Heat sealing device and method for controlled atmosphere storage of tobacco stacks

Abstract

The present disclosure provides a kind of heat sealing device, it is suitable for the edge of top film and bottom film heat sealing together, including heightening pad, heat sealing mechanism and at least three sets of flattening mechanism.The present disclosure also provides a kind of air conditioning curing method of smoke stack, including the edge of top film and bottom film with intermediate placed smoke stack is sealed and heat sealed together to form film cover using heat sealing device, and the regulating gas is introduced into film cover, to carry out air conditioning curing to smoke stack, improve work efficiency, while also can realize the regulation of heat sealing temperature and heat sealing time length, improve heat sealing quality.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of tobacco sheet curing, and in particular to a heat sealing device and a tobacco stack controlled atmosphere curing method. BACKGROUND

[0002] Controlled atmosphere curing is one of the tobacco sheet curing technologies. The principle is to form a closed space of a tobacco stack of any size by a special sealing film under normal temperature conditions, and to effectively control the oxygen concentration, carbon dioxide concentration and relative humidity in the closed space by using warehouse atmosphere control agents placed in the closed space, so as to achieve the purposes of preventing mold, keeping the moisture of tobacco leaves relatively constant, and effectively improving or maintaining the aging quality of tobacco leaves. Therefore, the sealing film cover is one of the key links to ensure the quality of controlled atmosphere. SUMMARY

[0003] Therefore, the present disclosure provides a heat sealing device and a tobacco stack controlled atmosphere curing method.

[0004] According to an aspect of the present disclosure, a heat sealing device is provided, which is suitable for heat sealing the edges of a top film and a bottom film together, comprising: a raised pad configured to horizontally support the top film and the bottom film with the edges aligned; a heat sealing mechanism configured to clamp the edges of the top film and the bottom film between the heat sealing mechanism and the edges of the top film and the bottom film, and to heat seal the edges of the top film and the bottom film together to form a film cover while moving along the edges of the top film and the bottom film; and at least three sets of flattening mechanisms configured to be respectively connected to the corners of the top film and the bottom film and to move towards or away from the center of the top film and the bottom film to flatten the top film and the bottom film.

[0005] According to an embodiment of the present disclosure, the heat sealing mechanism comprises: a base configured to move on a horizontal plane; a bracket uprightly mounted on the base; two sets of heat sealing rollers vertically and rotatably connected to the same side of the bracket, the edges of the top film and the bottom film being clamped between the two sets of heat sealing rollers, each set of heat sealing rollers being configured to heat seal the edges of the top film and the bottom film together while moving along the edges of the top film and the bottom film.

[0006] According to an embodiment of the present disclosure, each set of heat sealing rollers comprises a main heat sealing roller, which comprises: a main connecting rod, a first end of which is connected to the bracket; and at least one set of main heat conducting cylinders, which are rotatably sleeved on the main connecting rod and are configured to heat the edges of the top film and the bottom film by cooperating with the main heat conducting cylinders of the other heat sealing roller.

[0007] According to an embodiment of the present disclosure, each set of heat sealing rollers further comprises a secondary heat sealing roller, which comprises: a secondary connecting rod, a first end of which is detachably connected to a second end of the main heat sealing roller, and a second end of which is detachably connected to another secondary connecting rod or a positioning mechanism; and at least one set of secondary heat conducting cylinders, which are rotatably sleeved on the secondary connecting rod and are configured to heat the edges of the top film and the bottom film by cooperating with the secondary heat conducting cylinders of the other set of heat sealing rollers.

[0008] According to an embodiment of the present disclosure, each group of heat sealing rollers further comprises a heat insulation cylinder sleeved on the auxiliary connecting rod and located between the primary heat conducting cylinder and the auxiliary heat conducting cylinder.

[0009] According to an embodiment of the present disclosure, the heat sealing mechanism further comprises a rotating assembly rotatably mounted on the support and connected with the heat sealing rollers, the rotating assembly being configured to drive the heat sealing rollers to rotate in a horizontal plane relative to the support and / or adjust the distance between the two groups of heat sealing rollers.

