A packaging bag heat sealing device

Abstract

This invention discloses a heat-sealing device for packaging bags, relating to the field of packaging machinery technology. It includes a frame, an infeeding mechanism for quantitatively filling the packaging bag with material, and a heat-sealing assembly for heat-sealing the bag opening. The infeeding mechanism is equipped with an infeeding clamp for opening and holding the packaging bag. It also includes a flattening mechanism, positioned above the infeeding mechanism, for flattening and lifting the bag opening after material is added; and a sliding frame, slidably connected to the frame and positioned between the infeeding station and the heat-sealing station. This invention applies multi-dimensional physical constraints to the packaging bag throughout its transfer and heat-sealing process, directly limiting the alternating tensile stress on the bag body caused by motion inertia and material gravity, thus preventing interlayer slippage of the film. Without adding extra cycle time, it increases the overall geometric flatness of the bag opening upon reaching the heat-sealing station and the final seal tightness.

Description

Technical Field

[0001] This invention relates to the field of packaging machinery technology, and specifically to a heat-sealing device for packaging bags. Background Technology

[0002] Packaging bag heat sealing equipment is a core piece of equipment in automated packaging production lines. It is mainly used to apply mechanical pressure and heat conduction to the opening of the packaging bag after the material is filled, so that the film material will thermodynamically melt and bond to form a closed packaging form. The operation process of this type of equipment usually covers physical flow processes such as material filling, packaging bag space transfer and heat sealing. The control precision of its operation physical form directly determines the sealing tightness and appearance flatness of the finished product.

[0003] In existing heat sealing processes, after the loading mechanism completes the material filling, the bag opening is directly handled by the translational gripper, or the bag body is simply carried by the bottom conveyor belt to transfer the packaging bag to the heat sealing station. After reaching the heat sealing station, the packaging bag opening is directly clamped and heat-sealed by the heat sealing components which are in a high-temperature state. Throughout the entire flow and operation cycle, the inside of the packaging bag usually remains in a naturally inflated state after the filling is completed, and the bag body passively follows the physical transfer of the equipment.

[0004] However, the aforementioned existing technologies exhibit the following shortcomings in actual operation: During the transfer to the heat-sealing station, after the packaging bag is filled with material, the film at the bag opening is prone to initial downward collapse and wrinkles due to gravity; and if the bag opening is only clamped at a single point during transfer, the bag body suspended at the bottom will sway due to the inertia of motion, causing the bag opening to bear irregular alternating tensile stress, resulting in interlayer slippage and relative misalignment of the film. This causes the bag opening to be skewed and have disordered wrinkles when the packaging bag is handed over to the heat-sealing station, thereby affecting the heat-sealing effect, increasing the risk of physical air leakage in the finished product, and directly reducing the finished product qualification rate of the packaging production line. Summary of the Invention

[0005] The purpose of this invention is to provide a heat-sealing device for packaging bags to solve the problems of skewed bag openings, wrinkles, and insufficient final seal caused by gravity pull and inertial swaying when transferring packaging bags in existing equipment.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A heat-sealing device for packaging bags includes a frame, an infeeding mechanism for quantitatively filling the packaging bag with material, and a heat-sealing assembly for heat-sealing the bag opening. The infeeding mechanism is equipped with an infeeding clamp for opening and holding the packaging bag. It also includes a flattening mechanism, positioned above the infeeding mechanism, for flattening and lifting the bag opening after material is added; and a sliding frame, slidably connected to the frame and positioned between the infeeding station and the heat-sealing station. A transfer cylinder is mounted on the frame, and the piston rod of the transfer cylinder is connected to the sliding frame. The frame is fixedly connected; the bag opening front clamp is located on the upper part of one side of the sliding frame. The bag opening front clamp is used to physically clamp and constrain the bag opening before the packaging bag is removed from the loading fixture; the bag body front clamp is located on the side of the sliding frame near the bag opening front clamp and below the bag opening front clamp. The bag body front clamp includes two first clamping plates. The first clamping plates are configured to provide normal compressive force to the bag body of the packaging bag to expel some of the air inside the packaging bag; the support mechanism is set on the frame and configured to be able to move up and down in the vertical direction to lift the packaging bag from the bottom during the heat sealing operation.

[0008] By employing the above technical solution, the posture and internal air pressure of the packaging bag are controlled throughout the entire process from loading to heat sealing, preventing deformation, wrinkles, or skewing of the bag opening during heat sealing, thus improving the flatness of the heat-sealing interface and enhancing the overall sealing effect. Specifically, the upward lifting action of the flattening mechanism maintains the initial flatness of the bag opening before transfer; and the interaction between the front clamp of the bag opening and the loading clamp ensures that the packaging bag remains taut throughout the transfer process, reducing initial downward deformation; the front clamp of the bag body applies compressive force to the bag body... On the one hand, the sliding frame restricts the pendulum-like swaying of the bag body during the translation process, preventing unevenness or deformation of the bag opening caused by inertia. On the other hand, it expels some of the air inside the bag, keeping the internal and external air pressures balanced during heat sealing, and preventing wrinkles and bulges at the seal caused by the thermal expansion of the internal gas. Finally, the supporting mechanism lifts the packaging bag from the bottom at the heat sealing station, bearing the overall weight of the material and the bag body, preventing the film in the top heat sealing area from being stretched and deformed by gravity under the condition of high temperature softening, and further increasing the bonding stability of the heat melt interface.

[0009] In existing technologies, when transferring packaging bags, clamping mechanisms are usually only installed at the bag opening. During the acceleration and deceleration phases of the equipment's translation, the bag body, which is suspended at the bottom, will swing like a pendulum due to the inertia of motion. This causes the bag opening to be subjected to irregular alternating tensile stress, increasing the risk of misalignment and deformation of the bag opening film.

[0010] A further improvement of the technical solution of the present invention is that: the front clamp of the bag body also includes two first cylinders symmetrically fixedly connected to the top of the sliding frame, and the piston rod ends of the two first cylinders are fixedly connected to a first push plate; a first slide rod that can slide laterally is provided on each of the two first push plates, one end of the first slide rod is fixedly connected to a first end head, and the other end passes through to the inner side of the first push plate and is fixedly connected to a first pad; the two first pads are respectively hinged to the corresponding first clamping plates, and a first spring is sleeved on the outside of the first slide rod, the first spring being located between the first pad and the first push plate; a slide bar is fixedly connected to the top of the two first clamping plates on the side away from each other, and slide pins are symmetrically fixedly connected to both sides of the slide bar; a support plate is fixedly connected to both sides of the two first push plates, and a vertically extending strip groove is provided on the support plate, and the slide pin is slidably connected to the strip groove.

[0011] By adopting the above technical solution and setting a front clamp to physically constrain the bag body, the device of the present invention directly limits the shaking amplitude of the packaging bag during the transfer process, blocks the tensile stress generated by the inertia of motion on the bag opening, and increases the structural stability and alignment accuracy of the bag opening during the transfer.

[0012] However, in order to suppress bag shaking, if only a rigid parallel flat plate clamp is added to the bag body, the rigid plate cannot fit the ever-changing bag body contour due to the physical tolerance of the stacking shape of the material inside the packaging bag. On the one hand, rigid compression can easily cause local stress to exceed the yield limit of the material, causing physical fragmentation of the internal material; on the other hand, the rigid clamp cannot achieve uniform and appropriate air release. If too much air is trapped inside the bag, during the subsequent heat sealing operation, the gas inside the bag will expand due to heat, causing the bag body to produce varying degrees of local bulging and twisting deformation. This irregular twisting caused by bulging will be transmitted upward to the bag opening, directly destroying the flatness of the bag opening, and may cause the packaging bag to burst due to poor air release during compression.

