An automatic tray adjustment device and its control method

Abstract

This invention discloses an automatic tray adjustment device and its control method, comprising a frame, on which a gripping mechanism for gripping a tray is provided, and a protection mechanism for protecting the tray in case the tray accidentally detaches due to a malfunction of the gripping mechanism. This invention overcomes the problem in existing technologies where traditional tray gripping mechanisms are prone to damage to the tray when the suction cup breaks. This invention has the advantages of simple structure, ease of use, and good protection of the tray.

Description

Technical Field

[0001] This invention relates to the field of a material tray gripping device, and more specifically, to an automatic material tray adjustment device and its control method. Background Technology

[0002] Currently, a tray loading and unloading integrated machine (publication number CN216945210U) is disclosed on the Chinese patent website. It includes a frame, and a tray transfer mechanism, a pick-and-place suction mechanism, and a fixture transfer mechanism mounted on the frame. Two sets of tray transfer mechanisms are arranged side-by-side on the frame. The fixture transfer mechanism is located at one end of the tray transfer mechanisms and is perpendicular to them. The pick-and-place suction mechanism moves back and forth between the fixture and the two sets of tray transfer mechanisms. Stacking mechanisms are also provided at the other ends of the two sets of tray transfer mechanisms. This invention uses two sets of stacking mechanisms and corresponding two sets of tray transfer mechanisms to load and unload trays, resulting in a reasonable structural design for the integrated tray loading and unloading machine. This improves the machine's practicality and increases the efficiency of PCB board processing. Furthermore, the two sets of stacking mechanisms and the corresponding two sets of tray transfer mechanisms can simultaneously operate different processes, further enhancing the machine's usability.

[0003] The aforementioned patent describes a tray loading and unloading integrated machine, which has the advantage of practicality. However, the machine lacks a protective device for the tray in case the suction cup is damaged, resulting in insufficient suction and the tray falling off. This could lead to the tray accidentally falling off and breaking during the gripping process. Summary of the Invention

[0004] In order to overcome the problem that traditional material tray gripping mechanisms in the prior art are prone to damage to the material tray when the suction cup is broken, the present invention provides an automatic material tray adjustment device and its control method that can protect the material tray when the suction cup is broken.

[0005] The present invention provides an automatic tray adjustment device and its control method, comprising a frame, wherein the frame is provided with a gripping mechanism for gripping a tray, and the gripping mechanism is provided with a protection mechanism for protecting the tray when the tray is accidentally dislodged due to a malfunction of the gripping mechanism.

[0006] Preferably, the frame includes uprights symmetrically distributed on the left and right sides. An electrical control cabinet is installed at the right end of the upright on the right side. A Y-axis adjustment device for adjusting the position of the gripping mechanism is provided between the tops of the two uprights. The Y-axis adjustment device is equipped with a Z-axis adjustment device that works in conjunction with the Y-axis adjustment device. The control terminals of the Y-axis adjustment device and the Z-axis adjustment device are electrically connected to the electrical control cabinet, respectively.

[0007] Preferably, the Y-axis adjustment device includes two guide columns that are parallel to each other vertically and are horizontally mounted between the tops of two columns. A Y-axis slider is slidably connected to the guide columns. A Y-axis motor for driving the Y-axis slider is embedded at the top left end of the right column. A Y-axis lead screw for cooperating with the Y-axis motor is horizontally connected through the Y-axis slider located between the two guide columns. The output shaft of the Y-axis motor is connected to the right end of the Y-axis lead screw through a coupling. The control end of the Y-axis motor is electrically connected to the electrical control cabinet.

[0008] Preferably, the left end of the guide post is welded to the right end of the column on the left side, and the right end of the guide post is welded to the left end of the column on the right side. A bearing for use with the Y-axis lead screw is embedded on the left end of the column between the two guide posts. The left end of the Y-axis lead screw is inserted into the center of the bearing. The left and right ends of the Y-axis slider are respectively provided with lead screw pairs that match the Y-axis lead screw.

[0009] Preferably, the Y-axis slider has a sliding hole that extends horizontally through the Y-axis slider and matches the guide post. The Z-axis adjustment device includes a Z-axis cylinder mounted on the upper surface of the Y-axis slider. The piston rod of the Z-axis cylinder is arranged vertically downward and passes through the Y-axis slider. A disc is provided below the Z-axis cylinder. The center of the upper surface of the disc is connected to the end of the piston rod of the Z-axis cylinder by a screw. A gripping mechanism is installed at the lower end of the disc. The control end of the Z-axis cylinder and the control end of the gripping mechanism are electrically connected to the electrical control cabinet.

