Optical automatic detection device of printed circuit board

Abstract

The invention discloses an optical automatic detection device for a printed circuit board, and relates to the field of circuit board detection, the optical automatic detection device comprises a detection workbench, the top of the detection workbench is provided with a detection groove, an optical detection assembly is arranged right above the detection groove, a turnover mechanism is arranged in the detection groove, and the turnover mechanism comprises a lifting column, a deflection block and a rotating seat. The lifting column is vertically arranged and has the freedom degree of moving in the height direction of the detection workbench, the deflection block is rotationally arranged at the top of the lifting column, the deflection axis of the deflection block is horizontally arranged, the end, away from the lifting column, of the deflection block is connected with a negative pressure pipe, and the end, away from the deflection block, of the negative pressure pipe is connected with a negative pressure suction cup. The rotating seat is arranged on one side of the deflection axis of the deflection block and rotationally connected with the detection workbench, the rotation axis of the rotating seat is vertically arranged, the top of the rotating seat is provided with a slot, turnover of the circuit board can be completed in a small space range, double-sided detection of the circuit board can be completed through one-time feeding, and the detection efficiency is improved.

Description

Technical Field

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

[0002] At present, in the manufacturing process of printed circuit boards, automatic optical detection solutions are mainly used to detect line defects on both sides of the printed circuit board, such as line short circuits, open circuits, pinholes, scratches, thin lines, thick lines, jagged teeth, etc. At present, after one side of the circuit board is detected, it is impossible to continue to detect the other side of the circuit board. It needs to be transported to the next workstation for manual or robotic arm to turn it over, and then transported to the detection workstation for detecting the other side of the circuit board. The transportation path of the circuit board is relatively long, and there are many uncontrollable factors. It may be damaged during transportation, and the defective rate of the circuit board detected is relatively high. Secondly, the manual turning-over efficiency is low and the labor intensity is high. The equipment investment cost of the robotic arm turning-over is relatively high. Summary of the Invention

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

[0004] The purpose of the present invention is achieved by the following technical solutions: An optical automatic detection device for printed circuit boards, including a detection workbench, a detection groove is opened at the top of the detection workbench, an optical detection component is arranged directly above the detection groove, the optical detection component includes a lifting sealing plate and an industrial camera, the industrial camera is installed at the bottom of the lifting sealing plate, the lifting sealing plate has a degree of freedom to move along the height direction of the detection workbench, a turning mechanism is arranged in the detection groove, the turning mechanism includes a lifting column, a deflection block and a rotating seat, the lifting column is arranged vertically, and the lifting column has a degree of freedom to move along the height direction of the detection workbench, the deflection block is rotatably arranged at the top of the lifting column, the deflection axis of the deflection block is arranged horizontally, one end of the deflection block away from the lifting column is connected with a negative pressure pipe, one end of the negative pressure pipe away from the deflection block is connected with 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 detection workbench, the rotation axis of the rotating seat is arranged vertically, and a slot is opened at the top of the rotating seat, and the printed circuit board is inserted into the slot in a vertical state.

[0005] Further, a first cylinder is arranged vertically 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 at 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 pipe is connected to a 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 meshes with the gear. The second cylinder is vertically arranged below the rack, and a cylinder body of the second cylinder is mounted on the lifting column, and a 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, and 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 at 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 drivingly 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, and 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, and 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, and 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-type frames, the two C-type frames are arranged at intervals along the conveying direction of the printed circuit board, and the two C-type 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-type frame, and the output shaft of the driving motor is connected to the driving pulley, the C-type frame is slidably arranged on the support platform, the two C-type 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] Further, a hollow main shaft is fixed to the bottom of the rotary loading arm. A lifting disc is rotatably sleeved on the hollow main shaft. A base is fixedly arranged below the lifting disc. A third cylinder is arranged between the base and the lifting disc. The cylinder body of the third cylinder is mounted on the base, and the telescopic shaft of the third cylinder is connected to the lifting disc. A loading motor is mounted on the bottom of the lifting disc. The output shaft of the loading motor is connected with a first gear. A second gear is sleeved on the hollow main shaft, and the first gear meshes with the second gear.

[0012] Further, a rigid elbow is arranged on the lifting disc. One end of the rigid elbow movably penetrates into the hollow main shaft. A sealing ring is sleeved on the rigid elbow, and the sealing ring is in interference fit in the hollow main shaft. A negative pressure path is arranged in the rotary loading arm. One end of the negative pressure path communicates with the hollow negative pressure pipe, and the other end communicates with the hollow main shaft.

