Valve bag opening heat sealing device and method

Abstract

The invention relates to the technical field of heat sealing devices, in particular to a valve bag opening heat sealing device and method.The valve bag opening heat sealing device comprises a sealing box and a liftable lifting frame, a heat sealing cavity is formed in the sealing box, a bag body is movably arranged in the heat sealing cavity, and a heat sealing clamping mechanism for sealing the heat sealing cavity and clamping the bag body is arranged on the sealing box; a heat sealing table is arranged in the heat sealing cavity, an overturning table driven by an overturning motor is rotationally installed at the position, adjacent to the heat sealing table, in the heat sealing cavity, primary sealing grooves are formed in the heat sealing table and the overturning table, a heat sealing strip hole is formed in the overturning table, and a secondary sealing groove matched with the heat sealing strip hole is fixedly formed in the heat sealing table. The sealing device has the beneficial effects that by means of cooperation of the innovatively-designed primary sealing groove, the overturning table and the secondary sealing groove and combination of double preliminary sealing and triple sealing after folding, the problem that the sealing degree is insufficient due to the fact that a traditional device can only conduct single-time heat sealing is thoroughly solved.

Description

Technical Field

[0001] The invention relates to the technical field of heat sealing devices, in particular to a valve bag mouth heat sealing device and method. Background Art

[0002] Valve bags, commonly known as paste-bottom bags, are internationally popular packaging bags. They are fed from the top or bottom valve port and use special filling equipment. After filling the materials, they are packed into cubes. The bags are neatly stacked and beautiful. They are a kind of environmentally friendly bags. Valve bags can be divided into PP valve bags, PE valve bags, paper-plastic composite valve bags, kraft paper valve bags and multi-layer kraft paper valve bags according to their materials.

[0003] During the production and processing of valve bags, the sealing part of the valve bags needs to be hot-pressed and sealed; In the prior art, the patent document with publication number CN215620376U discloses a valve bag processing heat sealing device, including a bracket, a fixed plate and a belt conveyor, wherein the number of the fixed plates is two and they are installed in parallel on the top of the bracket, and the belt conveyor is arranged between the two fixed plates. When the above device is in use, the belt conveyor transfers the valve bag to be sealed to the heat sealing frame, and the pressure plate is driven downward by the No. 1 cylinder to facilitate the capping and positioning of the middle part of the valve bag, and then the hot pressure head is driven downward by the No. 2 cylinder to make the hot pressure head perform heat pressure sealing on the two ends of the valve bag. However, the above device has the following technical problems when in use: The existing device only uses a single cylinder-driven pressure plate to position the bag body, and lacks an adaptive clamping mechanism. During the hot press sealing process, especially when facing valve bags of different specifications (length / thickness), the fixed-size pressure plate cannot form an effective covering clamp, resulting in lateral displacement or wrinkle deformation of the bag mouth when the hot press head is pressed down.

[0004] This rigid clamping method is difficult to eliminate the assembly gap caused by the difference in bag size, which not only reduces the heat seal position accuracy (misalignment rate of more than 12%), but also causes discontinuous fusion of the PE composite layer due to uneven local pressure, directly causing the heat seal strength to drop to 60%-75% of the standard value, seriously affecting the air tightness and load-bearing performance of the valve bag. This defect is particularly prominent in rigid products such as paper-plastic composite bags and multi-layer kraft paper bags, becoming a key bottleneck restricting the improvement of the qualified rate of packaging bags.

[0005] Based on this, the present invention provides a valve bag bag opening heat sealing device and method to solve the problems raised in the above background technology. Summary of the invention

[0006] The present invention aims at the technical problems existing in the prior art and provides a valve bag mouth heat sealing device and method to solve the problem that the existing device causes the heat sealing strength to decrease, affecting the air tightness and load-bearing performance.

[0007] The technical solution of the present invention to solve the above technical problems is as follows: a valve bag bag mouth heat sealing device, including a sealing box and a liftable lifting frame, a heat sealing chamber is provided in the sealing box, a bag body is movably arranged in the heat sealing chamber, a heat sealing clamping mechanism for sealing the heat sealing chamber and clamping the bag body is provided on the sealing box, a heat sealing table is provided in the heat sealing chamber, a turning table driven by a turning motor is rotatably installed in the heat sealing chamber and adjacent to the heat sealing table, a primary sealing groove is provided on the heat sealing table and the turning table, a heat sealing strip hole is provided on the turning table, a secondary sealing groove cooperating with the heat sealing strip hole is fixedly provided on the heat sealing table, an adsorption positioning component for adsorbing and positioning the bag body is provided on the heat sealing table, and an extrusion exhaust component for extruding and exhausting the bag body is also provided in the heat sealing chamber. A vacuum pumping system for negative pressure suction before heat sealing of the bag body and a detection system for bag sealing detection, the bottom surface of the lifting frame is connected to a sealing pressure cover for sealing the top of the heat sealing cavity through a group of first elastic pressure elements, a heat pressing seat is fixedly installed on the lifting frame, the heat pressing seat is slidably connected to the sealing pressure cover, a primary heat pressing block is fixedly installed on the bottom surface of the heat pressing seat and corresponds to the position of the two primary sealing grooves, a secondary heat pressing block is slidably installed on the inner wall of the heat pressing seat and corresponds to the position of the secondary sealing groove, a group of heat pressing push rods are installed between the secondary heat pressing block and the heat pressing seat, a pre-pressing frame slidably connected to the heat pressing seat is installed on the secondary heat pressing block, a positioning pressure plate is fixedly installed on the bottom surface of the pre-pressing frame through a group of second elastic pressure elements, and the positioning pressure plate is slidably connected to the sealing pressure cover.

[0008] Based on the above technical solution, the present invention can also be improved as follows.

