is formed between every two adjacent fixed rollers and moving rollers. Each moving roller on the lifting frame is equipped with a rotary driver, which is used to drive the shaft to rotate around its own axis when the shaft is suspended in the air.

2. The machine vision inspection device for shafts according to claim 1, characterized in that, Both the fixed roller and the moving roller, which are rotatably connected to the lifting frame, are rubber rollers. Each rubber roller includes a metal roller core and an elastic material layer covering the outer periphery of the metal roller core. The elastic material layer is used to prevent damage to the surface of the shaft during rotation.

3. The machine vision inspection device for shafts according to claim 2, characterized in that, The testing station is equipped with a workbench for installing industrial cameras and a lifting frame, and the workbench is equipped with a lifting driver for driving the lifting frame to rise and fall.

4. A machine vision inspection device for shafts according to claim 3, characterized in that, The industrial camera located above the shaft is a top camera, used to photograph the shaft surface vertically downwards, while the industrial cameras located on both sides of the shaft are side cameras, used to photograph the shaft end face from a horizontal direction.

5. A machine vision inspection device for shafts according to claim 4, characterized in that, The workbench is provided with a top bracket for mounting the top camera and a side bracket for mounting the side camera. Each side bracket is provided with a position sensor along the shooting direction, and each side of the support plate is provided with a corresponding sensing point for detecting the position of the shaft.

6. A machine vision inspection device for shafts according to claim 3, characterized in that, Two inner push plates are symmetrically arranged on the workbench. The inner push plates are arranged perpendicular to the conveying direction and are used to center and reset the shaft to be returned to the placement slot.

7. A machine vision inspection device for shafts according to claim 6, characterized in that, Each inner push plate on the workbench is provided with a guide rail. The inner push plate is slidably mounted on the guide rail along the conveying direction. The workbench is provided with a first electric push rod for driving the guide rail to push towards the bearing plate, and the guide rail is provided with a second electric push rod for driving the inner push plate to push along the conveying direction.

8. A machine vision inspection device for shafts according to claim 1, characterized in that, The loading station is equipped with a test box and a loading robot. The unloading station is equipped with a defective product box, a qualified product box, and an unloading robot. The unloading robot has a gripping and steerable head that is linked to an industrial camera, which is used to uniformly steer the cross-section of the qualified product shaft towards a preset direction and then place it into the qualified product box.

9. A machine vision inspection device for shafts according to claim 1, characterized in that, The test box, defective product box, and qualified product box are all provided with a number of slots arranged in a matrix. The slots are spaced apart to accommodate the faceted shaft and are isolated from each other.

10. A machine vision inspection method for shafts, applied to a machine vision inspection device for shafts as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. At the loading station, the cut-faced shaft is loaded into the bearing plate placement slot and transported to the inspection station until the sensing point triggers the position sensor to confirm that the shaft is in place. S2. The lifting frame rises, lifting the shaft away from the bearing plate to a suspended state, and the rotary drive is started to drive the shaft to rotate 360°. S3. The top camera and the side camera simultaneously acquire images of the entire surface of the shaft to complete defect identification and classification; S4. The lifting frame descends, and the shaft falls back into the placement slot. The unloading robot sorts the products into qualified or defective boxes according to the inspection results, and the qualified products are oriented and placed with cross-sections.

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