A screw tightening device based on vision detection

Abstract

This invention provides a vision-based screw tightening device, comprising a production line and multiple workstations arranged along the production line. Each workstation is equipped with a stop module, a lifting and clamping module, a vision inspection module, a locking module, and a feeder. A material distribution module is located at the rear of the production line. Specifically, the stop module is located below the production line, the lifting and clamping module is located below the production line, the vision inspection module is located above the production line, and the locking module is located above the production line. This invention, through the vision inspection module, can capture and tighten screws of different positions or types at each workstation, and can promptly photograph and confirm the product. This allows the travel path of the screw being tightened by the electric screwdriver and the condition of the screw after installation to be known, reducing defective products caused by incorrect carrier positioning and increasing the number of screws tightened, thus greatly improving production efficiency.

Description

Technical Field

[0001] This invention relates to the field of automated equipment, and more particularly to a screw tightening device based on vision inspection. Background Technology

[0002] A screw-fastening machine is an automated device that replaces manual labor in picking up, placing, and tightening screws, and it has been widely used. Currently, many domestic enterprises have a very broad application prospect, mainly using it for the automated assembly of automotive parts, computers, displays, motors, lamps, mobile phones, printers, circuit boards, batteries, instruments, etc., which can greatly improve production efficiency, reduce production costs, and improve reliability.

[0003] Existing screw fastening machines generally perform screw fastening operations according to preset positions in the program. This places very high demands on the positioning of the production line, requiring the production line to accurately stop the product in a fixed position before performing a single screw fastening operation. Even so, due to possible changes in accuracy caused by mechanical wear, situations may occur where the screws are not fastened tightly or the product is damaged. This problem is particularly serious in precision products (such as mobile phones). Summary of the Invention

[0004] The purpose of this invention is to provide a screw tightening device based on vision detection.

[0005] To achieve the above objectives, the following technical solution is adopted:

[0006] A vision-based screw tightening device includes a production line and multiple workstations arranged along the production line. Each workstation is equipped with a stop module, a lifting and clamping module, a vision inspection module, a fastening module, and a feeder. A material distribution module is located at the rear end of the production line. The stop module is located below the production line, forming a barrier against a carrier loaded with products. The lifting and clamping module is located below the production line and is used to lift and clamp the carrier. The vision inspection module is located above the production line and is used to perform visual recognition of the products, including calculating the screws to be installed on the products. The position of the screw holes and the calculation of whether the installed screws on the product are in good condition; the fastening module is set above the production line, and includes an electric screwdriver with vacuum adsorption and a first execution component that drives the electric screwdriver to move in three-dimensional space. The electric screwdriver is used to adsorb screws from the feeder and install them into the screw holes to be installed calculated by the vision inspection module under the drive of the first execution component; the material distribution module includes a gripper assembly and a second execution component that drives the gripper assembly to move in three-dimensional space. The material distribution module is used to move the carrier to the corresponding position according to the result of the vision recognition.

[0007] Furthermore, both the front and rear ends of the production line are equipped with the stop module, which includes rollers and a stop cylinder that drives the rollers to extend from the middle of the production line. The stop module at the front end of the production line prevents other carriers on the production line from entering the locking device before the locking device has finished working. The stop device at the rear end of the production line prevents carriers from leaving the locking device before the material distribution device has finished distributing materials. Additionally, since the carrier is stopped before being lifted, using rollers to stop the carrier reduces friction during the lifting process, thereby preventing carrier displacement.

[0008] Furthermore, the roller is rotatably mounted on one end of a connecting rod, which is L-shaped. A fixed block is rotatably connected to the corner of the connecting rod, and the other end of the connecting rod is connected to the fixed block via an elastic element. The fixed block is located at the drive end of the stop cylinder. Under normal conditions, the section of the connecting rod with the roller is inclined at 30-60° to the drive shaft of the stop cylinder. The connecting rod and the elastic element form an elastic buffer for the vehicle, preventing the vehicle from experiencing a large impact force at the moment of stopping.

