Rotary air supply pneumatic clamping and spreading mechanism

Abstract

The present application relates to the technical field of packaging equipment, and discloses a rotary air supply pneumatic clamping and opening mechanism, which comprises a stand column fixed on a rotary table and a plurality of bag pulling and clamping assemblies with base plates, the plurality of bag pulling and clamping assemblies are arranged in an equidistant circular array along the outer periphery of the top of the stand column, and are suitable for multi-station cyclic operation of a rotary packaging machine; the bag pulling and clamping assembly takes a flat plate base plate as a unified installation reference, and integrates two sets of symmetrical linear sliding pneumatic clamping units and a synchronous opening double-shaft pneumatic driving unit. The bag pulling and clamping assembly is provided with a circumferential array bag pulling and clamping assembly matched with a diagonal self-locking concave-convex pattern clamping block structure, and is driven to rotate by a crank cylinder to clamp in a fan shape. The diagonal pattern engagement can form a diagonal self-locking friction, greatly improves the transverse anti-skid friction of the bag film, and the clamping force is moderate when the bag is loaded in an empty state, so that the thin composite bag will not be damaged, and the material falling tension can be offset when the bag is filled and loaded, thereby effectively solving the problems of bag body slipping and bag opening tearing in the traditional mechanism.

Description

Technical Field

[0001] This invention relates to the field of packaging equipment technology, and specifically to a rotary pneumatic clamping and opening mechanism. Background Technology

[0002] Rotary bag-feeding packaging machines are widely used in automated filling processes for powders and granules. The circumferentially arrayed bag clamping and opening units are the core actuators of the machine, directly determining the filling stability and production yield. Existing traditional pneumatic bag clamping and opening mechanisms only have independent clamping cylinders and opening cylinders, relying on a single layer of flat clamping blocks to clamp both ends of the bag opening to complete the locking and widening. This structural design has several inherent defects and is difficult to adapt to the continuous processing conditions of heavy-load materials and thin composite flexible packaging bags. Poor bag clamping and anti-slip capability, prone to slippage and tearing: Traditional mechanisms only use smooth or straight-lined single-layer clamping blocks to hold the bag film, resulting in limited clamping friction. During the filling process, the bag body and internal material generate a vertical downward load, which easily causes the bag film to slide laterally along the clamping block surface and fall off as a whole. If the cylinder clamping air pressure is increased to improve the clamping force, the stress will be concentrated at the local biting position at the bag opening. Thin composite packaging bags are prone to film layer delamination and bag opening tearing, making them unsuitable for continuous filling of high-load materials.

[0003] The clamping force cannot be adaptively adjusted according to the filling load: The clamping force of the existing clamping mechanism is entirely determined by the preset air pressure of the cylinder. The clamping force remains constant under both no-load feeding and full-load filling conditions. When the clamping force is too large when the bag is unloaded, it is easy to damage the bag film. When the bag is fully loaded, the clamping force is insufficient and cannot offset the downward pull of the material. There is no gravity adaptive pressure boosting structure, and it cannot dynamically increase the biting and locking force according to the real-time load of the bag body. The range of bag types and filling weights that can be adapted is narrow.

[0004] The lack of a double-layer composite pressure-bearing clamping structure leads to concentrated shear stress on the bag film: Traditional mechanisms rely on a single-layer clamping block to contact the bag film, and the vertical gravity of filling is concentrated on the narrow clamping and biting line. The bag film is subjected to huge shearing and tensile forces locally, and composite films and soft plastic bags are very easy to delaminate and break; without an independent planar pressure-bearing support structure to distribute the vertical load, the scrap rate of thin bag processing is high. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, this invention provides a rotary pneumatic clamping and opening mechanism that effectively solves the problems of poor bag clamping and anti-slipping ability, easy slippage and tearing failures, and inability of clamping force to adaptively adjust with filling load.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides a rotary pneumatic clamping and opening mechanism, including a column fixed on a rotating table and several sets of bag stretching clamping assemblies with base plates. The several sets of bag stretching clamping assemblies are arranged in an equally divided circular array along the outer periphery of the top of the column, which is suitable for multi-station cyclic operation of rotary packaging machines. The stretching bag clamping assembly uses a flat substrate as a unified mounting reference and integrates two sets of symmetrical linear sliding pneumatic clamping units and a synchronously opening dual-axis pneumatic drive unit; the two sets of pneumatic clamping units are symmetrically assembled on the substrate platform through linear sliding pairs of moving seats. A single pneumatic clamping unit includes a crank-hinged bag-clamping cylinder, a coaxially paired reference positioning part, and a fan-shaped rotary part. An adaptive composite clamping anti-slip component is assembled between the clamping end faces of the positioning part and the rotary part. The bag-clamping cylinder is used to drive the rotary part to rotate around the coaxial center in a fan shape to complete the single-sided clamping and locking of the bag. The drive cylinder of the dual-axis pneumatic drive unit is used to push and pull the two sets of moving seats in opposite directions / backwards in a bidirectional synchronous manner to realize the bidirectional opening and flaring of the packaging bag opening. The anti-slip assembly includes a pair of interlocking clamping blocks. The two clamping blocks are rigidly assembled on the clamping end faces of the positioning part and the rotating part, respectively. The clamping blocks have oblique self-locking grooves on their mating surfaces. When the clamping blocks are closed and clamped, the oblique grooves on both sides interlock and rely on the friction of the oblique surfaces to increase the clamping friction of the bag film, thereby inhibiting the bag from slipping, stretching, and tearing during the filling process.