[0013] Furthermore, by converting the absolute rigid displacement of the first cylinder into a flexible constant extrusion force and an adaptive angle deflection force, not only is the rigid displacement of the first cylinder converted into a flexible constant extrusion force, avoiding mechanical damage to the internal hard materials; it can also guide the first clamping plate to dynamically fit from bottom to top according to the bag body contour, thereby evenly expelling some of the air inside the bag, balancing the pressure inside the bag, effectively eliminating random bulging and twisting deformation of the bag body caused by heat sealing, so that the packaging bag maintains a smooth posture as a whole, thereby increasing the flatness of the interface in the heat sealing process.

[0014] When using existing technology to clamp packaging bags such as gusseted bags (M-type bags) or bags with side folding structures, there is a significant thickness difference at the bag opening because the folded areas on both sides of the bag opening have four layers of film, while the middle area has two layers of film. If a rigid metal clamp is used to clamp directly, the clamp can only compress the thicker four-layer area, resulting in the inner film being subjected to less force than the outer film. This makes it very easy for the inner film to slip off and misalign during subsequent air venting or transfer.

[0015] A further improvement of the technical solution of the present invention is that: the front clamp of the bag opening includes two support frames symmetrically and fixedly connected to the top of the sliding frame, and a second cylinder is fixedly connected to the top of each of the two support frames. A second push plate is fixedly connected to the piston rod of each of the two second cylinders. Two first guide rods are symmetrically and fixedly connected to the side of the two second push plates that are far apart. The first guide rods are slidably inserted on the support frame. Two flexible blocks are symmetrically arranged on the side of the two second push plates that are close to each other.

[0016] By adopting the above technical solution, a flexible block is set in front of the bag opening. The compressible deformation characteristics of the flexible material are used to perfectly absorb the thickness difference of the folded areas on both sides of the packaging bag. This structure enables the clamp to achieve full-wrap friction locking of the multi-layer film at the moment of clamping, blocking the relative sliding between the inner and outer layers of film and increasing the alignment stability of the bag opening fold.

[0017] However, since the above solution also includes a front clamp for the bag body with an air venting effect, and the bag opening is clamped with a rigid structure, there is still a middle area for air venting. If a flexible block that completely covers the bag opening is used directly, the air inside the bag cannot be vented, and in severe cases, the bag may be crushed.

[0018] Furthermore, the solution sets two flexible blocks on each side, covering the thicker four-layer folded area of ​​the bag and part of the central two-layer area. On the one hand, the device of the present invention utilizes the compressible deformation characteristics of flexible materials to perfectly absorb the thickness difference between the two sides of the packaging bag, achieving full-wrap friction locking of the multi-layer film, blocking the relative sliding between the inner and outer layers of film, and increasing the alignment stability of the bag opening fold. On the other hand, the segmented clamping structure physically reserves an unconstrained open area in the center of the bag opening. This area creates a smooth exhaust channel for the squeezing action of the front clamp of the bag body, ensuring that some air inside the bag can be discharged without obstruction, eliminating the risk of bag bursting caused by the exhaust action, and increasing the compatibility of the overall action logic of the device.

[0019] When the bag body is squeezed and vented by the front clamp, the bag body will inevitably expand laterally (i.e., bulge locally) as the airflow converges towards the bag opening. If the bag opening is rigidly locked horizontally by the front clamp, the lateral tensile force generated by the expansion of the bag body is often greater than the tensile yield strength of the film itself, which can easily lead to tearing at the edge of the bag opening. In addition, after the venting action is completed, if the bag opening lacks lateral tensile intervention, the film often exhibits microscopic relaxation and wrinkles due to the stress fluctuations in the early stage, which directly reduces the flatness of the heat-sealing interface when handed over to the heat-sealing station.

[0020] A further improvement of the technical solution of the present invention is that: the front clip of the bag opening also includes two sliding grooves symmetrically opened on the side of the second push plate away from the first guide rod, and a second sliding rod is fixedly connected inside the sliding groove. A sliding block is slidably connected to the outside of the second sliding rod, and a flexible block is fixedly connected to the corresponding sliding block; a second spring is sleeved on the outside of the second sliding rod and on the side of the sliding block near the center of the second push plate.

[0021] By adopting the above technical solution, the flexible block is set to a horizontally elastic floating state, enabling the front clamp of the bag opening to obtain passive adaptive lateral displacement and tension. During the venting stage, the structure allows the flexible block to retract towards the center as the bag body laterally contracts, absorbing the lateral tearing stress generated by the expansion of the bag body and reducing the damage rate of the packaging bag. After venting, the structure can use the reset thrust of the second spring to automatically push the flexible block outward, applying a constant horizontal tension force to the bag opening. This mechanism ensures that the bag opening handed over to the heat sealing station always maintains a physically stretched, wrinkle-free posture, and also allows the parts not pressed by the flexible block to be in a tight fit under tension, improving the smoothness and sealing tightness of the interface in subsequent heat sealing operations.

[0022] In existing technologies, when heat-sealing packaging bags, if the bottom lacks support, the bag opening film, which is softened at high temperatures, is easily stretched downwards and deformed by the weight of the material. Considering that the bottom of the packaging bag may have a part that is easy to carry, if a fixed tray is set, the part will be obstructed when entering the tray position, which will cause the packaging bag to tilt and easily cause the part to be folded irregularly, affecting the flatness of the packaging bag. Finally, considering that independent control requires consideration of the timing of actions, the control difficulty is increased. If the tray makes a rigid impact before the packaging bag has come to a complete stop, it will directly destroy the flatness of the bag opening after degassing.

[0023] A further improvement of the technical solution of the present invention is as follows: the supporting mechanism includes a mounting plate fixedly connected to the sliding frame, a third sliding rod slidably passing through the central part of the mounting plate, a support plate fixedly connected to the top of the third sliding rod, a wheel frame fixedly connected to the bottom of the third sliding rod, and a pulley rotatably connected to the bottom of the wheel frame; a third spring is sleeved on the outside of the third sliding rod and located between the mounting plate and the wheel frame; two second guide rods are symmetrically fixedly connected to the bottom of the support plate, and the second guide rods are slidably passing through the mounting plate; the supporting mechanism also includes a guide rail arranged on the frame along the moving direction of the sliding frame, and the bottom of the pulley rolls against the top surface of the guide rail; the guide rail has an upwardly protruding climbing section, a straight supporting section that smoothly transitions to the top of the climbing section, and a yielding section that smoothly transitions to the bottom of the climbing section.

[0024] By adopting the above technical solution and setting up a mechanical follow-up linkage mechanism, the vertical lifting action and the horizontal transfer displacement are physically and temporally bound together. Furthermore, the setting of the clearance section on the guide rail ensures that the pulley remains in contact with the guide rail throughout the entire cycle, eliminating the re-engagement impact in the suspended state. The climbing section allows the pallet to present a smooth upward motion when approaching the heat sealing station, eliminating the damage to the packaging bag posture caused by rigid impact. The flat support section provides absolutely rigid physical support during the heat sealing operation, minimizing the downward stress of gravity on the bag opening and increasing the structural stability of the heat-melt interface.

