An optical automatic detection device for printed circuit boards

Abstract

The present invention discloses an optical automatic inspection device for printed circuit boards, which relates to the field of circuit board inspection, including an inspection workbench, an inspection slot is provided on the top of the inspection workbench, an optical inspection component is provided directly above the inspection slot, and a flipping mechanism is provided in the inspection slot, the flipping mechanism includes a lifting column, a deflection block and a rotating seat, the lifting column is vertically arranged, and the lifting column has the freedom to move along the height direction of the inspection workbench, the deflection block is rotatably arranged on the top of the lifting column, the deflection axis of the deflection block is horizontally arranged, the end of the deflection block away from the lifting column is connected to a negative pressure tube, the end of the negative pressure tube away from the deflection block is connected to a negative pressure suction cup, the rotating seat is arranged on one side of the deflection axis of the deflection block, the rotating seat is rotatably connected to the inspection workbench, the rotating axis of the rotating seat is vertically arranged, and a slot is provided on the top of the rotating seat, which can complete the flipping of the circuit board within a small space, and the double-sided inspection of the circuit board can be completed by one loading, thereby improving the inspection efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board detection, in particular to an optical automatic detection device for a printed circuit board. Background Art

[0002] Currently, the manufacturing process for printed circuit boards (PCBs) primarily utilizes automated optical inspection solutions to detect defects on both sides of the PCB, such as shorts, opens, pinholes, scratches, thin or thick lines, and jagged edges. Currently, after inspecting one side of a PCB, it's impossible to inspect the other side. The PCB must be transported to the next workstation for manual or robotic flipping before being transported to the inspection station for inspection on the other side. This requires a long conveying path, with numerous uncontrollable factors, and the PCB may be damaged during transport, resulting in a high defective rate. Furthermore, manual flipping is inefficient and labor-intensive, while robotic flipping requires high equipment investment costs. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide an optical automatic detection device for a printed circuit board to solve the deficiencies of the prior art.

[0004] The objective of the present invention is achieved through the following technical solutions: An optical automatic inspection device for printed circuit boards, comprising an inspection workbench, an inspection slot being defined at the top of the inspection workbench, an optical inspection assembly being disposed directly above the inspection slot, the optical inspection assembly comprising a lifting seal and an industrial camera, the industrial camera being mounted at the bottom of the lifting seal, the lifting seal having the freedom to move in the height direction of the inspection workbench, a flipping mechanism being disposed within the inspection slot, the flipping mechanism comprising a lifting column, a deflection block, and a rotating seat, the lifting column being disposed vertically and having the freedom to move in the height direction of the inspection workbench, the deflection block being rotatably disposed at the top of the lifting column, the deflection axis of the deflection block being disposed horizontally, a negative pressure tube being connected to one end of the deflection block away from the lifting column, and a negative pressure suction cup being connected to the other end of the negative pressure tube away from the deflection block, the rotating seat being disposed on one side of the deflection axis of the deflection block, the rotating seat being rotatably connected to the inspection workbench, the rotation axis of the rotating seat being disposed vertically, a slot being defined at the top of the rotating seat, and a printed circuit board being vertically inserted into the slot.

[0005] Furthermore, a first cylinder is vertically arranged below the lifting column, the telescopic shaft of the first cylinder is connected to the bottom of the lifting column, a driving notch is opened on the top of the lifting column, a main shaft is arranged in the driving notch, the main shaft is rotatably connected to the lifting column, the deflection block is fixedly sleeved on the main shaft, and the side wall of the negative pressure tube is connected to the vacuum pump through a negative pressure hose.

[0006] Furthermore, a driving mechanism is provided on the side wall of the lifting column, and the driving mechanism includes a driving shaft, a rack and a second cylinder. The driving shaft is rotatably installed below the main shaft, and a first synchronous pulley is mounted on the main shaft. A second synchronous pulley and a gear are mounted on the driving shaft. The first synchronous pulley is connected to the second synchronous pulley through a synchronous belt transmission. The rack is slidably arranged on the lifting column, and the rack engages with the gear. The second cylinder is vertically arranged below the rack, and the cylinder body of the second cylinder is mounted on the lifting column. The telescopic shaft of the second cylinder is connected to the bottom of the rack.