[0009] Furthermore, the lifting and clamping module includes a lifting cylinder, a lifting seat connected to the driving end of the lifting cylinder, a first clamping jaw disposed on one side of the production line, and a second clamping jaw disposed on the other side of the production line. The end of the second clamping jaw away from the production line is connected to the driving end of a translation cylinder. When the lifting cylinder drives the lifting seat to rise, the carrier is lifted until both sides of the carrier are blocked by the first and second clamping jaws, thus fixing the carrier under the action of the lifting cylinder, the first clamping jaw, and the second clamping jaw. When the translation cylinder drives the second clamping jaw to extend, in addition to positioning the top of the carrier, it can also adjust the position of the carrier. For example, if the top of the carrier has a protrusion, the second clamping jaw pushes towards the protrusion, pushing the carrier closer to the first clamping jaw, thus completing the fine adjustment of the carrier's position.

[0010] Furthermore, the visual inspection module includes a CCD camera and a ring-shaped fill light. The CCD camera's shooting direction passes through the fill light and falls on the product. Besides providing supplemental lighting to the product and improving the CCD camera's shooting effect, the ring-shaped fill light also reduces interference in the captured image. That is, the controller connected to the CCD camera only needs to analyze the image within the ring of the fill light, thus greatly reducing workload and improving visual inspection speed.

[0011] Furthermore, the supplementary light is slidably mounted on the first guide rail via a connecting seat, which is also connected to the drive end of a linear cylinder. The driving direction of the linear cylinder is parallel to the production line. The supplementary light can be driven to move horizontally, thus making it suitable for products that do not require supplementary lighting or ring-shaped shielding.

[0012] Furthermore, the gripper assembly includes two sets of grippers, each fixed under a different slide plate. Each slide plate has a second slide rail on its top, with a slider slidably connected within the second slide rail. Each slide plate is connected to a different opening / closing cylinder. Both the opening / closing cylinder and the slider are fixed under a mounting plate, which is connected to the execution end of the second actuation component. The two sets of grippers are driven by the two opening / closing cylinders to clamp the carrier.

[0013] Furthermore, a barcode scanning module is also installed at the front end of the production line. The barcode scanning module includes a barcode scanner located above the production line, and the carrier is equipped with a tag that can be recognized by the barcode scanner. The processed products are recorded.

[0014] Furthermore, the production line passes through a frame equipped with a protective cover. The stop module, the lifting and clamping module, the vision inspection module, the locking module, the feeder, and the material distribution module are all housed within the protective cover. This device is easy to install into a production line, enabling rapid upgrades to ordinary production lines, and is easy to debug and install.

[0015] By adopting the above solution, the beneficial effects of the present invention are:

[0016] By using a visual inspection module, the product can be photographed and confirmed in a timely manner after screws of different positions or types are attracted and tightened at each workstation. This allows the travel path of the electric screwdriver and the condition of the screws after installation to be known, reducing defective products caused by incorrect carrier positioning and increasing the number of screws tightened, thus greatly improving production efficiency. Attached Figure Description

[0017] Figure 1 This is a top view of the locking device according to an embodiment of the present invention;

[0018] Figure 2 This is a three-dimensional structural diagram of the locking device according to an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the production line and lifting clamping module according to an embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of a partial production line and one of the lifting and clamping modules according to an embodiment of the present invention;

[0021] Figure 5 for Figure 4 A structural diagram omitting the vehicle;

[0022] Figure 6 This is a schematic diagram of the stop module according to an embodiment of the present invention;

[0023] Figure 7 This is a schematic diagram of the combined structure of multiple locking modules according to an embodiment of the present invention;

[0024] Figure 8 This is a schematic diagram of the locking module according to an embodiment of the present invention;

[0025] Figure 9 This is a schematic diagram of the combined structure of multiple visual inspection modules according to an embodiment of the present invention;

[0026] Figure 10 This is a schematic diagram of the overall structure of the material distribution module according to an embodiment of the present invention;

[0027] Figure 11 This is a schematic diagram of the overall structure of the gripper assembly according to an embodiment of the present invention;

[0028] Figure 12 This is a schematic diagram of the locking device of this invention installed in the protective cover and frame.