[0007] Furthermore, multiple sets of resistance strain gauge load cells are evenly distributed in a ring at the bottom of the column. The base plate of each bag clamping component is rigidly locked to the force measuring end of the load cell, forming an independent workstation material weight real-time acquisition unit. The acquired load signal is transmitted to the equipment to realize closed-loop control of filling weight and rejection of out-of-tolerance items. The top of the column is equipped with a non-winding rotating air source rotary box; a dynamic sealing air source rotary joint is set in the center of the air source rotary box, and the rotary joint is connected to the main fixed air source pipeline in the workshop; multiple independent distribution joints are arranged on the outer periphery of the air source rotary box, and each distribution joint is connected to all the actuator cylinders through an independent high-pressure branch pipe, so as to achieve non-winding air pipe and stable equal air supply under the 100° rotation condition.

[0008] Furthermore, the reference positioning part is rigidly fixed to the top surface of the moving seat, and the rotating part forms a coaxial rotary motion pair with the positioning part through a concentric rotary bearing; The bag clamping cylinder adopts a crank-connecting rod structure with hinged ends: the rear end of the bag clamping cylinder body is hinged to the moving seat mounting platform through a hinge seat one, and the end of the extension piston rod of the bag clamping cylinder is hinged to the side ear of the rotating part through a hinge seat two; when the cylinder piston rod retracts, it pulls the rotating part to rotate outward in a fan shape, and the clamping port opens to allow the bag to be fed; when the piston rod extends, it pushes the rotating part to rotate inward and close, forming a clamping surface with the positioning part to complete the single-sided locking of the bag.

[0009] Furthermore, the driving cylinder is a synchronous bidirectional output dual-axis cylinder. The two telescopic piston rods of the driving cylinder are respectively hinged to the two movable seats on both sides through the hinge seat three, and output push-pull driving force in both directions synchronously to drive the two sets of movable seats to slide towards each other / backward along the base plate guide rail. The center of the top surface of the substrate is equipped with a synchronous balancing frame via a rotary shaft. Two synchronous connecting rods are respectively hinged to the left and right ends of the balancing frame. The other end of the connecting rod is hinged to the corresponding moving seat via a hinge shaft, forming a parallelogram synchronous constraint linkage mechanism. The synchronous swing of the balancing frame constrains the sliding stroke and sliding speed of the moving seats on both sides to be completely consistent, eliminating the defects of asymmetrical opening of the bag mouth and unilateral stretching deformation of the bag film.

[0010] Furthermore, the anti-slip assembly also includes mounting blocks and a flat clamping plate; the two mounting blocks are respectively fixed to the positioning part and the clamping end face of the rotating part, serving as a layered mounting carrier for the clamping block and the flat clamping plate; The clamping block and the flat clamping plate are assembled in layers on the opposite clamping surfaces of the two mounting blocks. The flat clamping plate is arranged horizontally below the clamping block. The clamping block provides lateral anti-slip friction through the oblique concave and convex textures. The flat clamping plate forms a large-area pressure-bearing support surface to bear the vertical gravity of the filling material. The double-layer composite clamping disperses the local shear stress of the bag film and avoids tearing of the bag opening and delamination of the composite film.

[0011] Furthermore, both mounting blocks have a built-in gravity adaptive pressure boosting unit inside their cavities; the gravity adaptive pressure boosting unit includes multiple sets of hinge frames, a vertical reset elastic element, and a vertical sliding seat; Multiple hinge brackets are hinged at one end to the back of the clamping block, and the other end of the hinge bracket extends through the hinge opening on the surface of the mounting block to the inner cavity and is hinged to the cavity fulcrum; the sliding seat is rigidly fixed to the back of the clamping block, and the sliding seat passes through the vertical slide groove of the mounting block to form a vertical linear sliding pair; an elastic element is pre-installed vertically at the bottom of the inner cavity of the mounting block, and in normal condition, it continuously pushes the sliding seat upward to realize the automatic reset of the clamping block under no-load; When the bag is filled and a downward load is generated, the clamping block pulls down with the bag, causing the sliding seat to vertically compress the elastic element. Multiple sets of hinged frames synchronously retract inward with the internal fulcrum as a lever, converting the vertical downward displacement into a horizontal inward pressing force of the clamping block, achieving an adaptive pressurization effect where the greater the load, the synchronously enhanced clamping self-locking force. The flat clamping plate is assembled at the bottom of the clamping block and moves vertically in sync with the clamping block.

[0012] Furthermore, a positioning conversion port is opened in the middle of a single hinge frame. The inner cavity of the hinge port is coaxially fixed to the positioning shaft. The hinge frame is sleeved on the outer surface of the positioning shaft through the conversion port and can swing back and forth around the positioning shaft to form a force-saving lever transmission fulcrum. The inner cavities of the two mounting blocks are equipped with inclined surface force conversion wedge transmission units, which are used to receive the vertical displacement driving force transmitted by the hinge frame, converting the vertical downward movement of the clamping block into the horizontal feeding movement of the flat clamping plate towards the bag body, so as to realize the synchronous pressure locking of the double-layer clamping elements.

