An automatic strapping system

Abstract

The present application relates to a kind of automatic board system, including board, conveying unit, drying unit and take and place skin unit, board is conveyed between take and place skin unit and drying unit by conveying unit and is carried out flow, first guide rail is arranged on the board, and first guide rail is distributed radially outward with the center point of board as core point, one board clamp is arranged on each first guide rail, and each board clamp is driven by independent actuating mechanism to approach or away from the center point of board, board clamp includes board main body, skin component and one-way stop component, take and place skin unit includes lifting support, lifting support includes inner and outer arrangement movable support and fixed support, and execution seat is moved back and forth between first guide rail and second guide rail under the drive of moving roller.The automatic board system of the present application can stably clamp leather and can stop at any position.

Description

An automatic stretching system Technical Field

[0001] This invention relates to the field of leather processing, and in particular to an automatic stretching system. Background Technology

[0002] Leather stretching machines are one of the most important pieces of machinery in leather processing. Currently, the leather stretching process still relies on manual labor to clamp and stretch the leather, making automatic clamping impossible. Furthermore, leather stretching is an essential step in leather processing, increasing the yield and economic benefits.

[0003] For example, patent CN109306382B mentions an automatic leather stretching and drying machine, which includes a drying station, a leather picking and placing station, and an automatic stretching station. The drying station, leather picking and placing station, and automatic stretching station are connected by a conveying channel to form a cycle. Several stretching plates are also provided on the conveying channel that circulate between the three stations.

[0004] The stretching dryer in the aforementioned patent, while achieving automatic leather clamping and stretching, requiring only two personnel to perform leather removal and placement operations, significantly reducing manual labor and improving work efficiency, has revealed some other drawbacks upon further use: Firstly, when using the clamp to stretch the leather, the clamping method relies on the toothed structure on the bottom surface of the clamping block and the lower surface of the clamp's main body opening. This method forces the leather to enter the clamp's main body opening along the guide block, meaning the leather at the clamping position may detach from the first guide rail. This method has certain limitations: when the leather to be clamped is soft or thin, the unidirectional movement of the clamp cannot guarantee that the leather will smoothly enter the clamp's main body along the guide block. In the opening, the sides of the leather may wrinkle under the push of the guide block, requiring manual assistance to clamp the leather, which is very troublesome. Secondly, when the gripper moves back and forth on the first guide rail, it is achieved through the cooperation of the drive cylinder. This cooperation method has certain drawbacks: the translational stroke of the gripper on the first guide rail is limited by the stroke of the drive cylinder, and it cannot achieve translation and stopping at arbitrary positions. In addition, if the gripper needs to translate a long distance, the corresponding drive cylinder needs to be made relatively long. When clamping leather, multiple grippers in different directions are often needed to clamp and pull the leather simultaneously. The corresponding drive cylinders also need to be distributed in different positions to achieve different directions of movement of different grippers. Ultimately, this results in a relatively large area occupied by the entire stretching machine. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an automatic stretching system that can stably clamp leather and stop at any position.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: an automatic stretching system, the innovation of which is: including a stretching plate, a conveying unit, a drying unit and a leather picking and placing unit;

[0007] The stretching plate is transported between the leather picking and placing unit and the drying unit via the conveying unit. The stretching plate is provided with several first guide rails that are radially distributed outward from the center point of the stretching plate. Each first guide rail is provided with a stretching clamp, and each stretching clamp is driven by an independent actuator to move closer to or away from the center point of the stretching plate.

[0008] The clamp includes a clamping plate body, which has a through hole for the first guide rail to pass through and move. The clamping plate body is fitted over the first guide rail. A mating groove for cooperating with and connecting with the first linear brake is also provided on the clamping plate body.

[0009] At least one leather clamping assembly is provided on the front side of the stretching plate body, located next to the first guide rail. The leather clamping assembly includes a clamping bottom plate on the lower side and a clamping top plate on the upper side. A first tooth structure is provided on the upper end surface of the clamping bottom plate, and the upper end surface of the first guide rail is located between the tooth tip and tooth root of the first tooth structure. The clamping top plate is vertically arranged above the clamping bottom plate and is hinged to the stretching plate body. A first torsion spring is also provided between the clamping top plate and the stretching plate body. The leather is clamped by the cooperation of the clamping top plate and the clamping bottom plate. In the clamping state, the clamping top plate is inclined, and its inclination direction is gradually inclined from top to bottom towards the stretching plate body. The clamping top plate is driven by a second linear driver to swing and to conform to or move away from the clamping bottom plate.

[0010] A one-way anti-reverse assembly is provided on the rear side of the tension plate body. The one-way anti-reverse assembly includes an anti-reverse plate disposed below the first guide rail. The middle position of the anti-reverse plate is hinged to the tension plate body. A second tooth structure is also provided on the upper end surface of the anti-reverse plate. A second torsion spring is also provided between the anti-reverse plate and the tension plate body to keep the second tooth structure in contact with the lower end surface of the first guide rail. The anti-reverse plate is driven by a third linear actuator to swing up and down along the hinge point between the anti-reverse plate and the tension plate body, and to drive the second tooth structure to contact with or move away from the first guide rail.

