AGV fork device and control method thereof

Abstract

The application relates to the technical field of forklifts, and discloses an AGV (Automatic Guided Vehicle) fork device and a control method thereof. The AGV fork device comprises a pressing plate assembly arranged above a fork assembly, a lifting driving mechanism arranged at the upper portion of a base assembly, a first driving element and a first linear motion assembly, the pressing plate assembly is connected with the first linear motion assembly, and the first driving element drives the pressing plate assembly to move up and down on the first linear motion assembly. The lifting driving mechanism is compactly integrated at the upper portion of the base assembly, the first driving element with a built-in encoder, an electromagnetic holding brake and a torque acquisition module is matched with the first linear motion assembly, the use of the AGV fork device is adapted to a 700mm height-limited space and a narrow lane working condition, and the AGV fork device realizes efficient, stable, energy-saving and environment-friendly full-automatic unmanned carrying of multi-layer thin plate pieces.

Description

Technical Field

[0001] This invention relates to the field of forklift technology, and in particular to an AGV fork unit and its control method. Background Technology

[0002] In the field of automated warehousing and logistics, AGVs typically need to be equipped with specialized attachments featuring fork spacing adjustment capabilities when handling multi-layered stacked thin sheet metal parts without human intervention. In practical applications, some warehouse spaces have narrow aisle structures, which imposes strict requirements on the clearance height of the AGV and its fork attachments.

[0003] However, existing AGV fork attachments mostly use hydraulic cylinders or long-stroke electric cylinders as the main drive source. Limited by the axial dimensions of the hydraulic cylinder or electric cylinder itself, they require a significant amount of overall height or width space for installation, making them difficult to integrate into a compact space with a height limit of 700mm. Furthermore, if only the size of the attachment is considered, the functions of automatic fork spacing adjustment and load stabilization are often sacrificed, resulting in an inability to automatically adapt to pallets of different sizes and difficulty in stably and flexibly handling multi-layered thin sheet metal parts with a height limit of 300-500mm. Therefore, existing adjustable forks or load stabilizers, whether individually or integrated, cannot achieve the handling of 500mm high thin sheet metal parts in narrow aisles and under a height limit of 700mm. Summary of the Invention

[0004] The purpose of this invention is to provide an AGV forklift device and its control method to solve the problems in the prior art, enabling the handling of thin plate parts with a height of 500mm in a low headroom and narrow aisle environment with a height limit of 700mm, while integrating distance adjustment and load stabilization functions.

[0005] This invention provides an AGV fork assembly for handling thin sheet metal parts, including a base assembly and a fork assembly, and further comprising: The pressure plate assembly is located above the fork assembly and is arranged opposite to the fork assembly in the vertical direction; A lifting drive mechanism is located on the upper part of the base assembly, including a first drive member and a first linear motion component. The pressure plate assembly is connected to the first linear motion component, and the first drive member drives the pressure plate assembly to move up and down on the first linear motion component.

[0006] In the AGV forklift device described above, preferably, the first drive unit has an encoder, an electromagnetic brake, and a torque acquisition module built in; when the pressure plate assembly presses down and contacts the thin plate, the first drive unit determines that the clamping force has reached a set threshold based on the current signal fed back by the torque acquisition module, and locks the pressing position of the pressure plate assembly by closing the electromagnetic brake.

[0007] In the AGV forklift device described above, preferably, the first linear motion component includes a first lead screw and a first lead screw nut, the output end of the first drive member is connected to the first lead screw, the first lead screw nut is sleeved on the first lead screw, the pressure plate assembly is connected to the first lead screw nut, and the lifting drive mechanism further includes a first guide mechanism disposed on both sides of the first lead screw and slidably connected to the pressure plate assembly for guiding the pressure plate assembly when it moves along the first lead screw.

[0008] In the AGV fork device described above, preferably, the fork assembly includes a central fork, and the pressure plate assembly includes a pressure rod assembly, an elastic buffer, and a pressure plate assembly. The pressure plate assembly is located above the central fork and is vertically opposite to the central fork for jointly pressing the thin plate. One end of the pressure rod assembly is connected to the output end of the first linear motion component, and the other end is connected to the pressure plate assembly through the elastic buffer, so that the pressure plate assembly can adaptively adjust the pressing angle and pressing force when contacting the thin plate.