[0007] Furthermore, a positioning block is fixed to the side wall of the rack, and an upper limit block and a lower limit block are installed on the lifting column at intervals along its own height direction. Pressure sensors are installed on the upper limit block and the lower limit block. The positioning block is located between the detection axes of the two pressure sensors. When the positioning block contacts the detection axis of the upper pressure sensor, the axis of the negative pressure tube is set horizontally. When the positioning block contacts the detection axis of the lower pressure sensor, the axis of the negative pressure tube is set vertically.

[0008] Furthermore, a rotating spindle is fixed to the bottom of the rotating seat, and the rotating spindle is rotatably connected to the detection workbench. A stepper motor is installed on the detection workbench, and the output shaft of the stepper motor is transmission-connected to the rotating spindle.

[0009] Furthermore, it also includes a positioning and conveying mechanism, which includes a rotating loading arm and two groups of conveyor belts. The two groups of conveyor belts are arranged at intervals along a conveying direction perpendicular to the printed circuit board. A conveying channel for the printed circuit board is formed between the two groups of conveyor belts. The moving direction of the conveyor belt is perpendicular to the conveying direction of the printed circuit board. The moving directions of the two groups of conveyor belts are opposite. The rotating loading arm is arranged between the conveyor belt and the detection workbench. The rotating loading arm has linear lifting freedom and rotational freedom. The rotation axis of the rotating loading arm is vertically arranged, and a hollow negative pressure tube is connected to the bottom of one end of the rotating loading arm.

[0010] Furthermore, the conveyor belt includes a support platform, a pushing cylinder and two C-shaped frames, the two C-shaped frames are arranged at intervals along the conveying direction of the printed circuit board, and the two C-shaped frames are respectively rotatably connected with a driving pulley and a driven pulley, the driving pulley is connected to the driven pulley through a belt transmission, a driving motor is installed on the top of the C-shaped frame, and the output shaft of the driving motor is connected to the driving pulley, the C-shaped frame is slidably set on the support platform, the two C-shaped frames are connected by a cross plate, the pushing cylinder is horizontally installed on the support platform, and the telescopic shaft of the pushing cylinder is connected to the cross plate.

[0011] Furthermore, a hollow main shaft is fixed at the bottom of the rotating loading arm, a lifting plate is rotatably mounted on the hollow main shaft, a base is fixedly provided below the lifting plate, a third cylinder is provided between the base and the lifting plate, the cylinder body of the third cylinder is installed on the base, the telescopic shaft of the third cylinder is connected to the lifting plate, a loading motor is installed at the bottom of the lifting plate, the output shaft of the loading motor is connected to the first gear, a second gear is mounted on the hollow main shaft, and the first gear engages with the second gear.

[0012] Furthermore, a hard bent tube is provided on the lifting plate, one end of the hard bent tube is movably inserted into the hollow main shaft, a sealing ring is mounted on the hard bent tube, and the sealing ring is interference fit in the hollow main shaft, a negative pressure path is provided in the rotating loading arm, one end of the negative pressure path is connected to the hollow negative pressure tube, and the other end is connected to the hollow main shaft.

[0013] Furthermore, the optical detection assembly also includes a detection bracket and a fourth cylinder, the cylinder body of the fourth cylinder is vertically installed on the detection bracket, and the telescopic shaft of the fourth cylinder is connected to the top of the lifting sealing plate.

[0014] The beneficial effects of the present invention are:

[0015] The circuit board is loaded onto the negative pressure suction cup, and the circuit board is adsorbed by negative pressure. The lifting and sealing plate contacts the detection workbench, so that the detection tank is in a closed environment, which provides a better imaging environment for the industrial camera. The quality inspection of the upper surface of the circuit board is completed by the industrial camera imaging. When the inspection of one side of the printed circuit board is completed, the deflection block drives the circuit board to deflect 90°, so that the circuit board is in a vertical state, and then the lifting column drives the circuit board to move downward so that the circuit board is inserted into the slot of the rotating seat. The circuit board is driven to rotate 180° by the rotating seat, and then the circuit board is adsorbed by the negative pressure suction cup, and the circuit board is reset by the rotation of the deflection block. At this time, the other side of the circuit board is facing up in the detection state, so that the circuit board can be turned over in a small space. Double-sided inspection of the circuit board can be completed with one loading, which improves the inspection efficiency and avoids the quality of the circuit board being affected by the later transportation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of an optical automatic detection device for printed circuit boards of the present invention. Figure 1 ;

