Automatic detection device and method for bolt thread defects

Abstract

The present invention relates to the technical field of visual inspection of threads, and provides an automatic inspection device and method for bolt thread defects. The inspection device includes a chassis, and also includes: a feeding mechanism installed on the chassis. After the bolts are placed, they are transported to the inspection station and the unloading station in sequence through the rotation of the feeding mechanism. The feeding mechanism includes a rotating seat fixed on the chassis and a turntable rotatably set on the rotating seat and used to place the bolts. It can be understood that the present invention realizes automatic loosening of the bolts at the unloading and loading stations and automatic clamping of the inspection station through the driving cooperation of the positioning mechanism and the feeding mechanism, which is convenient for unloading and loading and can avoid vibration affecting the clarity of shooting; at the same time, the rotating mechanism is used to drive multiple cameras to rotate synchronously, so that a single camera can complete all-round thread shooting of the bolts, reducing costs while ensuring the comprehensiveness of detection; in addition, the rejection mechanism can directly reject unqualified bolts without releasing the clamping state, and the overall structure is efficient, simple and easy to operate.

Description

Technical Field

[0001] The present invention relates to the field of visual inspection of screw threads, and more specifically, to an automatic inspection device and method for defects in bolt threads. Background Art

[0002] Bolt thread defect detection is an important step in ensuring the reliability and safety of fasteners. Appropriate detection methods must be selected based on factors such as the application scenario, precision requirements, and cost. Thread defects mainly include cracks, wear, deformation, missing threads, and irregular threads. Cracks are usually caused by stress concentration or material fatigue, which may lead to the risk of breakage; wear can cause loose threads; deformation and missing threads are often caused by improper processing; and irregular threads are manifested as misaligned threads or irregular thread profiles. These defects will directly affect the connection strength and sealing performance of the bolts, and unqualified products must be promptly eliminated through testing.

[0003] Existing inspection methods include manual visual inspection and machine vision inspection. Manual visual inspection relies on operators to use magnifying glasses or thread go / no-go gauges for judgment. It is low-cost but has limited efficiency. It is suitable for small batch or temporary inspection scenarios, but the detection rate of minor defects (such as microcracks) is low. Machine vision inspection uses high-resolution industrial cameras to capture thread images and analyze defects in combination with edge detection algorithms (such as Canny) or deep learning models (such as YOLOv5). A ring light source is required to reduce reflective interference. The inspection speed can reach hundreds of pieces per minute, which is suitable for automated production lines. However, the algorithm needs to be trained for different thread specifications, and the initial data annotation cost is relatively high. The existing automated thread vision inspection equipment uses a bolt vibration feeder to feed the material. The feeder places the bolts on the inspection table and transports them to the visual inspection area. Cameras at multiple angles take pictures, and then use the image information to determine whether they are qualified. Unqualified products will be marked and then distinguished.

[0004] However, the initial cost of purchasing automated visual inspection equipment is too high for small-batch manufacturers, while the efficiency and reliability of manual visual inspection are low. Furthermore, the bolts are not properly positioned after being placed on the automated visual inspection equipment. The operation of the inspection equipment, feeder, and other equipment will generate certain vibrations. If the bolts are not positioned correctly, errors will occur during photography, which can easily lead to ghosting and blurring, affecting the efficiency and accuracy of image determination. Furthermore, an additional unloading mechanism is required after visual inspection to distinguish qualified from unqualified products, resulting in a high overall equipment investment.

[0005] In order to solve the above problems, this application proposes an automatic detection device and method for bolt thread defects. Summary of the Invention

[0006] The purpose of the present invention is to provide an automatic detection device and method for bolt thread defects to solve the problems in the prior art.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] An automatic detection device for bolt thread defects includes a chassis and:

[0009] The feeding mechanism installed on the chassis, after the bolts are placed, is transported to the inspection station and the unloading station in sequence through the rotation of the feeding mechanism. The feeding mechanism includes a rotating seat fixed on the chassis and a turntable rotatably set on the rotating seat and used to place the bolts. The rotating seat is fixed to the chassis through a bracket. The rotation between the turntable and the rotating seat adopts a ball connection. The ball is located on the side where the two contact, providing avoidance for the unloading of the bolts.

