CN109225915B - A rivet quality rating and automatic sorting system and method - Google Patents

Abstract

The invention discloses a rivet quality rating and automatic sorting system, which includes a material conveying device, a detection device, a screening device and an automatic control unit; the material conveying device transports rivets for the detection device, and outputs the rivets after detection to the screening device; The detection device includes a clamping mechanism and an information collection mechanism. After the rivet is clamped, the rod electronic ruler measures the diameter of the rivet rod, the camera collects the image of the rivet, and the industrial computer classifies the quality grade of the rivet according to the diameter of the rivet rod combined with image processing technology The results are recorded and transmitted to the screening device; the screening device includes a sorting tank and a sorting bucket, and the sorting tank is rotated according to the rivet quality grade division results, and the rivet is transported to the sorting bucket of the corresponding grade. The invention adopts the method of combining the rod electronic ruler and the image processing technology to effectively improve the detection accuracy, can select different evaluation standards, complete the quality rating and automatic sorting of various types of rivets, and has high work efficiency.

Description

A rivet quality rating and automatic sorting system and method

technical field

The invention relates to the technical field of parts automatic detection, in particular to a rivet quality rating and automatic sorting system and method.

Background technique

A rivet is a standard fastener used for cold joining of parts. It is widely used in aviation, railway, ship and other equipment. If the rivets in the equipment loosen or break due to quality problems, the connected parts will be loosened, resulting in serious accidents. Therefore, the quality of the rivets is directly related to the performance and safety of the equipment. The quality of rivets is reflected in two aspects of size and surface defects. Figure 1 shows a common countersunk head rivet. The size of the rivet mainly includes the taper angle of the countersunk head, the outer diameter of the top surface, the thickness of the head, the length of the rivet, and the diameter of the rivet shaft. Among them, since the rivet rod is in contact with the connected parts, the diameter of the rivet rod has the greatest influence on the connection performance. If the diameter is too large, the rivet is easily squeezed by the rivet hole on the part to deform, crack, or destroy the rivet hole; Small, the rivets cannot securely connect the two parts. The general rivet production process is that the metal wire is plastically deformed in the mold by the impact of the punch to produce the shape of the rivet. The impact surface of the punch is located on the top surface of the rivet. Therefore, most of the surface defects of the rivet are located on the top surface of the rivet, as shown in Figure 2 shown. When the rivet is stressed, defects such as surface cracks or material folds can easily cause stress concentration effects, resulting in a decrease in the strength of the rivet and the risk of rivet breakage.

Rivet quality grades can generally be divided into high-quality products, qualified products, and waste products. The traditional rivet quality sorting work is done manually. Due to the small size of rivets, it is inconvenient to measure, and the number of rivets in a batch is huge, therefore, the quality level of a batch is generally determined by manual random inspection. In the scene where the quality is strictly required, it is necessary to manually sort the quality of the rivets one by one, which is heavy workload, low efficiency, and prone to errors. The traditional manual operation method is difficult to meet the requirements of large-scale production and quality assurance of rivets, and it is urgent to develop a more efficient and accurate automatic rivet quality sorting system.

In the existing related technology, multiple industrial cameras are generally used to take images of rivets from different angles, and then the rivet size data is extracted and surface defects are detected through image processing technology, and finally, the actuator divides the rivets into different quality grades according to the processing results. For example, literature [1] proposed a blind rivet detection system, as shown in Figure 3, first, the electromagnetic suction head in the positioning mechanism accurately locates the rivet, and the rivet image is collected by the camera; then, the rivet size is detected through image processing; finally , the sorting mechanism classifies the rivets as qualified or unqualified products according to the image processing results. The conveying device in literature [1] can only adapt to rivets with a fixed diameter, and the electromagnetic suction head cannot absorb aluminum rivets. Factors that affect the accuracy of rivet image processing include reflections on the surface of the rivet, changes in the distance from the rivet to the camera, and distortion of the rivet in the image. In response to these problems, literature [2] proposed a rivet size measurement method based on distortion compensation, which improved the measurement accuracy to a certain extent. Literature [3] uses multiple cameras to shoot rivets, and improves the processing accuracy by integrating the images taken by multiple cameras, as shown in Figure 4.

Among them, the reference information cited above is: [1] Dai Yuhui. Research and Implementation of On-line Rivet Detection Electromechanical System [D]. Southwest University of Science and Technology, 2016.05. [2] Hu Jiangtao, Zhang Juntao, Tang Wei. Aircraft Rivet Based on Distortion Compensation Research on dimension measurement method[J].Journal of Shaanxi University of Science and Technology,2016,34(4):177-181.[3]Jiang Chaogen;Fu Yonggao;Yang Jie;Qi Hui;Wang Bo;Guo Fengfeng. A fully automatic precision rivet Detection and screening device [P]. Chinese patent: CN107941811A, 2018-04-20.