[0017] Figure 2 for Figure 1 Enlarged view of point B in the middle;

[0018] Figure 3 This is a schematic structural diagram of a detection workbench in an optical automatic detection device for printed circuit boards of the present invention;

[0019] Figure 4 for Figure 3 Enlarged view of point C in the middle;

[0020] Figure 5 A top view of an optical automatic detection device for printed circuit boards according to the present invention;

[0021] Figure 6 for Figure 5 Middle AA section view;

[0022] Figure 7 for Figure 6 Enlarged view of point A in the middle;

[0023] Figure 8 This is a schematic diagram of the structure of an optical automatic detection device for printed circuit boards of the present invention. Figure 2 ;

[0024] Figure 9 This is a schematic diagram of the assembly of a rotary loading arm in an optical automatic inspection device for printed circuit boards according to the present invention;

[0025] Figure 10 for Figure 9 Enlarged view of point D in the middle;

[0026] In the figure, 1- detection workbench, 2- detection slot, 3- lifting and closing plate, 4- industrial camera, 5- lifting column, 6- deflection block, 7- rotating seat, 8- negative pressure tube, 9- negative pressure suction cup, 10- slot, 11- first cylinder, 12- driving notch, 13- main shaft, 14- driving shaft, 15- rack, 16- second cylinder, 17- first synchronous pulley, 18- second synchronous pulley, 19- gear, 20- synchronous belt, 21- positioning block, 22- upper limit block, 23- lower limit block, 24- pressure sensor, 25- rotating main shaft, 26- Stepper motor, 27-rotating loading arm, 28-conveyor belt, 29-hollow negative pressure tube, 30-support platform, 31-pushing cylinder, 32-C-type frame, 33-driving pulley, 34-driven pulley, 35-belt, 36-driving motor, 37-hollow spindle, 38-lifting plate, 39-base, 40-third cylinder, 41-loading motor, 42-first gear, 43-second gear, 44-hard bent pipe, 45-sealing ring, 46-negative pressure path, 47-detection bracket, 48-fourth cylinder, 49-conveyor platform, 50-ball bearing. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0028] Example 1:

[0029] like Figures 1 to 10As shown, an optical automatic inspection device for printed circuit boards includes an inspection workbench 1, an inspection slot 2 is provided on the top of the inspection workbench 1, an optical inspection component is provided directly above the inspection slot 2, the optical inspection component includes a lifting sealing plate 3 and an industrial camera 4, the industrial camera 4 is installed at the bottom of the lifting sealing plate 3, a plurality of imaging light sources are installed at the bottom of the lifting sealing plate 3, the lifting sealing plate 3 has the freedom to move along the height direction of the inspection workbench 1, a flip mechanism is provided in the inspection slot 2, the flip mechanism includes a lifting column 5, a deflection block 6 and a rotating seat 7, the lifting column 5 is vertically arranged, and the lifting column 5 has the freedom to move along the height direction of the inspection workbench 1 The deflection block 6 is rotatably arranged on the top of the lifting column 5, and the deflection axis of the deflection block 6 is horizontally arranged. The end of the deflection block 6 away from the lifting column 5 is connected to the negative pressure tube 8, and the end of the negative pressure tube 8 away from the deflection block 6 is connected to the negative pressure suction cup 9. The rotating seat 7 is arranged on one side of the deflection axis of the deflection block 6. The rotating seat 7 is rotatably connected to the detection workbench 1. The rotation axis of the rotating seat 7 is vertically arranged. A slot 10 is provided on the top of the rotating seat 7. The printed circuit board is inserted into the slot 10 in a vertical state. The circuit board is loaded on the negative pressure suction cup 9. The negative pressure suction cup 9 is initially in a vertical state and adsorbs the circuit board by negative pressure, so that the circuit board is in a horizontal state for easy loading. The first side of the circuit board is inspected. During the inspection, the lifting sealing plate 3 moves downward to make the lifting sealing plate 3 contact the inspection workbench 1, so that the inspection tank 2 is in a closed environment, so that the industrial camera 4 has a better imaging environment, and the quality inspection of the upper surface of the circuit board is completed through the imaging of the industrial camera 4. When the inspection of one side of the printed circuit board is completed, the deflection block 6 drives the negative pressure tube 8 to deflect, and the negative pressure tube 8 drives the circuit board to deflect 90° through the negative pressure suction cup 9, so that the circuit board is in a vertical state, and then the lifting column 5 drives the circuit board to move downward, so that the circuit board is inserted into the slot 10 of the rotating seat 7, and then the deflection block 6 reverses to drive the negative pressure tube 8 to reset, and then, through the rotating seat 7 The circuit board is rotated 180°. Since the negative pressure tube 8 is reset to a vertical state, the rotating seat 7 can smoothly drive the circuit board to rotate 180°. Then, the deflection block 6 drives the negative pressure suction cup 9 to deflect 90° again. Then, the lifting column 5 drives the negative pressure suction cup 9 to move downward, so that the negative pressure suction cup 9 contacts the circuit board. The circuit board is adsorbed by the negative pressure suction cup 9 again, and then the deflection block 6 and the lifting column 5 are reset. At this time, the other side of the circuit board is facing up in the detection state, so that the circuit board can be turned over in a small space. The double-sided detection of the circuit board can be completed by one loading, which improves the detection efficiency and avoids the quality of the circuit board being affected by the later transportation process.