[0009] Furthermore, the heat-sealing clamping mechanism includes an outer frame, which is fixedly connected to the sealing box, and a bidirectional screw driven by a motor is rotatably installed on the outer frame, and a positive thread segment and a negative thread segment are respectively provided on the bidirectional screw, and a clamping frame is transmission-installed on the positive thread segment and the negative thread segment, and the two clamping frames are both slidably connected to the outer frame, and a sealing door body is fixedly installed on the clamping frame, and two symmetrically arranged clamping plates are slidably connected in the heat-sealing cavity, and a group of third elastic pressure elements are installed on the back of the two clamping plates, and the two groups of the first elastic pressure elements are respectively fixedly connected to the two clamping frames.

[0010] The beneficial effect of adopting the above further scheme is that the two clamping frames are driven to move synchronously and symmetrically by the positive and negative thread segments of the bidirectional screw, and the clamping plate is evenly pressed under the action of the third elastic pressure element to achieve stable clamping of the bag body and closing of the sealing door body. In the working process, the motor drives the bidirectional screw to rotate, driving the clamping frame to slide along the outer frame, so that the sealing door body is closely fitted to the opening of the heat sealing cavity, ensuring the airtightness during the heat sealing process; This design solves the problem of bag mouth deviation or air leakage caused by uneven force in traditional clamping mechanisms. Through elastic pressure and bidirectional synchronous movement, it significantly improves the clamping accuracy and sealing efficiency. It is especially suitable for the rapid adaptation of valve bags of different sizes, reducing the cost of manual adjustment.

[0011] Furthermore, a single chip microcomputer is installed on the top of the sealing box, and a vertically arranged screw lifting module is installed on the outer frame, and the screw lifting module is transmission-connected to the lifting frame.

[0012] The beneficial effect of adopting the above-mentioned further scheme is that the single-chip microcomputer accurately controls the operation of the screw lifting module through a preset program, and adjusts the height of the lifting frame to adapt to the heat sealing requirements of different bag openings. During the work process, the screw lifting module drives the lifting frame to move vertically, combined with the sliding connection between the heat pressing seat and the sealing cover, to ensure that the primary heat pressing block and the secondary heat pressing block are accurately aligned with the sealing groove. This solution solves the problem of heat sealing misalignment or uneven pressure caused by inaccurate height adjustment of traditional devices, realizes fully automated control, significantly improves the heat sealing consistency and production efficiency, and reduces the complexity of operation.

[0013] Furthermore, the extrusion exhaust assembly includes a charging pump installed on the sealing box, and an extrusion bag is installed on both inner sides of the heat-sealing cavity. The port of the charging pump is connected to the inner cavity of the two extrusion bags through a multi-way tube. The two extrusion bags are provided with a first air pressure probe for monitoring the inner cavity pressure of the extrusion bag. The data end of the first air pressure probe is connected to the data of the single-chip computer, and a pressure relief valve is connected to the multi-way tube and the heat-sealing cavity.

[0014] The beneficial effect of adopting the above further scheme is that when heat sealing and vacuuming, the pressure pump works synchronously, and the pressure pump supplies pressure to the extrusion bags on both sides through the multi-way pipe, so that the extrusion bags expand and squeeze the bag body, and the residual air in the bag is forced to be discharged; During the workflow, the first air pressure probe monitors the pressure inside the extrusion bag in real time, the single-chip microcomputer adjusts the power of the charging pump according to the feedback data, and the pressure relief valve automatically releases the pressure when overpressure occurs. This design effectively solves the problem of loose sealing or bulging caused by residual gas in the bag before heat sealing. Combined with elastic extrusion and intelligent pressure control, it improves the thoroughness of exhaust and ensures that the heat sealing surface is flat and free of bubbles.

[0015] Furthermore, the vacuum system includes a vacuum pump installed on a lifting frame, the negative pressure port of the vacuum pump is connected to the inner cavity of the heat sealing cavity through a vacuum hose, and a second air pressure probe for monitoring the internal air pressure of the heat sealing cavity is installed on the sealing box, and the data end of the second air pressure probe is connected to the microcontroller data.

[0016] The beneficial effect of adopting the above further solution is that the vacuum pump evacuates the heat sealing chamber through the vacuum hose, so that the bag body is closely attached to the heat sealing table, eliminating the interference of the air in the bag on the heat sealing; During the workflow, the second air pressure probe monitors the vacuum degree of the heat sealing chamber in real time, and the single-chip microcomputer dynamically adjusts the power of the vacuum pump to maintain a constant negative pressure environment. This solution solves the problem of seal stratification or insufficient strength caused by insufficient vacuum degree in the bag in traditional heat sealing, and significantly improves heat sealing reliability and product yield through closed-loop control.

[0017] Furthermore, the detection system includes a visual acquisition probe and an audio acquisition sensor installed in the heat sealing cavity, the visual acquisition probe is used for image acquisition of the bag body, and the audio acquisition sensor is used for audio acquisition in the heat sealing cavity, and the data ends of the visual acquisition probe and the audio acquisition sensor are both connected to the microcontroller data.

[0018] The beneficial effect of adopting the above further scheme is that after the heat sealing is completed and the pressure in the heat sealing chamber returns to normal pressure, the visual acquisition probe collects the surface deformation image of the bag body in real time, and the audio acquisition sensor collects the noise generated by the deformation of the bag body in real time. When the visual acquisition probe detects that the bag body expands when it returns to normal pressure, the single-chip microcomputer determines that the heat sealing effect of the bag body is poor. When the noise decibel of the bag body exceeds the set threshold, that is, the deformation amplitude of the bag body exceeds the set threshold, the single-chip microcomputer determines that the heat sealing effect of the bag body is poor.

[0019] Furthermore, the adsorption and positioning assembly includes a negative pressure pump installed on the back of the sealing box and a negative pressure chamber opened in the heat sealing table. The negative pressure end of the negative pressure pump is fixedly connected to the negative pressure chamber. Two groups of negative pressure adsorption holes are opened on the top surface of the heat sealing table. The primary sealing groove on the heat sealing table is arranged between the two groups of negative pressure adsorption holes.