[0009] In the AGV forklift device described above, preferably, the elastic buffer assembly includes a front conical spring and a rear conical spring arranged along the front-rear direction of the pressure plate assembly, and the bottom surface of the pressure plate assembly is provided with a vulcanized rubber plate.

[0010] In the AGV fork device described above, preferably, the fork assembly further includes a left fork and a right fork, and the AGV fork device further includes an adjusting mechanism, which is respectively disposed on both sides of the base assembly, for driving the left fork and the right fork to move closer or further apart from each other; The adjusting mechanism includes a second driving member, a synchronous transmission assembly, and a second linear motion assembly. The second linear motion assembly includes a second lead screw and a second lead screw nut. The second lead screw extends along the width direction of the base assembly, and the second lead screw nut is sleeved on the second lead screw. The left fork or the right fork is connected to the corresponding second lead screw nut. The second driving member and the second lead screw are arranged parallel to each other in the axial direction. The output end of the second driving member and the input end of the second lead screw are connected through the synchronous transmission assembly.

[0011] In the AGV forklift device described above, preferably, the synchronous transmission assembly is fixed on the base assembly and includes a first synchronous pulley, a second synchronous pulley, and a synchronous belt. The output shaft of the second drive member is connected to the first synchronous pulley, the second lead screw is connected to the second synchronous pulley, and the first synchronous pulley and the second synchronous pulley are connected by a synchronous belt drive.

[0012] In the AGV fork device described above, preferably, the base assembly is provided with a guide structure, which is arranged on at least one side above or below the second lead screw, for guiding the left and right forks as they move along the corresponding second lead screws.

[0013] In the AGV fork device described above, preferably, the guide structure includes a guide rod and a first sliding part. The guide rod is disposed on the upper side of the second lead screw and extends along the width direction of the base assembly. The first sliding part is connected to the left fork or the right fork and slides in cooperation with the guide rod. The guide structure also includes a second sliding part, which is disposed on the lower part of the left fork or the right fork and faces the base assembly. When the left fork or the right fork moves, the second sliding part slides on the surface of the base assembly.

[0014] The present invention also provides a control method for the above-mentioned AGV forklift device, comprising the following steps: S1. After the AGV arrives at the picking position, it obtains the pallet fork hole spacing and drives the left and right forks in the fork assembly to move to the target spacing corresponding to the pallet fork hole spacing. S2. The AGV moves forward so that the forks are inserted into the pallet fork holes. After the positioning detection is completed, the AGV stops moving forward and raises the forks to a safe height. S3. The lifting drive mechanism drives the pressure plate assembly to press down and monitors the clamping force in real time; S4. When the clamping force reaches the set torque value, the lifting drive mechanism brake closes, locking the pressure plate position. S5. The AGV, carrying a load, runs to the docking station. After the material is placed, the lifting drive mechanism releases the brake and lifts the pressure plate. The AGV then retreats and exits the pallet, completing one cycle.

[0015] Compared with the prior art, the present invention compactly integrates the lifting drive mechanism into the upper part of the base assembly, and uses a first drive component with built-in encoder, electromagnetic brake and torque acquisition module to cooperate with the first linear motion component, which solves the physical defects of traditional hydraulic cylinders or electric cylinders that are difficult to adapt to 700mm height restriction space due to their own excessive axial length, and is suitable for use in narrow aisle conditions.

[0016] The lifting drive mechanism accurately judges the clamping force based on the real-time feedback current signal from the torque acquisition module. When the set threshold is reached, it uses a built-in electromagnetic brake to achieve mechanical self-locking, eliminating the need for external pressure sensors and displacement detection elements required by traditional hydraulic systems, and preventing thin sheet metal parts from slipping or shaking during operation under load. In addition, in conjunction with the adjustable distance mechanism, it can flexibly adapt to pallets of different sizes, realizing highly efficient, stable, energy-saving, and environmentally friendly fully automated unmanned handling of multi-layer thin sheet metal parts. Attached Figure Description