In summary, the deficiencies of existing related technologies are as follows:

1) The existing technology relies entirely on image processing technology to extract rivet size data, and the image stability problem easily affects the dimensional accuracy. The size of the rivet in the image is affected by the distance between the rivet and the camera. The edge contour of the rivet in the image may be distorted, and the reflection on the surface of the rivet may cause contour deformation;

2) The existing technology requires multiple sets of cameras to collect images, and the system complexity and cost are relatively high. Extracting rivet size and surface defects requires at least side and top images of the rivet. Therefore, it is necessary to set up cameras and light sources in multiple directions to capture images, which makes the control system more complicated, and software algorithms need to integrate images from different directions. In addition, the cost of industrial cameras is relatively high, and multiple sets of cameras make the system cost high;

3) The functions of the prior art are relatively fixed, which is not conducive to function adjustment according to actual needs. For rivets of different specifications, the corresponding conveying device needs to be replaced. Rivets can only be sorted into several fixed quality grades, such as qualified or unqualified, and the number of quality grades cannot be adjusted according to demand, such as dividing the quality into three grades, and there is no multi-standard quality sorting function.

Contents of the invention

The technical problem to be solved by the present invention is: the type of rivet detection is very single, the detection efficiency is not high, the accuracy is limited, and there is no rating and screening process from high to low in the process of grade classification. The present invention provides a solution to the above problems. A rivet quality grading and automatic sorting system.

The present invention realizes through following technical scheme:

A rivet quality rating and automatic sorting system, including a material conveying device, a detection device, a screening device and an automatic control unit;

The material conveying device is used to convey rivets to the detection device, and output the rivets after detection to the screening device;

The detection device includes a clamping mechanism and an information collection mechanism. The clamping mechanism includes a pneumatic finger and a pneumatic turntable. The two fingers at the free end of the pneumatic finger are respectively provided with a first grasping plate and a second grasping plate. The pneumatic finger Control the opening or closing action of the first grasping plate and the second grasping plate for rivets; the pneumatic finger is connected with the pneumatic turntable, and the pneumatic turntable drives the pneumatic finger, the first grasping plate and the second grasping plate to rotate in a circumferential direction;

The information collection mechanism includes a pull rod electronic ruler and a camera; the pull rod electronic ruler is arranged on the first grasping plate, and the distance measuring plate adapted to the pull rod electronic ruler is arranged on the second grasping plate; the camera is arranged on the One side of the rivet clamped by the first grasping plate and the second grasping plate is used to obtain the image information of the rivet clamped between the first grasping plate and the second grasping plate;

The screening device includes a sorting trough and a number of sorting barrels, the input end of the sorting trough is placed at the output end of the material conveying device, and the driving mechanism drives the sorting trough to rotate, so that the output end of the sorting trough faces different sorting bin;

The automatic control unit includes a PLC controller, an industrial computer and a database; the industrial computer is used to receive the information collected by the information collection mechanism, and perform current detection on the rivets according to the types of rivets pre-stored in the database and the corresponding screening and grading standards. Quality classification, output detection results; the PLC controller is used to control the conveying action of the material conveying device, to control the clamping action of the clamping mechanism, to control the collection action of the information collection mechanism, and to control the sorting according to the detection results output by the industrial computer The groove rotation guides the rivets of different grades into the corresponding sorting bucket.

The working principle of the present invention is that the rivets are conveyed from the material conveying device to the detection device, the pneumatic fingers can be opened and closed under PLC control, and the pneumatic fingers drive the first grabbing plate and the second grabbing plate to grab the rivets on the material conveying device. The rod electronic ruler fixed relative to the first grasping plate can obtain the rivet rod diameter of the grasped rivet; the pneumatic turntable can drive the rivet to rotate, so that the camera can collect images of the side and top surface of the rivet. The rivet size data and surface defects are obtained by the industrial computer through image processing technology, combined with the high-precision diameter of the rivet rod obtained by the pull rod electronic ruler, the quality grade of the rivet can be determined; finally, the sorting slot is rotated left and right according to the quality grade, and the rivets are sent to the sorting table. The corresponding quality grade area in the bin.

Further, the material conveying device includes a vibrating plate and a conveyor belt, the output end of the vibrating plate is connected to the input end of the conveyor belt, the conveyor belt is located under the pneumatic fingers, and the conveyor belt is used to transport the rivets.

This application can directly use the existing vibrating plate as the rivet feeding equipment, and the conveyor belt as the rivet transportation equipment; the vibrating plate is a commonly used auxiliary feeding equipment, and the parts rise along the spiral track in the vibrating plate. A series of track screening and attitude changes, and finally, the parts are automatically output from the export in a unified state. The conveyor belt is also a common transportation equipment, and the parts move together with the belt; the cooperation between the vibrating plate and the conveyor belt is beneficial to realize the automatic feeding operation and improve the detection efficiency.

Further, a photoelectric switch is provided on the conveyor belt close to the side of the pneumatic finger, and the photoelectric switch is used to detect the position of the rivet on the conveyor belt, and transmit the detection information to the PLC controller, and the PLC controller controls the clamping according to the detection information. The mechanism completes the clamping action.

Further, the first grasping plate and the pull rod electronic ruler are fixed on one end of the pneumatic finger through the first connecting bar, and the second grasping plate and the distance measuring plate are fixed on the other end of the pneumatic finger through the second connecting bar. finger end.