[0025] As a general-purpose packaging equipment, when the production line changes to packaging bags of different capacities or lengths, if the relative height between the guide rail and the frame is a fixed value, the supporting mechanism cannot adapt to the varying bottom height of the material. This can lead to overload of the pallet (the lifting height is greater than the set value, causing stress wrinkles at the bag opening due to upward compression) or suspension (the lifting height is less than the set value, making it unable to bear the weight of the material), reducing the equipment's process compatibility in multi-specification production scenarios.

[0026] A further improvement of the technical solution of the present invention is that the guide rail is installed on the frame through a height adjustment component so that the vertical height of the guide rail from the frame is adjustable.

[0027] By adopting the above technical solution, the vertical height of the guide rail is made adjustable by setting a height adjustment component, which gives the device the ability to adapt to different sizes of packaging bags. This design allows the working height of the flat support section to accurately match the bottom position of different bag types, and increases the equipment's versatility for multiple product specifications without changing the core linkage support structure.

[0028] Considering that the packaging bags still need to be transferred to an external conveyor line after heat sealing, setting up a separate robotic arm would inevitably increase costs and would also require back-end coordination, making control difficult.

[0029] A further improvement of the technical solution of the present invention is that: a rear clamp is provided on the side of the sliding frame away from the front clamp of the bag opening, and the rear clamp includes two third cylinders symmetrically fixedly installed on the sliding frame, and the piston rods of the two third cylinders are respectively fixedly connected to a third push plate; a second clamping plate is provided on the side of the two third push plates that are close to each other.

[0030] By adopting the above technical solution, by integrating the rear clamp on the side of the sliding frame away from the front clamp of the bag opening, the device of the present invention utilizes the reciprocating linear motion of the sliding frame to construct a temporal physical binding between the front clamp and the rear clamp. This allows the equipment to simultaneously complete the action of "moving the heat-sealed finished product out of the heat-sealing station" while performing the action of "sending the new packaging bag into the heat-sealing station". This dual-station linkage mechanism achieves zero-time-difference handover between feeding and discharging, increases the overall operating cycle frequency and unit output efficiency of the equipment without adding any additional drive cycle, and ensures the regularity of the finished product output posture.

[0031] During the heat sealing process, packaging bags may experience "false seals" or leaks due to temperature fluctuations or material contamination at the bag opening. Conventional online leak detection often employs independent visual inspection stations or vacuum attenuation test chambers, which significantly increases the hardware investment and production line length.

[0032] A further improvement of the technical solution of the present invention is that: a plurality of fourth slide rods are slidably provided on both third push plates, one end of the fourth slide rod near the third cylinder is fixedly connected to a second end, and the other end is fixedly connected to the second clamping plate. A fourth spring is sleeved on the outside of the fourth slide rod and between the second clamping plate and the third push plate. A pressure sensor is fixedly installed on the side of the third push plate near the second clamping plate, and the detection end of the pressure sensor is in contact with the central part of the second clamping plate.

[0033] By adopting the above technical solution, the buffering characteristics of the fourth spring are used to convert the rigid thrust of the third cylinder into a constant flexible squeezing force on the packaging bag, thus avoiding mechanical damage to the finished product during the discharge clamping action. At the same time, the micro-yield displacement of the second clamping plate when subjected to the air pressure back force of the packaging bag directly triggers the pressure sensor. This mechanism enables the rear clamp to simultaneously complete the physical sealing test of the finished product within a very short cycle of performing the transfer discharge action. Without increasing any process time or independent workstation, the equipment is given the ability to identify and reject defective products online, thereby increasing the pass rate of the finished products leaving the factory.

[0034] A further improvement of the technical solution of the present invention is that: the flattening mechanism includes two symmetrically arranged vertical flattening cylinders, the piston rods of the two vertical flattening cylinders are fixedly connected to the frame, the side walls of the two vertical flattening cylinders are fixedly connected to flattening lifting platforms, the tops of the two flattening lifting platforms are fixedly connected to horizontal flattening cylinders, and the piston rods of the two horizontal flattening cylinders are fixedly connected to pressing plates.

[0035] By adopting the above technical solution, a composite interference of "first horizontal flattening and then vertical lifting" is achieved for the bag opening; this structure directly eliminates the initial random wrinkles of the bag opening film, and the vertical flattening cylinder drives the overall upward movement of the flattening lifting platform, providing the packaging bag with an upward straightening mechanical force to counteract the downward deformation caused by the weight of the material.

[0036] By adopting the above technical solution, the technical effects achieved by this invention compared to the prior art are as follows:

[0037] 1. This invention provides a heat-sealing device for packaging bags. By applying multi-dimensional physical constraints to the packaging bags throughout the entire cycle of transfer and heat-sealing operations, it directly restricts the alternating tensile stress generated by motion inertia and material gravity on the bag body, blocks the interlayer slippage of the film, and increases the geometric flatness and final sealing tightness of the bag opening when it reaches the heat-sealing station without adding extra cycle time.

[0038] 2. This invention provides a heat-sealing device for packaging bags. By setting a segmented flexible block combined with a horizontally elastic floating front clamp for the bag opening, the local compressible deformation of the flexible block absorbs the thickness difference on both sides of the folded bag, achieving full-wrap physical locking of the multi-layer film. At the same time, the horizontally floating structure allows the clamp to generate an inward passive yielding displacement when the bag body below is vented and expanded to prevent tearing of the bag opening. After the venting is completed, the elastic force is released to stretch the bag opening laterally outward, increasing the physical flatness of the interface when it is handed over to the heat-sealing component.

[0039] 3. This invention provides a heat-sealing device for packaging bags. By setting a front clamp for the bag body with flexible buffering and angle adaptive capabilities, this structure transforms the rigid displacement of the driving component into a flexible constant extrusion force. While restricting the movement and shaking of the bag body, it can guide the clamp to dynamically conform to the ever-changing bag body contour. Without damaging the internal material, it can evenly discharge some of the air inside the bag, balance the internal and external air pressure, and reduce local bulging and twisting deformation caused by the thermal expansion of residual air inside during subsequent heat sealing.

[0040] 4. This invention provides a heat-sealing device for packaging bags. By setting a mechanical follow-up linkage structure in which pulleys cooperate with the frame guide rail, the horizontal translation of the sliding frame is directly converted into the vertical lifting of the pallet. This enables the support action and the transfer displacement to achieve absolute time-series binding at the physical level, avoiding timing errors and rigid impacts caused by independent drive components. It also provides stable physical support for the bottom of the packaging bag during the heat-sealing operation, eliminating the downward stress of gravity on the bag opening under the condition of high temperature softening, and increasing the structural stability of the heat-sealing interface.

[0041] 5. The present invention provides a heat-sealing device for packaging bags. By setting a flattening mechanism, after applying a lateral squeezing and flattening action to the bag opening, the lifting platform is used to vertically move upward to provide an upward straightening mechanical force for the packaging bag. This eliminates the initial downward collapse and random wrinkles caused by gravity after the packaging bag is filled with material, offsets the downward deformation, and increases the geometric regularity of the bag opening before entering the clamping and handover stage. Attached Figure Description

[0042] The invention will now be further described with reference to the accompanying drawings.

[0043] Figure 1 This is a three-dimensional structural diagram of the entire invention;

[0044] Figure 2 This is one of the three-dimensional structural diagrams of the present invention after removing part of the peripheral structure;

[0045] Figure 3 This is the second schematic diagram of the three-dimensional structure of the present invention after removing part of the peripheral structure;

[0046] Figure 4 This is the third schematic diagram of the three-dimensional structure of the present invention after removing part of the peripheral structure;

[0047] Figure 5 This is a side view of the sliding frame and various mechanisms mounted thereon of the present invention.