[0030] Furthermore, the optical detection component also includes a detection bracket 47 and a fourth cylinder 48. The cylinder body of the fourth cylinder 48 is vertically installed on the detection bracket 47. The telescopic shaft of the fourth cylinder 48 is connected to the top of the lifting sealing plate 3. The lifting sealing plate 3 is driven up and down by the telescopic movement of the fourth cylinder 48 to realize the switching of the circuit board loading and unloading and detection actions.

[0031] Example 2:

[0032] Based on the first embodiment, Figures 1 to 8 As shown, it also includes a positioning conveying mechanism, which includes a rotating loading arm 27 and two sets of conveyor belts 28. The two sets of conveyor belts 28 are arranged at intervals along the conveying direction perpendicular to the printed circuit board. A conveying channel for the printed circuit board is formed between the two sets of conveyor belts 28. The moving direction of the conveyor belts 28 is perpendicular to the conveying direction of the printed circuit board. The moving directions of the two sets of conveyor belts 28 are opposite. The rotating loading arm 27 is arranged between the conveyor belts 28 and the detection workbench 1. The rotating loading arm 27 has linear lifting freedom and rotational freedom. The rotation axis of the rotating loading arm 27 is vertically arranged, and the bottom of one end of the rotating loading arm 27 is perpendicular to the conveying direction of the printed circuit board. The hollow negative pressure tube 29 is connected to the top of the conveyor belt 28, and the accurate loading of the circuit board is completed through the positioning conveying mechanism and the rotating loading arm 27. A conveying platform 49 is set between the two sets of conveyor belts 28. A plurality of balls 50 are rotatably set on the conveying platform 49. The plurality of balls 50 are arranged in a rectangular array along the length direction of the conveyor platform 49. The circuit board is placed on the conveying platform 49 and supported by the balls 50. The two sets of conveyor belts 28 move close to the circuit board to align the circuit board. Under the action of the balls 50, rolling friction is generated between the circuit board and the balls 50, which greatly reduces the friction force on the circuit board during movement, making the circuit board more stable and stable. And there will be no wear during the transportation process. When the two sets of conveyor belts 28 contact the two sides of the circuit board respectively, the circuit board is positioned, and then the two sets of conveyor belts 28 are started synchronously, and the circuit board is clamped and transported forward by the two sets of conveyor belts 28, and the circuit board is transported to the loading station of the rotating loading arm 27. Then the conveyor belts 28 stop, and the rotating loading arm 27 drives the hollow negative pressure tube 29 to move downward, so that the hollow negative pressure tube 29 contacts the circuit board to clamp the circuit board by negative pressure. Then, both sets of conveyor belts 28 move away from the circuit board to release the circuit board, and then the rotating loading arm 27 drives the circuit board to move upward The lifting column 5 drives the negative pressure suction cup 9 to move upward to adsorb the circuit board, thereby loading the circuit board onto the negative pressure suction cup 9. The lifting column 5 drives the circuit board to move downward into the inspection tank 2 for inspection. Finally, the rotating loading arm 27 is reset to prepare for loading the next circuit board. In this way, accurate loading of the circuit board is achieved, so that after the circuit board is loaded, it can be accurately located within the detection range of the industrial camera 4, making the inspection result more accurate.