[0010] According to an embodiment of the present disclosure, the rotating assembly comprises: a vertical rotating column rotatably mounted in the support via a rotating shaft, one end of the heat sealing rollers being connected to the rotating column; an adjusting assembly provided on the rotating column and configured to drive at least one of the heat sealing rollers to move vertically to clamp or release the edges of the top film and the bottom film; and a locking assembly mounted on the support and configured to lock or unlock the rotating shaft.

[0011] According to an embodiment of the present disclosure, the locking assembly comprises: a linkage gear connected to the rotating shaft, a circumferential sidewall of the linkage gear being formed with a plurality of locking grooves; a locking block provided with locking teeth matched with the locking grooves; a first driving mechanism configured to drive the locking block to move in a radial direction of the linkage gear so that the locking teeth are inserted into or separated from the locking grooves; and a locking mechanism configured to lock the locking block to the support when the locking teeth are inserted into the locking grooves to prevent the locking teeth from being separated from the locking grooves.

[0012] According to an embodiment of the present disclosure, each group of flattening mechanism comprises: a flattening frame configured to move in a horizontal plane, an upper surface of the flattening frame being provided with a sliding groove; a flattening block slidingly arranged in the sliding groove; a clamping assembly mounted on the flattening block and configured to clamp the corners of the top film and the bottom film; and a second driving mechanism configured to drive the flattening block to move on the flattening frame towards or away from the center of the top film and the bottom film.

[0013] According to an embodiment of the present disclosure, there is provided a method for air conditioning and curing a tobacco stack, comprising: placing a bottom film on a heightening pad, placing the tobacco stack on the bottom film, covering a top film above the tobacco stack, and aligning the edges of the top film and the bottom film; sealing and heat sealing the edges of the top film and the bottom film together by using the heat sealing device as described above, including: using the flattening mechanism to pull the corners of the top film and the bottom film and move towards or away from the center of the top film and the bottom film to flatten the top film and the bottom film; clamping the edges of the top film and the bottom film by the two groups of heat sealing rollers of the heat sealing mechanism; and driving the heat sealing mechanism to move along the edges of the top film and the bottom film and melt and seal the edges of the top film and the bottom film to form a film cover; and introducing conditioning gas into the film cover to air condition and cure the tobacco stack.

[0014] The heat sealing device of the present disclosure, when performing edge sealing, first extends the corner portions of the top film and the bottom film into different flattening mechanisms respectively, then starts the flattening mechanisms to flatten them, and then moves the heat sealing mechanism to melt and seal the edges of the top film and the bottom film. The above-mentioned edge sealing method only needs one worker to operate, improves work efficiency, and can also realize the regulation of heat sealing temperature and heat sealing time, and improves the heat sealing quality. BRIEF DESCRIPTION OF DRAWINGS

[0015] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, in which:

[0016] Figure 1 is a perspective view of the heat sealing device of the present disclosure during operation;

[0017] Figure 2 is a perspective view of the heat sealing mechanism of the present disclosure;

[0018] Figure 3 is a partial sectional view of the heat sealing mechanism of the present disclosure;

[0019] Figure 4 is an enlarged view of position A in Figure 3

[0020] Figure 5 is a perspective view of the stop assembly of the present disclosure;

[0021] Figure 6 is a perspective view of the flattening mechanism of the present disclosure.

[0022] BRIEF DESCRIPTION OF DRAWINGS

[0023] ​1, film cover; 2, heightening pad; 3, heat sealing mechanism; 4, flattening mechanism; 31, heat sealing frame; 311, base; 312, roller; 313, support; 314, rotating column; 315, rotating shaft; 316, mounting screw hole; 317, adjusting groove; 318, dovetail groove; 32, first heat sealing roller; 321, main heat sealing roller; 322, auxiliary heat sealing roller; 33, second heat sealing roller; 34, heat sealing space; 351, main connecting rod; 352, connecting stud; 353, connecting screw hole; 354, limiting ring; 355, positioning mechanism; 356, auxiliary connecting rod; 36, heat conducting cylinder; 361, main heat conducting cylinder; 362, auxiliary heat conducting cylinder; 37, heat insulation cylinder; 371, rolling ball; 38, bearing; 39, rotating assembly; 41, flattening frame; 411, sliding groove; 412, universal wheel; 42, flattening block; 421, sliding block; 43, clamping assembly; 431, clamping block; 432, clamping cylinder; 433, rubber pad; 44, second driving mechanism; 5, adjusting assembly; 51, adjusting rod; 511, threaded part; 512, light pole part; 52, adjusting motor; 6, stop assembly; 61, linkage gear; 611, stop groove; 62, stop block; 621, dovetail block; 63, extension block; 64, first driving mechanism; 65, locking mechanism. DETAILED DESCRIPTION

[0024] In order to make the objects, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to specific embodiments and drawings.