[0011] The actuator includes an actuator seat, on the lower side of which a pair of movable rollers are mounted, supported on a first guide rail and rolling along the first guide rail. The two movable rollers are driven by a linkage mechanism to roll synchronously in the same direction. The bottom end of the actuator seat is also provided with a limiting component for limiting the movable rollers.

[0012] The front side of the actuator is also provided with a docking assembly for cooperating with the clamp. The docking assembly includes a vertically arranged docking cylinder, which is installed upside down on the actuator. At the same time, a docking groove is opened on the upper end surface of the clamp to accommodate the piston rod of the docking cylinder. The second linear actuator and the third linear actuator are both installed on the actuator.

[0013] The leather picking and placing unit includes a lifting bracket, which includes an inner and outer movable bracket and a fixed bracket. A support platform for supporting the stretching plate is provided on the upper surface of the movable bracket. The movable bracket is driven by a lifting component to move up and down along the fixed bracket. The fixed bracket is also provided with a second guide rail that is connected to each of the first guide rails. The actuator moves back and forth between the first guide rail and the second guide rail under the drive of the moving roller.

[0014] The lifting assembly includes a lifting rack mounted on a movable bracket and lifting gears mounted on a fixed bracket. There are four lifting racks, which are vertically distributed at the four corners of the movable bracket. A toothed structure is provided on one side of the lifting rack in the first direction and one side in the second direction. The toothed structure in the first direction is defined as the first toothed structure, and the toothed structure in the second direction is defined as the second toothed structure. There are eight lifting gears in total, which mesh with the two toothed structures of the same lifting rack in pairs. The movable bracket is driven to move up and down by a lifting cylinder mounted on the fixed bracket.

[0015] The movable support is also equipped with a positioning component.

[0016] Furthermore, a guide slope is provided on the side of the clamping base plate away from the tensioning plate body, and the guide slope is inclined in a direction that gradually slopes downward from the side of the guide slope close to the tensioning plate body, and the height of the bottom end of the guide slope is lower than the height of the upper end surface of the first guide rail.

[0017] Furthermore, there are two clamping components, which are respectively disposed on both sides of the first guide rail.

[0018] Furthermore, the tension plate body is also provided with a pressure plate assembly that cooperates with the anti-reverse plate at the anti-reverse plate location. The pressure plate assembly includes a pressure plate seat, in which a pressure plate that moves up and down is provided. The pressure plate seat has a cavity for accommodating the installation and up-and-down movement of the pressure plate. The bottom end of the pressure plate is movably engaged with the anti-reverse plate. The top end of the pressure plate is driven to move up and down by a third linear actuator, which in turn causes the anti-reverse plate to swing. A limit component is also provided between the pressure plate and the pressure plate seat.

[0019] The limiting component includes a limiting bolt, which extends horizontally from the outside of the pressure plate seat into the cavity inside the pressure plate seat from the outside to the inside, and the limiting bolt is threadedly fixed to the pressure plate seat. A through hole is opened on the pressure plate to allow the limiting bolt to pass through, and the through hole is an oblong hole that extends in the vertical direction.

[0020] The top of the pressure plate has a horizontally bent section, so that the pressure plate as a whole forms an inverted L-shaped structure.

[0021] There are two pressure plate assemblies, located on both sides of the tension plate body.

[0022] Furthermore, the linkage mechanism is as follows: an active sprocket is provided on the execution seat above the two movable rollers, and a driven sprocket is connected to one side of each of the two movable rollers. The driven sprockets rotate synchronously with the movable rollers, and the active sprockets and driven sprockets rotate synchronously through a linkage chain. The active sprocket is driven to rotate by a walking motor installed on the execution seat, which in turn drives the driven sprockets to rotate, thereby driving the two movable rollers to roll on the first guide rail.

[0023] Furthermore, the limiting component includes a pair of limiting plates disposed at the bottom of the actuator, the two limiting plates being located on both sides of the first guide rail and extending along the long axis of the first guide rail, and the length of the limiting plate being longer than the distance between the two moving rollers.

[0024] The inner sides of the two limiting plates are each provided with a guide block. The guide block extends along the long axis of the limiting plate and has an inclined guide slope on both sides of the long axis of the guide block. The inclination direction of the guide slope is from the center position of the guide block to the end position of the guide block, gradually inclining away from the first guide rail.

[0025] Furthermore, the positioning component includes positioning plates disposed on the movable support. There are four positioning plates in total, with two plates distributed on both sides of the movable support in the second direction. The positioning plates are driven by independent positioning cylinders to move horizontally along the second direction, thereby moving closer to or further away from the tension plate placed on the support platform.

[0026] Furthermore, the lifting gear meshing with the first tooth structure is defined as the first lifting gear, and the lifting gear meshing with the second tooth structure is defined as the second lifting gear. The two first lifting gears on the same side of the movable support are connected by a first linkage shaft to achieve synchronous rotation in the same direction, and the two second lifting gears on the same side of the movable support are connected by a second linkage shaft to achieve synchronous rotation in the same direction.