[0017] Figure 1 This is a perspective view of the AGV forklift device provided in an embodiment of the present invention; Figure 2 This is a perspective view of the AGV forklift device provided in an embodiment of the present invention without the pressure plate assembly; Figure 3 yes Figure 2 Enlarged view of point A in the image; Figure 4 This is a perspective view of the lifting drive mechanism provided in an embodiment of the present invention; Figure 5 This is a partially enlarged view of the first guiding mechanism provided in an embodiment of the present invention; Figure 6 This is a perspective view of the pressure plate assembly provided in an embodiment of the present invention; Figure 7 This is a perspective view of the adjusting mechanism provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of the first sliding part provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of the second sliding part provided in an embodiment of the present invention; Figure 10 This is a system block diagram of the AGV forklift device provided in an embodiment of the present invention; Figure 11 This is a flowchart of the control method provided in an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 10. Base assembly; 11. Guide rod; 20. Fork assembly; 21. Center-mounted fork; 22. Left fork; 23. Right fork; 24. First sliding part; 25. Second sliding part; 30. Pressure plate assembly; 31. Pressure bar assembly; 32. Pressure plate assembly; 33. Front conical spring; 34. Rear conical spring; 35. Vulcanized rubber sheet; 40. Lifting drive mechanism; 41. First drive component; 42. First reducer; 43. Coupling; 44. First lead screw; 45. First lead screw nut; 46. First guide mechanism; 460. Guide rail; 461. Slider; 47. Position encoder; 48. Torque acquisition module; 49. Electromagnetic brake mechanism; 50. Adjusting mechanism; 51. Second drive component; 52. Second reducer; 53. Synchronous transmission assembly; 530. First synchronous pulley; 531. Second synchronous pulley; 532. Synchronous belt; 54. Second lead screw; 55. Second lead screw nut; 60. Main control unit; 61. Vision camera module; 62. Photoelectric sensor; 63. Position detection switch. Detailed Implementation

[0019] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] See Figure 1-2 As shown, this embodiment provides an AGV forklift device adapted for handling thin sheet metal parts in narrow aisles with a height limit of 700mm. The forklift device includes a base assembly 10, a fork assembly 20, a pressure plate assembly 30, a lifting drive mechanism 40, and an adjusting mechanism 50. The base assembly 10 is fixed to the gantry lifting slide of the forklift AGV. The fork assembly 20 is mounted on the base assembly 10 and includes a centrally located central fork 21, and left and right forks 22 and 23 that can move left and right. The central fork 21 is fixed, while the left and right forks 23 can open or retract simultaneously, achieving automatic adjustment of the fork spacing to accommodate pallets carrying thin sheet metal parts of different widths. The pressure plate assembly 30 is positioned directly above the fork assembly 20, vertically opposite the central fork 21 below, forming an upper and lower clamping space for pressing down stacked thin sheet metal parts.

[0021] See Figure 3-4 As shown, existing solutions using horizontal long electric cylinders and laterally arranged hydraulic cylinders suffer from the technical problem that the axial length of the cylinder body causes the total height of the attachment to exceed 750mm, making it impossible to enter a 700mm height-restricted passageway. In this embodiment, the lifting drive mechanism 40 is integrated on the base assembly 10, including a first drive member 41 and a first linear motion assembly. The pressure plate assembly 30 is connected to the first linear motion assembly, and the first drive member 41 drives the pressure plate assembly 30 to move up and down on the first linear motion assembly.

[0022] See Figure 4 As shown, specifically, the first driving component 41 adopts a first servo motor and is arranged in the upper region of the base assembly 10. The first linear motion component includes a first lead screw 44 and a first lead screw nut 45. The first lead screw 44 extends along the height direction of the base assembly and is built into the upper frame of the base assembly 10. The lower end of the first lead screw 44 is fixed to the base assembly 10 by a support. The output shaft of the first servo motor is vertically connected to the first reducer 42. The output end of the first reducer 42 is coaxially connected to the first lead screw 44 through a coupling 43. The first lead screw nut 45 moves vertically up and down along the first lead screw 44. The pressure plate assembly 30 is rigidly fixed to the first lead screw nut 45.

[0023] See Figure 5As shown, two sets of linear guide rails 460 are symmetrically arranged on both sides of the first lead screw 44 as the first guide mechanism 46. The pressure plate assembly 30 is also slidably connected to the linear guide rails 460 through a slider 461. The entire lifting and lowering process of the pressure plate assembly 30 is constrained by the linear guide rails 460 to prevent the pressure plate assembly 30 from shifting left or right. In this embodiment, the first drive component 41, the first lead screw 44, and the first guide mechanism 46 are arranged compactly vertically without any extra extended structures, significantly reducing the overall height occupied and solving the technical problem that traditional attachments cannot adapt to the height restriction conditions in narrow alleys.