[0013] Furthermore, the planar clamping plate is assembled to the bottom of the clamping block via a horizontal sliding pair, and can extend and retract laterally; the wedge-shaped transmission unit includes a vertical sliding sleeve, a horizontal sliding sleeve, and an inclined transmission wedge block; The sliding sleeve is vertically slidably assembled on the mounting block surface, and the sleeve block is horizontally embedded in the inner cavity of the sliding sleeve to form a transverse sliding pair; the outer end of the sleeve block is rigidly connected to the flat clamping plate, and the inner end of the sleeve block is equipped with a low-friction roller, which continuously conforms to the inclined transmission slope of the wedge block. When the clamping block is pulled vertically downward, it simultaneously drives the sliding sleeve frame to move downward. The roller rolls along the inclined surface of the wedge block, converting the vertical displacement into the horizontal feed displacement of the sleeve block, which pushes the flat clamping plate to press the bag body inward simultaneously.

[0014] Furthermore, the wedge block is horizontally slidably assembled into the inner cavity of the mounting block; the outer wall of the mounting block is threaded with a stroke adjustment bolt, the inner end of which extends into the cavity and is rotatably connected to the end face of the wedge block; rotating the adjustment bolt can drive the wedge block to move horizontally, change the initial contact height of the inclined surface and the transmission stroke, and precisely adjust the pre-tightening clamping force of the flat clamping plate base to adapt to packaging bags of different thicknesses and toughnesses. An embedded sliding groove is provided on the inner side of the flat clamping plate, and a force-bearing block is horizontally slidably assembled in the sliding groove. The force-bearing block is rigidly fixed to the sleeve block. A second horizontal reset elastic element is pre-installed between the force-bearing block and the side wall of the sliding groove. The second elastic element provides a pre-tightening force for loosening and resetting, and at the same time buffers the instantaneous impact load of the inclined plane transmission to avoid rigid extrusion and scratching the surface of the bag film.

[0015] Furthermore, a pre-supported bag-opening cylinder is vertically mounted in the center of the top surface of the substrate, and the negative pressure suction nozzle is rigidly fixed at the telescopic end of the bag-opening cylinder; the static initial position of the suction nozzle protrudes from the bag opening clamping baseline in advance, forming an independent pre-support structure in the middle of the bag opening. Multiple sets of negative pressure adsorption holes are evenly opened on the outer adsorption surface of the adsorption nozzle. The adsorption nozzle is connected to the air source rotary box distribution connector through a negative pressure pipeline. The negative pressure generator forms a stable negative pressure adsorption field in the adsorption hole area. After the pneumatic clamping units on both sides clamp the two ends of the bag opening, the adsorption nozzle adsorbs the film on the back of the bag body under negative pressure. The bag opening cylinder retracts backward in sync, pulling the middle of the bag body to bulge backward. With the help of the moving seats on both sides, the bag body is opened in both directions, so that the front and back of the bag body form a symmetrical bulge and a complete filling channel, which solves the problems of bag film sticking in the same direction and bag opening failure.

[0016] The technical solution provided by this invention has the following advantages compared with the prior art: 1. This invention employs a circumferential array stretching bag clamping assembly paired with an oblique self-locking textured clamping block structure. It utilizes a crank cylinder to drive a fan-shaped rotary clamping mechanism, while a dual-axis cylinder simultaneously opens the bag opening. The oblique meshing creates a self-locking friction on the inclined surface, significantly improving the lateral anti-slip friction of the bag film. During unloaded feeding, the clamping force is moderate and will not damage the thin composite bag. During filling, it can counteract the downward pull of the material, effectively solving the problems of bag slippage and tearing at the bag opening in traditional mechanisms. The synchronous dual-axis cylinders, in conjunction with a parallel linkage mechanism, ensure that the opening stroke on both sides of the bag opening is completely consistent, avoiding unilateral stretching deformation.

[0017] 2. This invention designs a double-layer composite clamping structure consisting of a clamping block and a flat clamping plate, and incorporates a gravity-adaptive pressure-boosting unit to optimize clamping performance from both stress dispersion and load self-pressure boosting aspects. The upper twill clamping block resists lateral slippage of the bag film, while the lower large-area flat clamping plate bears the vertical gravity of filling, dispersing the concentrated shear stress generated by single-layer clamping, preventing composite film delamination and damage, and reducing bag scrap rate.

[0018] 3. The wedge-shaped transmission unit of this invention can convert the vertical displacement of the clamping block into the horizontal feed of the planar clamping plate, realizing synchronous pressure locking of the double-layer clamping elements. The rotating adjusting bolt can move the wedge block horizontally, adjusting the inclined plane transmission stroke and the clamping plate preload; the planar clamping plate has a built-in force-bearing block and a horizontal reset elastic element, which automatically retracts when the clamp is released, and can also buffer the instantaneous impact of the inclined plane transmission to avoid rigid compression scratching the bag film; under the action of gravity, the clamping plate synchronously presses the bag body inward, and works together with the upper clamping block to further balance the pressure of the bag film, improve the stability of heavy-duty filling clamping, and extend the service life of the packaging bag. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional structural view of the present invention; Figure 2 This is a top view of the structure of the present invention; Figure 3 This is a schematic diagram of the structure of the column of the present invention; Figure 4 This is a schematic diagram of the structure of the stretch bag clamping assembly of the present invention; Figure 5 This is a schematic diagram illustrating the clamping principle of the stretch bag clamping assembly of the present invention; Figure 6 This is a schematic diagram of the stretch bag clamping assembly with an adsorption nozzle according to the present invention; Figure 7For the present invention Figure 6 Top view of the structure; Figure 8 This is a schematic diagram of the pneumatic clamping unit of the present invention. Figure 9 This is a schematic diagram of the anti-slip component of the present invention; Figure 10 This is a partial cross-sectional view of the anti-slip component of the present invention; Figure 11 This is an exploded view of the structure of the clamping block, mounting block, and planar clamping plate of the present invention; Figure 12 For the present invention Figure 11 A structural side view.