The pneumatic finger is a conventional pneumatic component that can be opened or closed; the electronic ruler of the rod is a displacement sensor that can measure the distance that the rod is extended or shortened; when the pneumatic finger is opened, the rod on the electronic ruler of the rod is extended; when When the pneumatic fingers are closed, the rivet is sandwiched between the first grab board and the second grab board, the pull rod on the pull rod electronic ruler is shortened, and the pull rod electronic ruler obtains the diameter size of the rivet rod.

In the existing technology, the size of the rivet is generally measured indirectly through image processing technology. Under the appropriate camera focal length and field of view, the highest resolution of the camera is about 5um. The distance between the rivet and the camera will change the size measurement result, and the size measurement Results are affected by reflections on the rivet surface and image distortion. Compared with the indirect measurement of size through image processing, the resolution of the drawbar electronic ruler is about 1um. By directly measuring the diameter of the rivet rod, the drawbar electronic ruler can overcome the influence of factors such as the distance change from the rivet to the camera, surface reflection and image distortion on the measurement results. influences.

Further, the information collection mechanism also includes a square light source and a ring light source, and the square light source, ring light source and camera are sequentially arranged on a straight line; when the image of the rivet is collected, the rivet is located on the straight line.

The image acquisition module in the information collection mechanism is composed of a camera, a square light source, a ring light source and corresponding brackets. The camera is used to collect images of rivets, and the size and defects of the rivet are detected through image processing and analysis; the ring light source and the camera are located on the same side of the rivet. It is to supplement the light for the camera, reduce the influence of external light, and ensure the clear and stable image of the rivet; the square light source and the camera are located on both sides of the rivet, and the rivet is located in the middle of the square light source and the camera; after the square light source is illuminated, the image background is brighter white, and the rivet Being a darker black, the strong contrast between the rivet and the background facilitates accurate detection of rivet size.

Further, the information collection mechanism also includes a positioning bracket, and a slide rail is provided on the positioning bracket, and the camera, the square light source and the ring light source are all connected to the slide rail through a fixing clip, and the fixing clip is connected to the sliding rail through a slider. Swipe to fit.

The camera, square light source and ring light source are slidably installed on the slide rail through the fixing clip, which is convenient to adjust the position and angle of the camera and light source according to the actual inspection at any time.

Further, the clamping mechanism also includes a pneumatic slide table; the pneumatic turntable is connected with the pneumatic slide table, the pneumatic slide table is installed on the fixed plate, and the pneumatic slide table drives the pneumatic turntable, the pneumatic fingers, the first grasping plate And the overall structure of the second grab board moves up and down.

The pneumatic sliding table of the present invention is connected with the pneumatic turntable, and is used to realize the rivet moving up and down, so that after the rivet is clamped by the pneumatic fingers, the rivet is moved up and away from the table where the rivet is placed for subsequent flipping action, and the moving distance is controlled by the pneumatic sliding table. The stroke limit device is set; the pneumatic slide table can be installed on the fixed plate through the connecting plate.

Further, the drive mechanism adopts a servo motor; the screening device also includes legs, the servo motor is arranged on the legs, and the output end of the servo motor is connected to the bottom plate at one end of the axial end of the sorting trough through a thrust bearing, driving the sorting trough to rotate ; The radial width of the sorting trough along the material flow direction decreases gradually, and a guide strip is provided in the middle of the sorting trough.

The screening method based on the above-mentioned rivet quality rating and automatic sorting system includes the following steps:

Step 1, place the rivets to be sorted with their heads facing down through the material conveying device, and transport them to the detection device according to a certain rivet arrangement spacing and transmission speed;

Step 2, the PLC controller controls the closing of the pneumatic fingers, and the first grasping plate and the second grasping plate grasp the rivets; through the cooperation of the electronic ruler set on the first grasping plate and the distance measuring plate set on the second grasping plate The diameter of the rivet rod is sent to the industrial computer;

Step 3: Obtain the side image of the rivet by taking pictures with the camera, and the industrial computer performs image processing according to the image of the side of the rivet to obtain the length of the rivet rod and the cone angle of the countersunk head;

Step 4, the PLC controller controls the pneumatic turntable to rotate counterclockwise by 90° so that the top surface of the rivet faces the camera, and the camera captures the image of the top surface of the rivet, and the industrial computer obtains the diameter size of the top surface of the rivet through image processing and detects defects on the top surface of the rivet; The hour hand rotates 90°, the pneumatic finger is released, and the rivet returns to the material conveying device;

Step 5, the industrial computer classifies the quality grade of the rivet according to the size data and surface defects of the rivet, and records the grade classification result and transmits it to the PLC controller;

In step 6, the PLC controller controls the rotation of the sorting trough according to the result of the grade classification, so as to transfer the rivets to the sorting barrels of the corresponding quality grade for recycling.

Further, in the step 6, the quality grades of the rivets from high to low are high-quality products, qualified products, and waste products.