[0010] A positioning mechanism is installed between the rotating base and the turntable. The positioning mechanism automatically tightens or loosens the bolts as the turntable rotates on the rotating base. The positioning mechanism is divided into two parts, one of which is synchronized with the rotation of the turntable, and the other is fixed to the rotating base. This part is located below the inspection station. When the two parts are in conjunction, the bolts are clamped, ensuring the stability of the bolts during inspection.

[0011] A support extends upward from the middle of the feeding mechanism and is fixed to the upper end of the chassis. The support is provided with a rotating mechanism that drives the camera to rotate. The rotating mechanism has multiple inspection stations, each of which is equipped with a camera. The rotation of the rotating mechanism drives the camera to shoot along the outer thread of the bolt. In order to improve the brightness of the shooting environment, a light source can be installed on the camera to serve as fill light.

[0012] A rejecting mechanism is provided between the support and the feeding mechanism, and the rejecting mechanism can remove the bolts at the inspection station, and the rejecting mechanism disengages the bolts from the positioning mechanism in a compressed state from top to bottom;

[0013] A control panel is fixed on the top of the chassis and located in the middle of the feeding mechanism, and an industrial computer electrically connected to the control panel is installed inside the chassis.

[0014] The feeding mechanism also includes a gear ring arranged on the inner ring of the turntable, a feeding motor is installed on the inner side of the rotating seat through a bracket, and a feeding gear engaged with the gear ring is fixed to the output end of the feeding motor. The connection relationship between the feeding gear and the feeding motor can ensure reliable power transmission while providing sufficient space for the installation of the support and control panel, making the equipment structure more compact.

[0015] The positioning mechanism includes a parts slot that runs through the turntable and through holes that are opened inside and outside the parts slot. The width of the parts slot is slightly larger than the minimum diameter of the bolt end cap and slightly smaller than the maximum diameter of the end cap, which serves the purpose of preventing mistakes when placing and is convenient for placement. The through holes are opened radially, and symmetrical sliding splints are provided in the parts slot. The ends of the two splints that are close to each other are V-shaped. A driving rod that slides in the through hole is fixed to one end of the splint, and the driving rod extends out of the outside of the parts slot away from one end of the splint. A return spring that fits on the outside of the driving rod and presses against each other is provided between the splint and the inner side of the parts slot.

[0016] The positioning mechanism also includes an inner drive plate and an outer drive plate that squeeze the drive rod from the inside and outside. The contact ends of the drive rod and the inner drive plate and the outer drive plate are point contacts. In order to reduce friction, lubricating oil can be applied to the connection. The inner drive plate and the outer drive plate are located directly below the detection station and are used to clamp the bolts in the detection state. A guide plate is fixed near the end where the bolt enters. The guide plate is used to guide the drive rod to enter the drive plate. The inner drive plate and the outer drive plate are fixedly mounted on the rotating seat through a connecting frame.

[0017] The rotating mechanism includes multiple circular rings rotatably mounted on a support. The circular rings are located directly above the turntable conveying path. The camera is fixed on the inner side of the circular rings in an inclined state with the shooting end facing the threaded portion of the bolt. The rotating setting only requires a single camera to achieve all-round shooting of the thread, ensuring the shooting effect while controlling costs. The camera transmits images through an electric slip ring.

[0018] The rotating mechanism also includes a rotating gear arranged on the support, and a plurality of circular rings are formed with tooth grooves on the outside that cooperate with the rotating gear. The rotating gear and the circular rings are synchronously transmitted through the tooth grooves and the synchronous belt. A rotating motor that drives the rotating gear is fixed on the top of the support, and the synchronous belt can simultaneously drive the plurality of circular rings to rotate synchronously, thereby realizing the synchronous rotation of multiple cameras, so that multiple bolts can be detected at the same time.

[0019] The rejection mechanism includes a discharge box located directly below the detection station and fixed to the bottom of the rotating seat. The rotating seat is penetrated by a first discharge hole that communicates with the discharge box. The upper end of the discharge box covers multiple first discharge holes at the same time, and the lower end is open. A pushing cylinder is fixed on the top of the support. The output end of the pushing cylinder is downward and fixed with a push rod that passes through the support. The push rod is coaxial with the bolt in the detection state, and the push rod is also cocentric with the first discharge hole. The diameter of the push rod is smaller than the diameter of the bolt to avoid being clamped by the positioning mechanism when pushing down.