[0021] The labels in the diagram represent: 10. Column; 11. Weighing sensor; 12. Air source rotary box; 20. Bag clamping assembly; 21. Base plate; 22. Movable seat; 23. Drive cylinder; 24. Bag clamping cylinder; 25. Balance frame; 26. Connecting rod; 27. Bag opening cylinder; 28. Suction nozzle; 30. Anti-slip assembly; 31. Clamping block; 32. Mounting block; 33. Flat clamping plate; 34. Reinforcing unit; 341. Hinge frame; 342. Elastic element one; 343. Sliding seat; 344. Positioning shaft; 35. Wedge-shaped transmission unit; 351. Sliding sleeve; 352. Sleeve block; 353. Wedge block; 354. Adjusting bolt; 355. Force-bearing block; 356. Elastic element two; 1. Positioning part; 2. Rotating part; 3. Embossed texture; 4. Transformation port; 5. Baseline. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] The present invention will be further described below with reference to embodiments.

[0024] Example 1: Please see Figures 1 to 12This invention provides a technical solution: a rotary pneumatic clamping and opening mechanism. This mechanism adopts an integrated rotary packaging execution architecture of a central rotating column 10 and a circular array of bag-stretching clamping components 20, which is suitable for the cyclic operation of a rotary fully automatic bag-feeding packaging machine. The core supporting body is the vertical rotating column 10, and the whole machine can rotate 360° with the bottom rotating table. Multiple sets of bag-stretching clamping components 20 are arranged in an equally divided circular array along the outer circle of the top of the column 10, realizing the parallel operation of bag picking, bag opening, filling, and sealing processes at multiple workstations, which greatly improves the workstation utilization rate and production cycle of the rotary packaging equipment.

[0025] The single-unit bag clamping assembly 20 uses the flat substrate 21 as the mounting reference carrier, integrating a symmetrical dual pneumatic clamping unit and a synchronous opening pneumatic drive unit with a drive cylinder 23 to form a two-stage pneumatic execution system of "bag clamping and locking + bag opening". The two sets of pneumatic clamping units are symmetrically assembled on the table surface of the substrate 21 based on the linear sliding pair of the moving seat 22. Each unit is coaxially equipped with a fixed positioning part 1 and a rotatable rotating part 2, and is matched with a bag clamping cylinder 24 to form a fan-shaped rotary clamping pair; the dual-axis drive cylinder 23 synchronously drives the two moving seats 22 to slide linearly towards / away from each other, completing the left and right double-sided opening and widening action of the packaging bag.

[0026] An anti-slip assembly 30 is integrated between the clamping end faces of the positioning part 1 and the rotating part 2. The core clamping element is a pair of clamping blocks 31. The two clamping blocks 31 are machined with oblique concave and convex textures 3 on their opposite sides. Based on the principle of self-locking friction of oblique tooth surface, after the clamping blocks 31 are closed, the two sets of oblique concave and convex textures 3 interlock and mesh with each other, which greatly improves the friction coefficient of the bag film interface, offsets the downward gravity component force brought by the filling material, solves the industry defects such as slippage during clamping of thin plastic packaging bags, filling falling off, and stretching and tearing of bag mouth, and achieves stable clamping and locking of heavy materials.

[0027] See attached document Figure 3 The bottom of the column 10 integrates a distributed gravity weighing sensor detection system, with multiple sets of weighing sensors 11 evenly distributed in a ring. The base plate 21 is rigidly connected to the force measuring end of the weighing sensor 11, enabling each set of bag clamping assembly 20 to form an independent weighing acquisition station. The weighing sensor 11 is based on the force measurement principle of resistance strain gauges, and collects the total load data of the material inside the clamped bag in real time. It converts the analog weight signal into a digital signal and transmits it to the equipment PLC control system, realizing closed-loop monitoring of filling weight, out-of-tolerance alarm, and material shortage rejection, ensuring the accuracy of material conveying and metering, and adapting to the needs of automated filling process control for quantitative powders, granules, and liquids.

[0028] The top of the column 10 is equipped with an air source rotating box 12, which is a non-winding rotating air supply and distribution mechanism: one end of the central air source rotating joint of the air source rotating box 12 is connected to the main fixed air source pipeline in the workshop, and the other end rotates synchronously with the column 10. The internal multi-channel independent air chambers are isolated. Several distribution joints on the air source rotating box 12 are connected to all the cylinders (bag clamping cylinder 24, drive cylinder 23, and bag opening cylinder 27) through independent high-pressure branch pipes. It adopts a dynamic sealing labyrinth-type airtight structure, so there is no air pipe winding and no air leakage pressure drop during the rotation process. It solves the problems of air pipe wear, pipeline interference, and uneven air supply pressure of multiple cylinders in traditional rotating mechanisms, and provides a stable and equally distributed pneumatic power source for all the bag stretching clamping components 20 in the circumferential array.