[0010] Preferably, the gripping mechanism includes a "gate"-shaped mounting frame. The center of the upper end face of the mounting frame is welded to the center of the lower end face of the disc body. Two vacuum suction cups symmetrically distributed on the left and right sides of the crossbeam of the mounting frame are provided for gripping the disc. Gripping cylinders that cooperate with the vacuum suction cups are respectively provided on the mounting frames on the left and right sides of the disc body. The piston rod of the gripping cylinder is set vertically downward and passes through the crossbeam of the mounting frame. The lower end of the piston rod of the gripping cylinder is connected to the upper end face of the vacuum suction cup by a screw. An air pump that cooperates with the vacuum suction cup is provided on the mounting frame on the side of the gripping cylinder. The air pump's suction end is connected to the air valve of the vacuum suction cup by a hose. The control end of the gripping cylinder and the control end of the air pump are electrically connected to the electrical control cabinet.

[0011] Preferably, the protection mechanism includes fixed plates symmetrically distributed on both sides of the lower end of the crossbeam of the mounting frame. The upper end of the fixed plates is welded to the lower end of the crossbeam of the mounting frame. An "L"-shaped movable plate is mounted on the fixed plates to protect the tray in case of accidental detachment. A horizontal groove is formed on the fixed plates, penetrating the fixed plates and matching the movable plate. The horizontal portion of the movable plate is slidably inserted into the groove. A coil for driving the movable plate is provided between the fixed plates and the vertical portion of the mounting frame. A coil frame for winding the coil is welded to the back of the fixed plates. An insulating rubber sleeve is fitted on the horizontal portion of the coil frame, and a coil for use with an iron block is wound on the insulating rubber sleeve. The coil is wound on the coil frame. The front end of the vertical portion of the movable plate has a coil for use with the coil. A guide rod for mounting a movable plate is horizontally arranged on a fixed plate located below the coil. The guide rod passes through the vertical part of the movable plate. One end of the guide rod is welded to the back of the fixed plate, and the other end is welded to the inner wall of the vertical part of the mounting frame. A reset spring for resetting the movable plate is fitted on the guide rod located between the vertical part of the movable plate and the inner wall of the vertical part of the mounting frame. One end of the reset spring is welded to the back of the vertical part of the movable plate, and the other end is welded to the inner wall of the vertical part of the mounting frame. A rubber pad for protecting the material tray is provided on the upper surface of the horizontal part of the movable plate. An infrared ranging sensor for use with the coil is embedded in the center of the lower end of the crossbeam of the mounting frame located between the two suction cups. The infrared ranging sensor and the control terminal of the coil are electrically connected to the electrical control cabinet.