[0029] The following are explanations of the labels in the attached diagram:

[0030] 1. Production line; 11. Carrier; 2. Stop module; 21. Roller; 22. Stop cylinder; 23. Connecting rod; 24. Fixing block; 25. Spring element; 3. Lifting and clamping module; 31. Lifting cylinder; 32. Lifting seat; 33. First gripper; 34. Second gripper; 35. Translation cylinder; 4. Vision inspection module; 41. CCD camera; 42. Fill light; 43. Connecting seat; 44. First slide rail; 45. 5. Linear cylinder; 6. Locking module; 7. Electric screwdriver; 8. First actuator; 9. Feeder; 10. Material distribution module; 11. Gripper assembly; 12. Gripper; 13. Slide plate; 14. Second slide rail; 15. Opening and closing cylinder; 16. Slider; 17. Mounting plate; 18. Second actuator; 19. Barcode scanning module; 20. Frame; 21. Protective cover; 22. Good product area; 33. Problem area. Detailed Implementation

[0031] Typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0032] like Figure 1-12As shown, a vision-based screw tightening device includes a production line 1 and multiple workstations arranged along the production line 1. Each workstation is equipped with a stop module 2, a lifting and clamping module 3, a vision inspection module 4, a locking module 5, and a feeder 6. A material distribution module 7 is located at the rear end of the production line 1. The stop module 2 is located below the production line 1 and forms a block for the carrier 11 loaded with products. The lifting and clamping module 3 is located below the production line 1 and is used to lift and clamp the carrier 11. The vision inspection module 4 is located above the production line 1 and is used for visual recognition of the products. The visual recognition includes calculating the screws to be installed on the products. The position of the screw hole and the status of the screws already installed on the product are calculated to ensure they are normal. The fastening module 5 is set above the production line 1 and includes an electric screwdriver 51 with vacuum adsorption and a first execution component 52 that drives the electric screwdriver 51 to move in three-dimensional space. The electric screwdriver 51 is used to adsorb screws from the feeder 6 and install them into the screw holes to be installed as calculated by the vision inspection module 4 under the drive of the first execution component 52. The material distribution module 7 includes a gripper assembly 71 and a second execution component 72 that drives the gripper assembly 71 to move in three-dimensional space. The material distribution module 7 is used to move the carrier 11 to the corresponding position according to the result of vision recognition.

[0033] In one embodiment, a stop module 2 is provided at both the front and rear ends of the production line 1. The stop module 2 includes a roller 21 and a stop cylinder 22 extending from the middle of the production line 1. The stop module 2 at the front end of the production line 1 can prevent other carriers 11 on the production line 1 from entering the locking device when the locking device has not completed its operation. The stop device at the rear end of the production line 1 can prevent the carriers 11 from leaving the locking device when the material distribution device has not completed its material distribution. In addition, since the carriers 11 are stopped before being lifted, using the roller 21 to stop the carriers 11 reduces the friction during the lifting process of the carriers 11, thereby preventing the carriers 11 from shifting. A roller 21 is rotatably mounted on one end of a connecting rod 23, which is L-shaped. A fixed block 24 is rotatably connected to the corner of the connecting rod 23, and the other end of the connecting rod 23 is connected to the fixed block 24 via an elastic element. The fixed block 24 is located at the drive end of the stop cylinder 22. Under normal conditions, the section of the connecting rod 23 with the roller 21 is inclined at 30-60° to the drive shaft of the stop cylinder 22. Through the connecting rod 23 and the elastic element, an elastic buffer is formed for the carrier 11, preventing the carrier 11 from being subjected to a large impact force at the moment of stopping.