The present invention has following advantage and beneficial effect:

1. In the present invention, the measurement accuracy and stability of the diameter of the rivet rod are relatively high. The diameter of the rivet rod is the size that has the greatest impact on the performance of the rivet. The present invention uses a pull rod electronic ruler to measure the diameter of the rivet rod, which has high measurement accuracy and good stability, and avoids the dimensional accuracy being affected by the camera object distance, image distortion, and surface reflection in image processing. issues affected by other factors;

2. In the present invention, the system hardware cost and structural complexity are low. On the one hand, in the prior art, multiple cameras are used to take multi-angle images of rivets, and the cost of the cameras is relatively high, and software is required to synthesize the processing results of multiple images. The present invention uses a pneumatic turntable to rotate the rivets, and only one camera is used to achieve this. Image acquisition of rivet side and top surfaces. On the other hand, the traditional sliding or rotating table driven by a motor has high cost, large volume, and complex structure. The pneumatic fingers, sliding table and turntable used in the present invention are low in cost, compact in structure, and can meet the functional requirements;

3. The present invention can realize quality sorting of different types of rivets. The grasping plate in the present invention can grasp rivets of different sizes (diameter, length), specifications (flat head, countersunk head, cone head), and materials (steel, aluminum). The distance from the axis of the rivets of different diameters to the camera lens remains constant, so the image of the side of the rivet used to extract the dimensions has stability. By comparing with the standard rivet size in the analysis software, the present invention can realize the quality sorting of different types of rivets;

4. The present invention has strong customization. First of all, the system can not only take and inspect images of the side and top surface of the rivet, but also can rotate the pneumatic turntable to take pictures of the bottom surface of the rivet as needed, so as to detect other defects. Secondly, by changing the software algorithm, strict or loose quality standards can be selected, and the rivets can be divided into three grades: excellent, qualified, and waste. Thirdly, by changing the software algorithm to further subdivide the rivets into four or more grades, and adding corresponding grade areas in the sorting bucket, more refined automatic sorting of rivet quality can be achieved.

Description of drawings

The drawings described here are used to provide a further understanding of the embodiments of the present invention, constitute a part of the application, and do not limit the embodiments of the present invention. In the attached picture:

Fig. 1 is the structural representation of the rivet of prior art;

In the figure, a represents the cone angle of the countersunk head, k represents the thickness of the rivet head, l represents the length of the rivet, d1 represents the diameter of the rivet shank, and d2 represents the diameter of the outer circle of the top surface of the rivet;

Fig. 2 is a structural schematic diagram of a defect on the top surface of a rivet in the prior art;

In the figure, Ⅰ indicates crack, Ⅱ indicates folding, and Ⅲ indicates falling block;

Fig. 3 is a schematic structural diagram of the rivet detection device in document [1];

In the figure, a1 represents the vibration plate, a2 represents the conveying device, a3 represents the computer, a4 represents the sorting mechanism, a5 represents the positioning mechanism, and a6 represents the detection and calibration device;

Fig. 4 is a schematic structural diagram of the rivet detection device in document [3];

In the figure, b1 represents camera No. 1, b2 represents camera No. 2, b3 represents camera No. 3, and b4 represents camera No. 4;

Fig. 5 is a schematic diagram of the overall three-dimensional structure of the present invention;

Fig. 6 (a) and Fig. 6 (b) are the partial structural schematic diagrams of A in Fig. 5;

Fig. 7 is an exploded view of the connection relationship between the pneumatic finger, the pneumatic turntable and the pneumatic slide table of the present invention;

Fig. 8 is an exploded view of the connection relationship between the pneumatic finger and the pull rod electronic scale, the first gripping plate and the second gripping plate of the present invention;

Fig. 9 is a schematic diagram of the three-dimensional structure of the material conveying device of the present invention;

Fig. 10 is a schematic diagram of the three-dimensional structure of the information collection mechanism of the present invention;

Figure 11 is an exploded view of the screening device of the present invention;

Fig. 12 is a three-dimensional structural schematic diagram of the working state of the screening device of the present invention;

Fig. 13 is a control schematic diagram of the present invention;

Fig. 14 is a flowchart of the rivet quality grading and automatic sorting method of the present invention.

The marks in the drawings and the names of corresponding parts: 1-material conveying device, 11-vibrating plate, 12-conveyor belt, 13-photoelectric switch, 14-installation bracket, 2-detection device, 21-clamping mechanism, 210-pneumatic Finger, 211-pneumatic turntable, 212-first grab board, 213-second grab board, 214-first connecting bar, 215-second connecting bar, 216-pneumatic sliding table, 217-fixing plate, 218-first Connecting board, 219-Second connecting board, 2110-Sleeve, 22-Information collection mechanism, 220-Electronic ruler, 221-Camera, 222-Distance measuring board, 223-Square light source, 224-Ring light source, 225-Positioning Bracket, 226-sliding rail, 227-fixing clip, 228-base, 229-L-shaped bracket, 3-screening device, 31-sorting slot, 32-sorting bucket, 33-leg, 34-servo motor, 35 -thrust bearing, 36-guide bar, 37-motor bracket, 38-screw, 39-end cover, 4-air compressor, 5-rivet, 6-control cabinet.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the examples and accompanying drawings. As a limitation of the present invention. As shown in Figure 5-13:

Example 1

This embodiment provides a rivet quality rating and automatic sorting system, including a material delivery device 1, a detection device 2, a screening device 3 and an automatic control unit; the material delivery device 1 is used to deliver rivets 5 to the detection device, and Output the rivet 5 after the detection to the screening device 3; the detection device 2 includes a clamping mechanism 21 and an information collection mechanism 22, the clamping mechanism 21 includes a pneumatic finger 210 and a pneumatic turntable 211, and the two free ends of the pneumatic finger 210 are A first gripping plate 212 and a second gripping plate 213 are respectively provided on the first finger, and the pneumatic finger 210 controls the first gripping plate 212 and the second gripping plate 213 to open or close together for the rivet 5;