[0027] The advantages of this invention are as follows: The clamp in this invention, by setting the leather clamping assembly on the side of the first guide rail and controlling the height position between the first toothed structure on the clamping base plate and the first guide rail, allows the leather to move smoothly from the first guide rail to the clamping base plate, avoiding wrinkles and other adverse phenomena caused by the pushing of this clamp, which would affect the subsequent smooth clamping.

[0028] The guide ramp on the clamping base plate is designed to guide the leather, allowing it to smoothly enter between the clamping base plate and the clamping top plate, thus facilitating subsequent clamping of the leather.

[0029] The design of the limiting component, through the cooperation of the limiting bolt and the through hole on the pressure plate, plays a guiding role in the pressure plate when it moves up and down, and also limits the stroke of the pressure plate when it moves up and down.

[0030] The design of the bent section at the top of the pressure plate is to increase the contact area between the pressure plate and the third linear actuator when the pressure plate is driven to move up and down, so that the pressure plate can move up and down smoothly, and the anti-reverse plate can swing smoothly.

[0031] Two pressure plate assemblies are used to cooperate with the anti-reverse plate to realize the up and down swing of the anti-reverse plate, making the up and down swing of the anti-reverse plate more stable and avoiding the phenomenon of jamming between the anti-reverse plate and the tension plate body caused by unilateral drive.

[0032] The actuator is designed to move horizontally on the first guide rail by cooperating with the actuator seat and the moving roller. A limiting component is used to limit the relative position between the actuator seat and the first guide rail. This method of moving the clamp is not limited by the stroke of the drive cylinder, and the clamp can be moved to any position. It also reduces the footprint required by the actuator, making the entire leather tightening device more compact.

[0033] By setting a limiting plate on each side of the bottom of the actuator, the horizontal movement of the actuator is guided and limited, ensuring that the actuator can move horizontally stably on the first guide rail and preventing the actuator from deviating and falling off the first guide rail.

[0034] The guide blocks on the two limit plates are designed to guide and limit the relative position between the actuator and the first guide rail when the actuator switches between two different first guide rails, ensuring that the actuator can smoothly switch between the first guide rails.

[0035] Two lifting gears are used to cooperate with the same lifting rack to realize the up and down movement of the movable bracket. The two toothed structures that cooperate with the two lifting gears are located on two perpendicular sides of the lifting rack. This distribution method ensures that the movable bracket is centered when it moves up and down, ensuring stable up and down movement of the movable bracket and avoiding the phenomenon of the movable bracket shifting during the lifting process. This also achieves stable lifting of the tension plate.

[0036] The positioning component is designed to position the tension plate by setting positioning plates on both sides of the movable bracket in the second direction. Even if the tension plate deviates during transportation, it will be positioned and corrected to improve the accuracy of the tension plate position and provide a good foundation for subsequent smooth docking.

[0037] By cooperating with the first and second linkage shafts, the synchronous rotation of two adjacent first or second lifting gears can be achieved. This design makes the movable support more stable when it is raised and lowered. Attached Figure Description

[0038] Figure 1 is a schematic diagram of the automatic stretching system of the present invention.

[0039] Figure 2 is a schematic diagram of the tensioning plate in this invention.

[0040] Figure 3 is a schematic diagram of the bandage in this invention.

[0041] Figure 4 is a front view of the bandage in this invention.

[0042] Figure 5 is a top view of the bandage in this invention.

[0043] Figure 6 is a schematic diagram of the actuator in this invention.

[0044] Figure 7 is a front view of the actuator in this invention.

[0045] Figure 8 is a top view of the actuator in this invention.

[0046] Figure 9 is a schematic diagram of the skin picking and placing unit in this invention.

[0047] Figure 10 is an enlarged schematic diagram of part A in Figure 9. Detailed Implementation

[0048] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0049] An automatic stretching system, as shown in Figures 1-10, includes a stretching plate, a conveying unit, a drying unit, and a leather picking and placing unit.

[0050] The stretching plate 4 is conveyed by the conveying unit between the leather handling unit and the drying unit. Several first guide rails 1 are arranged radially outward from the center point of the stretching plate 4. Each first guide rail 1 has a stretching clamp, and each clamp is driven by an independent actuator to move closer to or away from the center point of the stretching plate. The conveying unit and drying unit in this embodiment have the same structure and operating principle as the automatic leather stretching and drying machine mentioned in patent CN109306382B, and will not be described in detail in this embodiment.

[0051] The clamp is mounted on a horizontally positioned first guide rail 1 and is driven by an actuator to move horizontally along the extension direction of the first guide rail 1. As shown in the schematic diagrams in Figures 3 and 4, the clamp includes...