[0048] Figure 6 This is a partial top sectional view of the front clip of the bag opening of the present invention;

[0049] Figure 7 This is a three-dimensional structural diagram of a portion of the front clip at the bag opening of the present invention;

[0050] Figure 8 This is a three-dimensional structural diagram of a portion of the front clip of the bag body of the present invention;

[0051] Figure 9 This is a schematic diagram of the flattening mechanism of the present invention;

[0052] Figure 10 For the present invention Figure 2 Enlarged view of point A in the middle;

[0053] Figure 11 For the present invention Figure 4 Enlarged view of section B in the middle.

[0054] In the diagram: 1. Frame; 2. Bag opening front clamp; 201. Support frame; 202. Second cylinder; 203. Second push plate; 204. First guide rod; 205. Slide groove; 206. Second slide rod; 207. Sliding block; 208. Flexible block; 209. Second spring; 3. Bag body front clamp; 301. First clamping plate; 302. First cylinder; 303. First push plate; 304. First slide rod; 305. First end; 306. First pad; 307. First spring; 308. Sliding strip; 309. Sliding pin; 310. Support plate; 311. Strip groove; 4. Supporting mechanism; 401. Mounting plate; 402. Third slide rod; 403. Support plate; 404. Wheel frame 405. Pulley; 406. Third Spring; 407. Second Guide Rod; 408. Climbing Section; 409. Straight Support Section; 410. Yielding Section; 5. Rear Clamp; 501. Third Cylinder; 502. Third Push Plate; 503. Second Clamping Plate; 504. Fourth Slide Rod; 505. Second End; 506. Fourth Spring; 507. Pressure Sensor; 6. Loading Mechanism; 7. Flattening Mechanism; 701. Vertical Flattening Cylinder; 702. Flattening Lifting Platform; 703. Horizontal Flattening Cylinder; 704. Flattening Plate; 8. Height Adjustment Assembly; 801. Adjusting Frame; 802. Screw; 803. Adjusting Block; 9. Heat Sealing Assembly; 10. Transfer Cylinder; 11. Sliding Frame. Detailed Implementation

[0055] The present invention will be further described in detail below with reference to the embodiments.

[0056] Example 1

[0057] like Figures 1-11 As shown, the present invention provides a heat-sealing device for packaging bags, including a frame 1, an infeeding mechanism 6 for quantitatively filling the packaging bag with material, and a heat-sealing assembly 9 for heat-sealing the bag opening by heat-melting and pressing. The infeeding mechanism 6 is equipped with an infeeding clamp for opening and holding the packaging bag. It also includes a flattening mechanism 7, disposed above the infeeding mechanism 6, for flattening and lifting the bag opening after the material is filled into the packaging bag; and a sliding frame 11, slidably connected to the frame 1 and disposed between the infeeding station and the heat-sealing station. A transfer cylinder 10 is mounted on the frame 1, and the piston rod of the transfer cylinder 10 is connected to the sliding frame 11. The moving frame 11 is fixedly connected; the bag opening front clamp 2 is set on the upper part of one side of the sliding frame 11. The bag opening front clamp 2 is used to physically clamp and constrain the bag opening before the packaging bag is removed from the loading clamp; the bag body front clamp 3 is set on the side of the sliding frame 11 near the bag opening front clamp 2 and located below the bag opening front clamp 2. The bag body front clamp 3 includes two first clamping plates 301. The first clamping plates 301 are configured to provide normal extrusion force to the bag body of the packaging bag to expel some of the air inside the packaging bag; the supporting mechanism 4 is set on the frame 1 and is configured to be able to lift and lower in the vertical direction to lift the packaging bag from the bottom during the heat sealing operation.

[0058] In this embodiment, by controlling the posture and internal air pressure of the packaging bag throughout the entire process from loading to heat sealing, deformation, wrinkles, or skewing of the bag opening during heat sealing is avoided, improving the flatness of the heat-sealing interface and enhancing the overall sealing effect. Specifically, the upward lifting action of the flattening mechanism 7 ensures the bag opening remains initially flat before transfer; and the interaction between the bag opening clamp 2 and the loading clamp ensures the packaging bag remains taut throughout the transfer process, reducing initial downward deformation; the bag body clamp 3 applies pressure to the bag body, thus... During the translation of the sliding frame 11, the pendulum-like sway of the bag body is restricted, preventing unevenness or deformation of the bag opening caused by inertia. On the other hand, some air inside the bag is discharged, keeping the internal and external air pressures balanced during heat sealing and preventing wrinkling and bulging of the seal caused by the thermal expansion of the internal gas. Finally, the supporting mechanism 4 lifts the packaging bag from the bottom at the heat sealing station, bearing the overall weight of the material and the bag body, preventing the film in the top heat sealing area from being stretched and deformed by gravity under the softened state at high temperature, and further increasing the bonding stability of the heat-melt interface.

[0059] During operation, the loading clamp of the loading mechanism 6 first opens the packaging bag and completes the material loading; then, the flattening mechanism 7 located above the loading mechanism 6 is activated to press the opening of the packaging bag and perform an upward lifting and flattening action, so that the bag opening film exhibits a wrinkle-free flat state.

[0060] Then, the transfer cylinder 10 is controlled to work. Its pneumatic chamber is filled with air, which forces the piston rod to make a linear extension motion. Since the piston rod is fixedly connected to the sliding frame 11, the linear displacement of the piston rod is directly converted into the horizontal driving force of the sliding frame 11, which pushes or pulls the sliding frame 11 to move along the guide trajectory (such as the guide rail) on the frame 1. When the piston rod retracts, the sliding frame 11 is reset. During the movement of the sliding frame 11, it can transfer the packaging bag clamped by the bag opening front clamp 2 and the bag body front clamp 3.

[0061] When the sliding frame 11 moves horizontally to the loading station, the bag opening clamp 2 located on the upper side of it closes, physically clamping and constraining the bag opening; this clamping action is completed before the bag leaves the loading fixture, realizing the physical connection and handover of material loading and conveying transfer, ensuring that the bag opening is continuously in a state of force and shaping.

[0062] Then, the bag body front clamp 3 located below the bag opening front clamp 2 is activated, and its two first clamps 301 close to the bag body and provide normal extrusion force. This extrusion force forces some of the residual air in the bag to be discharged from the bottom to the top through the bag opening, so that the volume of the remaining air in the bag is constantly less than the critical threshold that causes heat-sealing expansion.

[0063] Subsequently, the sliding frame 11 drives the packaging bag, which is constrained by the front clamp 2 of the bag opening and the front clamp 3 of the bag body, to move horizontally to the station where the heat sealing assembly 9 is located. At this heat sealing station, the support mechanism 4 set on the frame 1 rises vertically to steadily lift the packaging bag from the bottom to bear the overall weight of the material and the bag body.

[0064] Finally, the heat-sealing assembly 9 closes to heat-seal the bag opening. Since the air pressure inside the bag has reached equilibrium at this time, and the bag opening is physically tensioned by the front clamp 2 and the bottom is supported by the support mechanism 4, the film molecules will not be subjected to destructive external deformation stress during the heat sealing process, thereby improving the heat sealing effect.

[0065] Preferably, the heat sealing assembly 9 adopts a QDF-600 pneumatic heat sealing structure, which includes heating blocks symmetrically installed on both sides of the frame and a sealing cylinder that drives the heating blocks to close.