[0034] In one embodiment, the lifting and clamping module 3 includes a lifting cylinder 31, a lifting seat 32 connected to the driving end of the lifting cylinder 31, a first gripper 71133 disposed on one side of the production line 1, and a second gripper 71134 disposed on the other side of the production line 1. The end of the second gripper 71134 away from the production line 1 is connected to the driving end of a translation cylinder 35. When the lifting cylinder 31 drives the lifting seat 32 to rise, the carrier 11 is lifted until both sides of the carrier 11 are blocked by the first gripper 71133 and the second gripper 71134, so that the carrier 11 is fixed under the action of the lifting cylinder 31, the first gripper 71133, and the second gripper 71134. When the translation cylinder 35 drives the second gripper 71134 to extend, in addition to positioning the top of the carrier 11, it can also adjust the position of the carrier 11. If the top of the carrier 11 has a protrusion, the second gripper 71134 pushes towards the protrusion, pushing the carrier 11 closer to the first gripper 71133, thus completing the fine adjustment of the position of the carrier 11.

[0035] In one embodiment, the visual inspection module 4 includes a CCD camera 41 and a ring-shaped fill light 42. The shooting direction of the CCD camera 41 passes through the fill light 42 and falls on the product. Besides providing supplementary lighting to the product, improving the shooting effect of the CCD camera 41, the ring-shaped fill light 42 also reduces interference in the captured image. That is, the controller connected to the CCD camera 41 only needs to analyze the image within the ring of the fill light 42, thus greatly reducing workload and improving visual inspection speed. The fill light 42 is slidably mounted on a first guide rail via a connecting seat 43, which is also connected to the drive end of a linear cylinder 45. The driving direction of the linear cylinder 45 is parallel to the production line 1. The fill light 42 can be driven to move, thus making it suitable for products that do not require a fill light 42 or do not require ring-shaped obstruction.

[0036] In one embodiment, the gripper assembly 71 includes two sets of grippers 711, each fixed under a different slide plate 712. Each slide plate 712 has a second slide rail 713 at its top, with a slider 715 slidably connected within the second slide rail 713. Each slide plate 712 is connected to a different opening / closing cylinder 714. Both the opening / closing cylinder 714 and the slider 715 are fixed under a mounting plate 716, which is connected to the actuating end of the second actuating assembly 72. The two sets of grippers 711 are driven by the two opening / closing cylinders 714 to clamp the carrier 11.

[0037] In one embodiment, a barcode scanning module 8 is also provided at the front end of production line 1. The barcode scanning module 8 includes a barcode scanner located above production line 1, and a tag that can be recognized by the barcode scanner is provided on the carrier 11, so that the processed products can be recorded. Production line 1 passes through a frame 91, and a protective cover 92 is provided on the frame 91. The stop module 2, lifting and clamping module 3, vision inspection module 4, locking module 5, feeder 6, and material distribution module 7 are all located in the protective cover 92. This device is easy to install into production line 1, thereby enabling rapid upgrades to ordinary production line 1, and is easy to debug and install.

[0038] Working principle: Carrier 11 enters production line 1 and is stopped by the stop module 2 at the front end of production line 1. The sensor connected to the controller detects carrier 11, and lifting cylinder 31 lifts carrier 11. The first gripper 71133 and the second gripper 71134 press against the two sides of carrier 11. Translation cylinder 35 drives the second gripper 71134 to correct the position of carrier 11 if it may have shifted. The barcode scanning module 8 identifies and records the label on carrier 11. The supplementary light 42 is constantly on, and the CCD camera 41 takes a picture of the screw holes of the product in carrier 11. The controller displays the screw holes in the picture. The drive path of the first execution component 52 is obtained by comparing and calculating the screw hole with the preset screw hole position. The calculation process can refer to the neural network model in the prior art, that is, a trained neural network model can be preset in the controller. Since the position of the CCD camera 41 is fixed, the deviation between the screw hole in the photo and the preset screw hole can be calculated. Based on the deviation calculation, the correction path can be obtained. Then, the electric screwdriver 51 picks up the screw from the feeder 6, and then the electric screwdriver 51 screws the screw into the screw hole of the product along the correction path.