[0020] The beneficial effect of adopting the above further scheme is that after the vacuum is completed, the negative pressure pump generates adsorption force on the bag body through the negative pressure chamber and the adsorption holes, so that it firmly fits the surface of the heat sealing table. In the working process, the negative pressure adsorption holes are distributed on both sides of the primary sealing groove to ensure that the bag opening is not displaced during the hot pressing process. This design solves the problem that the traditional positioning method relies on mechanical clamps to easily damage the bag body, and realizes flexible positioning through contactless adsorption, which is particularly suitable for high-precision heat sealing of thin-walled or easily deformed valve bags.

[0021] After the bag body is positioned by negative pressure adsorption, the lifting frame moves down. After the lifting frame moves down, the positioning plate first presses the joint between the bag body and the part to be heat-sealed. After pressing, the lifting frame continues to move down. After the lifting frame moves down, the two primary heat pressing blocks are respectively fitted with the two first sealing grooves, and then the double sealing of the part to be heat-sealed is completed. After the double sealing is completed, the lifting frame is reset. After the lifting frame is reset, the turning table is turned 90° in the direction of the heat sealing table. After the 90° turning is completed, the turning table is finally parallel to the heat sealing table, the heat sealing strip hole corresponds to the position of the secondary sealing groove, and the part to be heat-sealed is folded. After the folding is completed, the lifting frame continues to move down. When the lifting frame moves down, the hot pressing push rod drives the secondary heat pressing block to move down. After the secondary heat pressing block moves down, it passes through the heat sealing strip hole and performs triple heat sealing on the folded part to be heat-sealed. Through triple heat sealing, the heat sealing effect of the bag body is effectively guaranteed.

[0022] Furthermore, it also includes ventilation pipes installed on both sides of the sealing box, the tail ends of the two ventilation pipes are connected to the heat sealing cavity, and the inner wall of each ventilation pipe is installed with an axial flow fan and a ventilation valve in sequence from the inside to the outside.

[0023] The beneficial effect of adopting the above further scheme is that the axial flow fan delivers cold air to the heat sealing cavity through the ventilation duct, accelerating the cooling and shaping after heat sealing. The ventilation valve can adjust the air volume to match the thermal shrinkage characteristics of different materials. In the work process, the ventilation system is started after the heat sealing is completed, which quickly reduces the cavity temperature and discharges the hot melt waste gas. This solution solves the problem of bag mouth deformation caused by low cooling efficiency of traditional devices, while improving the safety of the working environment and meeting environmental protection production requirements.

[0024] Furthermore, it also includes a linear transmission module installed at the bottom of the heat sealing chamber, a material conveying platform is installed on the linear transmission module, and two guide rails slidably connected to the material conveying platform are fixedly installed at the bottom of the sealing box.

[0025] The beneficial effect of adopting the above further solution is that the linear transmission module drives the material conveying platform to slide along the guide rail to realize automatic loading and unloading of the valve bag.

[0026] Furthermore, a heat sealing method for a valve bag mouth heat sealing device comprises the following steps: SS01. Place the bag on the material conveying platform in the heat sealing chamber, and place the part of the bag to be heat-sealed on the heat sealing table in the heat sealing chamber. Start the heat sealing clamping mechanism, and the bidirectional screw is driven by the motor to rotate, driving the clamping frames on both sides to move synchronously and symmetrically, pushing the sealing door to close the heat sealing chamber opening. At the same time, the clamping plate applies pressure evenly through the third elastic pressure element to achieve stable clamping of the bag opening and cavity sealing. The single-chip microcomputer controls the screw lifting module to drive the lifting frame to move downward, and the sealing gland contacts the top of the heat sealing chamber to form a closed environment. SS02, start the vacuum pump, evacuate the heat sealing chamber through the vacuum hose, make the bag close to the heat sealing table, eliminate the air interference in the bag, start the charging pump simultaneously, supply pressure to the extrusion bags on both sides through the multi-way pipe, and apply uniform pressure to the bag after the extrusion bags expand to force the residual gas in the bag to be discharged. The first air pressure probe monitors the pressure data in real time, and the single chip microcomputer dynamically adjusts the power of the charging pump. When the pressure is over-pressured, the pressure relief valve automatically opens; SS03. After vacuuming is completed, the negative pressure pump starts to generate adsorption force on the bag through the negative pressure adsorption holes on the heat sealing table, so that it fits firmly to the surface of the heat sealing table to ensure no displacement during the heat sealing process; SS04, the primary heat pressing block moves down with the heat pressing seat, and is precisely aligned with the primary sealing groove on the heat sealing table and the turning table, completing the initial heat sealing of the bag mouth and forming a double seal. After the double heat sealing, the lifting frame is reset; SS05, after the lifting frame is reset, the flip motor drives the flip table to flip 90° toward the heat sealing table, so that the heat sealing strip hole is aligned with the secondary sealing groove on the heat sealing table, the lifting frame moves down for the second time, and the heat pressing push rod drives the secondary heat pressing block to pass through the heat sealing strip hole to heat seal the folded bag opening again. During this heat sealing, the multiple layers on the bag body are heat sealed at the same time, and finally a triple seal is formed; After SS06 and triple sealing is completed, the axial flow fan delivers cold air to the heat sealing chamber through the ventilation pipe to accelerate the cooling and shaping of the heat sealing part, and the ventilation valve adjusts the air volume according to the material characteristics; SS07, after heat sealing is completed, the visual acquisition probe collects the surface image of the bag mouth, and the audio acquisition sensor detects the deformation noise. If the image shows expansion or the noise decibel exceeds the standard, the single chip computer determines that the seal is unqualified and alarms; SS08. After passing the test, the heat-sealing clamping mechanism releases the bag body, and the material conveying platform slides along the guide rail driven by the linear transmission module to move the finished bag out of the heat-sealing chamber to complete the automatic unloading.

[0027] The beneficial effects of the present invention are: 1. The present invention completely solves the problem of insufficient sealing caused by single heat sealing of traditional devices through the innovative design of primary sealing groove, turning table and secondary sealing groove, combined with double initial sealing and triple sealing after folding. The turning table drives the heat sealing strip hole to accurately align with the secondary sealing groove, and the secondary hot pressing block penetrates the folded bag opening to achieve synchronous sealing of multiple layers of materials, forming a redundant sealing structure. Compared with the existing technology, this solution increases the compressive strength of the bag opening by more than 40%, which is particularly suitable for high-requirement packaging scenarios, and creatively solves the industry problem of single sealing prone to leakage and stratification.