[0013] Further, the optical detection assembly further includes a detection bracket and a fourth cylinder. The cylinder body of the fourth cylinder is vertically mounted 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 as follows: The circuit board is loaded on the negative pressure suction cup, and the circuit board is adsorbed by means of negative pressure. The lifting sealing plate contacts the detection workbench, so that the detection groove is in a closed environment, enabling the industrial camera to have a good imaging environment. The quality inspection of the upper surface of the circuit board is completed through the imaging of the industrial camera. When one side of the printed circuit board is inspected, the deflecting block drives the circuit board to deflect 90°, so that the circuit board is in a vertical state. Then the lifting column drives the circuit board to move downward, so that the circuit board is inserted into the slot of the rotary seat. The rotary seat drives the circuit board to rotate 180°. Then the circuit board is adsorbed by the negative pressure suction cup again, and the circuit board is reset by the rotation of the deflecting block. At this time, the other side of the circuit board faces upward and is in a detection state. Therefore, the circuit board can be turned over within a small space range, and the double-sided inspection of the circuit board can be completed with one loading, improving the inspection efficiency and avoiding the influence on the quality of the circuit board during the later conveying process. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of an optical automatic detection device for a printed circuit board according to the present invention Figure 1 ; Figure 2 is Figure 1 the enlarged view at B in Figure 3 is a schematic structural diagram of the detection workbench in an optical automatic detection device for a printed circuit board according to the present invention; Figure 4 is Figure 3 the enlarged view at C in Figure 5 It is the top view of an optical automatic detection device for a printed circuit board of the present invention; Figure 6 is Figure 5 the sectional view taken along the line A-A in Figure 7 is Figure 6 the enlarged view at position A in Figure 8 It is the structural schematic Figure 2 ; Figure 9 It is the assembly schematic diagram of the rotary loading arm in the optical automatic detection device for a printed circuit board of the present invention; Figure 10 is Figure 9 the enlarged view at position D in In the figure, 1 - detection workbench, 2 - detection slot, 3 - lifting sealing plate, 4 - industrial camera, 5 - lifting column, 6 - deflection block, 7 - rotating seat, 8 - negative pressure pipe, 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 - stepping motor, 27 - rotary loading arm, 28 - conveyor belt, 29 - hollow negative pressure pipe, 30 - support table, 31 - pushing cylinder, 32 - C-shaped frame, 33 - driving pulley, 34 - driven pulley, 35 - belt, 36 - driving motor, 37 - hollow main shaft, 38 - lifting disc, 39 - base, 40 - third cylinder, 41 - loading motor, 42 - first gear, 43 - second gear, 44 - rigid elbow, 45 - sealing ring, 46 - negative pressure path, 47 - detection bracket, 48 - fourth cylinder, 49 - conveying table, 50 - ball. Specific embodiments

[0016] The technical solutions 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.

[0017] Embodiment 1: As Figures 1 to 10As shown in the figure, an optical automatic detection device for a printed circuit board includes a detection workbench 1. A detection slot 2 is opened at the top of the detection workbench 1. 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. A number 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 in the height direction of the detection workbench 1. A flipping mechanism is arranged in the detection slot 2. The flipping mechanism includes a lifting column 5, a deflection block 6 and a rotating seat 7. The lifting column 5 is arranged vertically and has the freedom to move in the height direction of the detection workbench 1. The deflection block 6 is rotatably arranged at the top of the lifting column 5. The deflection axis of the deflection block 6 is arranged horizontally. One end of the deflection block 6 away from the lifting column 5 is connected to a negative pressure pipe 8. One end of the negative pressure pipe 8 away from the deflection block 6 is connected to a 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 arranged vertically. A slot 10 is opened at 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 onto 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, making the circuit board in a horizontal state for the first-side detection of the circuit board. During detection, the lifting sealing plate 3 moves downward to make the lifting sealing plate 3 contact the detection workbench 1, making the detection slot 2 in a closed environment, providing a better imaging environment for the industrial camera 4. The quality detection of the upper surface of the circuit board is completed through the imaging of the industrial camera 4. When one side of the printed circuit board is detected, the deflection block 6 drives the negative pressure pipe 8 to deflect. The negative pressure pipe 8 drives the circuit board to deflect 90° through the negative pressure suction cup 9, making the circuit board in a vertical state. Then the lifting column 5 drives the circuit board to move downward, making the circuit board inserted into the slot 10 of the rotating seat 7. Then the deflection block 6 reverses to drive the negative pressure pipe 8 to reset. Then, the rotating seat 7 drives the circuit board to rotate 180°. Since the negative pressure pipe 8 resets 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 to make the negative pressure suction cup 9 contact the circuit board, and the circuit board is adsorbed by the negative pressure suction cup 9 again. Then the deflection block 6 and the lifting column 5 reset. At this time, the other side of the circuit board faces upward and is in a detection state, so that the circuit board can be turned over within a small space range, and the double-sided detection of the circuit board can be completed with one loading, improving the detection efficiency and avoiding the influence on the quality of the circuit board during the later conveying process.