[0025] The terms used herein are merely used to describe specific embodiments, and are not intended to limit the present disclosure. The terms "include", "contain" and the like used herein indicate the existence of the described features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0026] All terms used herein, including technical and scientific terms, have meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted to have meanings consistent with the context of the present specification, and should not be interpreted in an idealized or overly formal manner.

[0027] In the event that a phrase such as "at least one of A, B, and C, etc." is used herein, it is meant that A alone, B alone, C alone, or any combination of A, B, and C can be used. In the event that a phrase such as "at least one of A or B, etc." is used herein, it is meant that A alone, B alone, or A and B combined can be used.

[0028] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only the directions of the drawings for reference, and are not intended to limit the protection scope of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. When it may cause confusion to the understanding of the present disclosure, the conventional structures or configurations will be omitted.

[0029] In the related art, the film cover for the controlled atmosphere curing of tobacco stacks generally includes a top film and a bottom film. When forming, the bottom film is first laid flat on a mat placed on the ground, the tobacco stack is then placed in the middle of the bottom film, and then the top film is laid flat on top of the tobacco stack and the edges of the top film and the bottom film are aligned. When processing, in order to reduce the risk of wrinkles in the film cover, improve the flatness and air tightness of the film cover, the two ends of the top film and the bottom film are often first pulled flat by two workers by hand, and then another worker holds a heat sealer to heat seal the four edges of the top film and the bottom film, so that the edges of the top film and the bottom film are melted and heat sealed, thereby completing the edge sealing processing to form a sealed space between the top film and the bottom film. However, the above edge sealing processing method requires three workers to operate and execute, which is labor-intensive and low in work efficiency, and it is difficult to control the temperature and time of heat sealing, which needs to be improved.

[0030] According to an embodiment of the present disclosure, as Figure 1As shown, a heat sealing device is provided, which is suitable for sealing the edges of a top film (not shown in the figure) and a bottom film (not shown in the figure) to form a film cover 1 for the controlled atmosphere curing of a tobacco stack. The heat sealing device comprises a raised pad 2, a heat sealing mechanism 3 and at least three sets of flattening mechanisms 4. The raised pad 2 is placed on the ground and is configured to horizontally support the edge-aligned top film and bottom film. The bottom film is placed on the raised pad 2 and the four corners of the bottom film respectively extend beyond the raised pad 2. A tobacco stack (not shown in the figure) is placed on the bottom film, the top film is placed on the tobacco stack, and the edges of the top film and the bottom film are aligned. The heat sealing mechanism 3 is configured to clamp the edges of the edge-aligned top film and bottom film and to move along the edges of the top film and the bottom film while sealingly and heat-sealing the edges of the top film and the bottom film together to form the film cover 1. The at least three sets of flattening mechanisms 4 (four sets are shown in the figure) are configured to be respectively connected to the corners of the top film and the bottom film and to move towards or away from the center of the top film and the bottom film, so that the forces exerted by the three sets of flattening mechanisms 4 on the top film and the bottom film are balanced to flatten the top film and the bottom film. During the edge sealing process, the corners of the edges are respectively inserted into the flattening mechanisms 4. After the flattening mechanisms 4 are started, the top film and the bottom film are pulled flat and kept in a taut state. Then the heat sealing mechanism 3 is started, and the heat sealing mechanism 3 moves along the edges and heats, thereby completing the edge sealing operation and forming the film cover 1. Figure 1

[0031] By the above technical solution, the above edge sealing operation only requires one worker, improves work efficiency, and can also realize the regulation of heat sealing temperature and heat sealing time, thereby improving heat sealing quality.