[0033] Further, if Figure 1 and Figure 8As shown, the conveyor belt 28 includes a support platform 30, a pushing cylinder 31 and two C-shaped frames 32. The two C-shaped frames 32 are spaced apart along the conveying direction of the printed circuit board. A driving pulley 33 and a driven pulley 34 are rotatably connected in the two C-shaped frames 32. The driving pulley 33 is connected to the driven pulley 34 through a belt 35. A driving motor 36 is installed on the top of the C-shaped frame 32. The output shaft of the driving motor 36 is connected to the driving pulley 33. The C-shaped frame 32 is slidably set on the support platform 30. The two C-shaped frames 32 are connected by a horizontal plate. Cylinder 31 is mounted horizontally on support platform 30. The telescopic shaft of cylinder 31 is connected to the horizontal plate, which is driven by a drive motor 36 to rotate a driving pulley 33. The driving pulley 33 then rotates a driven pulley 34 via a belt 35, vertically positioning the conveying surface of conveyor belt 28. This allows the two sets of conveyor belts 28 to clamp and transport the circuit boards forward, ensuring that the circuit boards do not deviate from the conveying process and improving loading accuracy. The telescopic movement of cylinder 31 drives the conveyor belts 28 toward or away from the circuit boards, completing the clamping and release operations. In specific implementation, the bottom of belt 35 is located above ball bearing 50, and the distance between belt 35 and ball bearing 50 is less than the thickness of the circuit board, allowing the belt 35 to clamp and transport the circuit board without contacting the ball bearing 50.

[0034] Further, if Figures 1 to 9 As shown, a hollow main shaft 37 is fixed to the bottom of the rotary loading arm 27, and a lifting plate 38 is rotatably mounted on the hollow main shaft 37. A base 39 is fixedly arranged below the lifting plate 38, and a third cylinder 40 is arranged between the base 39 and the lifting plate 38. The cylinder body of the third cylinder 40 is mounted on the base 39, and the telescopic shaft of the third cylinder 40 is connected to the lifting plate 38. A loading motor 41 is installed at the bottom of the lifting plate 38, and the output shaft of the loading motor 41 is connected to the first gear 42. A second gear 43 is mounted on the hollow main shaft 37, and the first gear 42 engages with the second gear 43. The loading motor 41 drives the hollow main shaft 37 to rotate through the engagement of the first gear 42 and the second gear 43, and drives the rotary loading arm 27 to rotate through the hollow main shaft 37, and then cooperates with the telescopic movement of the third cylinder 40 to drive the lifting plate 38 to move up and down, and the lifting plate 38 drives the rotary loading arm 27 to move up and down, so as to load the circuit board on the conveying table 49 onto the inspection workbench 1.

[0035] Example 3:

[0036] Since the rotating loading arm 27 needs to rotate to load materials, the negative pressure loading method needs to solve the problem of pipe winding. Therefore, based on the second embodiment, Figure 1 、 Figure 8 、 Figure 9 and Figure 10As shown, a hard bent tube 44 is provided on the lifting plate 38, one end of the hard bent tube 44 is movably inserted into the hollow main shaft 37, and a sealing ring 45 is mounted on the hard bent tube 44, which is interference fit in the hollow main shaft 37, and a negative pressure path 46 is provided in the rotating loading arm 27, one end of the negative pressure path 46 is connected to the hollow negative pressure tube 29, and the other end is connected to the hollow main shaft 37, the hard bent tube 44 is connected to the vacuum pump through a hose, and the negative pressure is transmitted by rotating the hard bent tube 44 to the hollow main shaft 37. A mounting vertical plate is fixed to the side wall of the lifting plate 38, and the hard bent tube 44 is fixedly mounted on the mounting vertical plate. Without affecting the negative pressure transmission, the hollow main shaft 37 can also have rotational freedom, and the negative pressure is applied to the hollow negative pressure tube 29 through the inner hole of the hollow main shaft 37 and the negative pressure path 46, so that the circuit board can be negatively adsorbed, thereby realizing the unwinding effect of the negative pressure pipeline arrangement.