[0024] See Figure 10 As shown, traditional hydraulic cylinders or ordinary electric push rods lack precise force feedback, which may lead to slippage and misalignment of thin plates during transport due to insufficient clamping force, or damage to the surface of thin plates due to excessive pressure. In this embodiment, the first drive unit 41 has a built-in encoder, torque acquisition module 48, and integrated electromagnetic brake mechanism 49. In some scenarios, it can be replaced by a ball self-locking nut at the end of the lead screw as a self-locking mechanical structure. During operation, after the servo-driven pressure plate assembly 30 descends to contact the top surface of the thin plate, the first servo motor continuously outputs torque, and the system reads the torque feedback signal in real time. When the clamping force obtained by torque conversion reaches the preset threshold of the program, such as the standard clamping force of 200-600N for thin plates, the parameters can be switched according to the thickness of the thin plate and the number of stacked layers. The servo motor stops feeding, the electromagnetic brake closes instantly to lock the lead screw, and the position of the pressure plate assembly 30 is completely fixed.

[0025] In this embodiment, the first drive unit 41 preferably uses an AC servo motor of model SMC60S-0040-30QBK-5DSU. This model of motor has a flange mounting dimension of 60mm × 60mm, featuring a compact, short-body design, and incorporates a high-resolution photoelectric encoder and a torque acquisition module 48. In practical applications, this encoder module can not only provide real-time feedback of the lead screw nut position information to the AGV main control unit 60, but also simultaneously provide feedback on the motor's rotational speed.

[0026] Compared to traditional hydraulic attachments that require external wire-type displacement sensors to detect stroke and external pressure transmitters to detect pressure, this embodiment determines the height of the pressure plate simply by reading the encoder position data inside the servo driver. The analog current output from the driver can be accurately converted into the linear thrust of the lead screw, saving the cumbersome process of additional wiring inside and outside the forklift carriage and installing external sensors. Furthermore, the electromagnetic brake function prevents the pressure plate from springing back and loosening during AGV acceleration, deceleration, and turning, ensuring the overall stability of multi-layer thin sheet metal stacks with a height of 300-500mm and preventing the sheets from scattering or deforming due to impact.

[0027] It should be noted that in some offline transport scenarios without power supply, the servo motor electromagnetic brake can be omitted, and a ball-type self-locking nut can be fitted to the lower end of the first lead screw 44 as a self-locking mechanical structure. After the pressure plate is pressed down into place, the self-locking of the nut thread counteracts the upward rebound force of the thin plate, and the pressure plate can be stably locked in the state of machine stoppage and power failure, reducing electrical dependence.

[0028] In actual working conditions, stacked multi-layer thin plates may exhibit slight height differences and localized warping of the top surface. When a rigid pressure plate presses down, localized point contact and uneven distribution of clamping force may occur. (See also...) Figure 6 As shown, in this embodiment, the pressure plate assembly 30 includes a pressure rod assembly 31, an elastic buffer assembly, and a pressure plate assembly 32. The pressure rod assembly 31 extends in a direction perpendicular to the base assembly 10, and the pressure plate assembly 32 is arranged directly above the central fork 21. One end of the pressure rod assembly 31 is connected to the first lead screw nut 45, and the other end is connected to the top of the pressure plate assembly 32. An elastic buffer assembly is provided between the pressure rod assembly 31 and the pressure plate assembly 32. The elastic buffer assembly uses a pair of conical springs arranged front and rear. The front conical spring 33 and the rear conical spring 34 are respectively installed on the front and rear sides of the lower end of the pressure rod assembly 31 to form a floating buffer structure. The pressure plate can adaptively deflect to adapt to the angle of the thin plate, increase the contact with the thin plate, thereby improving the holding stability, realizing flexible and close clamping, and solving the defects of rigid pressure plates that have poor adaptability and are prone to damaging thin plate workpieces.

[0029] See Figure 6 As shown, further, the bottom surface of the pressure plate assembly 32 is provided with multiple vulcanized rubber plates 35 to increase friction with the thin plate, disperse pressure, and prevent indentations from appearing on the surface of the thin plate.

[0030] See Figure 2 As shown, traditional adjustable forks mostly use hydraulic or electric cylinder drives, which increases the overall width of the attachment, resulting in insufficient clearance for AGV passage in narrow aisles. In this embodiment, the adjustable fork mechanism 50 is provided in two sets, respectively arranged on the left and right sides of the base assembly 10, to drive the left fork 22 and right fork 23 to move laterally, realizing automatic fork spacing adjustment, adapting to thin pallets of different widths, while reducing the lateral width occupied, and adapting to passage in narrow aisles.