[0052] A tension plate body 2 has a through hole inside it to allow a first guide rail 1 to pass through and move. The tension plate body 2 is fitted onto the outside of the first guide rail 1 and slides along it. A docking groove 201 for connecting with a first linear brake is also provided on the upper surface of the tension plate body 2. Positioning the docking groove 201 on the upper surface of the tension plate body 2 facilitates the subsequent docking of the actuator with the tension plate body 2, driving the tension plate body 2 to slide along the first guide rail 1. When the actuator engages with the tension plate body 2, a vertically mounted cylinder is installed at the front of the actuator. The piston rod of the cylinder is inserted into the docking groove 201 to achieve docking between the actuator and the tension plate body 2.

[0053] Two leather clamping assemblies are located on the front side of the main body 2, next to the first guide rail. These assemblies are positioned on opposite sides of the first guide rail 1. The two clamping assemblies on opposite sides of the first guide rail 1 work together to clamp the leather at the same clamping point, resulting in a more stable grip and preventing the leather from detaching from the clamp when the leather is stretched taut, thus ensuring stable clamping of the leather.

[0054] The clamping assembly includes a clamping base plate 201 located on the lower side and a clamping top plate 203 located on the upper side. One side of the clamping base plate 201 is fixedly connected to the tension plate body 2 by bolts. A first tooth structure is provided on the upper end surface of the clamping base plate 202, and the upper end surface of the first guide rail 2 is located between the tooth tip and tooth root of the first tooth structure.

[0055] The clamping top plate 203 is vertically positioned above the clamping bottom plate 201 and hinged to the tension plate body 2. A horizontally extending hinge shaft 204 is also provided on the tension plate body 2. A through hole for the hinge shaft 204 is also provided on the clamping top plate 203. The clamping top plate 203 is directly fitted onto the hinge shaft and rotates and swings along the hinge shaft 204. A first torsion spring is also provided between the clamping top plate 203 and the tension plate body 2, and the first torsion spring is directly fitted onto the hinge shaft. On the connecting shaft 204, the leather is clamped by the cooperation of the clamping top plate 203 and the clamping bottom plate 201. In the clamping state, the clamping top plate 203 is tilted, and the tilting direction of the clamping top plate 203 is gradually tilted from top to bottom towards the tension plate body 2. The clamping top plate 203 is driven by the second linear driver to swing along the connection point between the clamping top plate 203 and the hinge shaft 204, so that the clamping top plate 203 is in contact with or away from the clamping bottom plate 201. The second linear actuator is a vertically positioned cylinder. A plate is also provided at the bottom of the second linear actuator. Through the cooperation of the plate, the two clamping top plates 203 on both sides can be pressed down simultaneously. When cooperating, the second linear actuator drives the plate downward, and the plate presses on the top of the clamping top plate 203, and drives the top of the clamping top plate 203 downward together. Since the clamping top plate 203 is inclined, when the top of the clamping top plate 203 moves downward, the bottom of the clamping top plate 203 moves upward, so that the clamping top plate 203 moves away from the clamping bottom plate 201. When the second linear actuator drives the plate upward, the force applied to the top of the clamping top plate 203 disappears, and the clamping top plate 203 will return to its original position under the action of the first torsion spring and continue to adhere to the clamping bottom plate 201.

[0056] A guide ramp is provided on the side of the clamping base plate 202 away from the stretching plate body 2. The guide ramp slopes downwards gradually from the side closest to the stretching plate body 2, and the bottom of the guide ramp is lower than the top surface of the first guide rail 1. The guide ramp on the clamping base plate 202 is designed to guide the leather, allowing it to smoothly enter between the clamping base plate 202 and the clamping top plate 203, thus facilitating the subsequent clamping of the leather.

[0057] A one-way anti-reverse assembly is provided on the rear side of the tensioning plate body 2. The one-way anti-reverse assembly includes an anti-reverse plate 205 disposed below the first guide rail 1. The middle position of the anti-reverse plate 205 is hinged to the tensioning plate body. A second toothed structure is also provided on the upper end surface of the anti-reverse plate 205. A second torsion spring is also provided between the anti-reverse plate 205 and the tensioning plate body 2 to keep the second toothed structure in contact with the lower end surface of the first guide rail 1. The anti-reverse plate 205 is driven by a third linear actuator to swing up and down along the hinge point between the anti-reverse plate and the tensioning plate body, thereby causing the second toothed structure to contact with or move away from the first guide rail. The third linear actuator is a cylinder.

[0058] On the tensioning plate body 2, at the anti-reverse plate 205, there are also two pressure plate assemblies that cooperate with the anti-reverse plate. These two pressure plate assemblies cooperate with the anti-reverse plate 205 to achieve the up-and-down swing of the anti-reverse plate 205, making the up-and-down swing of the anti-reverse plate 205 more stable and avoiding jamming between the anti-reverse plate 205 and the tensioning plate body 2 caused by unilateral drive.