[0037] Example 4:

[0038] Based on the third embodiment, Figures 1 to 7As shown, a first cylinder 11 is vertically arranged below the lifting column 5, and the telescopic shaft of the first cylinder 11 is connected to the bottom of the lifting column 5. A driving notch 12 is opened at the top of the lifting column 5, and a main shaft 13 is arranged in the driving notch 12. The main shaft 13 is rotatably connected to the lifting column 5, and the deflection block 6 is fixedly sleeved on the main shaft 13. The side wall of the negative pressure tube 8 is connected to the vacuum pump through a negative pressure hose. A driving mechanism is provided on the side wall of the lifting column 5, and the driving mechanism includes a driving shaft 14, a rack 15 and a second cylinder 16. The driving shaft 14 is rotatably installed below the main shaft 13, and a first synchronous pulley 17 is sleeved on the main shaft 13. The second synchronous pulley 17 is sleeved on the driving shaft 14. Two synchronous pulleys 18 and gear 19, the first synchronous pulley 17 is connected to the second synchronous pulley 18 through a synchronous belt 20, the rack 15 is slidably set on the lifting column 5, the rack 15 engages the gear 19, the second cylinder 16 is vertically set below the rack 15, the cylinder body of the second cylinder 16 is installed on the lifting column 5, the telescopic shaft of the second cylinder 16 is connected to the bottom of the rack 15, the bottom of the rotating seat 7 is fixed with a rotating spindle 25, the rotating spindle 25 is rotatably connected to the detection workbench 1, and a stepping motor 26 is installed on the detection workbench 1. The output shaft of the stepping motor 26 is connected to the rotating spindle 25 and driven by the second cylinder 16 The rack 15 moves, and the engagement of the rack 15 with the gear 19 drives the drive shaft 14 to rotate. The drive shaft 14 drives the second synchronous pulley 18 thereon to rotate. The second synchronous pulley 18 drives the first synchronous pulley 17 to rotate through the synchronous belt 20. The first synchronous pulley 17 drives the main shaft 13 to rotate, and the deflection block 6 is deflected by the main shaft 13, each deflection is 90°, and the rotating main shaft 25 is driven to rotate by the stepping motor 26. The rotating main shaft 25 drives the rotating seat 7 to rotate to flip the vertical circuit board, and then cooperates with the 90° deflection of the deflection block 6 to complete the flipping operation of the circuit board. It is worth noting that due to the motor The motor is large in size and the space in the detection tank 2 is limited. The motor cannot be directly installed on the lifting column 5. At the same time, directly installing the motor will interfere with the circuit board. Therefore, the second cylinder 16 is used as the power source, and the gear 19 is engaged with the rack 15 to change the linear motion into rotational motion. The transmission method of the synchronous belt 20 can remotely control the rotation of the main shaft 13 to ensure that the rotation of the driving main shaft 13 will not affect the loading of the circuit board. The small volume is satisfied, which meets the driving requirements in a narrow range. The stepper motor 26 is directly installed under the detection tank 2, and there is enough space for the installation of the stepper motor 26.