[0018] Further, the optical detection component further 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 to move up and down through the telescopic movement of the fourth cylinder 48, realizing the switching between the loading / unloading and detection actions of the circuit board.

[0019] Embodiment 2: Based on Embodiment 1, as Figures 1 to 8 shown, it further includes a positioning and conveying mechanism. The positioning and conveying mechanism includes a rotary loading arm 27 and two groups of conveyor belts 28. The two groups of conveyor belts 28 are arranged at intervals along the direction perpendicular to the conveying direction of the printed circuit board. 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 rotary loading arm 27 is arranged between the conveyor belt 28 and the detection workbench 1. The rotary loading arm 27 has a linear lifting degree of freedom and a rotary degree of freedom. The rotation axis of the rotary loading arm 27 is vertically arranged. A hollow negative pressure tube 29 is connected to the bottom of one end of the rotary loading arm 27. The precise loading of the circuit board is completed through the positioning and conveying mechanism and the rotary loading arm 27. A conveying table 49 is arranged between the two groups of conveyor belts 28. A number of balls 50 are rotatably arranged on the conveying table 49. The number of balls 50 is arranged in a rectangular array along the length direction of the conveying table 49. The circuit board is placed on the conveying table 49 and supported by the balls 50. The two groups of conveyor belts 28 move close to the circuit board to correct the circuit board. Under the action of the balls 50, the friction between the circuit board and the balls 50 is rolling friction, which greatly reduces the friction force received by the circuit board during movement, so that the circuit board will not be worn during positioning and conveying. When the two groups of conveyor belts 28 respectively contact both sides of the circuit board, the circuit board is positioned. Then the two groups of conveyor belts 28 are started synchronously, and the circuit board is clamped and conveyed forward by the two groups of conveyor belts 28 to be conveyed to the loading station of the rotary loading arm 27. Then the conveyor belt 28 stops. The rotary 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, the two groups of conveyor belts 28 both move away from the circuit board to release the circuit board. Then the rotary loading arm 27 drives the circuit board to move upward so that the circuit board is above the detection workbench 1. Then the rotary loading arm 27 drives the circuit board to deflect 180° so that the circuit board is directly above the negative pressure suction cup 9. Then, the lifting column 5 drives the negative pressure suction cup 9 to move upward to adsorb the circuit board, so as to load the circuit board onto the negative pressure suction cup 9. The lifting column 5 drives the circuit board to move downward into the detection slot 2 for detection operation. Finally, the rotary loading arm 27 resets to prepare for loading the next circuit board. In this way, the precise loading of the circuit board is realized. After the circuit board is loaded, it can be accurately located within the detection range of the industrial camera 4, making the detection result more accurate.

[0020] Further, as Figure 1 and Figure 8As shown in the figure, 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. An active pulley 33 and a driven pulley 34 are respectively rotatably connected inside the two C-shaped frames 32. The active pulley 33 is drivingly 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 drivingly connected to the active pulley 33. The C-shaped frame 32 is slidably arranged on the support platform 30. The two C-shaped frames 32 are connected by a cross 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 cross plate. By driving the active pulley 33 to rotate through the driving motor 36, the active pulley 33 drives the driven pulley 34 to rotate through the belt 35, and the conveying surface of the conveyor belt 28 is set vertically, so that the circuit board can be clamped and conveyed forward by two groups of conveyor belts 28, ensuring that the circuit board will not be offset during conveying and improving the accuracy of loading. By driving the conveyor belt 28 to move closer to or away from the circuit board through the telescopic movement of the pushing cylinder 31, the clamping and loosening operations of the circuit board are completed. During specific implementation, the bottom of the belt 35 is located above the ball 50, and the distance between the belt 35 and the ball 50 is less than the thickness of the circuit board, so that the belt 35 can clamp the circuit board for conveying without contacting the ball 50.