[0020] A feeding trough is fixed at the bottom of the rotating seat, and the position where the feeding mechanism installs the feeding trough is the feeding station. A second feeding hole that is interconnected with the feeding trough is opened through the rotating seat. When the parts slot conveys the bolts to the top of the feeding trough, the bolts can be automatically unloaded through the second feeding hole.

[0021] The object of the present invention can also be achieved by the following technical solution: a method for automatically detecting bolt thread defects. According to the above-mentioned automatic detection device for bolt thread defects, the detection method steps are as follows:

[0022] S1. Place the bolt inside the part slot and on the top of the rotating seat from the loading station, with the bolt cap between the two clamping plates.

[0023] S2. Start the feeding motor by pressing the operating button on the control panel to drive the feeding gear to mesh with the ring gear. The ring gear drives the turntable to rotate on the rotating seat and drives the spiral to move. The inner and outer drive rods are in contact with the inner drive plate and the outer drive plate at the same time. The return spring is stretched and the two clamping plates apply pressure to clamp the bolt at the same time. As the feeding mechanism conveys the bolt, it rotates to the inspection station. At this time, the bolt is located directly above the first feeding hole.

[0024] S3, start the rotary motor to drive the circular ring and the camera to rotate on the support through the rotating gear and the synchronous belt, use the camera to photograph the bolt from multiple angles based on the single rotation angle of the rotary motor, and then transmit the data to the industrial computer;

[0025] S401. When the industrial computer detects that the bolt is unqualified, the push cylinder is activated to drive the push rod downward, so that the unqualified bolt is separated from the lower end of the positioning mechanism and passes through the first discharge hole into the discharge box. The unqualified bolt is collected by a basket placed at the discharge box outlet, and then the push cylinder drives the push rod upward to reset.

[0026] S402: When the bolt passes the inspection, it is continuously fed by the feeding mechanism. The driving rod is disengaged from the inner drive plate and the outer drive plate. The bolt is loosened by the return spring. When the feeding mechanism moves the bolt to the second discharge hole, the bolt is discharged through the discharge chute.

[0027] The detection method in the above technical solution has the advantages of low cost and high efficiency. At the same time, the bolts can be stably clamped during the detection process to ensure the clarity of the shooting.

[0028] In step 3, the camera 6 rotates one circle when photographing the thread once. The camera 6 rotates one circle to ensure the complete collection of the thread. The camera 6 is a high-resolution industrial camera.

[0029] Beneficial effects of the present invention:

[0030] The present invention provides a positioning mechanism and a driving cooperation with the feeding mechanism. The positioning mechanism automatically loosens the bolts at the loading and unloading stations and automatically clamps them at the detection station. Automatic loosening facilitates loading and unloading, and automatic clamping prevents the bolts from shaking due to equipment vibration, thereby ensuring shooting clarity.

[0031] The present invention installs a camera on a rotating mechanism, which can simultaneously drive multiple cameras to rotate, thereby realizing simultaneous inspection of multiple bolts. Only one camera is needed to capture all threads of each bolt during inspection, ensuring comprehensive coverage while reducing the cost of multiple cameras.

[0032] The present invention can directly reject bolts that fail inspection through the provided rejection mechanism, without the need to separately disengage the positioning mechanism from the clamping mechanism, and has the advantages of high structural coordination, simple structure, and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0034] Figure 1 It is a structural schematic diagram of the present invention;

[0035] Figure 2 for Figure 1 Schematic diagram of the structure viewed from the rear;

[0036] Figure 3 It is a schematic structural diagram of the main view of the present invention;

[0037] Figure 4 A schematic diagram of the structure of the bracket and its connecting parts viewed from above;

[0038] Figure 5 It is a schematic diagram of the structure of the feeding mechanism and its connecting parts that are partially disassembled;

[0039] Figure 6 This is a schematic diagram of the structure of the partial disassembly of the connection between the positioning mechanism and the turntable;

[0040] Figure 7 It is a structural diagram of the connection part between the positioning mechanism and the rotating seat;

[0041] Figure 8 This is a schematic diagram of the internal structure of the chassis;