[0039] Further, if Figures 1 to 7As shown, a positioning block 21 is fixed to the side wall of the rack 15, and an upper limit block 22 and a lower limit block 23 are installed on the lifting column 5 at intervals along its own height direction. A pressure sensor 24 is installed on the upper limit block 22 and the lower limit block 23. The positioning block 21 is located between the detection axes of the two pressure sensors 24. When the positioning block 21 contacts the detection axis of the upper pressure sensor 24, the axis of the negative pressure tube 8 is set horizontally. When the positioning block 21 contacts the detection axis of the lower pressure sensor 24, the axis of the negative pressure tube 8 is set vertically. The cylinder is less accurate than the motor. In order to ensure that the deflection block 6 can smoothly drive the circuit board to deflect 90° so that the circuit board can be accurately inserted into the slot 10, a limiting mechanism is set. When one side of the circuit board is detected When the circuit board needs to be turned over, the second cylinder 16 is started, so that the deflection block 6 drives the circuit board to deflect, and when the rack 15 moves, it will drive the positioning block 21 to move. When the positioning block 21 acts on the pressure sensor 24 on the upper limit block 22, the pressure sensor 24 feedbacks a signal to stop the second cylinder 16. At this time, the deflection block 6 drives the circuit board to accurately deflect 90°, so that the circuit board can be smoothly inserted into the slot 10. When the deflection block 6 is reset, the rack 15 drives the positioning block 21 to move close to the lower limit block 23. When the positioning block 21 contacts the pressure sensor 24 on the lower limit block 23, the deflection block 6 puts the negative pressure tube 8 in a vertical state, thereby realizing the precise turning over of the circuit board and solving the problem of low control accuracy of the second cylinder 16.

Claims

1. An optical automatic inspection device for printed circuit boards, comprising an inspection workbench (1), characterized in that: The top of the detection workbench (1) is provided with a detection slot (2), and an optical detection component is arranged directly above the detection slot (2). The optical detection component includes a lifting sealing plate (3) and an industrial camera (4). The industrial camera (4) is installed at the bottom of the lifting sealing plate (3). The lifting sealing plate (3) has the freedom to move along the height direction of the detection workbench (1). A flip mechanism is arranged in the detection slot (2), and the flip mechanism includes a lifting column (5), a deflection block (6) and a rotating seat (7). The lifting column (5) is vertically arranged and has the freedom to move along the height direction of the detection workbench (1). The deflection block (6) is rotatably arranged on the top of the lifting column (5). The deflection axis of the block (6) is arranged horizontally, and the end of the deflection block (6) away from the lifting column (5) is connected to a negative pressure tube (8), and the end of the negative pressure tube (8) away from the deflection block (6) is connected to a negative pressure suction cup (9), and the negative pressure tube (8) drives the circuit board to deflect 90 degrees through the negative pressure suction cup (9), so that the circuit board is in a vertical state, and the rotating seat (7) is arranged on one side of the deflection axis of the deflection block (6), and the rotating seat (7) is rotatably connected to the detection workbench (1), and the rotating axis of the rotating seat (7) is arranged vertically, and a slot (10) is opened on the top of the rotating seat (7), and the printed circuit board is inserted into the slot (10) in a vertical state, and the circuit board is driven to rotate 180 degrees through the rotating seat (7).

2. The optical automatic inspection device for printed circuit boards according to claim 1, characterized in that: A first cylinder (11) is vertically arranged below the lifting column (5), a telescopic shaft of the first cylinder (11) is connected to the bottom of the lifting column (5), a driving notch (12) is opened at the top of the lifting column (5), a main shaft (13) is arranged in the driving notch (12), the main shaft (13) is rotatably connected to the lifting column (5), the deflection block (6) is fixedly sleeved on the main shaft (13), and the side wall of the negative pressure tube (8) is connected to the vacuum pump through a negative pressure hose.

3. The optical automatic inspection device for printed circuit boards according to claim 2, characterized in that: The side wall of the lifting column (5) is provided with a driving mechanism, which includes a driving shaft (14), a rack (15) and a second cylinder (16). The driving shaft (14) is rotatably mounted below the main shaft (13). The main shaft (13) is provided with a first synchronous pulley (17). The driving shaft (14) is provided with a second synchronous pulley (18) and a gear (19). The first synchronous pulley (17) is connected to the second synchronous pulley (18) via a synchronous belt (20). The rack (15) is slidably mounted on the lifting column (5). The rack (15) engages with the gear (19). The second cylinder (16) is vertically arranged below the rack (15). The cylinder body of the second cylinder (16) is mounted on the lifting column (5). The telescopic shaft of the second cylinder (16) is connected to the bottom of the rack (15).