[0039] After the screws at the current workstation are tightened, the lifting cylinder 31 descends, and the carrier 11 moves along production line 1 to the next workstation, allowing other types of screws to be screwed into the product. At each workstation, the CCD camera 41, in addition to calculating the position of the screw holes, can also calculate whether the screws tightened at the previous workstation are up to standard. By taking photos, it analyzes whether the screws in the photos have a series of faults such as missing screws, missing feeds, stripped threads, or loose screws. The analysis process can also be performed through the controller's neural network model. When a screw fault is detected, the product is marked on the software. After the product arrives at the material distribution module 7, the material distribution module 7 moves the product to the problem area 102 on one side of production line 1 based on the analysis results. If the product has no problems, it is moved to the good product area 101.

[0040] Although this disclosure has been described with reference to several typical embodiments, it should be understood that the terminology used is descriptive and exemplary, and not restrictive. Because this disclosure can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A screw tightening device based on vision detection, characterized in that, The production line includes a production line and multiple workstations arranged along the production line. Each workstation is equipped with a stop module, a lifting and clamping module, a vision inspection module, a locking module, and a feeder. A material distribution module is located at the rear end of the production line. The stop module is located below the production line and forms a blockage against the carriers carrying the products; The lifting and clamping module is located below the production line and is used to lift and clamp the carrier. The visual inspection module is located above the production line and is used to perform visual recognition on the product. The visual recognition includes calculating the position of the screw holes to be installed on the product and calculating whether the status of the screws already installed on the product is normal. The locking module is located above the production line and includes an electric screwdriver with vacuum adsorption and a first execution component that drives the electric screwdriver to move in three-dimensional space. The electric screwdriver is used to adsorb screws from the feeder under the drive of the first execution component and install them into the screw holes to be installed calculated by the vision inspection module. The material distribution module includes a gripper assembly and a second execution component that drives the gripper assembly to move in three-dimensional space. The material distribution module is used to move the carrier to the corresponding position according to the result of the visual recognition. The stop module is provided at both the front and rear ends of the production line. The stop module includes a roller and a stop cylinder that drives the roller to extend from the middle of the production line. The roller is rotatably mounted on one end of a connecting rod. The connecting rod is L-shaped. A fixed block is rotatably connected to the corner of the connecting rod. The other end of the connecting rod is connected to the fixed block through an elastic element. The fixed block is located at the drive end of the stop cylinder. Under normal conditions, the section of the connecting rod with the roller is inclined at 30-60° to the drive shaft of the stop cylinder. The gripper assembly includes two sets of grippers, which are respectively fixed under different slide plates. Each slide plate has a second slide rail on its top, and a slider is slidably connected in the second slide rail. Each slide plate is connected to a different opening and closing cylinder. The opening and closing cylinder and the slider are both fixed under a mounting plate, which is connected to the execution end of the second execution component.

2. The screw tightening device based on vision detection according to claim 1, characterized in that, The lifting and clamping module includes a lifting cylinder, a lifting seat connected to the driving end of the lifting cylinder, a first clamping jaw disposed on one side of the production line, and a second clamping jaw disposed on the other side of the production line. The end of the second clamping jaw away from the production line is connected to the driving end of a translation cylinder.

3. The screw tightening device based on vision detection according to claim 1, characterized in that, The visual inspection module includes a CCD camera and a ring-shaped fill light. The shooting direction of the CCD camera passes through the fill light and falls on the product.

4. The vision-based screw tightening device according to claim 3, characterized in that, The supplementary light is slidably mounted on the first guide rail via a connecting seat. The connecting seat is also connected to the drive end of a linear cylinder, and the driving direction of the linear cylinder is parallel to the production line.

5. The screw tightening device based on vision detection according to claim 1, characterized in that, The production line is also equipped with a barcode scanning module, which includes a barcode scanner located above the production line and a tag that can be recognized by the barcode scanner on the carrier.

6. The screw tightening device based on vision detection according to claim 1, characterized in that, The production line passes through a frame, on which a protective cover is installed. The stop module, the lifting and clamping module, the vision inspection module, the locking module, the feeder, and the material distribution module are all installed in the protective cover.

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