[0029] See attached document Figures 4 to 8 The positioning part 1 is a fixed reference clamping seat, rigidly locked onto the moving seat 22; the rotating part 2 forms a coaxial rotational kinematic pair with the positioning part 1 through a concentric slewing bearing, and the two share the same clamping rotation center axis. The bag clamping cylinder 24 adopts a crank-connecting rod drive structure with hinged ends: the rear end of the bag clamping cylinder 24 is hinged to the top mounting platform of the moving seat 22 through a hinge seat one, and the telescopic end of the bag clamping cylinder 24 is hinged to the side ear of the rotating part 2 through a hinge seat two, forming a crank-slider transmission mechanism.

[0030] When the piston rod of the bag clamping cylinder 24 retracts, it pulls the rotating part 2 to rotate outward in a fan shape around the coaxial center of the positioning part 1, and the clamping opening of the positioning part 1 and the rotating part 2 opens, completing the feeding and placement of the packaging bag; when the piston rod of the bag clamping cylinder 24 extends, it pushes the rotating part 2 to rotate inward and close, forming a clamping surface with the positioning part 1, completing the single-sided locking and clamping of the packaging bag.

[0031] See attached document Figure 4 , Figure 6 and Figure 7 The bag opening is powered by a dual-axis drive cylinder 23. The two ends of the two telescopic piston rods of the drive cylinder 23 are respectively hinged to two sets of moving seats 22 through the hinge seat three. The extension and retraction of the drive cylinder 23 directly outputs bidirectional synchronous push and pull driving force, which drives the two moving seats 22 to slide towards each other / backward along the linear guide rail of the base plate 21 to complete the bag opening or closing action.

[0032] The top center of the substrate 21 is rotatably connected to the balance frame 25 via a rotating shaft. Two connecting rods 26 are hinged to the left and right ends of the balance frame 25, respectively. The other ends of the two connecting rods 26 are hinged to the corresponding moving seats 22 via hinge shafts, forming a parallelogram synchronous linkage constraint mechanism. Based on the principle of rigid body parallel transmission, when the drive cylinder 23 outputs power, the balance frame 25 swings synchronously to constrain the sliding stroke and sliding speed of the moving seats 22 on both sides to be completely consistent. This eliminates the defects of left and right stroke offset and asymmetrical bag opening that are easy to occur in single cylinder double-sided drive, ensuring that the bag opening opens evenly, preventing one-sided bag film deformation and bag opening skew, and providing a regular rectangular feeding channel for filling.

[0033] See attached document Figures 8 to 12 The anti-slip assembly 30 adopts a double-layer composite clamping structure with upper clamping block 31 with oblique meshing clamping and lower flat clamping plate 33 with planar pressure clamping. It consists of mounting block 32, clamping block 31, and flat clamping plate 33. The two mounting blocks 32 are rigidly fixed to the clamping end faces of positioning part 1 and rotating part 2, respectively, serving as a unified mounting base for clamping block 31 and flat clamping plate 33. The clamping block 31 and flat clamping plate 33 are assembled in layers on the opposing clamping surfaces of the two mounting blocks 32, with the flat clamping plate 33 horizontally arranged below the clamping block 31.

[0034] Working mechanics logic: The oblique concave-convex groove 3 meshing structure of the clamping block 31 mainly provides horizontal anti-slip friction to resist the lateral slippage of the packaging bag; the lower flat clamping plate 33 forms a large-area planar support and pressure-bearing area to bear the vertical downward gravity load brought by the filling material and disperse the local stress of the bag film. If the clamping block 31 relies solely on the meshing point of the oblique concave-convex groove 3 for force, the bag's own weight will be concentrated on the oblique groove meshing line, generating huge shearing and tensile forces, which can easily cause the composite film to delaminate and the bag opening to tear; the double-layer clamping evenly distributes the gravity load to the entire contact area of ​​the flat clamping plate 33, greatly reducing the shear stress at the meshing point of the oblique concave-convex groove 3, while taking into account both anti-slip and packaging bag surface protection functions.

[0035] See attached document Figures 10 to 12 Both mounting blocks 32 have built-in gravity-type reinforcing units 34. The gravity-type reinforcing unit 34 consists of a composite linkage transmission mechanism composed of several hinge frames 341, elastic element 342, and sliding seat 343. One end of the multiple hinge frames 341 is hinged to the back of the clamping block 31, and the other end of the hinge frame 341 extends through the hinge opening on the surface of the mounting block 32 into the cavity of the mounting block 32 and is hinged to the fulcrum inside the cavity. The sliding seat 343 is rigidly fixed to the back of the clamping block 31 and slides vertically through the vertical groove of the mounting block 32. The elastic element 342 is vertically fixed to the bottom of the inner cavity of the mounting block 32 and continuously applies a pre-tightening reset elastic force to the sliding seat 343 upward under normal conditions.

[0036] Under no-load bag opening conditions, the elastic element 342 pushes the sliding seat 343 upward, causing the clamping block 31 to remain in the reset state; when the filling material inside the bag generates a downward gravity load, the packaging bag pulls the clamping block 31 to slide downward vertically, and the sliding seat 343 simultaneously presses down to compress the elastic element 342. Multiple sets of hinge frames 341 use the hinge fulcrum inside the mounting block 32 as levers to synchronously retract and swing inward, converting the vertical displacement of the clamping block 31 into a horizontal inward clamping force, automatically increasing the meshing and clamping force of the two sets of clamping blocks 31 with oblique concave and convex textures 3, realizing an adaptive pressure enhancement effect where the greater the load, the automatically enhanced clamping force, adapting to the anti-dropping requirements of filling heavy materials; the flat clamping plate 33 is assembled as a whole at the bottom of the clamping block 31, synchronously following the clamping block 31 to complete vertical linkage.