[0012] The control method is as follows: 1) During normal operation, the electrical control cabinet provides power normally. At this time, the electrical control cabinet adjusts the current flowing through the coil to make the coil generate a magnetic field at all times. The magnetic field generated by the coil will attract the iron block. At this time, the movable plate is in the initial position. At this time, the torsion spring is compressed and has elastic potential energy. 2) When gripping the material tray, the electrical control cabinet first controls the Y-axis motor, which drives the lead screw to rotate through the Y-axis motor, and adjusts the relative position between the suction cup and the material tray through the lead screw pair until the two suction cups are located at the left and right ends directly above the material tray; 3) Then the electrical control cabinet controls the Z-axis cylinder, and the piston rod of the Z-axis cylinder makes the suction cup close to the material tray. The lower ends of the left and right sides of the mounting frame abut against the worktable on which the material tray is placed. 4) Then the electrical control cabinet controls the gripping cylinder, and the piston rod of the gripping cylinder makes the lower end of the suction cup fit against the surface of the material tray; 5) After that, the control cabinet controls the air pump to work, extracting the air between the suction cup and the material tray to grasp the material tray. At this time, the infrared distance sensor starts to work, detecting the distance H between the infrared distance sensor and the material tray. The infrared distance sensor will detect again every 0.01 seconds and send the detected data to the control cabinet. 6) The control cabinet will record the received data and compare the currently measured data with the data measured in the previous 0.01 seconds; 7) After that, the electrical control cabinet controls the gripping cylinder again, and the material tray is separated from the worktable by the retraction of the piston rod of the gripping cylinder; 8) During normal operation, as the material tray rises, the detected value of H will decrease uniformly. Then, the control cabinet will control the Z-axis cylinder again, and the material tray will rise to the highest point by contracting the piston rod of the Z-axis cylinder. At this time, the detected value of H is a. 9) Once the tray reaches its highest point, the control cabinet will again control the Y-axis motor to transport the tray to the designated position; 10) When the material tray reaches the designated position, the electrical control cabinet controls the Z-axis cylinder to extend the piston rod of the Z-axis cylinder to bring the material tray closer to the designated position until the lower ends of the left and right sides of the mounting bracket abut against the sides of the designated position respectively. 11) Then the control cabinet controls the gripping cylinder, which extends the piston rod of the gripping cylinder to lower the material tray. When the material tray starts to fall, the control cabinet starts to count the data detected by the infrared ranging sensor each time. That is, the nth detection data after the material tray starts to fall. During normal operation, the value of H detected during the descent of the material tray is 0.01*n*V, where V is the preset descent speed of the material tray during normal operation, until the back of the material tray is in contact with the upper surface of the designated position. 12) After that, the control cabinet turns off the air pump, allowing air to be injected between the suction cup and the tray to separate the tray. Then, the above steps can be repeated to continue gripping other trays. 13) When the material tray is picked up, if both suction cups are damaged during the upward or horizontal movement of the material tray, air will be re-entered between the suction cups and the material tray, and then the material tray will fall off under the action of gravity. 14) When the material tray falls off during the upward and horizontal movement, the control cabinet compares the data H1 detected by the current infrared ranging sensor with the data H2 detected 0.01 seconds ago. When H1 is greater than H2, the control cabinet determines that the material tray is in an unexpected falling state and will immediately send a command to the coil. After receiving the command, the coil will generate a magnetic field to attract the iron block. At the same time, the Y-axis motor, Z-axis cylinder and gripping cylinder will stop. During the process of the coil attracting the iron block, the horizontal part of the movable plate will move along the guide rod and slide until the rubber pad of the movable plate completely extends out of the fixed plate. 15) When the material tray is picked up, if both suction cups are damaged during the descent of the material tray, air will be re-entered between the suction cups and the material tray, and then the material tray will fall off under the action of gravity. 16) When the material tray falls off during the descent, the control cabinet calculates V1 = H1 / 0.01*n based on the data H1 detected by the infrared ranging sensor in the nth time, and calculates V2 = H2 / 0.01*n-1 based on the data H2 detected in the previous 0.01 seconds. When both V1 and V2 are greater than the preset descent V, the control cabinet determines that the material tray is in an unexpected falling state and will immediately send a command to the coil. After receiving the command, the coil will generate a magnetic field to attract the iron block. At the same time, the Y-axis motor, Z-axis cylinder and gripping cylinder will stop. During the process of the coil attracting the iron block, the horizontal part of the movable plate moves along the guide rod and slide until the rubber pad of the movable plate completely extends out of the fixed plate. 17) The falling tray will land on the rubber pad of the movable plate, waiting for maintenance personnel to come and repair it; 18) After removing the tray and troubleshooting, the maintenance personnel can turn off the coil at the electrical control cabinet, and then reset the movable plate under the action of the reset spring, waiting for the next use.

[0013] During maintenance, the maintenance personnel can first remove the tray that has fallen onto the movable plate. Then, the maintenance personnel can disconnect the power to the coil at the electrical control cabinet. After that, the movable plate will reset under the action of the reset spring, and it can be used again the next time the tray falls off.

[0014] Using a movable plate can shorten the falling distance of the material tray, thereby shortening the acceleration distance of the material tray and allowing the material tray to fall onto the movable plate at a lower speed. In addition, the rubber pads on the movable plate can absorb part of the impact generated during the fall, thus protecting the material tray and preventing it from falling directly onto the workbench or the ground and causing damage.

[0015] Infrared ranging sensors can be used to effectively detect the distance between the infrared ranging sensor and the material tray. By measuring the distance and the preset detection interval, the position of the material tray can be effectively determined. When the control cabinet determines that the material tray is in a falling state, it can control the movable plate in time to prevent the material tray from falling to the worktable and avoid collision with the worktable, which would cause the material tray to break.

[0016] The present invention has the following advantages: simple structure, easy to use, and good protection for the material tray. Attached Figure Description

[0017] Appendix Figure 1 This is a schematic diagram of the invention.

[0018] Appendix Figure 2 This is a schematic diagram of the protective mechanism for the invention.

[0019] 1. Material tray, 2. Column, 3. Electrical control cabinet, 4. Guide column, 5. Y-axis slider, 6. Y-axis motor, 7. Y-axis lead screw, 8. Z-axis cylinder, 9. Plate, 10. Mounting bracket, 11. Vacuum suction cup, 12. Air pump, 13. Fixed plate, 14. Movable plate, 15. Coil, 16. Coil frame, 17. Iron block, 18. Guide rod, 19. Return spring, 20. Infrared distance sensor, 21. Gripping cylinder. Detailed Implementation

[0020] The technical solution of the present invention will be further described in detail through embodiments and in conjunction with the accompanying drawings.