[0059] The pressure plate assembly includes a pressure plate seat 206, which is integrally formed with the tension plate body 2. A vertically movable pressure plate 207 is provided in the pressure plate seat 206. The pressure plate 207 is a vertical flat plate. A cavity is opened in the pressure plate seat 206 to accommodate the installation and vertical movement of the pressure plate 207. The bottom end of the pressure plate 207 is movably connected to the anti-reverse plate 205. Specifically, a pressure shaft that cooperates with the pressure plate 207 is also provided on the side end of the anti-reverse plate 205. The pressure shaft extends horizontally into the cavity of the pressure plate seat 206. The bottom end of the pressure plate 207 is in contact with the pressure shaft. The downward movement of the pressure plate 207 presses the pressure shaft downward synchronously, thereby realizing the swing of the anti-reverse plate 205.

[0060] The top of the pressure plate 207 is driven to move up and down by the third linear actuator, which in turn causes the stop plate 205 to swing. A transition pressure plate is also provided at the lower end of the third linear actuator. The transition pressure plate is in the shape of an inverted U and cooperates with the two pressure plates 207 respectively, so that only one third linear actuator is needed to drive the two pressure plates 207 downward at the same time.

[0061] A limiting component is also provided between the pressure plate 207 and the pressure plate seat 206. The limiting component includes a limiting bolt 208, which extends horizontally from the outside to the inside of the pressure plate seat 206 into the cavity inside the pressure plate seat 206. The limiting bolt 208 is threadedly fixed to the pressure plate seat 206. A through hole is provided on the pressure plate 207 to allow the limiting bolt 208 to pass through. The through hole is an oblong hole that extends vertically. The design of the limiting component, through the cooperation between the limiting bolt 208 and the through hole on the pressure plate 207, guides the pressure plate 207 when it moves up and down, and also limits the stroke of the pressure plate 207, preventing the pressure plate 207 from exceeding the stroke limit and causing a deviation in the fit between the pressure plate 207 and the anti-reverse plate 205.

[0062] The pressure plate 207 has a horizontally bent section 209 at its top, which makes the pressure plate 207 form an inverted L-shaped structure, and the bent section 209 bends away from the main body 2 of the tension plate. The design of the bent section 209 at the top of the pressure plate 207 is to increase the contact area between the pressure plate 207 and the third linear actuator when the pressure plate 207 is driven to move up and down, so that the pressure plate 207 can move up and down smoothly, and thus the anti-reverse plate 205 can swing smoothly.

[0063] As shown in the schematic diagrams in Figures 6-8, the actuator includes

[0064] An actuator 3 has a pair of movable rollers 301 mounted on its lower side, supported on a first guide rail 1 and rolling along the first guide rail. The two sides of the movable rollers 301 are mounted on the actuator 3 via bearings and bearing housings, and roll in contact with the actuator 3. The two movable rollers 301 are driven by a linkage mechanism to roll synchronously in the same direction. The linkage mechanism consists of a drive sprocket 302 located above the two movable rollers 301 on the actuator 3, and a drive sprocket 302 connected to one side of each of the two movable rollers 301. There is a driven sprocket 303, and the driven sprocket 303 rotates synchronously with the moving roller 301. The driving sprocket 302 and the driven sprocket 303 rotate synchronously through the cooperation of the linkage chain 304. The driving sprocket 302 is driven to rotate by a walking motor 305 mounted on the actuator 3, which in turn drives the driven sprocket 303 to rotate. The rotation of the driven sprocket 303 will drive the two moving rollers 301 to rotate synchronously in the same direction, thereby realizing the horizontal movement of the actuator 3 on the first guide rail 1.

[0065] A limiting component for limiting the movement of the rollers 301 is also provided at the bottom of the actuator 3. The limiting component includes a pair of limiting plates 306 disposed at the bottom of the actuator 3. The two limiting plates 306 are respectively located on both sides of the first guide rail 1 and extend along the long axis of the first guide rail 1. The length of the limiting plate 306 is longer than the distance between the two movement rollers 301, and the height of the bottom end of the limiting plate 306 is lower than the height of the lower end face of the first guide rail 1. By providing a limiting plate 306 on each side of the bottom of the actuator 3, the horizontal movement of the actuator 3 is guided and limited, ensuring that the actuator 3 can move horizontally stably on the first guide rail 1, preventing the actuator 3 from deviating and falling off the first guide rail. Moreover, the limiting plates 306 can also provide a certain degree of protection for the movement of the rollers 301, preventing external factors from interfering with the movement of the rollers 301.

[0066] Each of the two limiting plates 306 has a guide block 307 on its inner side. The guide block 307 is fixed to the limiting plate 306 by bolts. The height of the guide block 307 is lower than the height of the upper end face of the first guide rail 1 and higher than the height of the lower end face of the first guide rail 1. The guide block 307 extends along the long axis of the limiting plate 306. There is an inclined guide slope on both sides of the long axis of the guide block 307. The inclination direction of the guide slope is from the center position of the guide block 307 to the end position of the guide block 307, gradually tilting away from the first guide rail 1. The design of the guide block 307 on the two limiting plates 306 is to guide and limit the relative position between the actuator 3 and the first guide rail 1 when the actuator 3 switches between two different first guide rails 1, ensuring that the actuator 3 can switch between the first guide rails 1 smoothly.