[0037] See attached document Figures 10 to 12 Each hinge frame 341 has a conversion port 4 in the middle, and a positioning shaft 344 is coaxially fixed inside the hinge port. The hinge frame 341 is sleeved on the outer surface of the positioning shaft 344 through the conversion port 4. The hinge frame 341 can swing freely back and forth around the positioning shaft 344, forming a force-saving lever transmission fulcrum. When the clamping block 31 slides down under the weight of the packaging bag, multiple sets of hinge frames 341 synchronously retract and swing inward, synchronously transmitting the driving force for the vertical downward movement of the clamping block 31 to the input end of the wedge-shaped transmission unit 35.

[0038] Both mounting blocks 32 are equipped with wedge-shaped transmission units 35. The wedge-shaped transmission units 35 receive the vertical displacement driving force transmitted by the hinge frame 341, converting the vertical linear motion into the horizontal feeding motion of the flat clamping plate 33 towards the bag body. This drives the two clamping elements, clamping block 31 and flat clamping plate 33, to press inward synchronously, simultaneously increasing the clamping pressure of the double-layer clamping. This avoids local stress concentration and damage to the bag film caused by only a single layer of clamping being subjected to force, and achieves synchronous adaptive reinforcement of the double-layer clamping under gravity load.

[0039] Example 2: The difference from Example 1 is that; See attached document Figures 10 to 12 The flat clamping plate 33 is mounted on the bottom of the clamping block 31 via a horizontal sliding pair and can freely extend and retract in the horizontal direction. The wedge-shaped transmission unit 35 consists of a sliding sleeve 351, a sleeve block 352, and a wedge block 353, forming an inclined displacement amplification transmission pair. The sliding sleeve 351 is vertically slidably mounted on the vertical surface of the mounting block 32. The sleeve block 352 is horizontally embedded in the inner cavity of the sliding sleeve 351 and can slide laterally. The outer end of the sleeve block 352 is connected to the flat clamping plate 33, and the inner end of the sleeve block 352 is equipped with a low-friction roller. The roller is in continuous contact with the inclined surface of the wedge block 353.

[0040] When the clamping block 31 slides downward, it drives the sliding sleeve frame 351 to move vertically downward simultaneously. The roller at the end of the sleeve block 352 rolls along the inclined surface of the wedge block 353. The inclined surface structure converts the vertical downward displacement into the horizontal feed displacement of the sleeve block 352 towards the packaging bag, pushing the flat clamping plate 33 to press the bag body inward simultaneously, completing the force conversion from vertical gravity to horizontal clamping force. The wedge block 353 is horizontally slidably assembled in the inner cavity of the mounting block 32. The outer wall of the mounting block 32 is threaded with an adjusting bolt 354. The inner end of the adjusting bolt 354 extends into the cavity and is rotatably connected to the end face of the wedge block 353. Rotating the adjusting bolt 354 can drive the wedge block 353 to move horizontally, changing the initial contact height of the inclined surface and the effective transmission stroke, accurately adjusting the maximum horizontal feed of the flat clamping plate 33, and correspondingly adjusting the clamping pre-tightening force of the basic plane of the flat clamping plate 33 to adapt to the clamping force adjustment of packaging bags with different thicknesses and toughnesses.

[0041] An embedded groove is provided on the inner side of the flat clamping plate 33. A force-bearing block 355 is horizontally slidably assembled inside the embedded groove. The force-bearing block 355 is rigidly fixed to the sleeve block 352. An elastic element 356 is arranged between the force-bearing block 355 and the side wall of the embedded groove. The elastic element 356 provides a horizontal reset pre-tightening force. When the clamping is released, it pushes the flat clamping plate 33 to automatically retract and reset. At the same time, it buffers the instantaneous impact load generated by the inclined transmission of the wedge block 353, and avoids the flat clamping plate 33 rigidly squeezing and scratching the surface of the packaging bag film.

[0042] Example 3: The difference from Example 1 is that; See attached document Figure 6 and Figure 7 A bag-opening cylinder 27 is vertically fixed in the center of the top surface of the substrate 21. The extension end of the bag-opening cylinder 27 is rigidly fixed to the suction nozzle 28. The static initial position of the suction nozzle 28 is pre-protruding from the bag mouth clamping baseline 5, forming an independent pre-support structure in the middle of the bag mouth. Traditional double-sided clamping relies solely on the moving seat 22 to push the left and right ends of the bag mouth inward. The front and back sides of the bag film are prone to simultaneous and unidirectional bending and adhesion, and the middle of the bag mouth cannot form an effective filling channel. This structure first uses the suction nozzle 28 to support the middle of the bag mouth to form an arc-shaped protrusion, so that the front and back of the bag body protrude in the same direction. Then, the suction nozzle 28 contracts and the back of the bag body is adsorbed by negative pressure (at this time, since the front of the bag body is already in a protruding state, the back of the bag body protrudes in the opposite direction by the contraction of the suction nozzle 28 and the negative pressure adsorption on the back of the bag body, forming a symmetrical protrusion of the front and back of the bag body). Finally, the moving seats 22 on both sides move in opposite directions to increase the two protrusion ranges, solving the bag mouth adhesion and bag opening failure faults from the root of the structure.