[0066] It should be noted that the mechanical actions and control logic of the loading mechanism 6 and its loading fixture in physically opening the packaging bag and quantitatively filling the material are all existing conventional technologies in the field of packaging machinery. Those skilled in the art can directly adopt mature components such as suction cup bag opening, robotic arm bag holding and gravity quantitative feeding in existing bag packaging equipment according to actual production needs. The core improvement of this invention does not involve the reshaping of the hardware structure of the pre-filling process. Therefore, this specification will not elaborate further on its specific internal mechanical transmission connection relationship.

[0067] Example 2

[0068] like Figure 4 , Figure 5 and Figure 8 As shown, based on Embodiment 1, the present invention provides a technical solution: Preferably, the front clip 3 of the bag body further includes two first cylinders 302 symmetrically fixedly connected to the top of the sliding frame 11, and the piston rod ends of the two first cylinders 302 are fixedly connected to first push plates 303; each of the two first push plates 303 is provided with a first sliding rod 304 that can slide laterally, one end of the first sliding rod 304 is fixedly connected to a first end 305, and the other end passes through to the inner side of the first push plate 303 and is fixedly connected to a first pad 306; the two first pads 306... 06 is hinged to the corresponding first clamping plate 301. The first slide rod 304 is fitted with a first spring 307, which is located between the first pad 306 and the first push plate 303. The top of the two first clamping plates 301 on the side away from each other is fixedly connected to a slide bar 308. The two sides of the slide bar 308 are symmetrically fixedly connected to slide pins 309. The two sides of the two first push plates 303 are fixedly connected to a support plate 310. The support plate 310 is provided with a vertically extending strip groove 311. The slide pin 309 is slidably connected to the strip groove 311.

[0069] In this embodiment, by setting the front clamp 3 of the bag body to physically constrain the bag body, the device of the present invention directly limits the shaking amplitude of the packaging bag during the transfer process, blocks the tensile stress generated by the motion inertia on the bag opening, and increases the structural stability and alignment accuracy of the bag opening during the transfer.

[0070] In this embodiment, by converting the absolute rigid displacement of the first cylinder 302 into a flexible constant extrusion force and an adaptive angle deflection force, not only is the rigid displacement of the first cylinder 302 converted into a flexible constant extrusion force, avoiding mechanical damage to the internal hard materials; it can also guide the first clamping plate 301 to dynamically fit from bottom to top according to the bag body contour, thereby evenly discharging some of the air inside the bag, balancing the pressure inside the bag, effectively eliminating random bulging and twisting deformation of the bag body caused by heat sealing, so that the packaging bag maintains a smooth posture, thereby increasing the flatness of the interface in the heat sealing process.

[0071] During operation, the two first cylinders 302 start synchronously, and their piston rods push the first push plate 303 to close towards the center of the packaging bag. The first push plate 303 transmits the thrust to the first pad 306 through the first spring 307, which in turn drives the first clamping plate 301 hinged on the first pad 306 to contact the body of the packaging bag.

[0072] In the initial stage of compression, the reverse resistance is small, and the first clamping plate 301 moves forward synchronously with the first cylinder 302 to expel some of the air inside the bag. When the first clamping plate 301 compresses the main body of the material inside the bag, the reverse resistance transmitted by the packaging bag to the first clamping plate 301 increases. When this resistance is greater than the pre-tightening force of the first spring 307, the first spring 307 undergoes compression deformation, and the first slide rod 304 slides outward relative to the first push plate 303, causing the first pad 306 and the first clamping plate 301 to produce a flexible yielding displacement away from the packaging bag.

[0073] During this extrusion process, due to the difference in the surface contour of the material, the first clamping plate 301 experiences uneven forces from top to bottom. The first clamping plate 301 undergoes a slight angular deflection around its hinge point with the first pad 306 to perfectly fit the contour of the bag body. During this deflection and retraction, the sliding strip 308 and sliding pin 309 fixed to the top of the first clamping plate 301 slide up and down within the vertical strip groove 311 of the support plate 310, ensuring that the first clamping plate 301 will not overturn or lose control when it undergoes flexible adaptive action. The rigid thrust of the first cylinder 302 is absorbed by the first spring 307 and transformed into a continuous and gentle elastic force that compresses the bag body, squeezing out the remaining air inside the bag from bottom to top, thus avoiding damage to the internal material structure caused by hard interference.

[0074] Example 3

[0075] like Figure 5 , Figure 6 and Figure 7As shown, based on Embodiment 2, the present invention provides a technical solution: Preferably, the front clip 2 of the bag opening includes two support frames 201 symmetrically fixedly connected to the top of the sliding frame 11. A second cylinder 202 is fixedly connected to the top of each of the two support frames 201. A second push plate 203 is fixedly connected to the piston rod of each of the second cylinders 202. Two first guide rods 204 are symmetrically fixedly connected to the side of the two second push plates 203 that are far apart. The first guide rods 204 are slidably passed through the support frame 201. Two flexible blocks 208 are symmetrically arranged on the side of the two second push plates 203 that are close to each other.

[0076] When using existing technology to clamp packaging bags such as gusseted bags (M-type bags) or bags with side folding structures, there is a significant thickness difference at the bag opening because the folded areas on both sides of the bag opening have four layers of film, while the middle area has two layers of film. If a rigid metal clamp is used to clamp the bag directly, the clamp can only press the thicker four-layer area, resulting in the inner film being subjected to less force than the outer film. This makes it very easy for the inner film to slip off and misalign during subsequent air venting or transfer.

[0077] By setting a flexible block 208 in front of the bag opening clamp 2, the thickness difference of the folded areas on both sides of the packaging bag is perfectly absorbed by utilizing the compressible deformation characteristics of the flexible material. This structure enables the clamp to achieve full-wrap friction locking of the multi-layer film at the moment of clamping, blocking the relative sliding between the inner and outer layers of film and increasing the alignment stability of the bag opening fold.

[0078] However, since the above solution also includes a front clamp 3 for the bag body with an exhaust function, and the bag opening is clamped by a rigid structure, there is still a middle area for exhaust. If the flexible block 208 that completely covers the bag opening is used directly, the air inside the bag cannot be exhausted, and in severe cases, the bag may be crushed.

[0079] Furthermore, the solution sets two flexible blocks 208 on each side, covering the thicker four-layer folded area of ​​the bag and part of the central two-layer area. On the one hand, the device of the present invention utilizes the compressible deformation characteristics of flexible materials to perfectly absorb the thickness difference between the two sides of the packaging bag, achieving full-wrap friction locking of the multi-layer film, blocking the relative sliding between the inner and outer layers of film, and increasing the alignment stability of the bag opening fold. On the other hand, the segmented clamping structure physically reserves an unconstrained open area in the center of the bag opening. This area creates a smooth exhaust channel for the squeezing action of the front clamp 3 of the bag body, ensuring that some air inside the bag can be discharged without obstruction, eliminating the risk of bag bursting caused by the exhaust action, and increasing the compatibility of the overall action logic of the device.

[0080] During operation, the second cylinder 202 of the bag opening clamp 2 is activated, and the piston rod pushes the second push plate 203 to close the bag opening. The two flexible blocks 208 installed on the second push plate 203 (actually indirectly installed through the sliding block 207 described later) first contact the two sides of the bag opening. Under the action of clamping force, the flexible blocks 208 undergo local concave deformation, which covers and tightly adheres to the junction of films of different thicknesses, firmly locking the inner and outer multi-layer films on both sides. The area in the center of the bag opening that is not covered by the flexible blocks 208 remains open to allow the compressed air below to flow out.