[0067] A docking assembly for cooperating with the clamp 2 is also provided on the front side of the actuator 3. The docking assembly includes a vertically arranged docking cylinder 308, which is installed upside down on the actuator 3. At the same time, a docking groove 201 is opened on the upper end surface of the clamp 2 to accommodate the piston rod of the docking cylinder 308. The second linear actuator and the third linear actuator are also installed on the front side of the actuator 3, and the docking cylinder 308 is located between the second linear actuator and the third linear actuator.

[0068] As shown in the schematic diagrams in Figures 9 and 10, the leather picking and placing unit includes a lifting bracket. The lifting bracket includes a movable bracket 501 and a fixed bracket 5 arranged inside and outside. Both the movable bracket 501 and the fixed bracket 5 are hollow rectangular frame structures welded from several profiles. The fixed bracket 5 has a cavity for placing the movable bracket 501 and allowing it to move up and down. The fixed bracket 5 is also provided with a second guide rail 509 that is connected to each of the first guide rails 1.

[0069] A support platform for supporting the tension plate 4 is provided on the upper surface of the movable bracket 501. The movable bracket 501 is driven by a lifting assembly to move up and down along the fixed bracket 5. The lifting assembly includes a lifting rack 503 installed on the movable bracket 501 and lifting gears installed on the fixed bracket 5. There are four lifting racks 503 in total, which are vertically distributed at the four corners of the movable bracket 501. A toothed structure is provided on one side of the lifting rack 503 in the first direction and one side in the second direction. The toothed structure in the first direction is defined as the first toothed structure 504, and the toothed structure in the second direction is defined as the second toothed structure. There are eight lifting gears in total, which are paired up and mesh one-to-one with the two toothed structures of the same lifting rack 503.

[0070] The lifting gear meshing with the first tooth structure 504 is defined as the first lifting gear 505, and the lifting gear meshing with the second tooth structure is defined as the second lifting gear 506. The two first lifting gears 505 located on the same side of the movable bracket 501 are connected by a first linkage shaft 508 to achieve synchronous and co-directional rotation. The first linkage shaft 508 is mounted on the fixed bracket 5 through the cooperation of a bearing and a bearing seat. The first lifting gear 505 and the first linkage shaft 508 are fixedly connected, thereby achieving synchronous and co-directional rotation of the first lifting gear 505 and the first linkage shaft 508. The two second lifting gears 506 located on the same side of the movable bracket 501 are connected by a second linkage shaft to achieve synchronous and co-directional rotation. The second linkage shaft is also mounted on the fixed bracket 5 through the cooperation of a bearing and a bearing seat. The second lifting gear 506 and the second linkage shaft are fixedly connected, thereby achieving synchronous and co-directional rotation of the second lifting gear 506 and the second linkage shaft. By cooperating with the first linkage shaft 508 and the second linkage shaft, the synchronous rotation of two adjacent first lifting gears 505 or second lifting gears 506 can be achieved. This design makes the movable support 501 more stable when it is raised and lowered.

[0071] The movable support 501 is driven to move up and down by lifting cylinders 507 installed on the fixed support 5. There are four lifting cylinders 507 in total, and they are distributed in pairs on both sides of the movable support 501 in the second direction. The bottom end of the cylinder body of the lifting cylinder 507 is hinged to the fixed support 5. The top end of the piston rod of the lifting cylinder 507 is connected to the movable support 501 through a connecting plate. The two lifting cylinders 507 located on the same side of the movable support 501 are respectively located on both sides of the movable support 501 in the first direction.

[0072] A positioning assembly is also provided on the movable support 501. The positioning assembly includes four positioning plates mounted on the movable support 501, arranged in pairs on both sides of the movable support 501 in the second direction. The positioning plates are driven by independent positioning cylinders to move horizontally along the second direction, thereby moving closer to or further away from the tension plate 4 placed on the support platform. The positioning cylinders are pneumatic cylinders, and their bodies are fixed to the movable support 501. The positioning assembly is designed to position the tension plate 4 by setting positioning plates on both sides of the movable support 501 in the second direction. Even if the tension plate 4 deviates during transport, it will correct its position, improving the accuracy of the tension plate 4's position and providing a good foundation for subsequent smooth docking. The accuracy of the tension plate 4 in the first direction is provided by the conveying device that moves the tension plate 4, so there is no need to set positioning plates in the first direction to correct the position of the tension plate 4. Only positioning plates in the second direction are needed to correct the position of the tension plate 4.

[0073] When the movable support 501 moves up and down, four lifting cylinders 507 provide power to drive the up and down movement of the movable support 501. During the up and down movement of the movable support 501, the first lifting gear 505, the second lifting gear 506 and the lifting rack 503 work together to guide the up and down movement of the movable support 501 from two perpendicular directions at each position, so as to achieve the centering of the movable support 501 relative to the fixed support 5, ensure the stability of the up and down movement of the movable support 501 and avoid the phenomenon of the movable support 501 shifting. The stable up and down movement of the movable support 501 also realizes the stable up and down movement of the tension plate 4 placed on the movable support 501. Then, the positioning plate set on the movable support 501 corrects and positions the tension plate 4 in the second direction, ensuring the accuracy of the tension plate 4 position during subsequent docking.