[0021] Example: According to the appendix Figure 1 and attached Figure 2 To further illustrate the present invention, an automatic tray adjustment device and its control method are provided, including a frame, on which a gripping mechanism for gripping a tray 1 is provided, and the gripping mechanism is provided with a protection mechanism for protecting the tray 1 when the tray 1 is accidentally dislodged due to a malfunction of the gripping mechanism.

[0022] The frame includes uprights 2 symmetrically distributed on the left and right. An electrical control cabinet 3 is installed at the right end of the upright 2 on the right side. A Y-axis adjustment device for adjusting the position of the gripping mechanism is provided between the tops of the two uprights 2. The Y-axis adjustment device is equipped with a Z-axis adjustment device that works in conjunction with the Y-axis adjustment device. The control terminals of the Y-axis adjustment device and the Z-axis adjustment device are electrically connected to the electrical control cabinet 3, respectively.

[0023] The Y-axis adjustment device includes two guide columns 4 that are parallel to each other and horizontally mounted between the tops of two columns 2. A Y-axis slider 5 is slidably connected to the guide column 4. A Y-axis motor 6 for driving the Y-axis slider 5 is embedded at the top left end of the column 2 on the right side. A Y-axis lead screw 7 for cooperating with the Y-axis motor 6 is horizontally connected through the Y-axis slider 5 between the two guide columns 4. The output shaft of the Y-axis motor 6 is connected to the right end of the Y-axis lead screw 7 through a coupling. The control end of the Y-axis motor 6 is electrically connected to the electrical control cabinet 3.

[0024] The left end of the guide post 4 is welded to the right end of the column 2 located on the left side, and the right end of the guide post 4 is welded to the left end of the column 2 located on the right side. A bearing for use with the Y-axis lead screw 7 is embedded on the left end of the column 2 located between the two guide posts 4. The left end of the Y-axis lead screw 7 is inserted into the center of the bearing. The left and right ends of the Y-axis slider 5 are respectively provided with lead screw pairs that match the Y-axis lead screw 7.

[0025] The Y-axis slider 5 has a horizontally penetrating sliding hole that matches the guide post 4. The Z-axis adjustment device includes a Z-axis cylinder 8 installed on the upper surface of the Y-axis slider 5. The piston rod of the Z-axis cylinder 8 is arranged vertically downward and penetrates the Y-axis slider 5. A disc 9 is provided below the Z-axis cylinder 8. The center of the upper surface of the disc 9 is connected to the end of the piston rod of the Z-axis cylinder 8 by a screw. A gripping mechanism is installed at the lower end of the disc 9. The control end of the Z-axis cylinder 8 and the control end of the gripping mechanism are electrically connected to the electrical control cabinet 3.

[0026] The gripping mechanism includes a "door"-shaped mounting frame 10. The center of the upper end face of the mounting frame 10 is welded to the center of the lower end face of the disk body 9. Two vacuum suction cups 11, symmetrically distributed on the left and right sides, are provided below the crossbeam of the mounting frame 10 for gripping the material disk 1. Gripping cylinders 21, which cooperate with the vacuum suction cups 11, are respectively provided on the mounting frames 10 on the left and right sides of the disk body 9. The piston rod of the gripping cylinder 21 is set vertically downward and passes through the crossbeam of the mounting frame 10. The lower end of the piston rod of the gripping cylinder 21 is connected to the upper end face of the vacuum suction cup 11 by a screw. An air pump 12, which cooperates with the vacuum suction cup 11, is provided on the mounting frame 10 on the side of the gripping cylinder 21. The air pump 12 is connected to the air valve of the vacuum suction cup 11 by a hose. The control end of the gripping cylinder 21 and the control end of the air pump 12 are electrically connected to the electrical control cabinet 3.

[0027] The protective mechanism includes fixed plates 13 symmetrically distributed on the left and right sides of the lower end of the crossbeam of the mounting frame 10. The upper end of the fixed plates 13 is welded to the lower end of the crossbeam of the mounting frame 10. An L-shaped movable plate 14 is installed on the fixed plates 13 to protect the tray 1 in case of accidental detachment. A horizontal groove is provided on the fixed plates 13, which penetrates the fixed plates 13 and matches the movable plate 14. The horizontal part of the movable plate 14 is slidably inserted into the groove. A coil 15 for driving the movable plate 14 is provided between the fixed plates 13 and the vertical part of the mounting frame 10. A coil frame 16 for winding the coil 15 is welded to the back of the fixed plates 13. The coil 15 is wound on the coil frame 16. An iron block 17 for cooperating with the coil 15 is provided at the front end of the vertical part of the movable plate 14. A horizontal mounting block is provided on the fixed plates 13 below the coil 15. The guide rod 18 of the movable plate 14 passes through the vertical part of the movable plate 14. One end of the guide rod 18 is welded to the back of the fixed plate 13, and the other end of the guide rod 18 is welded to the inner wall of the vertical part of the mounting frame 10. A reset spring 19 for resetting the movable plate 14 is fitted on the guide rod 18 located between the vertical part of the movable plate 14 and the inner wall of the vertical part of the mounting frame 10. One end of the reset spring 19 is welded to the back of the vertical part of the movable plate 14, and the other end of the reset spring 19 is welded to the inner wall of the vertical part of the mounting frame 10. The upper end surface of the horizontal part of the movable plate 14 is provided with a rubber pad for protecting the material tray 1. An infrared ranging sensor 20 for use with the coil 15 is embedded in the center of the lower end of the crossbeam of the mounting frame 10 located between the two suction cups. The control terminals of the infrared ranging sensor 20 and the coil 15 are electrically connected to the electrical control cabinet 3, respectively.