[0028] 2. The present invention adopts a symmetrical clamping mechanism driven by a bidirectional screw rod, combined with an elastic pressure element and a sealing door body to achieve uniform clamping of the bag mouth and instantaneous sealing of the heat-sealing cavity. The clamping pressure and closing accuracy are dynamically adjusted by a single-chip microcomputer to ensure stable positioning of valve bags of different sizes. The clamping error is less than 0.5mm. Compared with traditional mechanical clamps, this design avoids wrinkles or dislocations at the bag mouth caused by uneven clamping force, improves adaptability by 70%, and shortens the construction time of the sealing cavity by 50%, significantly improving production efficiency.

[0029] 3. The present invention uses closed-loop control of the vacuum pump and the extrusion bag assembly to first draw a vacuum to make the bag close to the heat sealing table, and then use the charging pump to drive the extrusion bag to expand and pressurize, forcing the residual gas to be discharged. The first air pressure probe feeds back pressure data in real time, and the single-chip microcomputer dynamically adjusts the charging intensity. Combined with the overpressure protection of the pressure relief valve, the exhaust is ensured to be thorough. Experiments show that this solution reduces the bubble rate in the bag from 15% in the traditional process to below 1%, and improves the flatness of the heat sealing surface by 90%, solving the pain points of bulging and reduced sealing strength.

[0030] 4. The present invention integrates visual acquisition probes and audio sensors, analyzes the deformation characteristics of the bag mouth through images, and determines the sealing integrity in combination with the noise decibel threshold. The detection data is transmitted to the single-chip microcomputer in real time, and an abnormal situation automatically alarms and interrupts the process. Compared with traditional manual visual inspection, this solution reduces the missed detection rate from 20% to less than 2%, and improves the detection efficiency by 5 times. At the same time, a dynamic optimization database of process parameters is formed to provide data support for subsequent production. It is an industry-first intelligent solution.

[0031] 5. In the present invention, a negative pressure adsorption hole group is built into the heat sealing table, and a uniform adsorption force is generated by a negative pressure pump, so that the bag mouth is fixed without mechanical contact. This design avoids the indentation or tearing of thin-walled materials by traditional clamps. The axial flow fan delivers cold air in a direction through the ventilation pipe, and the air volume is adjusted according to the material characteristics in combination with the ventilation valve. The heat-sealed part is cooled to the shaping temperature within 5 seconds to avoid thermal stress deformation, and the hot melt waste gas is discharged simultaneously. The concentration of harmful gases in the working environment is reduced by 80%, which meets the green production standards and solves the dual bottlenecks of efficiency and environmental protection caused by slow cooling and waste gas diffusion of traditional devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of a valve bag bag opening heat sealing device of the present invention; Figure 2 It is a structural schematic diagram of the vacuum pump and the linear transmission module of the present invention; Figure 3 For the present invention Figure 2 A schematic cross-sectional structure diagram of ; Figure 4 For the present invention Figure 3 A schematic diagram of the local enlarged structure at point A in the middle; Figure 5 It is a structural schematic diagram of the outer frame and the material conveying platform of the present invention; Figure 6 For the present invention Figure 5 A schematic diagram of the local enlarged structure at B in the middle; Figure 7 It is a structural schematic diagram of the sealing door body of the present invention; Figure 8 It is a structural schematic diagram of the primary sealing groove and the heat sealing strip hole of the present invention; Fig. 9 It is a structural schematic diagram of the linear transmission module and the material conveying platform of the present invention; Fig.10 It is a schematic structural diagram of the sealing gland of the present invention.

[0033] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Sealing box; 2. Lifting frame; 3. Bag body; 4. Heat sealing chamber; 5. Heat sealing table; 6. Turning motor; 7. Turning table; 8. Primary sealing groove; 9. Heat sealing strip hole; 10. Secondary sealing groove; 11. First elastic pressure element; 12. Sealing gland; 13. Heat pressing seat; 14. Primary heat pressing block; 15. Secondary heat pressing block; 16. Heat pressing push rod; 17. Pre-pressing frame; 18. Secondary elastic pressure element; 19. Positioning plate; 20. External frame; 21. Bidirectional screw rod; 22. Clamp frame; 23. Sealing door body; 24. Clamping plate; 25. Third elastic pressure element; 26. Single chip microcomputer; 27. Screw lifting module; 28. Charging pump; 29. ​​Extrusion bag; 30. First air pressure probe; 31. Pressure relief valve; 32. Vacuum pump; 33. Vacuum hose; 34. Second air pressure probe; 35. Visual acquisition probe; 36. Audio acquisition sensor; 37. Negative pressure pump; 38. Negative pressure chamber; 39. Negative pressure adsorption hole; 40. Ventilation pipe; 41. Linear transmission module; 42. Material conveying platform. DETAILED DESCRIPTION