[0074] Working principle: When clamping leather, firstly, the stretching plate 4 is conveyed to the lifting bracket by the conveying unit and falls on the support platform of the movable bracket 501. The positioning plate corrects and positions the stretching plate 4 in the second direction. Then the movable bracket 501 moves down and drives the stretching plate 4 down to the fixed position. At this time, the second guide rail 509 is connected to the end of the first guide rail 1.

[0075] Secondly, the travel motor 305 operates, driving the drive sprocket 302 to rotate. This, in turn, drives the driven sprocket 303 and the linkage chain 304 to operate the two moving rollers 301. The rotation of the moving rollers 301 causes the actuator 3 to move from the second guide rail 509 to the first guide rail 1 and towards the clamp 2. When the actuator 3 reaches the clamp 2 position, the travel motor 305 stops operating. Then, the docking cylinder 308 operates, inserting the piston rod into the docking groove 201 on the clamp 2. Simultaneously, the second and third linear actuators also move downwards, clamping the top plate 203 on the second linear... Under the action of the linear actuator, the clamping plate 202 is kept away from the clamping base plate 202. The second toothed structure on the anti-reverse plate 205 is kept away from the first guide rail 1 under the action of the third linear actuator. At this time, the locking between the clamping plate and the first guide rail 1 is released. The walking motor 305 continues to work. The clamping body 2 moves along the first guide rail 1 towards the leather under the drive of the actuator 3. When the clamping body 2 moves to the leather, the leather will enter the upper end face of the clamping base plate 202. Then the second linear actuator moves upward, and the clamping top plate 203 is reset under the action of the first torsion spring. Together with the clamping base plate 202, the leather is clamped.

[0076] Then, the walking motor 305 continues to work, pulling the clamping body 2 in the opposite direction, causing the clamping body 2 to move away from the leather, thereby tightening the leather. After moving into position, the third linear drive moves upward, and the anti-reverse plate 205 resets under the action of the second torsion spring, so that the second toothed structure fits against the lower end face of the first guide rail 1. The cooperation of the second toothed structure realizes the one-way anti-reverse fixation of the clamping body 2, preventing the clamping body 2 from moving towards the leather. Then, the actuator contacts the connection with the clamping body 2, and the clamping body 2 remains stationary on the first guide rail 1 under the cooperation of the second toothed structure, thus achieving the tightening of the leather.

[0077] Finally, the docking cylinder 308 moves upward, disengaging from the clamp, and the walking motor 305 continues to work, driving the actuator 3 to move from the first guide rail 1 to the second guide rail 509. Then, the movable bracket 501 moves upward, pushing the stretching plate 4 to the conveying unit. The conveying unit then drives the clamp 4 to move towards the drying unit, thus drying the leather on the stretching plate 4.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An automatic stretching system, characterized in that: The system includes a stretching plate, a conveying unit, a drying unit, and a leather handling unit. The stretching plate is conveyed between the leather handling unit and the drying unit via the conveying unit. The stretching plate has several first guide rails radiating outwards from its center point. Each first guide rail has a stretching clamp, and each clamp is driven by an independent actuator to move closer to or away from the center point of the stretching plate. Each clamp includes a stretching plate body with a through hole for the first guide rails to pass through and move. The stretching plate body is fitted over the first guide rails and also has a mating groove for connecting with a first linear brake. At least one leather clamping assembly is provided on the front side of the main body of the board, located beside the first guide rail. The leather clamping assembly includes a clamping base plate on the lower side and a clamping top plate on the upper side. A first toothed structure is provided on the upper surface of the clamping base plate, and the upper surface of the first guide rail is located between the tooth tip and tooth root of the first toothed structure. The clamping top plate is vertically arranged above the clamping base plate and is hinged to the main body of the stretching board. A first torsion spring is also provided between the clamping top plate and the stretching board body. The leather is clamped by the cooperation of the clamping top plate and the clamping base plate. In the clamping state, the clamping top plate is inclined, and its inclination direction is gradually from top to bottom towards the stretching board body. The clamping top plate is tilted and oscillates, driven by a second linear actuator, to contact or move away from the clamping bottom plate. A one-way anti-reverse assembly is provided on the rear side of the tensioning plate body. This assembly includes an anti-reverse plate located below the first guide rail, hinged to the tensioning plate body at its center. A second toothed structure is also provided on the upper surface of the anti-reverse plate. A second torsion spring is also provided between the anti-reverse plate and the tensioning plate body to keep the second toothed structure in contact with the lower surface of the first guide rail. The anti-reverse plate is driven by a third linear actuator to oscillate up and down along the hinge point between the anti-reverse plate and the tensioning plate body, causing the second toothed structure to contact or move away from the first guide rail. The actuator includes an actuator seat, on the lower side of which is mounted a pair of movable rollers supported on a first guide rail and rolling along the first guide rail. The two movable rollers are driven by a linkage mechanism to roll synchronously in the same direction. The bottom end of the actuator seat is also provided with a limiting component for limiting the movable rollers. The front side of the actuator seat is also provided with a docking component for cooperating with the clamp. The docking component includes a vertically arranged docking cylinder, which is installed upside down on the actuator seat. At the same time, a docking groove is opened on the upper end surface of the clamp to accommodate the piston rod of the docking cylinder. The second linear actuator and the third linear actuator are both mounted on the actuator seat.The leather loading and unloading unit includes a lifting bracket, which comprises an inner and outer movable bracket and a fixed bracket. A support platform for supporting the stretcher is provided on the upper surface of the movable bracket. The movable bracket is driven by a lifting assembly to move up and down along the fixed bracket. The fixed bracket is also provided with second guide rails that mate with each of the first guide rails. The actuator moves back and forth between the first and second guide rails under the drive of moving rollers. The lifting assembly includes a lifting rack mounted on the movable bracket and lifting gears mounted on the fixed bracket. There are four lifting racks, vertically distributed at the four corners of the movable bracket. A toothed structure is provided on one side of the lifting rack in the first direction and one side in the second direction. The toothed structure in the first direction is defined as the first toothed structure, and the toothed structure in the second direction is defined as the second toothed structure. There are eight lifting gears, arranged in pairs, meshing with the two toothed structures of the same lifting rack. The movable bracket is driven by a lifting cylinder mounted on the fixed bracket to move up and down. A positioning assembly is also provided on the movable bracket.