[0031] See Figure 7As shown, specifically, each set of pitch adjustment mechanisms 50 includes a second drive component 51, a synchronous transmission assembly 53, and a second linear motion assembly. The second drive component 51 uses a second servo motor of the same model as the first drive component 41. The second linear motion assembly consists of a second lead screw 54 arranged laterally along the width of the base and a matching second lead screw nut 55. The left fork 22 and the right fork 23 are respectively fixed to the second lead screw nut 55 on their respective sides. In this embodiment, the second drive component 51 and the second lead screw 54 are arranged axially parallel, rather than in a traditional coaxial series arrangement. The synchronous transmission assembly 53 is fixed to the base assembly 10 and includes a first synchronous pulley 530, a second synchronous pulley 531, and a synchronous belt 532. The output end of the servo motor is connected to a second reducer 52, the output end of the second reducer 52 is connected to the first synchronous pulley 530, the second synchronous pulley 531 is connected to the input end of the second lead screw 54, and the synchronous belt 532 transmits power around the two sets of pulleys. In this embodiment, the second servo motor and the second lead screw 54 are placed parallel to each other on the side. The synchronous belt 532 is used for reversing transmission, eliminating the axial outward protrusion and reducing the overall lateral width of the base, thus improving the passage performance in narrow passages. In other embodiments, the synchronous transmission assembly 53 can also be replaced by a chain drive mechanism with a chain and sprocket.

[0032] Under heavy loads, relying solely on the lead screw to drive the forks results in high load capacity, low precision, and the forks are prone to misalignment, potentially colliding with the base assembly 10. To address this issue, the base assembly 10 is equipped with a guide structure, located on at least one side above or below the second lead screw 54, for guiding the left fork 22 and right fork 23 as they move along their respective second lead screws 54.

[0033] See Figure 8 As shown, in this embodiment, guide structures are provided on both the upper and lower sides of the fork assembly 20. First sliding parts 24 are respectively connected to the upper parts of the left fork 22 and the right fork 23. Guide rods 11 are installed along the width direction of the base assembly 10, and the guide rods 11 are arranged on the upper side of the second lead screw 54. The first sliding parts 24 are slidably connected to the corresponding guide rods 11 to realize the limiting and guiding of the upper part of the fork. In this embodiment, the first sliding parts 24 adopt steel back bearings and are sleeved on the guide rods 11.

[0034] See Figure 9 As shown, a second sliding part 25 is provided at the lower end of the fork, which can slide and support against the surface of the base assembly 10. The second sliding part 25 consists of rollers symmetrically arranged on the left and right sides of the fork, which are rotatably connected by a mounting base. During the movement of the fork, the rollers roll against the surface of the base assembly 10. The fork translation trajectory is synchronously constrained by the upper and lower double-layer guides, and the horizontal thrust of the adjustable pitch is borne only by the lead screw. The vertical load is entirely borne by the guide rod 11 and the sliding part, which avoids long-term bending deformation of the lead screw and extends the service life of the lead screw.

[0035] During the picking operation, the AGV upper system reads the pallet size data and sends the target fork distance signal. The left and right sets of distance adjustment mechanisms 50 operate synchronously, and drive the second lead screws 54 on both sides to rotate synchronously through the synchronous belt 532, driving the left and right forks 23 to move towards or away from each other, and quickly switching the fork distance. During the movement of the forks, the upper and lower guide structures are synchronously limited to reduce the swaying of the forks up and down and left and right. After the distance adjustment is completed, the first drive component 41 brakes and locks the first lead screw 44. The distance between the forks will not shift during the transfer process. It can automatically adapt to thin plate pallets of different widths, solving the problem that the distance adjustment function of the existing equipment is incompatible with the compact height limit structure.

[0036] See Figure 10-11 As shown, this embodiment also provides a control method for the above-mentioned AGV forklift device, which includes the following steps: S1. After the AGV arrives at the picking position, it obtains the pallet fork hole spacing and drives the left fork 22 and right fork 23 in the fork assembly 20 to move to the target spacing corresponding to the pallet fork hole spacing. S2. The AGV moves forward so that the forks are inserted into the pallet fork holes. After the positioning detection is completed, the AGV stops moving forward and raises the forks to a safe height. S3, the lifting drive mechanism 40 drives the pressure plate assembly 30 to press down and monitors the clamping force in real time; S4. When the clamping force reaches the set torque value, the lifting drive mechanism 40 brake closes, locking the pressure plate position. S5. The AGV, carrying a load, runs to the docking station. After the material is placed, the lifting drive mechanism 40 releases the brake and lifts the pressure plate. The AGV then retreats and exits the pallet, completing one cycle.