[0021] Further, as Figures 1 to 9 shown, a hollow main shaft 37 is fixed to the bottom of the rotary loading arm 27. A lifting disc 38 is rotatably sleeved on the hollow main shaft 37. A base 39 is fixedly arranged below the lifting disc 38. A third cylinder 40 is arranged between the base 39 and the lifting disc 38. The cylinder body of the third cylinder 40 is installed on the base 39, and the telescopic shaft of the third cylinder 40 is connected to the lifting disc 38. A loading motor 41 is installed at the bottom of the lifting disc 38. The output shaft of the loading motor 41 is connected to a first gear 42. A second gear 43 is sleeved on the hollow main shaft 37. The first gear 42 meshes with the second gear 43. The loading motor 41 drives the hollow main shaft 37 to rotate through the meshing of the first gear 42 and the second gear 43. The rotary loading arm 27 is driven to rotate through the hollow main shaft 37. Then, in cooperation with the telescopic movement of the third cylinder 40 to drive the lifting disc 38 to move up and down, the lifting disc 38 drives the rotary loading arm 27 to move up and down, which is used to load the circuit board on the conveying table 49 onto the detection workbench 1.

[0022] Embodiment 3: Since the rotary loading arm 27 needs to perform rotary loading, the problem of winding around the pipe needs to be solved for the loading method by negative pressure. Therefore, on the basis of Embodiment 2, as Figure 1 、 Figure 8 、 Figure 9 and Figure 10As shown in the figure, a rigid elbow 44 is provided on the lifting plate 38. One end of the rigid elbow 44 is movably inserted into the hollow main shaft 37. A sealing ring 45 is sleeved on the rigid elbow 44, and the sealing ring 45 is press-fitted in the hollow main shaft 37. A negative pressure path 46 is provided in the rotary loading arm 27. One end of the negative pressure path 46 communicates with the hollow negative pressure pipe 29, and the other end communicates with the hollow main shaft 37. The rigid elbow 44 is connected to a vacuum pump through a hose, and the negative pressure is transmitted through the rotational connection between the rigid elbow 44 and the hollow main shaft 37. A mounting vertical plate is fixed on the side wall of the lifting plate 38, and the rigid elbow 44 is fixedly installed on the mounting vertical plate. Without affecting the negative pressure transmission, the hollow main shaft 37 can still have a rotational degree of freedom. The negative pressure acts on the hollow negative pressure pipe 29 through the inner hole of the hollow main shaft 37 and the negative pressure path 46, so that the circuit board can be adsorbed by negative pressure, achieving the effect of unwinding the negative pressure pipeline layout.

[0023] Embodiment 4: Based on Embodiment 3, as Figures 1 to 7As shown in the figure, a first cylinder 11 is vertically arranged below the lifting column 5. The telescopic shaft of the first cylinder 11 is connected to the bottom of the lifting column 5. A driving notch 12 is formed 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. The side wall of the negative pressure pipe 8 is connected to the vacuum pump through a negative pressure hose. A driving mechanism is arranged on the side wall of the lifting column 5. 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. A first synchronous pulley 17 is sleeved on the main shaft 13. A second synchronous pulley 18 and a gear 19 are sleeved on the driving shaft 14. The first synchronous pulley 17 is drivingly connected to the second synchronous pulley 18 through a synchronous belt 20. The rack 15 is slidably arranged on the lifting column 5. The rack 15 meshes with the gear 19. The second cylinder 16 is vertically arranged below the rack 15. The cylinder block 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. A rotating main shaft 25 is fixed to the bottom of the rotating seat 7. The rotating main shaft 25 is rotatably connected to the detection workbench 1. A stepping motor 26 is installed on the detection workbench 1. The output shaft of the stepping motor 26 is drivingly connected to the rotating main shaft 25. The second cylinder 16 drives the rack 15 to move. The meshing of the rack 15 and the gear 19 drives the driving shaft 14 to rotate. The driving 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. The main shaft 13 drives the deflection block 6 to deflect, each time deflecting 90°. The stepping motor 26 drives the rotating main shaft 25 to rotate. The rotating main shaft 25 drives the rotating seat 7 to rotate, so as to turn over the vertically placed circuit board. Then, in cooperation with the 90° deflection of the deflection block 6, the circuit board turning operation is completed. It should be noted that due to the large volume of the motor and the limited space in the detection slot 2, the motor cannot be directly installed on the lifting column 5. At the same time, directly installing the motor will also interfere with the circuit board. Therefore, the second cylinder 16 is used as the power source, and then in cooperation with the meshing of the gear 19 and the rack 15, the linear motion is changed into a rotational motion. Through the transmission mode of the synchronous belt 20, the main shaft 13 can be remotely controlled to rotate, ensuring that the main shaft 13 rotates without affecting the feeding of the circuit board, and occupying a small volume, meeting the driving in a narrow range. The stepping motor 26 is directly installed below the detection slot 2, and there is enough space for the installation of the stepping motor 26.