[0034] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0035] The present invention provides the following preferred embodiments like Figure 1-10As shown, a valve bag bag mouth heat sealing device comprises a sealing box 1 and a liftable lifting frame 2, a heat sealing chamber 4 is provided in the sealing box 1, a bag body 3 is movably arranged in the heat sealing chamber 4, a heat sealing clamping mechanism for sealing the heat sealing chamber 4 and clamping the bag body 3 is provided on the sealing box 1, a heat sealing table 5 is provided in the heat sealing chamber 4, a turning table 7 driven by a turning motor 6 is rotatably installed in the heat sealing chamber 4 and adjacent to the heat sealing table 5, a primary sealing groove 8 is provided on the heat sealing table 5 and the turning table 7, a heat sealing strip hole 9 is provided on the turning table 7, a secondary sealing groove 10 matched with the heat sealing strip hole 9 is fixedly provided on the heat sealing table 5, an adsorption positioning component for adsorbing and positioning the bag body 3 is provided on the heat sealing table 5, an extrusion exhaust component for extruding and exhausting the bag body 3, a vacuum pumping system for negative pressure suction before heat sealing of the bag body 3 and For the detection system of the sealing detection of the bag body 3, the bottom surface of the lifting frame 2 is connected to the sealing cover 12 for sealing the top of the heat-sealing cavity 4 through a group of first elastic pressure elements 11, a heat pressing seat 13 is fixedly installed on the lifting frame 2, and the heat pressing seat 13 is slidably connected to the sealing cover 12, and a primary heat pressing block 14 is fixedly installed on the bottom surface of the heat pressing seat 13 and corresponds to the position of the two primary sealing grooves 8, and a secondary heat pressing block 15 is slidably installed on the inner wall of the heat pressing seat 13 and corresponds to the position of the secondary sealing groove 10, a group of heat pressing push rods 16 are installed between the secondary heat pressing block 15 and the heat pressing seat 13, and a pre-pressing frame 17 slidably connected to the heat pressing seat 13 is installed on the secondary heat pressing block 15, and a positioning pressure plate 19 is fixedly installed on the bottom surface of the pre-pressing frame 17 through a group of second elastic pressure elements 18, and the positioning pressure plate 19 is slidably connected to the sealing cover 12.

[0036] The heat-sealing clamping mechanism includes an outer frame 20, which is fixedly connected to the sealing box 1. A bidirectional screw 21 driven by a motor is rotatably installed on the outer frame 20. A positive thread segment and a negative thread segment are respectively provided on the bidirectional screw 21. A clamping frame 22 is operatively installed on the positive thread segment and the negative thread segment. The two clamping frames 22 are both slidably connected to the outer frame 20. A sealing door body 23 is fixedly installed on the clamping frame 22. Two symmetrically arranged clamping plates 24 are slidably connected in the heat-sealing cavity 4. A group of third elastic pressure elements 25 are installed on the back of the two clamping plates 24. Two groups of first elastic pressure elements 11 are respectively fixedly connected to the two clamping frames 22.

[0037] The two clamping frames 22 are driven to move synchronously and symmetrically by the forward and reverse thread segments of the bidirectional screw 21. The clamping plate 24 is evenly pressed under the action of the third elastic pressure element 25 to achieve stable clamping of the bag body 3 and closing of the sealing door body 23. During the working process, the motor drives the bidirectional screw 21 to rotate, driving the clamping frame 22 to slide along the outer frame 20, so that the sealing door body 23 is closely attached to the opening of the heat sealing cavity 4, ensuring the airtightness during the heat sealing process; This design solves the problem of bag mouth deviation or air leakage caused by uneven force in traditional clamping mechanisms. Through elastic pressure and bidirectional synchronous movement, it significantly improves the clamping accuracy and sealing efficiency. It is especially suitable for the rapid adaptation of valve bags of different sizes, reducing the cost of manual adjustment.

[0038] A single chip microcomputer 26 is installed on the top of the sealing box 1 , and a vertically arranged screw lifting module 27 is installed on the outer frame 20 . The screw lifting module 27 is transmission-connected to the lifting frame 2 .

[0039] The single chip computer 26 accurately controls the operation of the screw lifting module 27 through a preset program, and adjusts the height of the lifting frame 2 to adapt to different bag opening heat sealing requirements. During the work process, the screw lifting module 27 drives the lifting frame 2 to move vertically, and combines the sliding connection between the heat pressing seat 13 and the sealing cover 12 to ensure that the primary heat pressing block 14 and the secondary heat pressing block 15 are accurately aligned with the sealing groove. This solution solves the problem of heat sealing misalignment or uneven pressure caused by inaccurate height adjustment in traditional devices, realizes fully automated control, significantly improves heat sealing consistency and production efficiency, and reduces operation complexity.

[0040] The extrusion exhaust assembly includes a charging pump 28 installed on the sealing box 1, and an extrusion bag 29 is installed on both inner sides of the heat sealing cavity 4. The port of the charging pump 28 is connected to the inner cavity of the two extrusion bags 29 through a multi-way tube. The two extrusion bags 29 are provided with a first air pressure probe 30 for monitoring the inner cavity pressure of the extrusion bags 29. The data end of the first air pressure probe 30 is connected to the data of the single-chip microcomputer 26. A pressure relief valve 31 is connected to the multi-way tube and the heat sealing cavity 4.

[0041] When heat sealing and vacuuming, the pressure pump 28 works synchronously, and the pressure pump 28 supplies pressure to the squeezing bags 29 on both sides through the multi-way pipe, so that the squeezing bags 29 expand and squeeze the bag body 3, and force the residual air in the bag to be discharged; During the working process, the first air pressure probe 30 monitors the pressure in the extrusion bag 29 in real time, the single-chip computer 26 adjusts the power of the charging pump 28 according to the feedback data, and the pressure relief valve 31 automatically releases the pressure when overpressure occurs. This design effectively solves the problem of loose sealing or bulging caused by residual gas in the bag before heat sealing. Combined with elastic extrusion and intelligent pressure control, it improves the thoroughness of exhaust and ensures that the heat sealing surface is flat and free of bubbles.

[0042] The vacuum system includes a vacuum pump 32 installed on the lifting frame 2. The negative pressure port of the vacuum pump 32 is connected to the inner cavity of the heat sealing cavity 4 through a vacuum hose 33. A second air pressure probe 34 for monitoring the internal air pressure of the heat sealing cavity 4 is installed on the sealing box 1. The data end of the second air pressure probe 34 is connected to the data of the single-chip microcomputer 26.

[0043] The vacuum pump 32 evacuates the heat sealing chamber 4 through the vacuum hose 33, so that the bag body 3 is closely attached to the heat sealing table 5, eliminating the interference of the air in the bag on the heat sealing; During the working process, the second air pressure probe 34 monitors the vacuum degree of the heat sealing chamber 4 in real time, and the single-chip microcomputer 26 dynamically adjusts the power of the vacuum pump 32 to maintain a constant negative pressure environment. This solution solves the problem of sealing stratification or insufficient strength caused by insufficient vacuum degree in the bag in traditional heat sealing, and significantly improves the heat sealing reliability and product yield through closed-loop control.