[0037] Specifically, in step S1, the AGV travels along a preset navigation path to the designated thin-plate pallet pickup location and completes precise alignment with the pallet. The main control unit 60 activates the matching vision camera module 61. After the camera captures an image of the pallet, it identifies the width of the pallet fork holes using existing mature algorithms. After calculating the target distance required for the left and right forks 23, the main control unit 60 sends a position control command to the distance adjustment mechanism 50.

[0038] The second drive unit 51 drives the corresponding second lead screw 54 to rotate via the synchronous belt 532, driving the left fork 22 and the right fork 23 to move towards each other or away from each other until the position encoder 47 feeds back the real-time position that has reached the target spacing, and the fork spacing adjustment is completed.

[0039] In step S2, the main control unit 60 controls the AGV to move forward slowly, aligning the forks with the pallet fork holes. During the fork insertion process, photoelectric sensors 62 and position detection switches 63, located on the front end and base of the forks, continuously monitor the insertion depth of the forks. When the position detection switch 63 is triggered, and the sensor determines that the forks have passed through the fork holes and reached the set position, the AGV stops moving forward in time to prevent the forks from hitting the rear of the pallet. Subsequently, the main control unit 60 controls the AGV's lifting mechanism to lift the forks and the thin-plate pallet as a whole to a preset safe height.

[0040] In step S3, after the forks are raised to a safe height, the material clamping process begins. The main control unit 60 switches the operating mode of the lifting drive mechanism 40 from "position mode" to "torque mode," driving the first lead screw 44 to slowly displace the pressure plate assembly 30 downwards.

[0041] During the descent of the pressure plate assembly 30, the vulcanized rubber plate 35 at its bottom first contacts the upper surface of the thin plate. As the first lead screw 44 continues to press down, the elastic buffer assembly at the top of the pressure plate begins to be stressed and compressed, creating a flexible buffer zone. Simultaneously, the servo drive system acquires the current and torque feedback signals of the first drive component 41 in real time. Since the current is positively correlated with the motor output torque, the main control unit 60 can monitor the current actual clamping force by reading this feedback value.

[0042] In step S4, as the spring compression increases, the motor current feedback value continues to rise. When the feedback signal reaches the preset clamping force threshold in the main control unit 60, the system determines that the pressure plate has applied sufficient and safe downward pressure to the thin plate.

[0043] The main control unit 60 sends a command to the lifting drive mechanism 40, and the electromagnetic brake built into the servo motor is immediately energized and closed, achieving mechanical self-locking. After the brake is locked, even if the external power is disconnected or a bump is encountered, the first lead screw 44 cannot generate backlash, and the pressure plate assembly 30 is firmly locked at the current height, effectively preventing the thin plate from slipping or tipping over during transportation.

[0044] In step S5, after the pressure plate is locked, the AGV carries the sheet metal smoothly to the unloading rack position according to the path planned by the system. After reaching the target position, the AGV performs positioning calibration and slowly lowers the forks and sheet metal, placing them smoothly on the bearing surface of the docking station.

[0045] After placement and confirmation of no external interference, the main control unit 60 sends a reverse action command to the lifting drive mechanism 40. The servo motor brake is released, the motor rotates in the opposite direction, and the pressure plate assembly 30 is lifted upwards, releasing the clamping state on the thin plate. Subsequently, the AGV performs a slow backward movement, smoothly withdrawing the forks from the bottom of the pallet fork holes. The device returns to its initial standby state, awaiting the start of the next work cycle.

[0046] The above description, based on the embodiments shown in the figures, details the structure, features, and effects of the present invention. The above description is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.

Claims

1. An AGV fork assembly for handling thin sheet metal parts, comprising a base assembly and a fork assembly, characterized in that, Also includes: The pressure plate assembly is located above the fork assembly and is arranged opposite to the fork assembly in the vertical direction; A lifting drive mechanism is located on the upper part of the base assembly, including a first drive member and a first linear motion component. The pressure plate assembly is connected to the first linear motion component, and the first drive member drives the pressure plate assembly to move up and down on the first linear motion component.