2. The automatic stretching system according to claim 1, characterized in that: The clamping base plate is provided with a guide slope on the side away from the tension plate body, and the guide slope is inclined downward from the side of the guide slope close to the tension plate body. The height of the bottom end of the guide slope is lower than the height of the upper end of the first guide rail.

3. The automatic stretching system according to claim 1, characterized in that: There are two clamping assemblies, which are respectively located on both sides of the first guide rail.

4. The automatic stretching system according to claim 1, characterized in that: The tensioning plate body is equipped with a pressure plate assembly that cooperates with the anti-reverse plate at the anti-reverse plate location. The pressure plate assembly includes a pressure plate base, within which a vertically movable pressure plate is disposed. The pressure plate base has a cavity for accommodating the pressure plate and allowing it to move vertically. The bottom end of the pressure plate is movably engaged with the anti-reverse plate, and the top end of the pressure plate is driven to move up and down by a third linear actuator, causing the anti-reverse plate to swing. A limit assembly is also provided between the pressure plate and the pressure plate base. The limit assembly includes a limit bolt, which extends horizontally from the outside of the pressure plate base into the cavity within the pressure plate base and is threadedly fixed to the pressure plate base. A through hole, which is an oblong hole, is provided on the pressure plate to allow the limit bolt to pass through, and the through hole extends vertically. The top end of the pressure plate has a horizontally bent section, thus forming an inverted L-shaped structure. There are two pressure plate assemblies, located on both sides of the tensioning plate body.

5. The automatic stretching system according to claim 1, characterized in that: The linkage mechanism is as follows: an active sprocket is provided on the execution seat above the two movable rollers, and a driven sprocket is connected to one side of each of the two movable rollers. The driven sprockets and the movable rollers rotate synchronously. The active sprocket and the driven sprockets rotate synchronously through a linkage chain. The active sprocket is driven to rotate by a walking motor installed on the execution seat, which in turn drives the driven sprockets to rotate, thereby driving the two movable rollers to roll on the first guide rail.

6. The automatic stretching system according to claim 1, characterized in that: The limiting assembly includes a pair of limiting plates disposed at the bottom of the actuator. The two limiting plates are respectively located on both sides of the first guide rail and extend along the long axis of the first guide rail. The length of the limiting plates is longer than the distance between the two moving rollers. A guide block is also disposed on the inner side of each of the two limiting plates. The guide block extends along the long axis of the limiting plate and has an inclined guide slope on both sides of the long axis of the guide block. The inclination direction of the guide slope is from the center position of the guide block to the end position of the guide block, gradually tilting away from the first guide rail.

7. The automatic stretching system according to claim 1, characterized in that: The positioning component includes positioning plates mounted on the movable support. There are four positioning plates in total, with two plates distributed on both sides of the movable support in the second direction. The positioning plates are driven by independent positioning cylinders to move horizontally along the second direction, thereby moving closer to or further away from the tension plate placed on the support platform.

8. The automatic stretching system according to claim 1, characterized in that: The lifting gear meshing with the first tooth structure is defined as the first lifting gear, and the lifting gear meshing with the second tooth structure is defined as the second lifting gear. The two first lifting gears on the same side of the movable support are connected by the first linkage shaft to achieve synchronous rotation in the same direction, and the two second lifting gears on the same side of the movable support are connected by the second linkage shaft to achieve synchronous rotation in the same direction.

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