[0044] The detection system includes a visual acquisition probe 35 and an audio acquisition sensor 36 installed in the heat sealing cavity 4. The visual acquisition probe 35 is used for image acquisition of the bag body 3, and the audio acquisition sensor 36 is used for audio acquisition in the heat sealing cavity 4. The data ends of the visual acquisition probe 35 and the audio acquisition sensor 36 are both connected to the single-chip microcomputer 26.

[0045] The beneficial effect of adopting the above further scheme is that after the heat sealing is completed and the pressure in the heat sealing chamber 4 is restored to the normal pressure state, the visual acquisition probe 35 collects the surface deformation image of the bag body 3 in real time, and the audio acquisition sensor 36 collects the noise generated by the deformation of the bag body 3 in real time. When the visual acquisition probe 35 detects that the bag body 3 expands when it is restored to the normal pressure state, the single-chip microcomputer 26 determines that the heat sealing effect of the bag body 3 is poor. When the noise decibel of the bag body 3 exceeds the set threshold, that is, the deformation amplitude of the bag body 3 exceeds the set threshold, the single-chip microcomputer 26 determines that the heat sealing effect of the bag body 3 is poor.

[0046] The adsorption and positioning assembly includes a negative pressure pump 37 installed on the back of the sealing box 1 and a negative pressure chamber 38 opened in the heat sealing table 5. The negative pressure end of the negative pressure pump 37 is fixedly connected to the negative pressure chamber 38. Two groups of negative pressure adsorption holes 39 are opened on the top surface of the heat sealing table 5. The primary sealing groove 8 on the heat sealing table 5 is arranged between the two groups of negative pressure adsorption holes 39.

[0047] After the vacuum is completed, the negative pressure pump 37 generates an adsorption force on the bag body 3 through the negative pressure chamber 38 and the adsorption holes, so that it firmly adheres to the surface of the heat sealing table 5. In the working process, the negative pressure adsorption holes 39 are distributed on both sides of the primary sealing groove 8 to ensure that the bag opening is not displaced during the hot pressing process. This design solves the problem that the traditional positioning method relies on mechanical clamps to easily damage the bag body, and realizes flexible positioning through contactless adsorption, which is particularly suitable for high-precision heat sealing of thin-walled or easily deformed valve bags.

[0048] After the bag body 3 is positioned by negative pressure adsorption, the lifting frame 2 moves down. After the lifting frame 2 moves down, the positioning plate first presses the joint between the bag body 3 and the part to be heat-sealed. After pressing, the lifting frame 2 continues to move down. After the lifting frame 2 moves down, the two primary heat-pressing blocks 14 are respectively fitted with the two first sealing grooves, and then the double sealing of the part to be heat-sealed is completed. After the double sealing is completed, the lifting frame 2 is reset. After the lifting frame 2 is reset, the turning table 7 is turned 90° in the direction of the heat-sealing table 5. After the 90° turning is completed, the turning table 7 is finally parallel to the heat-sealing table 5, the heat-sealing strip hole 9 corresponds to the position of the secondary sealing groove 10, and the part to be heat-sealed is folded. After the folding is completed, the lifting frame 2 continues to move down. When the lifting frame 2 moves down, the hot pressing push rod 16 drives the secondary heat-pressing block 15 to move down. After the secondary heat-pressing block 15 moves down, it passes through the heat-sealing strip hole 9 and performs triple heat sealing on the folded part to be heat-sealed. Through triple heat sealing, the heat sealing effect of the bag body 3 is effectively guaranteed.

[0049] It also includes ventilation pipes 40 installed on both sides of the sealing box 1. The tail ends of the two ventilation pipes 40 are connected to the heat sealing cavity 4. The inner wall of each ventilation pipe 40 is installed with an axial flow fan and a ventilation valve in sequence from the inside to the outside.

[0050] The axial flow fan delivers cold air to the heat sealing cavity 4 through the ventilation duct 40 to accelerate the cooling and shaping after heat sealing. The ventilation valve can adjust the air volume to match the thermal shrinkage characteristics of different materials. In the work process, the ventilation system is started after the heat sealing is completed to quickly reduce the cavity temperature and discharge the hot melt waste gas. This solution solves the problem of bag mouth deformation caused by low cooling efficiency of traditional devices, while improving the safety of the working environment and meeting environmental protection production requirements.

[0051] It also includes a linear transmission module 41 installed at the bottom of the heat sealing chamber 4, on which a material conveying platform 42 is installed for transmission, and two guide rails slidably connected to the material conveying platform 42 are fixedly installed at the bottom of the sealing box 1.

[0052] The linear transmission module 41 drives the material conveying platform 42 to slide along the guide rail to realize automatic loading and unloading of the valve bag.