2. The AGV forklift device according to claim 1, characterized in that, The first driving component has a built-in encoder, electromagnetic brake and torque acquisition module; when the pressure plate assembly presses down to contact the thin plate, the first driving component determines that the clamping force has reached the set threshold according to the current signal fed back by the torque acquisition module, and locks the pressing position of the pressure plate assembly by closing the electromagnetic brake.

3. The AGV forklift device according to claim 1, characterized in that, The first linear motion component includes a first lead screw and a first lead screw nut. The output end of the first drive component is connected to the first lead screw. The first lead screw nut is sleeved on the first lead screw. The pressure plate assembly is connected to the first lead screw nut. The lifting drive mechanism also includes a first guide mechanism, which is located on both sides of the first lead screw and is slidably connected to the pressure plate assembly for guiding the pressure plate assembly when it moves along the first lead screw.

4. The AGV forklift device according to claim 1, characterized in that, The fork assembly includes a centrally mounted fork, and the pressure plate assembly includes a pressure bar assembly, an elastic buffer, and a pressure plate assembly. The pressure plate assembly is located above the centrally mounted fork and is vertically opposite to the centrally mounted fork, and is used to jointly press the thin plate. One end of the pressure bar assembly is connected to the output end of the first linear motion component, and the other end is connected to the pressure plate assembly through the elastic buffer, so that the pressure plate assembly can adaptively adjust the pressing angle and pressing force when contacting the thin plate.

5. The AGV forklift device according to claim 4, characterized in that, The elastic buffer assembly includes a front conical spring and a rear conical spring arranged along the front-rear direction of the pressure plate assembly, and the bottom surface of the pressure plate assembly is provided with a vulcanized rubber plate.

6. The AGV forklift device according to claim 1, characterized in that, The fork assembly also includes a left fork and a right fork, and the AGV fork device also includes an adjustment mechanism, which is respectively located on both sides of the base assembly, for driving the left fork and the right fork to move closer or further apart from each other; The adjusting mechanism includes a second driving member, a synchronous transmission assembly, and a second linear motion assembly. The second linear motion assembly includes a second lead screw and a second lead screw nut. The second lead screw extends along the width direction of the base assembly, and the second lead screw nut is sleeved on the second lead screw. The left fork or the right fork is connected to the corresponding second lead screw nut. The second driving member and the second lead screw are arranged parallel to each other in the axial direction. The output end of the second driving member and the input end of the second lead screw are connected through the synchronous transmission assembly.

7. The AGV forklift device according to claim 6, characterized in that, The synchronous transmission assembly is fixed on the base assembly and includes a first synchronous pulley, a second synchronous pulley, and a synchronous belt. The output shaft of the second drive member is connected to the first synchronous pulley, and the second lead screw is connected to the second synchronous pulley. The first synchronous pulley and the second synchronous pulley are connected by a synchronous belt drive.

8. The AGV forklift device according to claim 5, characterized in that, The base assembly is provided with a guide structure, which is arranged on at least one side above or below the second lead screw, for guiding the left fork and the right fork as they move along the corresponding second lead screw.

9. The AGV forklift device according to claim 7, characterized in that, The guide structure includes a guide rod and a first sliding part. The guide rod is located on the upper side of the second lead screw and extends along the width direction of the base assembly. The first sliding part is connected to the left fork or the right fork and slides with the guide rod. The guide structure also includes a second sliding part, which is located at the lower part of the left fork or the right fork and faces the base assembly. When the left fork or the right fork moves, the second sliding part slides on the surface of the base assembly.

10. A control method for an AGV fork unit as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. After the AGV arrives at the picking position, it obtains the pallet fork hole spacing and drives the left and right forks in the fork assembly to move to the target spacing corresponding to the pallet fork hole spacing. S2. The AGV moves forward so that the forks are inserted into the pallet fork holes. After the positioning detection is completed, the AGV stops moving forward and raises the forks to a safe height. S3. The lifting drive mechanism drives the pressure plate assembly to press down and monitors the clamping force in real time; S4. When the clamping force reaches the set torque value, the lifting drive mechanism brake closes, locking the pressure plate position. S5. The AGV, carrying a load, runs to the docking station. After the material is placed, the lifting drive mechanism releases the brake and lifts the pressure plate. The AGV then retreats and exits the pallet, completing one cycle.

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