[0043] The suction nozzle 28 has several negative pressure holes evenly distributed on its outer suction surface. The suction nozzle 28 is connected to the air source rotary box 12 distribution connector via a negative pressure air pipe. The negative pressure generator continuously forms a stable negative pressure suction field in the suction hole area. After the pneumatic clamping units on both sides clamp the left and right ends of the bag opening, the suction nozzle 28 uses negative pressure to suction the film on the back of the packaging bag. Simultaneously, the bag opening cylinder 27 retracts backward, pulling the middle of the back of the bag to bulge backward. Combined with the opposing sliding of the two moving seats 22, the bag opening is opened, forming a complete filling opening. This solves the problem that simply moving two pneumatic clamping units in opposite directions can cause the front and back of the bag to bend in the same direction, leading to bag opening failure.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rotary pneumatic clamping and opening mechanism, characterized in that: It includes a column (10) fixed on a rotating platform and several sets of stretch bag clamping assemblies (20) with base plates (21). The several sets of stretch bag clamping assemblies (20) are arranged in an equally divided circular array along the outer periphery of the top of the column (10). The stretching bag clamping assembly (20) uses the flat substrate (21) as a unified installation reference and integrates two sets of symmetrical linear sliding pneumatic clamping units and a synchronous opening dual-axis pneumatic drive unit; the two sets of pneumatic clamping units are symmetrically assembled on the substrate (21) table surface through the linear sliding pair of the moving seat (22); A single pneumatic clamping unit includes a crank-hinged bag clamping cylinder (24), a coaxially paired reference positioning part (1), and a fan-shaped rotary part (2). An adaptive composite clamping anti-slip assembly (30) is assembled between the clamping end faces of the positioning part (1) and the rotary part (2). The bag clamping cylinder (24) is used to drive the rotary part (2) to rotate around the coaxial center in a fan shape to complete the single-sided clamping and locking of the bag. The drive cylinder (23) of the dual-axis pneumatic drive unit is used to push and pull the two sets of moving seats (22) in both directions synchronously to slide towards each other / backwards, so as to realize the bidirectional opening and expansion of the packaging bag opening. The anti-slip assembly (30) includes a pair of interlocking clamping blocks (31). The two clamping blocks (31) are rigidly assembled on the clamping end faces of the positioning part (1) and the rotating part (2), respectively. The clamping blocks (31) have oblique self-locking grooves (3) machined on their respective contact surfaces. When the clamping blocks (31) are closed and clamped, the oblique grooves (3) on both sides interlock. The anti-slip assembly (30) also includes mounting blocks (32) and flat clamping plates (33); the two mounting blocks (32) are respectively fixed to the clamping end faces of the positioning part (1) and the rotating part (2), serving as the layered mounting carriers for the clamping blocks (31) and the flat clamping plates (33); The clamping block (31) and the flat clamping plate (33) are assembled in layers on the opposite clamping surfaces of the two mounting blocks (32). The flat clamping plate (33) is arranged horizontally below the clamping block (31). The clamping block (31) provides lateral anti-slip friction by relying on the oblique concave and convex texture (3). The flat clamping plate (33) forms a large area of ​​pressure-bearing support surface to bear the vertical gravity of the filling material. Both mounting blocks (32) have a gravity adaptive pressure boosting unit (34) built into their inner cavities; the gravity adaptive pressure boosting unit (34) includes multiple sets of hinge frames (341), a vertical reset elastic element (342), and a vertical sliding seat (343); One end of multiple hinge brackets (341) is hinged to the back of the clamping block (31), and the other end of the hinge brackets (341) passes through the hinge opening on the surface of the mounting block (32) and extends to the inner cavity to be hinged to the cavity fulcrum; the sliding seat (343) is rigidly fixed to the back of the clamping block (31), and the sliding seat (343) passes through the vertical slide groove of the mounting block (32) to form a vertical linear sliding pair; the elastic element (342) is vertically pre-installed at the bottom of the inner cavity of the mounting block (32), and in normal condition, it continuously pushes the sliding seat (343) upward to realize the automatic reset of the clamping block (31) under no-load; When the bag is filled and a downward load is generated, the clamping block (31) pulls down with the bag and drives the sliding seat (343) to vertically compress the elastic element (342). Multiple sets of hinge frames (341) use the internal fulcrum as levers to synchronously retract inward, converting the vertical downward displacement into the horizontal inward pressing force of the clamping block (31). The flat clamping plate (33) is assembled at the bottom of the clamping block (31) and moves vertically in sync with the clamping block (31). A positioning conversion port (4) is provided in the middle of a single hinge frame (341). A fulcrum positioning shaft (344) is coaxially fixed in the inner cavity of the hinge port. The hinge frame (341) is sleeved on the outer surface of the positioning shaft (344) through the conversion port (4) and can swing back and forth around the positioning shaft (344) to form a force-saving lever transmission fulcrum. The inner cavity of the two mounting blocks (32) is provided with a wedge-shaped transmission unit (35) for converting inclined force, which is used to receive the vertical displacement driving force transmitted by the hinge frame (341), and convert the vertical downward movement of the clamping block (31) into the horizontal feeding movement of the flat clamping plate (33) towards the bag body, so as to realize the synchronous pressure locking of the double-layer clamping elements.