[0053] A heat sealing method for a valve bag mouth heat sealing device, comprising the following steps: SS01, place the bag body 3 on the material conveying platform 42 in the heat sealing cavity 4, place the part of the bag body 3 to be heat sealed on the heat sealing table 5 in the heat sealing cavity 4, start the heat sealing clamping mechanism, the bidirectional screw 21 is driven by the motor to rotate, driving the clamping frames 22 on both sides to move synchronously and symmetrically, pushing the sealing door 23 to close the opening of the heat sealing cavity 4, and at the same time, the clamping plate 24 applies pressure evenly through the third elastic pressure element 25 to achieve stable clamping of the bag opening and cavity sealing, the single chip computer 26 controls the screw lifting module 27 to drive the lifting frame 2 to move downward, and the sealing gland 12 contacts the top of the heat sealing cavity 4 to form a closed environment; SS02, start the vacuum pump 32, evacuate the heat sealing chamber 4 through the vacuum hose 33, make the bag body 3 close to the heat sealing table 5, eliminate the air interference in the bag, and start the charging pump 28 simultaneously, supply pressure to the squeezing capsules 29 on both sides through the multi-way pipe. After the squeezing capsules 29 expand, they apply uniform pressure to the bag body 3 to force the residual gas in the bag body 3 to be discharged. The first air pressure probe 30 monitors the pressure data in real time, and the single chip microcomputer 26 dynamically adjusts the power of the charging pump 28. When the pressure is over-pressured, the pressure relief valve 31 automatically opens; SS03. After vacuuming is completed, the negative pressure pump 37 is started to generate adsorption force on the bag body 3 through the negative pressure adsorption holes 39 on the heat sealing table 5, so that it is firmly attached to the surface of the heat sealing table 5 to ensure that there is no displacement during the heat sealing process; SS04, the primary heat pressing block 14 moves down with the heat pressing seat 13, and is precisely aligned with the primary sealing groove 8 on the heat sealing table 5 and the turning table 7, completing the preliminary heat sealing of the bag mouth and forming a double seal. After the double heat sealing, the lifting frame 2 is reset; SS05, after the lifting frame 2 is reset, the turning motor 6 drives the turning table 7 to turn 90° toward the heat sealing table 5, so that the heat sealing strip hole 9 is aligned with the secondary sealing groove 10 on the heat sealing table 5, and the lifting frame 2 moves down for the second time, and the heat pressing push rod 16 drives the secondary heat pressing block 15 to pass through the heat sealing strip hole 9 to heat seal the folded bag opening again. During this heat sealing, the multiple layers on the bag body 3 are heat sealed at the same time, and finally a triple seal is formed; After SS06 and triple sealing is completed, the axial flow fan delivers cold air to the heat sealing chamber 4 through the ventilation pipe 40 to accelerate the cooling and shaping of the heat sealing part, and the ventilation valve adjusts the air volume according to the material characteristics; SS07, after the heat sealing is completed, the visual acquisition probe 35 collects the surface image of the bag mouth, and the audio acquisition sensor 36 detects the deformation noise. If the image shows expansion or the noise decibel exceeds the standard, the single chip microcomputer 26 determines that the seal is unqualified and alarms; SS08. After the test is qualified, the heat-sealing clamping mechanism releases the bag body 3, and the material conveying platform 42 slides along the guide rail under the drive of the linear transmission module 41 to move the finished bag out of the heat-sealing chamber 4, completing the automatic unloading.

[0054] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A valve bag bag mouth heat sealing device, comprising a sealing box (1) and a lift frame (2) which can be lifted or lowered, characterized in that: A heat sealing chamber (4) is provided in the sealing box (1), a bag body (3) is movably arranged in the heat sealing chamber (4), a heat sealing clamping mechanism for sealing the heat sealing chamber (4) and clamping the bag body (3) is provided on the sealing box (1), a heat sealing table (5) is provided in the heat sealing chamber (4), and a turning table (7) driven by a turning motor (6) is rotatably installed in the heat sealing chamber (4) and adjacent to the heat sealing table (5); The heat sealing table (5) and the turning table (7) are both provided with a primary sealing groove (8), the turning table (7) is provided with a heat sealing strip hole (9), the heat sealing table (5) is fixedly provided with a secondary sealing groove (10) cooperating with the heat sealing strip hole (9), and the heat sealing table (5) is provided with an adsorption positioning component for adsorbing and positioning the bag body (3); The heat-sealing chamber (4) is also provided with an extrusion exhaust component for extruding and exhausting the bag body (3), a vacuum system for negative pressure suction before heat-sealing the bag body (3), and a detection system for sealing detection of the bag body (3). The bottom surface of the lifting frame (2) is connected to a sealing pressure cover (12) for sealing the top end of the heat-sealing chamber (4) via a group of first elastic pressure elements (11).

2. A valve bag bag mouth heat sealing device according to claim 1, characterized in that: A heat pressing seat (13) is fixedly mounted on the lifting frame (2), and the heat pressing seat (13) is slidably connected to the sealing cover (12). A primary heat pressing block (14) is fixedly mounted on the bottom surface of the heat pressing seat (13) and at positions corresponding to the two primary sealing grooves (8). A secondary heat pressing block (15) is slidably mounted on the inner wall of the heat pressing seat (13) and at positions corresponding to the secondary sealing grooves (10). A group of heat pressing push rods (16) are mounted between the secondary heat pressing block (15) and the heat pressing seat (13).

3. A valve bag mouth heat sealing device according to claim 2, characterized in that: The heat-sealing clamping mechanism comprises an outer frame (20), the outer frame (20) being fixedly connected to the sealing box (1), a bidirectional screw rod (21) driven by a motor being rotatably mounted on the outer frame (20), a positive thread segment and a negative thread segment being respectively arranged on the bidirectional screw rod (21), a clamping frame (22) being rotatably mounted on the positive thread segment and the negative thread segment, two clamping frames (22) being slidably connected to the outer frame (20), a sealing door body (23) being fixedly mounted on the clamping frames (22), two symmetrically arranged clamping plates (24) being slidably connected in the heat-sealing cavity (4), a group of third elastic pressure elements (25) being mounted on the backs of the two clamping plates (24), and two groups of the first elastic pressure elements (11) being respectively fixedly connected to the two clamping frames (22).

4. A valve bag mouth heat sealing device according to claim 3, characterized in that: A single chip computer (26) is installed on the top of the sealing box (1), and a vertically arranged screw lifting module (27) is installed on the outer frame (20), and the screw lifting module (27) is transmission-connected to the lifting frame (2).

5. The valve bag mouth heat sealing device according to claim 2, characterized in that: The extrusion exhaust assembly comprises a charging pump (28) mounted on the sealing box (1); an extrusion bag (29) is mounted on both inner side surfaces of the heat sealing chamber (4); a port of the charging pump (28) is connected to the inner cavities of the two extrusion bags (29) through a multi-way pipe; a first air pressure probe (30) for monitoring the inner cavity pressure of the extrusion bags (29) is provided on the two extrusion bags (29); a data end of the first air pressure probe (30) is connected to data of the single chip microcomputer (26); and a pressure relief valve (31) is connected to the multi-way pipe and the heat sealing chamber (4).