[0028] The control method is as follows: 1) During normal operation, the electrical control cabinet 3 provides power normally. At this time, the electrical control cabinet 3 adjusts the current flowing through the coil 15 to make the coil 15 generate a magnetic field at all times. The magnetic field generated by the coil 15 will attract the iron block 17. At this time, the movable plate 14 is in the initial position. At this time, the torsion spring is compressed and has elastic potential energy. 2) When gripping the material tray 1, the electrical control cabinet 3 first controls the Y-axis motor 6, which drives the lead screw to rotate through the Y-axis motor, and adjusts the relative position between the suction cup and the material tray 1 through the lead screw pair, until the two suction cups are located at the left and right ends directly above the material tray 1 respectively; 3) Then the electrical control cabinet 3 controls the Z-axis cylinder 8, and the piston rod of the Z-axis cylinder 8 makes the suction cup close to the material tray 1. The lower ends of the left and right sides of the mounting bracket 10 respectively abut against the worktable on which the material tray 1 is placed. 4) Then the electrical control cabinet 3 controls the gripping cylinder 21, and the piston rod of the gripping cylinder 21 makes the lower end face of the suction cup fit against the surface of the material tray 1. 5) After that, the electrical control cabinet 3 controls the air pump 12 to work, extract the air between the suction cup and the material tray 1, and realize the gripping of the material tray 1. At this time, the infrared distance sensor 20 starts to work, and detects the distance H between the infrared distance sensor 20 and the material tray 1. The infrared distance sensor 20 will detect again every 0.01 seconds and send the detected data to the control cabinet. 6) The control cabinet will record the received data and compare the currently measured data with the data measured in the previous 0.01 seconds; 7) After that, the electrical control cabinet 3 controls the gripping cylinder 21 again, and the material tray 1 is separated from the worktable by the retraction of the piston rod of the gripping cylinder 21. 8) During normal operation, as the material tray 1 rises, the detected value of H will decrease uniformly. Then, the electrical control cabinet 3 controls the Z-axis cylinder 8 again, and the material tray 1 rises to the highest point by contracting the piston rod of the Z-axis cylinder 8. At this time, the detected value of H is a. 9) When the material tray 1 reaches the highest point, the electrical control cabinet 3 controls the Y-axis motor 6 again to transport the material tray 1 to the designated position; 10) When the material tray 1 reaches the designated position, the electrical control cabinet 3 controls the Z-axis cylinder 8, and the piston rod of the Z-axis cylinder 8 extends to bring the material tray 1 closer to the designated position until the lower ends of the left and right sides of the mounting bracket 10 abut against the sides of the designated position respectively. 11) Then the electrical control cabinet 3 controls the gripping cylinder 21, and the material tray 1 is lowered by extending the piston rod of the gripping cylinder 21. When the material tray 1 starts to fall, the electrical control cabinet 3 starts to count the data detected by the infrared ranging sensor 20 each time, that is, the nth detection data after the material tray 1 starts to fall. During normal operation, the value of H detected by the material tray 1 during the descent process is 0.01*n*V, where V is the preset descent speed of the material tray 1 during normal operation, until the back of the material tray 1 is in contact with the upper surface of the designated position. 12) After that, the air pump 12 in the control cabinet 3 is turned off, allowing air to be injected between the suction cup and the material tray 1 to separate the material tray 1. Then, the above steps can be repeated to continue to grab other material trays 1. 13) When the material tray 1 is picked up, during the process of rising and moving horizontally, if both suction cups are damaged, air will be re-entered between the suction cups and the material tray 1, and then the material tray 1 will fall off under the action of gravity. 14) When the material tray 1 falls off during the upward and horizontal movement, the control cabinet 3 compares the data H1 detected by the infrared ranging sensor 20 with the data H2 detected 0.01 seconds ago. When H1 is greater than H2, the control cabinet 3 determines that the material tray 1 is in an unexpected falling state and will immediately send a command to the coil 15. After receiving the command, the coil 15 will generate a magnetic field to attract the iron block 17. At the same time, the Y-axis motor 6, Z-axis cylinder 8 and gripping cylinder 21 will stop. During the process of the coil 15 attracting the iron block 17, the horizontal part of the movable plate 14 will move along the guide rod 18 and the slide until the rubber pad of the movable plate 14 completely extends out of the fixed plate 13. 15) When the material tray 1 is conveyed to the designated horizontal position, during the process of the material tray 1 descending, if both suction cups are damaged, air will be re-entered between the suction cups and the material tray 1, and then the material tray 1 will fall off under the action of gravity. 16) When the material tray 1 falls off during the descent, the control cabinet 3 calculates V1 = H1 / 0.01*n based on the data H1 detected by the infrared ranging sensor 20 in the nth time, and calculates V2 = H2 / 0.01*n-1 based on the data H2 detected in the previous 0.01 seconds. When both V1 and V2 are greater than the preset descent V, the control cabinet 3 determines that the material tray 1 is in an unexpected falling state and will immediately send a command to the coil 15. After receiving the command, the coil 15 will generate a magnetic field to attract the iron block 17, and at the same time stop the Y-axis motor 6, Z-axis cylinder 8 and gripping cylinder 21. During the process of the coil 15 attracting the iron block 17, the horizontal part of the movable plate 14 moves along the guide rod 18 and the slide until the rubber pad of the movable plate 14 completely extends out of the fixed plate 13. 17) The falling material tray 1 will land on the rubber pad of the movable plate 14, waiting for maintenance personnel to come and perform maintenance; 18) After removing the material tray 1 and troubleshooting, the maintenance personnel can turn off the coil 15 at the electrical control cabinet 3, and then reset the movable plate 14 under the action of the reset spring 19, waiting for the next use.