[0042] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0043] In the figure: 1. Chassis; 2. Feeding mechanism; 21. Rotating seat; 22. Turntable; 23. Ring gear; 24. Feeding gear; 25. Feeding motor; 3. Positioning mechanism; 31. Parts slot; 32. Through hole; 33. Clamp; 34. Drive rod; 35. Return spring; 36. Inner drive plate; 37. Outer drive plate; 38. Guide plate; 39. Connecting frame; 4. Support; 5. Rotating mechanism; 51. Circular ring; 52. Rotating gear; 53. Synchronous belt; 54. Rotating motor; 6. Camera; 7. Rejecting mechanism; 71. First discharge hole; 72. Discharge box; 73. Push cylinder; 74. Push rod; 8. Discharge chute; 81. Second discharge hole; 9. Control panel; 10. Industrial computer. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0045] like Figure 1 - Figure 8 As shown: This embodiment provides an automatic detection device for bolt thread defects, including a chassis 1, and also includes: a feeding mechanism 2, the feeding mechanism 2 is sequentially formed with a loading station, a detection station, and a unloading station in a counterclockwise direction, the bolts are placed on the feeding mechanism 2 at the loading station, and the positioning mechanism 3 automatically clamps the bolts when the feeding mechanism 2 moves the bolts to the detection station, and then the rotating mechanism 5 drives the camera 6 to rotate to detect the bolts, and unqualified bolts are first rejected by the rejection mechanism 7, and qualified bolts continue to be transported by the feeding mechanism 2, and then the positioning mechanism 3 automatically disengages the pressure on the bolts and moves to the unloading chute 8 for automatic unloading; the control panel 9 is fixed on the top of the chassis 1 and is located in the middle of the feeding mechanism 2, and the chassis 1 is equipped with a control panel 9. The industrial computer 10 is electrically connected, and the camera 6 is also electrically connected to the industrial computer 10. As the core component of image acquisition, the camera 6 is responsible for obtaining high-quality thread images. When the bolt is conveyed to the inspection station, the control panel adopts PLC, which senses the position of the bolt through the photoelectric sensor and then sends a trigger signal to the camera 6. After receiving the trigger signal, the camera 6 takes a picture and transmits the image data to the industrial computer through the high-speed interface. The industrial computer serves as the intelligent processing center of the system and runs professional image processing software and algorithms. After receiving the image transmitted by the camera, the industrial computer immediately starts the preset inspection program, which may include edge detection algorithm to identify the thread profile, template matching technology to check the tooth profile standard, or deep learning model to classify the defect type.

[0046] As an embodiment of the present invention, the feeding mechanism 2 is installed on the chassis 1. After the bolts are placed at the loading station, they are transported to the inspection station and the unloading station in sequence through the rotation of the feeding mechanism 2. The feeding mechanism 2 includes a rotating seat 21 fixed on the chassis 1 and a turntable 22 rotatably set on the rotating seat 21 and used to place the bolts. The feeding mechanism 2 also includes a ring gear 23 set on the inner ring of the turntable 22. A feeding motor 25 is installed on the inner side of the rotating seat 21 through a bracket. A feeding gear 24 engaged with the ring gear 23 is fixed to the output end of the feeding motor 25. Specifically, the output of the feeding motor 25 drives the feeding gear 24 to engage with the ring gear 23, driving the turntable 22 to rotate on the rotating seat 21, and the rotating turntable 22 drives the bolts to rotate synchronously.

[0047] As an embodiment of the present invention, the positioning mechanism 3 is installed between the rotating seat 21 and the turntable 22. The positioning mechanism 3 automatically clamps or loosens the bolt by rotating the turntable 22 on the rotating seat 21. The positioning mechanism 3 includes a part groove 31 that runs through the turntable 22 and a through hole 32 that is provided on the inside and outside of the part groove 31. A symmetrical sliding clamp 33 is provided in the part groove 31. A driving rod 34 that slides in the through hole 32 is fixed at one end of the clamp 33. A return spring 35 that fits on the outside of the driving rod 34 and presses against each other is provided between the clamp 33 and the inner side of the part groove 31. The positioning mechanism 3 also includes an inner drive plate 36 and an outer drive plate 37 that squeeze the driving rod 34 from the inside and outside. The drive plate 36 and the outer drive plate 37 are located directly below the inspection station, and a guide plate 38 is fixed to the end close to where the bolt enters. The inner drive plate 36 and the outer drive plate 37 are fixed to the rotating seat 21 through the connecting frame 39. Specifically, when the drive rod 34 is not squeezed by the inner drive plate 36 and the outer drive plate 37, the return spring 35 drives the clamping plate 33 to move outward to disengage from the clamping of the bolt. When the drive rod 34 contacts the inner drive plate 36 and the outer drive plate 37, the drive rod 34 and the clamping plate 33 squeeze inward to clamp the bolt. At this time, the return spring 35 is in a stretched state. The drive rod 34 in this clamped state can also move on the inner drive plate 36 and the outer drive plate 37 to transport the bolt in a clamped state.