The pneumatic finger 210 is connected to the pneumatic turntable 211, specifically, the pneumatic finger 210 is connected to the pneumatic turntable 211 through a first connection plate 218 and a second connection plate 219 arranged in parallel, and between the first connection plate 218 and the second connection plate 219 Sleeve 2110 is set between them, which can effectively avoid the collision of the connecting screws between the first connecting plate 218 and the second connecting plate 219, and ensure the parallelism between the pneumatic finger 210 and the pneumatic turntable 211; the pneumatic turntable 211 drives the pneumatic finger 210 and The first grasping plate 212 and the second grasping plate 213 rotate in the circumferential direction;

The information collection mechanism 22 includes a drawbar electronic ruler 220 and a camera 221; the drawbar electronic ruler 220 is arranged on the first grasping plate 212, and the distance measuring plate 222 adapted to the drawbar electronic ruler 220 is arranged on the second grasping plate 213 The camera 221 is located on one side of the rivet 5 clamped by the first grasping plate 212 and the second grasping plate 213, for obtaining the image of the rivet 5 clamped between the first grasping plate 212 and the second grasping plate 213 Information; the screening device 3 includes a sorting tank 31 and a number of sorting barrels 32, the input end of the sorting tank 31 is placed at the output end of the material conveying device 1, and the sorting tank 31 is driven by a driving mechanism to rotate, so that the sorting tank The output end of the sorting slot 31 faces different sorting buckets 32;

The automatic control unit includes a PLC controller, an industrial computer and a database; the industrial computer is used to receive the information collected by the information collection mechanism 22, and according to the 5 types of rivets pre-stored in the database and the corresponding screening and grading standards, for the current detection The rivet 5 performs quality classification and outputs detection results; the PLC controller is used to control the conveying action of the material conveying device 1, to control the clamping action of the clamping mechanism 21, to control the collection action of the information collection mechanism 22, and to output according to the industrial computer. The detection result controls the rotation of the sorting tank 31 to guide the rivets 5 of different grades into the corresponding sorting bucket 32.

The quality grade of the rivet is evaluated by the industrial computer, and the size data of the rivet is extracted from the side image of the rivet through image processing technology, including the length of the rivet, the thickness of the head, and the cone angle of the countersunk head. The measurement result of the rod electronic ruler 220. From the image of the top surface of the rivet 5, the roundness of the top surface is calculated by image processing technology, and surface defects such as cracks, folds, and falling blocks are detected. The industrial computer is provided with a rivet 5 template database, which records the standard sizes of rivets 5 of different specifications. The detected size of the rivet 5 is compared with the standard size, combined with the surface defect detection results, and the quality grade of the rivet 5 is divided into high-quality products, qualified products or waste products. The specific quality grade standards are more detailed, roughly as follows.

1) High-quality products: the diameter of the rivet 5 rod is within the tolerance range of 0.3 times, and the tolerance value is determined by referring to the national standard (GB). The deviation between the other dimensions of the rivet 5 and the standard size is less than 2%, and there is no obvious surface defect;

2) Qualified product: the diameter of rivet 5 rods is within the tolerance range of 0.3 to 1 times, and the deviation between other dimensions and standard dimensions is between 2% and 5%, and there are a small number of minor defects;

3) Waste product: The diameter of the 5 rods of the rivet exceeds the tolerance range, and other dimensions deviate from the standard dimensions by more than 5%, and there are obvious defects.

Finally, the rivet 5 size, surface defect and quality grade are stored in the database. After the sorting work of a batch of rivets is completed, the distribution of the size, defects, and quality grades of the batch of rivets can be statistically analyzed, so as to obtain the overall quality of the batch of rivets and find out the quality problems. The reason is to improve the production process.

Example 2

Further improvement on the basis of Embodiment 1, the material conveying device 1 includes a vibrating plate 11 and a conveyor belt 12, the output end of the vibrating plate 11 is connected to the input end of the conveyor belt 12, the conveyor belt 12 is located below the pneumatic finger 210, and the conveyor belt 12 Used to transport rivets 5. The conveyor belt 12 is provided with a photoelectric switch 13 near the side of the pneumatic finger 210, and the photoelectric switch 13 is used to detect the position of the rivet 5 on the conveyor belt 12, and transmits the detection information to the PLC controller, and the PLC controller according to the detection information The clamping mechanism 21 is controlled to complete the clamping action.

Example 3

Further improvement on the basis of Embodiment 2, the first grasping plate 212 and the electronic ruler 220 of the pull rod are fixed on one of the finger ends of the pneumatic finger 210 through the first connecting bar 214, specifically, the electronic ruler 220 of the pull rod passes through the base 228 and The L-shaped bracket 229 is fixed on the first connecting bar 214; the second grasping plate 213 and the distance measuring plate 222 are fixed on the other finger end of the pneumatic finger 210 by the second connecting bar 215; the first connecting bar 214 and the second connecting bar 215 are C-shaped structure. The information collection mechanism 22 also includes a square light source 223 and a ring light source 224, the square light source 223, the ring light source 224 and the camera 221 are sequentially arranged on a straight line; when the camera 221 takes pictures to collect graphic information, the rivet 5 is located on the straight line . The information collection mechanism 22 also includes a positioning bracket 225, the positioning bracket 225 is provided with a slide rail 226, the camera 221, the square light source 223 and the ring light source 224 are all connected to the slide rail 226 through a fixing clip 227, and the fixing clip 227 slides and fits with slide rail 226 through slide block.