2. The rotary pneumatic clamping and opening mechanism according to claim 1, characterized in that: The bottom of the column (10) is evenly distributed with multiple sets of resistance strain gauge load cells (11), and the base plate (21) of each stretching bag clamping assembly (20) is rigidly locked to the force measuring end of the load cell (11). The top of the column (10) is equipped with a non-winding rotating air source rotating box (12); the center of the air source rotating box (12) is provided with a dynamic sealing air source rotating joint, and the rotating joint is connected to the workshop fixed main air source pipeline; multiple independent distribution joints are arranged on the outer periphery of the air source rotating box (12), and each distribution joint is connected to all the actuator cylinders through an independent high-pressure branch pipe.

3. The rotary pneumatic clamping and opening mechanism according to claim 1, characterized in that: The reference positioning part (1) is rigidly fixed to the top surface of the movable seat (22), and the rotating part (2) forms a coaxial rotary motion pair with the positioning part (1) through a concentric rotary bearing; The bag clamping cylinder (24) adopts a crank connecting rod structure with hinged ends: the rear end of the bag clamping cylinder (24) is hinged to the mounting platform of the moving seat (22) through a hinge seat one, and the end of the extension piston rod of the bag clamping cylinder (24) is hinged to the side ear of the rotating part (2) through a hinge seat two; the cylinder piston rod retracts and pulls the rotating part (2) to flip outward in a fan shape, and the clamping port opens to feed the bag; the piston rod extends and pushes the rotating part (2) to rotate inward and close, forming a clamping surface with the positioning part (1) to complete the single-sided locking of the bag.

4. The rotary pneumatic clamping and opening mechanism according to claim 1, characterized in that: The drive cylinder (23) is a synchronous bidirectional output dual-axis cylinder. The two telescopic piston rods of the drive cylinder (23) are respectively hinged to the two moving seats (22) on both sides through the hinge seat three. The bidirectional synchronous output push-pull driving force drives the two sets of moving seats (22) to slide towards each other / backward along the guide rail of the base plate (21). The center of the top surface of the substrate (21) is equipped with a synchronous balance frame (25) via a rotary shaft. Two synchronous connecting rods (26) are respectively hinged at the left and right ends of the balance frame (25). The other end of the connecting rod (26) is hinged to the corresponding moving seat (22) via a hinge shaft, forming a parallelogram synchronous constraint linkage mechanism.

5. The rotary pneumatic clamping and opening mechanism according to claim 1, characterized in that: The planar clamping plate (33) is mounted on the bottom of the clamping block (31) via a horizontal sliding pair for lateral extension and retraction; the wedge-shaped transmission unit (35) includes a vertical sliding sleeve (351), a horizontal sliding sleeve (352), and an inclined transmission wedge block (353). The sliding sleeve (351) is vertically slidably assembled on the face of the mounting block (32), and the sleeve block (352) is horizontally embedded in the inner cavity of the sliding sleeve (351) to form a transverse sliding pair; the outer end of the sleeve block (352) is rigidly connected to the flat clamping plate (33), and the inner end of the sleeve block (352) is equipped with a low-friction roller, which continuously fits against the inclined transmission slope of the wedge block (353); When the clamping block (31) is pulled vertically downward, it simultaneously drives the sliding sleeve (351) to move downward. The roller rolls along the inclined surface of the wedge block (353), converting the vertical displacement into the horizontal feed displacement of the sleeve block (352), which pushes the flat clamping plate (33) to press the bag body inward simultaneously.

6. The rotary pneumatic clamping and opening mechanism according to claim 5, characterized in that: The wedge block (353) is horizontally slidably assembled in the inner cavity of the mounting block (32); the outer wall of the mounting block (32) is threaded with a stroke adjustment bolt (354), the inner end of the adjustment bolt (354) extends into the cavity and is rotatably connected to the end face of the wedge block (353); rotating the adjustment bolt (354) drives the wedge block (353) to move horizontally, changing the initial contact height of the inclined surface and the transmission stroke; The inner side of the flat clamp (33) has an embedded sliding groove, and a force-bearing block (355) is horizontally slidably assembled in the sliding groove. The force-bearing block (355) is rigidly fixed to the sleeve block (352). A horizontal reset elastic element (356) is pre-installed between the force-bearing block (355) and the side wall of the sliding groove.

7. The rotary pneumatic clamping and opening mechanism according to claim 1, characterized in that: The top surface of the substrate (21) is vertically mounted with a bag-opening cylinder (27) in the center. The extension end of the bag-opening cylinder (27) is rigidly fixed with a negative pressure suction nozzle (28). The suction nozzle (28) is pre-protruding from the bag opening clamping baseline (5) in the static initial position, forming an independent pre-support structure in the middle of the bag opening. The outer adsorption surface of the adsorption nozzle (28) is evenly provided with multiple sets of negative pressure adsorption holes; after the pneumatic clamping units on both sides clamp the two ends of the bag opening, the adsorption nozzle (28) adsorbs the membrane on the back of the bag body under negative pressure, and the bag opening cylinder (27) retracts backward in sync, pulling the middle part of the bag body to bulge backward, and in conjunction with the moving seats (22) on both sides to open in both directions, so that the front and back of the bag body form a symmetrical bulge complete filling channel.

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