[0081] Since the front clip 2 of the bag opening needs to carry the packaging bag into the heat sealing station and is very close to the high-temperature heat sealing component 9, ordinary rubber is prone to melting or sticking under high-temperature radiation. Therefore, the flexible block 208 is made of an elastomer material with heat-resistant properties. The following options are available:

[0082] Made of high-temperature resistant silicone rubber in one piece, the material has a Shore hardness change rate of less than a preset threshold at ambient temperatures above 200°C, which not only provides sufficient elastic deformation to match the film thickness difference, but also prevents melting and stringing when close to the heat-sealing component 9.

[0083] Fluororubber composite blocks are used. This material provides an excellent coefficient of friction (increasing gripping force) while having extremely high thermal stability and anti-adhesion properties. This prevents thermal adhesion to the packaging bag film after long-term operation at high-temperature workstations, thus increasing the service life of the mechanism.

[0084] like Figure 6 and Figure 7 As shown, in this embodiment, preferably, the front clip 2 of the bag opening further includes two sliding grooves 205 symmetrically opened on the side of the second push plate 203 away from the first guide rod 204. The interior of each sliding groove 205 is fixedly connected to a second sliding rod 206, and the exterior of each second sliding rod 206 is slidably connected to a sliding block 207. Flexible blocks 208 are respectively fixedly connected to the corresponding sliding blocks 207. A second spring 209 is sleeved on the exterior of the second sliding rod 206 and on the side of the sliding block 207 near the center of the second push plate 203.

[0085] In this embodiment, by setting the flexible block 208 to a horizontally elastic floating state, the front clamp 2 of the bag opening obtains passive adaptive lateral displacement and tension capability. During the venting stage, this structure allows the flexible block 208 to retract towards the center following the lateral contraction of the bag body, absorbing the lateral tearing stress generated by the expansion of the bag body and reducing the damage rate of the packaging bag tearing. After the venting is completed, the structure can use the reset thrust of the second spring 209 to automatically push the flexible block 208 outward and apply a constant horizontal tension force to the bag opening. This mechanism ensures that the bag opening handed over to the heat sealing station always maintains a physically stretched, wrinkle-free posture, and also allows the parts not pressed by the flexible block 208 to be in a tight fit under tension, improving the smoothness and sealing tightness of the interface in subsequent heat sealing operations.

[0086] During operation, the bag opening is clamped by the flexible block 208 fixed to the sliding block 207. When the front clamp 3 squeezes and vents the bag body, the air inside the bag rushes upward, causing the upper part of the bag body to bulge laterally. Due to the change in geometric shape, the projected width of the packaging bag in the horizontal direction narrows, thereby generating a lateral pulling force towards the center of the bag opening. This pulling force is transmitted through the bag opening film to the clamping flexible block 208 and the sliding block 207. When this lateral pulling force is greater than the preload of the second spring 209, it forces the sliding blocks 207 on both sides to overcome the elastic force of the second spring 209 and slide along the second slide rod 206 in the slide groove 205 towards the center of the second push plate 203 (i.e., generating an inward yielding displacement), thereby making physical space for the venting and expansion of the packaging bag and protecting the bag opening from tearing. Once the venting action is completed and excess air inside the bag is squeezed out, the packaging bag returns to a flat state, and the lateral tension towards the center decreases and disappears. At this time, the second spring 209, which is in a compressed state, releases its elasticity, pushing the sliding block 207 to slide outward along the second sliding rod 206 to reset. This reset action causes the flexible block 208 to move laterally to both sides, instantly stretching the bag opening film to both sides. When it is handed over to the heat sealing assembly 9, the bag opening exhibits an absolutely flat force posture under the continuous thrust of the second spring 209.

[0087] Example 4

[0088] like Figure 2 , Figure 3 and Figure 5As shown, based on Embodiment 3, the present invention provides a technical solution: Preferably, the supporting mechanism 4 includes a mounting plate 401 fixedly connected to the sliding frame 11, a third sliding rod 402 slidably passing through the central part of the mounting plate 401, a support plate 403 fixedly connected to the top of the third sliding rod 402, a wheel frame 404 fixedly connected to the bottom of the third sliding rod 402, and a pulley 405 rotatably connected to the bottom of the wheel frame 404; a third spring 406 is sleeved outside the third sliding rod 402 and located between the mounting plate 401 and the wheel frame 404; two second guide rods 407 are symmetrically fixedly connected to the bottom of the support plate 403, and the second guide rods 407 are slidably passed through the mounting plate 401; the supporting mechanism 4 also includes a guide rail arranged on the frame 1 along the moving direction of the sliding frame 11, and the bottom of the pulley 405 abuts and rolls against the top surface of the guide rail; as Figure 10 As shown, the guide rail has an upwardly protruding climbing section 408, a flat support section 409 that smoothly transitions to the top of the climbing section 408, and a yielding section 410 that smoothly transitions to the bottom of the climbing section 408.

[0089] In this embodiment, by setting a mechanical follow-up linkage mechanism, the vertical lifting action and the horizontal transfer displacement are physically and temporally bound together. Furthermore, the setting of the clearance section 410 on the guide rail ensures that the pulley 405 remains in contact with the guide rail throughout the entire cycle, eliminating the re-engagement impact in the suspended state. The climbing section 408 allows the pallet 403 to present a smooth upward motion when approaching the heat sealing station, eliminating the damage to the packaging bag posture caused by rigid impact. The flat support section 409 provides absolutely rigid physical support during the heat sealing operation, minimizing the downward stress of gravity on the bag opening and increasing the structural stability of the heat-melt interface.

[0090] During operation, the sliding frame 11 moves the clamped packaging bag towards the heat-sealing station. During horizontal movement, the pulley 405 mounted at the bottom of the sliding frame 11 rolls on the top surface of the guide rail on the frame 1. In the non-heat-sealing area, the pulley 405 rolls in the clearance section 410 of the guide rail. At this time, the third spring 406 is in a naturally extended state and presses downwards against the wheel frame 404, while the support plate 403 is in a low-position clearance state, without physical interference with the bottom of the packaging bag.

[0091] When the sliding frame 11 approaches the heat sealing station, the pulley 405 smoothly transitions and rolls to the ramp section 408 of the guide rail. The inclined profile of the guide rail forces the pulley 405 to overcome the elastic force of the third spring 406 and gradually move upward. The pulley 405 drives the third slide rod 402 to slide upward in the mounting plate 401 through the wheel frame 404, thereby pushing the top support plate 403 to rise. During this process, the two second guide rods 407 slide synchronously in the mounting plate 401, providing guidance and anti-deflection rigidity. When the sliding frame 11 comes to a complete stop at the heat sealing station, the pulley 405 just passes the ramp section 408 and enters the flat support section 409. At this time, the pallet 403 is precisely pushed up to the highest working position, firmly supporting the bottom of the packaging bag. After the heat sealing is completed, the sliding frame 11 moves away, the pulley 405 slides down the ramp section 408 and re-enters the yielding section 410, the third spring 406 releases the compressive potential energy, and pushes the wheel frame 404 and the pallet 403 to reset and descend, completing one impact-free operation cycle.

[0092] like Figure 2 and Figure 10 As shown, in this embodiment, preferably, the guide rail is mounted on the frame 1 via a height adjustment component 8 so that the vertical height of the guide rail from the frame 1 is adjustable.

[0093] In this embodiment, by setting the height adjustment component 8, the vertical height of the guide rail is configured to be adjustable, which gives the device the ability to adapt to different sizes of packaging bags. This design allows the working height of the flat support section 409 to accurately match the bottom position of different bag types, increasing the equipment's versatility for multiple product specifications without changing the core linkage support structure.