When collecting the side image of the rivet 5, the motion of the pneumatic finger 210 is symmetrical, and can drive the first grasping plate 212 and the second grasping plate 213 to move synchronously at the same time, so that the axis of the grasped rivet 5 is located in the middle of the pneumatic finger 210, so, The distance between the axis of the rivet 5 and the lens of the camera 221 is fixed and will not change with the diameter of the rivet 5, thereby ensuring the stability of the size of the rivet 5 in the image. The square light source 223 is energized and irradiated at the moment when the camera 221 takes a photo. The rivet 5 forms a darker black in the image due to blocking the irradiating light source. The other background areas are brighter white due to the light source. There is a strong light-dark contrast between the rivet 5 and the background. Facilitates extraction of rivet 5 profile dimensions from images.

Most surface defects of the rivet 5 are concentrated on the top surface. Therefore, after the side image is taken, the rivet 5 is rotated 90° counterclockwise so that the top surface of the rivet 5 faces the camera 221 . After the rotation, the top surface of the rivet 5 is still located directly in front of the camera 221, ensuring that the top surface of the rivet 5 in the image is in the middle position, and preventing the rivet 5 from exceeding the field of view of the image. The ring light source 224 is energized to irradiate the top surface of the rivet 5 at the moment when the camera 221 takes a picture, which can improve the clarity of the image, thereby helping to find surface defects from the top surface image.

Example 4

Further improvement on the basis of Embodiment 3, the clamping mechanism 21 also includes an air slide 216; the air turntable 211 is connected with the air slide 216, the air slide 216 is installed on the fixed plate 217, and the air slide 216 drives The overall structure of the pneumatic turntable 211, the pneumatic finger 210, the first grasping plate 212 and the second grasping plate 213 moves up and down, and an upper stroke limiting device and a lower stroke limiting device are respectively provided on the fixed end of the pneumatic slide table 216. The travel limit device ensures that the first grasping plate 212 and the second grasping plate 213 accurately grasp the rivet 5 on the conveyor belt 12, and the upper stroke limit device ensures that the rivet 5 is positioned directly in front of the lens of the camera 221. Screening device 3 also comprises support leg 33, is provided with servomotor 34 by motor bracket 37 on support leg 33, and servomotor 34 is used as the driving mechanism that drives sorting tank 31 to rotate; Parts such as the thrust bearing 35 and the rotating shaft of the servo motor 34 remain relatively fixed, so that the sorting chute 31 rotates with the rotating shaft of the servo motor 34 as the axis. The radial width of the sorting groove 31 along the material flow direction gradually decreases. The PLC controller controls the servo motor 34 to rotate the corresponding angle according to the quality grade of the currently detected rivet 5, so that the outlet of the sorting tank 31 faces the different grade areas in the sorting bucket 32, and the rivet 5 slides down to the corresponding grade along the sorting tank 31 area. In order to prevent the longer rivet 5 from being stuck horizontally at the exit of the sorting slot 31 during the sliding process, a guide piece 36 is arranged in the middle of the sorting slot 31 so that the rivet 5 can slide out of the sorting slot 31 smoothly.

Example 5

The automatic control principle of a kind of rivet quality rating and automatic sorting system that embodiment 4 provides includes the following parts:

(1) Control principle of pneumatic components:

The pneumatic components include a pneumatic finger 210 , a pneumatic turntable 211 and a pneumatic slide 216 . When the photoelectric switch 13 senses the passing of the rivet 5, it transmits the sensing signal to the PLC controller, and the PLC controller controls the action of the above-mentioned pneumatic components through the solenoid valve. The pneumatic components are connected to the solenoid valve through the air pipe. The solenoid valve realizes the opening and closing of fingers, the rotation of the turntable, and the up and down movement of the slide table by changing the direction of the airflow in the cylinder. The solenoid valve is controlled by the PLC controller. The magnetic switch is installed in the slot of the pneumatic component, and can sense the action state of the pneumatic component, including whether the pneumatic finger 210 is opened or closed, the rotation angle of the pneumatic turntable 211, whether the pneumatic sliding table 216 is above or below, and the magnetic switch will sense the signal Send to the PLC controller;

The air compressor 4 outputs high-pressure gas to provide a power source for the pneumatic components. The gas source distributor delivers high-pressure gas to the pneumatic finger 210, the pneumatic turntable 211 and the pneumatic slide 216 respectively. The pressure reducing valve changes the speed and force of the pneumatic element by adjusting the gas pressure, for example, to prevent the rivet 5 from being scratched by too much clamping force of fingers. The gas source processor is used to separate impurities such as water and oil in the gas to reduce damage to the solenoid valve and pneumatic components;

(2) The control principle of the rod electronic ruler 220:

When the magnetic switch in the pneumatic finger 210 senses that the fingers are closed, the industrial computer directly reads the measurement data of the electronic rod ruler 220, thereby obtaining the rod diameter of the rivet 5;

(3) The control principle of camera 221 and light source:

The phase 221 is controlled by the PLC to take pictures, and the light source is energized and irradiated and turned off. The image taken by the camera 221 is input into the industrial computer, and the rivet 5 quality analysis software carried on the industrial computer performs image processing to extract dimensions and defects;

(4) The control principle of the sorting tank 31:

The industrial computer transmits the quality analysis results of the rivet 5 to the PLC controller, and the PLC controller controls the servo motor 34 to drive the sorting slot 31 to rotate.