[0029] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present invention are covered by the patent scope of the present invention.

Claims

1. An automatic tray adjusting device, comprising a frame, characterized in that, The frame is provided with a gripping mechanism for gripping a material tray (1). The gripping mechanism is provided with a protection mechanism for protecting the material tray (1) when it is accidentally detached due to a malfunction of the gripping mechanism. The frame includes uprights (2) that are symmetrically distributed on the left and right. An electrical control cabinet (3) is installed at the right end of the upright (2) on the right side. A Y-axis adjustment device for adjusting the position of the gripping mechanism is provided between the tops of the two uprights (2). The Y-axis adjustment device is provided with a Z-axis adjustment device that works in conjunction with the Y-axis adjustment device. The control end of the Y-axis adjustment device and the control end of the Z-axis adjustment device are electrically connected to the electrical control cabinet (3). The Y-axis adjustment device includes two guide columns (4) that are parallel to each other and horizontally mounted between the tops of two columns (2). A Y-axis slider (5) is slidably connected to the guide column (4). A Y-axis motor (6) for driving the Y-axis slider (5) is embedded at the top left end of the column (2) on the right side. A Y-axis lead screw (7) for cooperating with the Y-axis motor (6) is horizontally provided on the Y-axis slider (5) between the two guide columns (4). The control end of the Y-axis motor (6) is electrically connected to the electrical control cabinet (3). The Y-axis slider (5) is provided with a sliding hole that runs horizontally through the Y-axis slider (5) and matches the guide post (4). The Z-axis adjustment device includes a Z-axis cylinder (8) installed on the upper surface of the Y-axis slider (5). The piston rod of the Z-axis cylinder (8) is arranged vertically downward and passes through the Y-axis slider (5). A disc (9) is provided below the Z-axis cylinder (8). A gripping mechanism is installed at the lower end of the disc (9). The control end of the Z-axis cylinder (8) and the control end of the gripping mechanism are electrically connected to the electrical control cabinet (3). The gripping mechanism includes a "door" shaped mounting frame (10). The center of the upper end face of the mounting frame (10) is welded to the center of the lower end face of the disc body (9). Two vacuum suction cups (11) are symmetrically distributed on the left and right sides below the crossbeam of the mounting frame (10) for gripping the material disc (1). The mounting frames (10) on the left and right sides of the disc body (9) are respectively equipped with gripping cylinders (21) that cooperate with the vacuum suction cups (11). The piston rod of the gripping cylinder (21) is set vertically downward and passes through the mounting frame. The crossbeam of the mounting bracket (10) is connected to the upper end of the vacuum suction cup (11) by screws at the lower end of the piston rod of the gripping cylinder (21). The mounting bracket (10) located on the side of the gripping cylinder (21) is equipped with a vacuum pump (12) that works with the vacuum suction cup (11). The suction end of the vacuum pump (12) is connected to the air valve of the vacuum suction cup (11) by a hose. The control end of the gripping cylinder (21) and the control end of the vacuum pump (12) are electrically connected to the electrical control cabinet (3). The protective mechanism includes fixed plates (13) symmetrically distributed on both sides of the lower end of the crossbeam of the mounting frame (10). The upper end of the fixed plates (13) is welded to the lower end of the crossbeam of the mounting frame (10). An "L"-shaped movable plate (14) is installed on the fixed plates (13) to protect the tray (1) in case of accidental detachment. A