[0048] As an embodiment of the present invention, the support 4 extends upward from the middle of the feeding mechanism 2 and is fixed to the upper end of the chassis 1. The support 4 is provided with a rotating mechanism 5 that drives the camera 6 to rotate. The rotating mechanism 5 includes a plurality of circular rings 51 rotatably mounted on the support 4. The circular rings 51 are located directly above the conveying path of the turntable 22. The camera 6 is fixed on the inner side of the circular ring 51 in an inclined state with the shooting end facing the threaded portion of the bolt. After a single shooting is completed, the camera 6 avoids the conveying path of the bolt through the rotating mechanism 5. There are multiple inspection stations in the rotating mechanism 5, and each station is equipped with a camera 6. The rotation of the rotating mechanism 5 drives the camera 6 to shoot along the outer thread of the bolt. The rotating mechanism 5 also includes a device The rotating gear 52 is placed on the support 4, and multiple circular rings 51 have tooth grooves on the outside that cooperate with the rotating gear 52. The rotating gear 52 and the circular rings 51 are synchronously transmitted through the tooth grooves and the synchronous belt 53. A rotating motor 54 that drives the rotating gear 52 is fixed on the top of the support 4. Specifically, the rotating motor 54 drives the rotating gear 52 to engage with the synchronous belt 53. The synchronous belt 53 drives the multiple circular rings 51 to rotate synchronously through engagement. The circular ring 51 then drives the inner camera 6 to rotate. One circle of the camera 6 can be divided into multiple times. After each rotation of a certain angle, the rotating motor 54 stops. At this time, the camera 6 takes a picture, and the rotating motor 54 continues to work, thereby collecting threads from multiple positions in the circumferential direction.

[0049] As an embodiment of the present invention, the rejection mechanism 7 is arranged between the support 4 and the feeding mechanism 2. The rejection mechanism 7 can take out the bolt at the inspection station. The rejection mechanism 7 disengages the bolt from the positioning mechanism 3 in the compressed state from top to bottom. The rejection mechanism 7 includes a discharge box 72 located just below the inspection station and fixed to the bottom of the rotating seat 21. The rotating seat 21 is penetrated by a first discharge hole 71 which is interconnected with the discharge box 72. A pushing cylinder 73 is fixed on the top of the support 4. The output end of the pushing cylinder 73 is downward and fixed with a push rod 74 which passes through the support 4. The push rod 74 is coaxial with the bolt in the inspection state, and the push rod 74 is also cocentric with the first discharge hole 71. Specifically, when the industrial computer 10 detects that the corresponding bolt is unqualified, the pushing cylinder 73 is started to drive the push rod 74 to move downward. The push rod 74 pushes the bolt downward in the clamping state and then enters the discharge box 72 through the first discharge hole 71 and is collected by the basket at the opening of the discharge box 72.

[0050] A feeding trough 8 is fixed at the bottom of the rotating seat 21. The position where the feeding trough 8 is installed by the feeding mechanism 2 is the feeding station. A second feeding hole 81 which is interconnected with the feeding trough 8 is opened through the rotating seat 21. When the bolt moves to the top of the feeding trough 8, the positioning mechanism 3 is in a loosened state. When the part slot 31 coincides with the second feeding hole 81, the bolt automatically passes through the feeding trough 8 and is discharged and collected by the basket placed below the feeding trough 8.