Example 6

A kind of rivet quality rating and the screening method of automatic sorting system that embodiment 5 provides, concrete steps are as follows:

Step 1: Pour the rivets 5 to be sorted into the vibrating plate 11, and the vibrating plate 11 vibrates and stirs the rivets 5 therein so that the rivets 5 are placed head-down and output to the conveyor belt 12 at a certain distance and speed. A photoelectric switch 13 is installed on one side of the conveyor belt 12, and the photoelectric switch 13 will send a signal to the PLC controller when sensing the passing of the rivet 5;

Step 2, after the PLC controller receives the signal from the photoelectric switch 13, it controls the pneumatic sliding table 216 to move downward, controls the pneumatic fingers 210 to close, and the first grasping plate 212 and the second grasping plate 213 grasp the rivet 5;

Step 3, the drawbar electronic ruler 220 is relatively fixed to the first grasping plate 212, and after the rivet 5 is grasped by the first grasping plate 212 and the second grasping plate 213, the drawbar on the drawbar electronic ruler 220 is shortened, and the drawbar electronic ruler 220 obtains the rivet 5 rod diameter size, and sent to the industrial computer;

Step 4, the PLC controller controls the pneumatic sliding table 216 to move upwards, so that the rivet 5 is located directly in front of the camera 221, the square light source 223 emits light, the camera 221 shoots the side image of the rivet 5, and the industrial computer performs image processing according to the side image of the rivet 5 to obtain the rivet 5 rod length, countersunk face cone angle; camera 221 adopts industrial camera;

Step 5, the PLC controller controls the pneumatic turntable 211 to rotate counterclockwise by 90° so that the top surface of the rivet 5 faces the camera 221, the ring light source 224 emits light, the camera 221 takes an image of the top surface of the rivet 5 and sends it to the industrial computer, and the industrial computer processes the image Obtain the diameter size of the top surface of the rivet 5 and detect the defect on the top surface of the rivet 5; the pneumatic turntable 211 rotates 90° clockwise, the pneumatic sliding table 216 moves downward, the pneumatic finger 210 is released, and the rivet 5 is put back on the conveyor belt 12;

Step 6. According to the rivet 5 rod diameter, rivet 5 side image, and rivet 5 top surface image obtained in the above steps, the industrial computer divides the currently detected rivet 5 into quality grades. The quality grades from high to low are high-quality products, qualified products, and waste products. Three grades, and the results of quality grade division are recorded and transmitted to the PLC controller at the same time;

Step 7, the PLC controller controls the rotation of the sorting tank 31 according to the result of the grade classification, so that the output port of the sorting tank 31 faces the sorting bucket 32 of the corresponding grade, so that the rivet 5 falls into the sorting bucket 32 of the quality grade, and the rivet is completed 5 quality classification screening.

The above specific implementation manners have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation modes of the present invention, and are not used to limit the protection scope of the present invention. Within the spirit and principles of the present invention, any modifications, equivalent replacements, improvements, etc., shall be included in the protection scope of the present invention.

Claims (10)