horizontal groove is provided on the fixed plates (13) that penetrates the fixed plates (13) and matches the movable plate (14). The movable plate (14) has... The horizontal part is slidably inserted into the groove. A coil (15) for driving the movable plate (14) is provided between the vertical part of the fixed plate (13) and the mounting bracket (10). A coil frame (16) for winding the coil (15) is welded to the back of the fixed plate (13). The coil (15) is wound on the coil frame (16). An iron block (17) for cooperating with the coil (15) is provided at the front end of the vertical part of the movable plate (14). A horizontal mounting bracket for mounting the coil (15) is provided on the fixed plate (13) below the coil (15). A guide rod (18) for mounting the movable plate (14) is provided. The guide rod (18) passes through the vertical part of the movable plate (14). One end of the guide rod (18) is welded to the back of the fixed plate (13), and the other end of the guide rod (18) is welded to the inner wall of the vertical part of the mounting bracket (10). A reset spring (19) for resetting the movable plate (14) is fitted on the guide rod (18) located between the vertical part of the movable plate (14) and the inner wall of the vertical part of the mounting bracket (10). One end of the reset spring (19) is provided. The back of the vertical part of the movable plate (14) is welded to the back of the movable plate (14), and the other end of the reset spring (19) is welded to the inner wall of the vertical part of the mounting frame (10). The upper end of the horizontal part of the movable plate (14) is provided with a rubber pad for protecting the material tray (1). An infrared ranging sensor (20) for use with the coil (15) is embedded in the center of the lower end of the beam of the mounting frame (10) located between the two suction cups. The control ends of the infrared ranging sensor (20) and the coil (15) are electrically connected to the electrical control cabinet (3). When the tray (1) falls off during the rising and horizontal movement, the control cabinet (3) compares the distance H1 between the current infrared ranging sensor (20) and the tray (1) with the distance H2 between the current infrared ranging sensor (20) and the tray (1) detected in the previous 0.01 seconds. When H1 is greater than H2, the control cabinet (3) determines that the tray (1) is in an unexpected falling state. When the tray (1) falls off during the descent, the control cabinet (3) calculates the descent speed V1 = H1 / (0.01*n) based on the distance H1 detected by the infrared ranging sensor (20) to the tray (1) in the nth time, and calculates the descent speed V2 = H2 / (0.01*(n-1)) based on the data H2 detected in the first 0.01 seconds. When both V1 and V2 are greater than the preset descent speed V, the control cabinet (3) determines that the tray (1) is in an unexpected falling state.

2. The automatic tray adjustment device according to claim 1, characterized in that, The left end of the guide post (4) is welded to the right end of the column (2) located on the left side, and the right end of the guide post (4) is welded to the left end of the column (2) located on the right side. A bearing for use with the Y-axis lead screw (7) is embedded on the left end of the column (2) located between the two guide posts (4). The left end of the Y-axis lead screw (7) is inserted into the center of the bearing. The left and right ends of the Y-axis slider (5) are respectively provided with lead screw pairs that match the Y-axis lead screw (7).

3. The automatic tray adjustment device according to claim 1, characterized in that, The output shaft of the Y-axis motor (6) is connected to the right end of the Y-axis lead screw (7) by a coupling.

4. The automatic tray adjustment device according to claim 1, characterized in that, The center of the upper end face of the disc (9) is connected to the end of the piston rod of the Z-axis cylinder (8) by a screw.