[0051] This embodiment also provides: a method for automatically detecting bolt thread defects. According to the above-mentioned automatic detection device for bolt thread defects, the detection method steps are as follows:

[0052] S1. Place the bolts from the loading station inside the part slot 31 and on the top of the rotating seat 21, with the bolt caps located between the two clamping plates 33;

[0053] S2. The feeding motor 25 is started by pressing the operating button on the control panel 9 to drive the feeding gear 24 to mesh with the ring gear 23. The ring gear 23 drives the turntable 22 to rotate on the rotating seat 21 and drives the spiral to move. The inner and outer driving rods 34 are in contact with the inner drive plate 36 and the outer drive plate 37 at the same time. The return spring 35 is stretched, and the two clamping plates 33 apply pressure to clamp the bolt at the same time. As the feeding mechanism 2 is transported, the bolt is rotated to the detection station. At this time, the bolt is located directly above the first discharge hole 71.

[0054] S3. Start the rotary motor 54 to rotate the circular ring 51 and the camera 6 on the support 4 via the rotating gear 52 and the synchronous belt 53. The bolt is photographed from multiple angles by the camera 6 according to the single rotation angle of the rotary motor 54. The camera 6 rotates one circle when photographing the bolt, ensuring that the entire bolt thread is fully captured. The data is then transmitted to the industrial computer 10.

[0055] S401. When the industrial computer 10 detects that a bolt is unqualified, the push cylinder 73 is activated to drive the push rod 74 downward, causing the unqualified bolt to detach from the lower end of the positioning mechanism 3 and pass through the first discharge hole 71 into the discharge box 72. The unqualified bolt is collected by a basket placed at the outlet of the discharge box 72. Then, the push cylinder 73 drives the push rod 74 upward to reset.

[0056] S402. When the bolt passes the inspection, it continues to be transported by the feeding mechanism 2, the driving rod 34 disengages from the inner drive plate 36 and the outer drive plate 37, and the bolt is loosened under the action of the return spring 35. When the feeding mechanism 2 moves the bolt to the second discharge hole 81, it is discharged through the discharge chute 8.

[0057] It can be understood that the present invention realizes automatic loosening of bolts at the loading and unloading stations and automatic clamping at the inspection station through the driving coordination of the positioning mechanism and the feeding mechanism, which is convenient for loading and unloading and can avoid vibration affecting the shooting clarity; at the same time, the rotating mechanism is used to drive multiple cameras to rotate synchronously, so that a single camera can complete the full-dimensional thread shooting of the bolt, reducing costs while ensuring the comprehensiveness of the inspection; in addition, the rejection mechanism can directly reject unqualified bolts without releasing the clamping state, and the overall structure is efficient, simple and easy to operate.

[0058] In the description of the present invention, unless otherwise specified, “plurality” means two or more; it should be understood that terms such as “opening”, “upper”, “lower”, “thickness”, “top”, “middle”, “length”, “inner”, “around”, etc., indicating orientation or positional relationship, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0059] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An automatic detection device for bolt thread defects, comprising a chassis, characterized in that: Also includes: A feeding mechanism is installed on the chassis. After the bolts are placed, they are transported to the inspection station and the unloading station in sequence through the rotation of the feeding mechanism. The feeding mechanism includes a rotating seat fixed to the chassis and a turntable rotatably arranged on the rotating seat and used to place the bolts. A positioning mechanism installed between the rotating seat and the turntable, wherein the positioning mechanism automatically tightens or loosens the bolts by the rotation of the turntable on the rotating seat; A support extends upward from the middle of the feeding mechanism and is fixed to the upper end of the chassis. The support is provided with a rotating mechanism that drives the camera to rotate. The rotating mechanism has multiple inspection stations, each station is equipped with a camera. The rotation of the rotating mechanism drives the camera to shoot along the outer thread of the bolt; A rejecting mechanism is provided between the support and the feeding mechanism, and the rejecting mechanism can remove the bolts at the inspection station, and the rejecting mechanism disengages the bolts from the positioning mechanism in a compressed state from top to bottom; A control panel is fixed on the top of the chassis and located in the middle of the feeding mechanism, and an industrial computer electrically connected to the control panel is installed inside the chassis.