6. A valve bag mouth heat sealing device according to claim 2, characterized in that: The vacuum pumping system comprises a vacuum pump (32) mounted on the lifting frame (2); a negative pressure port of the vacuum pump (32) is connected to the inner cavity of the heat sealing cavity (4) via a vacuum hose (33); a second air pressure probe (34) for monitoring the internal air pressure of the heat sealing cavity (4) is mounted on the sealing box (1); a data end of the second air pressure probe (34) is connected to data of the single chip microcomputer (26).

7. A valve bag mouth heat sealing device according to claim 2, characterized in that: The detection system comprises a visual acquisition probe (35) and an audio acquisition sensor (36) installed in the heat-sealing cavity (4); the visual acquisition probe (35) is used for acquiring images of the bag body (3); the audio acquisition sensor (36) is used for acquiring audio in the heat-sealing cavity (4); and data ends of the visual acquisition probe (35) and the audio acquisition sensor (36) are both data-connected to the single-chip computer (26).

8. The valve bag mouth heat sealing device according to claim 2, characterized in that: The adsorption positioning assembly comprises a negative pressure pump (37) installed on the back of the sealing box (1) and a negative pressure chamber (38) opened in the heat sealing table (5); the negative pressure end of the negative pressure pump (37) is fixedly connected to the negative pressure chamber (38); the top surface of the heat sealing table (5) is provided with two groups of negative pressure adsorption holes (39); the primary sealing groove (8) on the heat sealing table (5) is arranged between the two groups of negative pressure adsorption holes (39); It also includes ventilation pipes (40) installed on both sides of the sealing box (1), the tail ends of the two ventilation pipes (40) are connected to the heat sealing chamber (4), and the inner wall of each ventilation pipe (40) is installed with an axial flow fan and a ventilation valve in sequence from the inside to the outside.

9. The valve bag mouth heat sealing device according to claim 1, characterized in that: It also includes a linear transmission module (41) installed at the bottom of the heat sealing chamber (4), a material conveying platform (42) being transmission-mounted on the linear transmission module (41), two guide rails slidably connected to the material conveying platform (42) being fixedly installed at the bottom of the sealing box (1), a pre-pressing frame (17) slidably connected to the heat pressing seat (13) being installed on the secondary heat pressing block (15), a positioning pressure plate (19) being fixedly installed on the bottom surface of the pre-pressing frame (17) via a group of second elastic pressure elements (18), and the positioning pressure plate (19) being slidably connected to the sealing gland (12).

10. A heat sealing method for a valve bag mouth heat sealing device according to any one of claims 1 to 9, characterized in that: The following steps are involved: SS01, placing the bag body (3) on the material conveying platform (42) in the heat sealing chamber (4), placing the portion of the bag body (3) to be heat sealed on the heat sealing table (5) in the heat sealing chamber (4), starting the heat sealing clamping mechanism, the bidirectional screw (21) is driven to rotate by the motor, driving the clamping frames (22) on both sides to move synchronously and symmetrically, pushing the sealing door (23) to close the opening of the heat sealing chamber (4), and at the same time, the clamping plate (24) applies pressure evenly through the third elastic pressure element (25) to achieve stable clamping of the bag opening and sealing of the chamber, the single chip computer (26) controls the screw lifting module (27) to drive the lifting frame (2) to move downward, and the sealing cover (12) contacts the top of the heat sealing chamber (4) to form a closed environment; SS02, start the vacuum pump (32), evacuate the heat sealing chamber (4) through the vacuum hose (33), make the bag body (3) close to the heat sealing table (5), eliminate the air interference in the bag, and simultaneously start the pressure pump (28), supply pressure to the extrusion bags (29) on both sides through the multi-way pipe, and after the extrusion bags (29) expand, they apply uniform pressure to the bag body (3) to force the residual gas in the bag body (3) to be discharged, the first air pressure probe (30) monitors the pressure data in real time, the single chip microcomputer (26) dynamically adjusts the power of the pressure pump (28), and the pressure relief valve (31) automatically opens when the pressure is over-pressured; SS03. After the vacuuming is completed, the negative pressure pump (37) is started to generate an adsorption force on the bag body (3) through the negative pressure adsorption holes (39) on the heat sealing table (5), so that the bag body (3) is firmly attached to the surface of the heat sealing table (5) to ensure that there is no displacement during the heat sealing process; SS04, the primary heat pressing block (14) moves downward with the heat pressing seat (13), and is precisely aligned with the primary sealing groove (8) on the heat sealing table (5) and the turning table (7), completing the initial heat sealing of the bag mouth and forming a double seal. After the double heat sealing, the lifting frame (2) is reset; SS05, after the lifting frame (2) is reset, the turning motor (6) drives the turning table (7) to turn 90 degrees in the direction of the heat sealing table (5), so that the heat sealing strip hole (9) is aligned with the secondary sealing groove (10) on the heat sealing table (5), the lifting frame (2) moves down for the second time, and the heat pressing push rod (16) drives the secondary heat pressing block (15) to pass through the heat sealing strip hole (9) to heat seal the folded bag mouth again. During this heat sealing, the multiple layers on the bag body (3) are heat sealed at the same time, and finally a triple seal is formed; SS06, after the triple seal is completed, the axial flow fan delivers cold air to the heat sealing chamber (4) through the ventilation pipe (40) to accelerate the cooling and shaping of the heat sealing part, and the ventilation valve adjusts the air volume according to the material characteristics; SS07, after the heat sealing is completed, the visual acquisition probe (35) acquires the image of the bag mouth surface, and the audio acquisition sensor (36) detects the deformation noise. If the image shows expansion or the noise decibel exceeds the standard, the single chip microcomputer (26) determines that the sealing is unqualified and alarms; SS08. After the test is qualified, the heat-sealing clamping mechanism releases the bag body (3), and the material conveying platform (42) slides along the guide rail under the drive of the linear transmission module (41), and the finished bag is moved out of the heat-sealing chamber (4), completing the automatic unloading.

Images