[0094] Preferably, the height adjustment assembly 8 includes an adjustment frame 801 fixedly connected to the top of the frame 1, a screw 802 rotatably connected to the inner side of the adjustment frame 801, an adjustment block 803 threadedly connected to the outer side of the screw 802, the adjustment block 803 slidably connected to the inner side of the adjustment frame 801, the adjustment block 803 fixedly connected to the guide rail, and the top of the screw 802 extending above the adjustment frame 801 and fixedly connected to a throttle handle.

[0095] When the production line changes to packaging bags of longer or shorter specifications, the operator rotates the screw 802 via a throttle. Because the adjustment block 803's rotational freedom is restricted by the adjustment frame 801, the rotational motion of the screw 802 is converted into the vertical linear motion of the adjustment block 803. The adjustment block 803 drives the fixedly connected guide rail to move vertically upwards or downwards to the target height mark. After rotation stops, the mechanical self-locking force of the thread firmly locks the guide rail at the current height. After adjustment, when the sliding frame 11 operates again and the pulley 405 enters the flat support section 409 of the guide rail, the pallet 403 is pushed to a new highest working position. The height of this new working position physically coincides with the bottom height of the current specification packaging bag, thus achieving precise support operations across specifications.

[0096] Example 5

[0097] like Figure 4 and Figure 11 As shown, based on embodiment 4, the present invention provides a technical solution: preferably, a rear clamp 5 is provided on the side of the sliding frame 11 away from the front clamp 2 of the bag opening, and the rear clamp 5 includes two third cylinders 501 symmetrically fixedly installed on the sliding frame 11, and the piston rods of the two third cylinders 501 are respectively fixedly connected to third push plates 502; a second clamping plate 503 is provided on the side of the two third push plates 502 that are close to each other.

[0098] In this embodiment, by integrating the rear clamp 5 on the side of the sliding frame 11 away from the front clamp 2 of the bag opening, the device of the present invention utilizes the reciprocating linear motion of the sliding frame 11 to construct a temporal physical binding between the front clamp and the rear clamp 5, so that when the device performs the action of "sending the new packaging bag into the heat sealing station", it can simultaneously complete the action of "moving the heat-sealed finished product out of the heat sealing station". This dual-station linkage mechanism realizes zero-time difference handover between feeding and discharging, increases the overall operating cycle frequency and unit output efficiency of the equipment without adding any additional drive cycle, and ensures the regularity of the finished product output posture.

[0099] During operation, after the heat sealing assembly 9 completes the heat-sealing of the previous packaging bag and the supporting mechanism 4 descends and resets, the sliding frame 11 retracts to the loading position. At this time, the bag opening clamp 2 and the bag body clamp 3 located at the front of the sliding frame 11 (near the loading mechanism 6) hold the new packaging bag to be sealed. At the same time, the rear clamp 5 located at the rear of the sliding frame 11 is in the heat sealing position. Its two third cylinders 501 are activated, and the piston rod pushes the third push plate 502 and the second clamping plate 503 to close, accurately holding the finished packaging bag that has just been heat-sealed.

[0100] Subsequently, the sliding frame 11 moves forward as a whole. This single translational displacement produces two working results: the front bag opening clamp 2 and the front bag body clamp 3 accurately deliver the new packaging bag into the working area of ​​the heat sealing component 9; while the rear clamp 5 carries the heat-sealed finished product out of the heat sealing area and arrives at the designated unloading station. After arriving at the unloading station, the third cylinder 501 controls the second clamp 503 to release, and the finished packaging bag falls into the finished product conveyor belt in a controlled vertical posture.

[0101] like Figure 11 As shown, in this embodiment, preferably, a plurality of fourth slide rods 504 are slidably mounted on both third push plates 502. One end of the fourth slide rod 504 near the third cylinder 501 is fixedly connected to a second end 505, and the other end is fixedly connected to the second clamping plate 503. A fourth spring 506 is sleeved on the outside of the fourth slide rod 504 and located between the second clamping plate 503 and the third push plate 502. A pressure sensor 507 is fixedly mounted on the side of the third push plate 502 near the second clamping plate 503, and the detection end of the pressure sensor 507 is in contact with the central part of the second clamping plate 503.

[0102] In this embodiment, the buffering characteristics of the fourth spring 506 are used to convert the rigid thrust of the third cylinder 501 into a constant flexible squeezing force on the packaging bag, thus avoiding mechanical damage to the finished product caused by the discharge clamping action. At the same time, the micro-yield displacement of the second clamping plate 503 when subjected to the air pressure back force of the packaging bag directly triggers the pressure sensor 507. This mechanism enables the rear clamp 5 to simultaneously complete the physical sealing test of the finished product within a very short cycle of performing the transfer discharge action. Without increasing any process time or independent work station, the equipment is given the ability to identify and reject defective products online, thereby increasing the pass rate of the finished products leaving the factory.

[0103] During operation, when the rear clamp 5 is ready to clamp the sealed packaging bag at the heat sealing station, the third cylinder 501 drives the third push plate 502 forward. The third push plate 502 gently transmits the thrust to the second clamping plate 503 by compressing the fourth spring 506. The second clamping plate 503 contacts and squeezes the packaging bag body (preferably clamped above the material and containing residual air).

[0104] When squeezed by the second clamping plate 503, if the packaging bag is heat-sealed (successfully sealed), the residual air inside the bag forms a closed pneumatic support force. This reverse support force causes the second clamping plate 503 to stop moving forward, while the third push plate 502 behind it continues to move slightly under the continuous thrust of the cylinder, causing the fourth spring 506 to compress. At this time, the pressure sensor 507 installed on the third push plate 502 presses its detection end tightly against the back of the second clamping plate 503 and reads a stable physical rebound force greater than the preset threshold (characterized as qualified).

[0105] Conversely, if the packaging bag has heat-sealed leakage (false seal), the air inside the bag will be discharged through the leakage hole when compressed, and it will not be able to provide effective pneumatic support. The second clamp 503 will close without resistance under the thrust of the cylinder, the compression of the fourth spring 506 will be extremely small, and the pressure value read by the pressure sensor 507 will be less than the preset threshold, or it will show a physical curve of rapid decay (poor characterization).

[0106] After receiving a signal from the pressure sensor 507 indicating that the pressure is below the threshold, the control system determines that the bag is defective. When the sliding frame 11 moves to the unloading area, the control system triggers the scrap rejection logic (for example, a scrap box is set between the working area and the external unloading station, and the rear clamp 5 is released in advance to let the scrap fall into the scrap box when the scrap rejection logic is triggered; or the external flipping mechanism is linked to guide the scrap), thereby achieving physical isolation of non-conforming products.

[0107] like Figure 2 and Figure 9 As shown, preferably, the flattening mechanism 7 includes two symmetrically arranged vertical flattening cylinders 701. The piston rods of the two vertical flattening cylinders 701 are fixedly connected to the frame 1. The side walls of the two vertical flattening cylinders 701 are fixedly connected to flattening lifting platforms 702. The tops of the two flattening lifting platforms 702 are fixedly connected to horizontal flattening cylinders 703. The piston rods of the two horizontal flattening cylinders 703 are fixedly connected to pressing plates 704.

[0108] In this embodiment, by employing a flattening mechanism 7 that combines vertical and horizontal cylinders, a composite interference of "first horizontal flattening, then vertical lifting" is achieved for the bag opening. This structure directly eliminates the initial random wrinkles of the bag opening film, and by driving the flattening lifting platform 702 to move upward as a whole through the vertical flattening cylinder 701, it provides an upward straightening mechanical force for the packaging bag, thus offsetting the downward deformation caused by the weight of the material.