2. The automatic detection device for bolt thread defects according to claim 1, characterized in that: The feeding mechanism also includes a gear ring arranged on the inner ring of the turntable, a feeding motor is installed on the inner side of the rotating seat through a bracket, and a feeding gear meshing with the gear ring is fixed to the output end of the feeding motor.

3. The automatic detection device for bolt thread defects according to claim 1, characterized in that: The positioning mechanism includes a parts slot that passes through the turntable and through holes that are provided inside and outside the parts slot. A symmetrical sliding clamp is provided in the parts slot, and a driving rod that slides in the through hole is fixed to one end of the clamp. A return spring is provided between the clamp and the inner side of the parts slot, which is sleeved on the outside of the driving rod and presses against each other.

4. The automatic detection device for bolt thread defects according to claim 3 is characterized in that: The positioning mechanism also includes an inner drive plate and an outer drive plate that squeeze the drive rod from the inside and outside. The inner drive plate and the outer drive plate are located directly below the detection station, and a guide plate is fixed to the end close to where the bolt enters. The inner drive plate and the outer drive plate are fixed to the rotating seat through a connecting frame.

5. The automatic detection device for bolt thread defects according to claim 1, characterized in that: The rotating mechanism includes a plurality of circular rings rotatably mounted on a support, the circular rings are located directly above the turntable conveying path, and the camera is fixed inside the circular rings in an inclined state with the shooting end facing the threaded portion of the bolt.

6. The automatic detection device for bolt thread defects according to claim 5, characterized in that: The rotating mechanism also includes a rotating gear arranged on the support, and multiple circular rings are formed with tooth grooves on the outside to cooperate with the rotating gear. The rotating gear and the circular rings are synchronously transmitted through the tooth grooves and the synchronous belt. A rotating motor that drives the rotating gear is fixed on the top of the support.

7. The automatic detection device for bolt thread defects according to claim 1, characterized in that: The rejection mechanism includes a discharge box located directly below the detection station and fixed to the bottom of the rotating seat. A first discharge hole communicating with the discharge box is opened through the rotating seat. A pushing cylinder is fixed to the top of the support. The output end of the pushing cylinder is downward and fixed with a push rod passing through the support. The push rod is coaxial with the bolt in the detection state, and the push rod is also concentric with the first discharge hole.

8. The automatic detection device for bolt thread defects according to claim 1, characterized in that: A material discharge trough is fixed at the bottom of the rotating seat, and the position where the material discharge trough is installed in the feeding mechanism is the material discharge station. A second material discharge hole communicating with the material discharge trough is opened through the rotating seat.

9. A method for automatically detecting bolt thread defects, according to the device for automatically detecting bolt thread defects according to any one of claims 1 to 8, characterized in that: The detection method steps are as follows: S1. Place the bolt inside the part slot and on the top of the rotating seat from the loading station, with the bolt cap between the two clamping plates. S2. Start the feeding motor by pressing the operating button on the control panel to drive the feeding gear to mesh with the ring gear. The ring gear drives the turntable to rotate on the rotating seat and drives the spiral to move. The inner and outer drive rods are in contact with the inner drive plate and the outer drive plate at the same time. The return spring is stretched and the two clamping plates apply pressure to clamp the bolt at the same time. As the feeding mechanism conveys the bolt, it rotates to the inspection station. At this time, the bolt is located directly above the first feeding hole. S3, start the rotary motor to drive the circular ring and the camera to rotate on the support through the rotating gear and the synchronous belt, use the camera to photograph the bolt from multiple angles based on the single rotation angle of the rotary motor, and then transmit the data to the industrial computer; S401. When the industrial computer detects that the bolt is unqualified, the push cylinder is activated to drive the push rod downward, so that the unqualified bolt is separated from the lower end of the positioning mechanism and passes through the first discharge hole into the discharge box. The unqualified bolt is collected by a basket placed at the discharge box outlet, and then the push cylinder drives the push rod upward to reset. S402. When the bolt passes the inspection, it continues to be transported by the feeding mechanism, the driving rod is disengaged from the inner drive plate and the outer drive plate, and the bolt is loosened under the action of the return spring. When the feeding mechanism moves the bolt to the second discharge hole, it is discharged through the discharge chute.

10. The method for automatically detecting bolt thread defects according to claim 9, characterized in that: In step 3, the camera rotates one circle when taking a single shot of the bolt.

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