1. A rivet quality rating and automatic sorting system, is characterized in that, comprises material delivery device (1), detection device (2), screening device (3) and automatic control unit; The material conveying device (1) is used to convey rivets to the detection device, and output the rivets after detection to the screening device (3); The detection device (2) includes a clamping mechanism (21) and an information collection mechanism (22), the clamping mechanism (21) includes a pneumatic finger (210) and a pneumatic turntable (211), and the free end of the pneumatic finger (210) The two fingers are respectively provided with a first grasping plate (212) and a second grasping plate (213), and the pneumatic fingers (210) control the first grasping plate (212) and the second grasping plate (213) to open or close together The action is used for rivets; the pneumatic finger (210) is connected with the pneumatic turntable (211), and the pneumatic turntable (211) drives the pneumatic finger (210), the first grasping plate (212) and the second grasping plate (213) to rotate circumferentially sports; The information collection mechanism (22) includes a pull rod electronic ruler (220) and a camera (221); the pull rod electronic ruler (220) is arranged on the first grasping plate (212), and is adapted to the pull rod electronic ruler (220). The matching distance measuring plate (222) is arranged on the second grasping plate (213); the camera (221) is arranged on one side of the rivet clamped by the first grasping plate (212) and the second grasping plate (213), It is used to obtain the image information of the rivets clamped between the first grasping plate (212) and the second grasping plate (213); The screening device (3) comprises a sorting trough (31) and several sorting barrels (32), and the input end of the sorting trough (31) is placed at the output end of the material conveying device (1), driven by a driving mechanism The sorting trough (31) rotates so that the output end of the sorting trough (31) faces different sorting buckets (32); The automatic control unit includes a PLC controller, an industrial computer and a database; the industrial computer is used to receive the information collected by the information collection mechanism (22), and according to the pre-stored rivet types in the database and the corresponding screening and grading standards, the current Detecting rivets for quality classification and outputting test results; the PLC controller is used to control the conveying action of the material conveying device (1), to control the clamping action of the clamping mechanism (21), and to control the collection action of the information collection mechanism (22) , and control the rotation of the sorting slot (31) according to the detection result output by the industrial computer to guide the rivets of different levels into the corresponding sorting bucket (32). 2. A kind of rivet quality rating and automatic sorting system according to claim 1, characterized in that, the material conveying device (1) comprises a vibrating plate (11) and a conveyor belt (12), and the vibrating plate (11 ) is connected to the input end of the conveyor belt (12), the conveyor belt (12) is located under the pneumatic finger (210), and the conveyor belt (12) is used to transport rivets. 3. A rivet quality rating and automatic sorting system according to claim 2, characterized in that a photoelectric switch (13) is provided on the conveyor belt (12) near the side of the pneumatic finger (210), and the photoelectric switch (13) is The switch (13) is used to detect the position of the rivet on the conveyor belt (12), and transmits the detection information to the PLC controller, and the PLC controller controls the clamping mechanism (21) to complete the clamping action according to the detection information. 4. A kind of rivet quality rating and automatic sorting system according to claim 1, characterized in that, the first grasping plate (212) and the pull rod electronic ruler (220) are fixed on the One finger end of the pneumatic finger (210), the second grasping plate (213) and the distance measuring plate (222) are fixed on the other finger end of the pneumatic finger (210) through the second connecting bar (215). 5. A kind of rivet quality rating and automatic sorting system according to claim 1, characterized in that, the information collection mechanism (22) also includes a square light source (223) and a ring light source (224), and the square light source (223), the ring light source (224) and the camera (221) are sequentially arranged on a straight line. 6. A rivet quality rating and automatic sorting system according to claim 5, characterized in that, the information collection mechanism (22) also includes a positioning bracket (225), and the positioning bracket (225) is provided with Slide rail (226), described camera (221), square light source (223) and ring light source (224) are all connected with slide rail (226) by fixing clip (227), and fixing clip (227) passes slide block and slide The rail (226) slides to fit. 7. A kind of rivet quality rating and automatic sorting system according to claim 1, characterized in that, the clamping mechanism (21) also includes a pneumatic slide table (216); the pneumatic turntable (211) and the pneumatic The slide table (216) is connected, and the pneumatic slide table (216) is installed on the fixed plate (217), and the pneumatic slide table (216) drives the pneumatic turntable (211), the pneumatic finger (210), the first grasping plate (212 ) and the second grasping plate (213) overall structure moves up and down. 8. A kind of rivet quality rating and automatic sorting system according to claim 1, characterized in that, the drive mechanism adopts a servo motor (34); the screening device (3) also includes legs (33), the servo motor (34) is located on the leg (33), the output end of the servo motor (34) is connected with the bottom plate at one end of the axial end of the sorting trough (31) through the thrust bearing (35), and drives the sorting trough (31) to rotate; The radial width of the sorting trough (31) decreases gradually along the direction of material flow, and a guide bar (36) is provided in the middle of the sorting trough (31). 9. The screening method based on a kind of rivet quality rating and automatic sorting system according to any one of claims 1-8, is characterized in that, comprises the following steps: Step 1, place the rivets to be sorted with their heads facing down through the material conveying device (1), and transport them to the detection device (2) according to a certain rivet arrangement spacing and transmission speed; Step 2, the PLC controller controls the closing of the pneumatic fingers (210), and the first grasping plate (212) and the second grasping plate (213) grasp the rivets; ) cooperate with the distance measuring plate (222) arranged on the second grasping plate (213) to obtain the diameter of the rivet rod and send it to the industrial computer; Step 3, obtain the side image of the rivet by taking pictures with the camera (221), and the industrial computer performs image processing according to the side image of the rivet to obtain the length of the rivet rod and the taper angle of the countersunk face; Step 4, the PLC controller controls the pneumatic turntable (211) to rotate counterclockwise by 90° so that the top surface of the rivet faces the camera (221), and the camera (221) takes an image of the top surface of the rivet, and the industrial computer obtains the diameter size of the top surface of the rivet through image processing and Detect defects on the top surface of the rivet; the pneumatic turntable (211) rotates 90° clockwise, the pneumatic finger (210) is released, and the rivet returns to the material conveying device (1); Step 5, the industrial computer classifies the quality grade of the rivet according to the size data and surface defects of the rivet, and records the grade classification result and transmits it to the PLC controller; In step 6, the PLC controller controls the rotation of the sorting chute (31) according to the result of grade classification, so as to transfer the rivets to the sorting bucket (32) of the corresponding quality grade for recycling. 10. A rivet quality rating and automatic sorting method according to claim 9, characterized in that, in the step 6, the quality grades of rivets from high to low are three grades of excellent product, qualified product and waste product .