[0109] During operation, after the loading mechanism 6 completes the material filling, it controls the two horizontal flattening cylinders 703 to synchronously drive the pressing plate 704 towards the center of the packaging bag opening, physically squeezing and flattening the bag opening film from both sides towards the middle; then, while the pressing plate 704 remains clamped, the cylinder bodies of the two vertical flattening cylinders 701 move upward along their fixed piston rods. Since the flattening lifting platform 702 is fixed to the side wall of the cylinder body, it drives the horizontal flattening cylinders 703 and the pressing plate 704 to rise synchronously. This upward displacement generates an upward lifting force on the packaging bag, straightening the bag opening film upward and eliminating the collapse of the bag opening; in this state, the bag opening clamp 2 intervenes and completes the clamping of the bag opening after it has been lifted and flattened. Then, the horizontal flattening cylinders 703 drive the pressing plate 704 to retract, and the vertical flattening cylinders 701 reset and descend, completing one pre-processing cycle.

[0110] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A heat-sealing device for packaging bags, comprising a frame (1), an infeeding mechanism (6) for quantitatively filling material into the packaging bag, and a heat-sealing assembly (9) for heat-sealing the opening of the packaging bag, wherein the infeeding mechanism (6) is equipped with an infeeding clamp for opening and holding the packaging bag; characterized in that, Also includes: The flattening mechanism (7) is located above the loading mechanism (6) and is used to flatten the bag opening and lift it upward after the material is loaded into the packaging bag. A sliding frame (11) is slidably connected to the frame (1) and is set between the loading station and the heat sealing station. A transfer cylinder (10) is installed on the frame (1), and the piston rod of the transfer cylinder (10) is fixedly connected to the sliding frame (11). The front clamp (2) is located on the upper part of one side of the sliding frame (11). The front clamp (2) is used to physically clamp and constrain the opening of the packaging bag before the packaging bag is removed from the loading clamp. The front clamp (3) of the bag body is disposed on the side of the sliding frame (11) near the front clamp (2) of the bag opening and below the front clamp (2) of the bag opening. The front clamp (3) of the bag body includes two first clamps (301). The first clamps (301) are configured to provide normal compression force to the body of the packaging bag to expel part of the air inside the packaging bag. A support mechanism (4) is provided on the frame (1) and configured to be vertically movable for lifting the packaging bag from the bottom during heat sealing operations; The bag opening front clip (2) includes two support frames (201) symmetrically fixedly connected to the top of the sliding frame (11). A second cylinder (202) is fixedly connected to the top of each of the two support frames (201). A second push plate (203) is fixedly connected to the piston rod of each of the second cylinders (202). Two first guide rods (204) are symmetrically fixedly connected to the two second push plates (203) on the side away from each other. The first guide rods (204) are slidably passed through the support frame (201). Two flexible blocks (208) are symmetrically arranged on the side of the two second push plates (203) that are close to each other.

2. The heat-sealing device for packaging bags according to claim 1, characterized in that: The front clamp (3) of the bag body also includes two first cylinders (302) symmetrically fixedly connected to the top of the sliding frame (11). The piston rod ends of the two first cylinders (302) are fixedly connected to a first push plate (303). The two first push plates (303) are each provided with a first slide rod (304) that can slide laterally. One end of the first slide rod (304) is fixedly connected to a first end (305), and the other end passes through to the inside of the first push plate (303) and is fixedly connected to a first pad (306). The two first pads (306) are respectively hinged to the corresponding first clamping plate (301). A first spring (307) is sleeved on the outside of the first slide bar (304), and the first spring (307) is located between the first pad (306) and the first push plate (303); a slide bar (308) is fixedly connected to the top of the two first clamping plates (301) on the side away from each other, and a sliding pin (309) is fixedly connected to both sides of the slide bar (308); a support plate (310) is fixedly connected to both sides of the two first push plates (303), and a vertically extending strip groove (311) is opened on the support plate (310), and the sliding pin (309) is slidably connected to the strip groove (311).

3. A bag heat sealing apparatus according to claim 2, wherein: The front clip (2) of the bag opening also includes two sliding grooves (205) symmetrically opened on the side of the second push plate (203) away from the first guide rod (204). The interior of each sliding groove (205) is fixedly connected to a second sliding rod (206). The exterior of each second sliding rod (206) is slidably connected to a sliding block (207). The flexible block (208) is fixedly connected to the corresponding sliding block (207). A second spring (209) is sleeved on the exterior of the second sliding rod (206) and on the side of the sliding block (207) close to the center of the second push plate (203).

4. The heat-sealing device for packaging bags according to claim 3, characterized in that: The supporting mechanism (4) includes a mounting plate (401) fixedly connected to the sliding frame (11). A third slide rod (402) is slidably threaded through the central part of the mounting plate (401). A support plate (403) is fixedly connected to the top of the third slide rod (402), and a wheel frame (404) is fixedly connected to the bottom of the third slide rod (402). A pulley (405) is rotatably connected to the bottom of the wheel frame (404). A third spring (406) is sleeved outside the third slide rod (402) and between the mounting plate (401) and the wheel frame (404). The support plate... Two second guide rods (407) are symmetrically fixedly connected to the bottom of (403), and the second guide rods (407) are slidably passed through the mounting plate (401); the support mechanism (4) also includes a guide rail arranged on the frame (1) along the moving direction of the sliding frame (11), and the bottom of the pulley (405) rolls against the top surface of the guide rail; the guide rail is provided with an upwardly protruding climbing section (408), a flat support section (409) that smoothly transitions to the top of the climbing section (408), and a yielding section (410) that smoothly transitions to the bottom of the climbing section (408).

5. A bag heat sealing apparatus according to claim 4, wherein: The guide rail is mounted on the frame (1) via a height adjustment component (8) so that the vertical height of the guide rail from the frame (1) is adjustable.

6. A bag heat sealing apparatus as claimed in claim 5, wherein: The sliding frame (11) is provided with a rear clamp (5) on the side away from the front clamp (2) of the bag opening. The rear clamp (5) includes two third cylinders (501) symmetrically fixedly installed on the sliding frame (11). The piston rods of the two third cylinders (501) are respectively fixedly connected to third push plates (502). A second clamp (503) is provided on the side of the two third push plates (502) that are close to each other.

7. A bag heat sealing apparatus as defined in claim 6, wherein: A plurality of fourth slide rods (504) are slidably mounted on both of the third push plates (502). A second end (505) is fixedly connected to one end of the fourth slide rod (504) near the third cylinder (501), and the other end is fixedly connected to the second clamping plate (503). A fourth spring (506) is sleeved on the outside of the fourth slide rod (504) and between the second clamping plate (503) and the third push plate (502). A pressure sensor (507) is fixedly mounted on the side of the third push plate (502) near the second clamping plate (503). The detection end of the pressure sensor (507) is in contact with the central part of the second clamping plate (503).

8. A bag heat sealing apparatus according to claim 7, wherein: The flattening mechanism (7) includes two symmetrically arranged vertical flattening cylinders (701). The piston rods of the two vertical flattening cylinders (701) are fixedly connected to the frame (1). The side walls of the two vertical flattening cylinders (701) are fixedly connected to flattening lifting platforms (702). The tops of the two flattening lifting platforms (702) are fixedly connected to horizontal flattening cylinders (703). The piston rods of the two horizontal flattening cylinders (703) are fixedly connected to pressing plates (704).

Images