4. The optical automatic inspection device for printed circuit boards according to claim 3, characterized in that: A positioning block (21) is fixed to the side wall of the rack (15), and an upper limit block (22) and a lower limit block (23) are installed on the lifting column (5) at intervals along its own height direction. A pressure sensor (24) is installed on both the upper limit block (22) and the lower limit block (23). The positioning block (21) is located between the detection axes of the two pressure sensors (24). When the positioning block (21) contacts the detection axis of the upper pressure sensor (24), the axis of the negative pressure tube (8) is horizontally arranged. When the positioning block (21) contacts the detection axis of the lower pressure sensor (24), the axis of the negative pressure tube (8) is vertically arranged.

5. The optical automatic inspection device for printed circuit boards according to claim 1, characterized in that: A rotating spindle (25) is fixed to the bottom of the rotating seat (7), and the rotating spindle (25) is rotatably connected to the detection workbench (1). A stepper motor (26) is installed on the detection workbench (1), and the output shaft of the stepper motor (26) is transmission-connected to the rotating spindle (25).

6. The optical automatic inspection device for printed circuit boards according to claim 1, characterized in that: The invention also includes a positioning and conveying mechanism, which includes a rotating loading arm (27) and two groups of conveyor belts (28). The two groups of conveyor belts (28) are arranged at intervals along a conveying direction perpendicular to the printed circuit board, and a conveying channel for the printed circuit board is formed between the two groups of conveyor belts (28). The moving direction of the conveyor belt (28) is perpendicular to the conveying direction of the printed circuit board, and the moving directions of the two groups of conveyor belts (28) are opposite. The rotating loading arm (27) is arranged between the conveyor belt (28) and the detection workbench (1). The rotating loading arm (27) has a linear lifting degree of freedom and a rotational degree of freedom. The rotation axis of the rotating loading arm (27) is arranged vertically, and the bottom of one end of the rotating loading arm (27) is connected to a hollow negative pressure tube (29).

7. The optical automatic inspection device for printed circuit boards according to claim 6, characterized in that: The conveyor belt (28) includes a support platform (30), a pushing cylinder (31) and two C-shaped frames (32). The two C-shaped frames (32) are arranged at intervals along the conveying direction of the printed circuit board. A driving pulley (33) and a driven pulley (34) are rotatably connected in the two C-shaped frames (32). The driving pulley (33) is connected to the driven pulley (34) through a belt (35). A driving motor (36) is installed on the top of the C-shaped frame (32). The output shaft of the driving motor (36) is connected to the driving pulley (33). The C-shaped frame (32) is slidably arranged on the support platform (30). The two C-shaped frames (32) are connected through a transverse plate. The pushing cylinder (31) is horizontally installed on the support platform (30). The telescopic shaft of the pushing cylinder (31) is connected to the transverse plate.

8. The optical automatic inspection device for printed circuit boards according to claim 6, characterized in that: A hollow main shaft (37) is fixed at the bottom of the rotating loading arm (27), a lifting plate (38) is rotatably mounted on the hollow main shaft (37), a base (39) is fixedly arranged below the lifting plate (38), a third cylinder (40) is arranged between the base (39) and the lifting plate (38), a cylinder body of the third cylinder (40) is mounted on the base (39), a telescopic shaft of the third cylinder (40) is connected to the lifting plate (38), a loading motor (41) is mounted at the bottom of the lifting plate (38), an output shaft of the loading motor (41) is connected to a first gear (42), a second gear (43) is mounted on the hollow main shaft (37), and the first gear (42) is engaged with the second gear (43).

9. The optical automatic inspection device for printed circuit boards according to claim 8, characterized in that: A hard curved tube (44) is provided on the lifting plate (38), one end of the hard curved tube (44) is movably inserted into the hollow main shaft (37), a sealing ring (45) is sleeved on the hard curved tube (44), and the sealing ring (45) is interference fit in the hollow main shaft (37), a negative pressure path (46) is provided in the rotating loading arm (27), one end of the negative pressure path (46) is connected to the hollow negative pressure tube (29), and the other end is connected to the hollow main shaft (37).

10. The optical automatic inspection device for printed circuit boards according to claim 1, characterized in that: The optical detection assembly further comprises a detection bracket (47) and a fourth cylinder (48), wherein the cylinder body of the fourth cylinder (48) is vertically mounted on the detection bracket (47), and the telescopic shaft of the fourth cylinder (48) is connected to the top of the lifting sealing plate (3).

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