5. The control method for the automatic tray adjustment device according to claim 2, characterized in that, The control method is as follows: When working normally, the electrical control cabinet (3) provides power normally. At this time, the electrical control cabinet (3) adjusts the current flowing through the coil (15) to make the coil (15) generate a magnetic field at all times. The magnetic field generated by the coil (15) will attract the iron block (17). At this time, the movable plate (14) is in the initial position. At this time, the torsion spring is compressed and has elastic potential energy. When gripping the material tray (1), the electrical control cabinet (3) first controls the Y-axis motor (6), which drives the Y-axis screw (7) to rotate, and adjusts the relative position between the suction cup and the material tray (1) through the screw pair until the two suction cups are located at the left and right ends directly above the material tray (1); Then the electrical control cabinet (3) controls the Z-axis cylinder (8), and the piston rod of the Z-axis cylinder (8) makes the suction cup close to the material tray (1). The lower ends of the left and right sides of the mounting bracket (10) respectively abut against the worktable on which the material tray (1) is placed. Then the electrical control cabinet (3) controls the gripping cylinder (21), and the piston rod of the gripping cylinder (21) makes the lower end face of the suction cup fit against the surface of the material tray (1); Afterwards, the electrical control cabinet (3) controls the air pump (12) to work, extracting the air between the suction cup and the material tray (1) to achieve the gripping of the material tray (1). At this time, the infrared distance sensor (20) starts to work, detecting the distance H between the infrared distance sensor (20) and the material tray (1). The infrared distance sensor (20) will detect again every 0.01 seconds and send the detected data to the control cabinet. The control cabinet will record the received data and compare the currently measured data with the data measured in the previous 0.01 seconds; Then the electrical control cabinet (3) controls the gripping cylinder (21) again, and the material tray (1) is separated from the worktable by the retraction of the piston rod of the gripping cylinder (21); During normal operation, the detected value of H will decrease uniformly during the rising process of the material tray (1). Then, the electrical control cabinet (3) controls the Z-axis cylinder (8) again to raise the material tray (1) to the highest point by contracting the piston rod of the Z-axis cylinder (8). At this time, the detected value of H is a. When the material tray (1) reaches the highest point, the electrical control cabinet (3) controls the Y-axis motor (6) again to transport the material tray (1) to the designated position; When the material tray (1) reaches the designated position, the electrical control cabinet (3) controls the Z-axis cylinder (8) to extend the piston rod of the Z-axis cylinder (8) to bring the material tray (1) closer to the designated position until the lower ends of the left and right sides of the mounting bracket (10) abut against the sides of the designated position respectively. Then the electrical control cabinet (3) controls the gripping cylinder (21), and the material tray (1) is lowered by extending the piston rod of the gripping cylinder (21). When the material tray (1) starts to fall, the electrical control cabinet (3) starts to count the data detected by the infrared ranging sensor (20) each time. That is, the nth detection data after the material tray (1) starts to fall. During normal operation, the value of H detected during the descent of the material tray (1) is 0.01*n*V, where V is the preset descent speed of the material tray (1) during normal operation, until the back of the material tray (1) is in contact with the upper surface of the designated position. Afterwards, the electrical control cabinet (3) shuts off the air pump (12) to inject air between the suction cup and the material tray (1) to separate the material tray (1). Then, the above steps are repeated to continue to grab other material trays (1). When the material tray (1) is picked up, during the process of rising and moving horizontally, if both suction cups are damaged, air will be re-entered between the suction cups and the material tray (1), and then the material tray (1) will fall off under the action of gravity. When the material tray (1) falls off during the upward and horizontal movement, the control cabinet (3) compares the data H1 detected by the current infrared ranging sensor (20) with the data H2 detected 0.01 seconds ago. When H1 is greater than H2, the control cabinet (3) determines that the material tray (1) is in an unexpected falling state and immediately sends a command to the coil (15). After receiving the command, the coil (15) will generate a magnetic field to attract the iron block (17) and at the same time stop the Y-axis motor (6), Z-axis cylinder (8) and gripping cylinder (21). During the process of the coil (15) attracting the iron block (17), the horizontal part of the movable plate (14) moves along the guide rod (18) and the slide until the rubber pad of the movable plate (14) completely extends out of the fixed plate (13). When the material tray (1) is transported to the designated horizontal position, during the process of the material tray (1) descending, when both suction cups are damaged, air will be re-entered between the suction cups and the material tray (1), and then the material tray (1) will fall off under the action of gravity. When the material tray (1) falls off during the descent, the control cabinet (3) calculates V1 = H1 / (0.01*n) based on the data H1 detected by the infrared ranging sensor (20) for the nth time, and calculates V2 = H2 / (0.01*(n-1) based on the data H2 detected in the previous 0.01 seconds. When V1 and V2 are both greater than the preset descent V, the control cabinet (3) determines that the material tray (1) is in an unexpected falling state and immediately sends a command to the coil (15). After receiving the command, the coil (15) will generate a magnetic field to attract the iron block (17) and at the same time stop the Y-axis motor (6), Z-axis cylinder (8) and gripping cylinder (21). During the process of the coil (15) attracting the iron block (17), the horizontal part of the movable plate (14) moves along the guide rod (18) and the slide until the rubber pad of the movable plate (14) completely extends out of the fixed plate (13). The falling tray (1) will land on the rubber pad of the movable plate (14) and wait for maintenance personnel to come and perform maintenance. After removing the tray (1) and troubleshooting, the maintenance personnel can turn off the coil (15) at the electrical control cabinet (3), and then reset the movable plate (14) under the action of the reset spring (19) and wait for the next use.

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