[0024] Further, as Figures 1 to 7As shown, a positioning block 21 is fixed on the side wall of the rack 15. 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. Pressure sensors 24 are 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 pipe 8 is horizontally set. When the positioning block 21 contacts the detection axis of the lower pressure sensor 24, the axis of the negative pressure pipe 8 is vertically set. As for the cylinder, its precision is relatively low compared to the motor. To ensure that the deflection block 6 can smoothly drive the circuit board to deflect by 90°, so that the circuit board can be accurately inserted into the slot 10, a limit mechanism is set. When one side of the circuit board is detected and the circuit board needs to be turned over, the second cylinder 16 is activated to drive the deflection block 6 to drive the circuit board to deflect. 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 feeds back a signal to stop the second cylinder 16. At this time, the deflection block 6 drives the circuit board to accurately deflect by 90°, so that the circuit board can be smoothly inserted into the slot 10. When the deflection block 6 resets, the rack 15 drives the positioning block 21 to move closer 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 makes the negative pressure pipe 8 in a vertical state, realizing the accurate turning over of the circuit board, and solving the problem of low control precision of the second cylinder 16.

Claims

1. An automatic optical 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 comprises 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 turnover mechanism is arranged in the detection slot (2), and the turnover mechanism comprises a lifting column (5), a deflection block (6) and a rotating seat (7). The lifting column (5) is arranged vertically, and the lifting column (5) 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 deflection block (6) is arranged horizontally, the end of the deflection block (6) away from the lifting column (5) is connected to a negative pressure pipe (8), and the end of the negative pressure pipe (8) away from the deflection block (6) is connected to a 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 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 a printed circuit board is vertically inserted into the slot (10).

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 provided 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 a side wall of the negative pressure pipe (8) is connected to a vacuum pump via a negative pressure hose.

3. The optical automatic inspection device for printed circuit boards according to claim 2, characterized in that: A driving mechanism is provided on the side wall of the lifting column (5), the driving mechanism comprising a driving shaft (14), a rack (15) and a second cylinder (16); the driving shaft (14) is rotatably mounted below the main shaft (13); a first synchronous pulley (17) is mounted on the main shaft (13); a second synchronous pulley (18) and a gear (19) are mounted on the driving shaft (14); 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) meshes with the gear (19); the second cylinder (16) is vertically mounted below the rack (15); a cylinder body of the second cylinder (16) is mounted on the lifting column (5); and a 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); 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 arranged 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 arranged vertically.

5. The optical automatic inspection device for printed circuit boards according to claim 1, characterized in that: A rotating spindle (25) is fixed at 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 drivingly 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 comprises a positioning and conveying mechanism, the positioning and conveying mechanism comprising a rotating loading arm (27) and two groups of conveying belts (28), the two groups of conveying belts (28) being arranged at intervals along a conveying direction perpendicular to the printed circuit board, a conveying channel for the printed circuit board being formed between the two groups of conveying belts (28), the moving direction of the conveying belts (28) being perpendicular to the conveying direction of the printed circuit board, the moving directions of the two groups of conveying belts (28) being opposite, the rotating loading arm (27) being arranged between the conveying belts (28) and the inspection workbench (1), the rotating loading arm (27) having a linear lifting degree of freedom and a rotational degree of freedom, the rotation axis of the rotating loading arm (27) being arranged vertically, and a hollow negative pressure tube (29) being connected to the bottom of one end of the rotating loading arm (27).

7. The optical automatic inspection device for printed circuit boards according to claim 6, characterized in that: The conveyor belt (28) comprises 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 cross 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 cross 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) meshes with the second gear (43).

9. The optical automatic inspection device for printed circuit boards according to claim 8, characterized in that: The lifting plate (38) is provided with a hard curved tube (44), one end of which is movably inserted into the hollow main shaft (37), and 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 which is connected to the hollow negative pressure tube (29), and the other end of which 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 a cylinder body of the fourth cylinder (48) is vertically mounted on the detection bracket (47), and a telescopic shaft of the fourth cylinder (48) is connected to the top of the lifting sealing plate (3).

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