[0032] According to an embodiment of the present disclosure, as shown in Figure 2 the heat sealing mechanism comprises a base 311, a support 313 and two sets of heat sealing rollers. The base 311 is configured to move on a horizontal plane; the support 313 is vertically installed on the base; the two sets of heat sealing rollers comprise a first heat sealing roller 32 and a second heat sealing roller 33, which are vertically and rotatably connected to the same side of the support, the edges are clamped between the two sets of heat sealing rollers, and each set of heat sealing rollers is configured to move along the edges while sealingly and heat-sealing the edges of the top film and the bottom film together. In an embodiment, as shown in Figure 2 the heat sealing mechanism 3 comprises a heat sealing frame 31, the first heat sealing roller 32 is located on the upper side of the second heat sealing roller 33, and the two form a heat sealing space 34. A plurality of rollers 312 are installed below the base 311, which can reduce the frictional resistance when the heat sealing mechanism 3 moves on the ground, and help to reduce the labor cost when the worker pushes the heat sealing mechanism 3.

[0033] ​According to an embodiment of the present disclosure, each group of heat sealing rollers comprises a main heat sealing roller 321, the main heat sealing roller 321 comprising a main connecting rod 351 and at least one group of main heat conducting cylinders 361, the first end of the main connecting rod 351 being connected to the support 313; the at least one group of main heat conducting cylinders 361 being rotatably sleeved on the main connecting rod 351 and being configured to heat the edges of the top film and the bottom film by cooperating with the main heat conducting cylinders of another heat sealing roller.

[0034] According to an embodiment of the present disclosure, each group of heat sealing rollers further comprises a secondary heat sealing roller 322, the secondary heat sealing roller 322 comprising a secondary connecting rod 356 and at least one group of secondary heat conducting cylinders 362, the secondary connecting rod 356 having a first end detachably connected to the second end of the main heat sealing roller 321 and a second end detachably connected to another secondary connecting rod 356 or a positioning mechanism 355; the at least one group of secondary heat conducting cylinders 362 being rotatably sleeved on the secondary connecting rod 356 and being configured to heat the edges of the top film and the bottom film by cooperating with the secondary heat conducting cylinders of another group of heat sealing rollers.

[0035] According to an embodiment of the present disclosure, each group of heat sealing rollers further comprises a heat insulation cylinder 37 sleeved on the secondary connecting rod and located between the main heat conducting cylinders and the secondary heat conducting cylinders, the heat insulation cylinder 37 being located between the main heat conducting cylinders 361 and the secondary heat conducting cylinders 362 or between adjacent secondary heat conducting cylinders 362.

[0036] In an embodiment, referring to Figure 3 , Figure 4 The main connecting rod 351 and the secondary connecting rod 356 may, for example, comprise an electric heating rod, one side of each main connecting rod being provided with a connecting stud 352 and the other side being provided with a connecting screw hole 353,

[0037] The connecting stud 352 on one of the main connecting rods 351 can be threadedly connected to the connecting screw hole 353 on the other connecting rod 353, so that the secondary heat sealing roller 322 is connected to the main heat sealing roller 321. The second end of the main heat sealing roller 321 can be connected to the secondary heat sealing roller 322 or the positioning mechanism 355, and the second end of the secondary heat sealing roller 322 can be connected to the next secondary heat sealing roller or the positioning mechanism 355. The width of the positioning mechanism 355 is greater than the inner diameter of the heat conducting cylinder 36. The first end of the main connecting rod and the support 313 can further comprise a limiting ring 354 sleeved on the main connecting rod 351, and each heat conducting cylinder 36 and heat insulation cylinder 37 are located between the limiting ring 354 and the positioning mechanism 355.

[0038] The outer diameter of the heat insulation cylinder 37 is smaller than the outer diameter of the heat conducting cylinder 36, and the heat conducting cylinder 36 is made of a material capable of conducting heat, such as metal or ceramic. The heat insulation cylinder 37 is made of a material capable of blocking the transfer of heat flow, such as glass fiber or asbestos. After the electric heating rod is powered on, the electric heating rod generates heat and transfers the heat to the edges of the top film and the bottom film in the heat sealing space 34 along the heat conducting cylinder 36, so as to facilitate heat sealing.

[0039] Since the heat sealing mechanism 3 needs to move when working, the heat conducting cylinder 36 will rotate under the friction force of the edges of the top film and the bottom film. In order to improve the rotation smoothness of the heat conducting cylinder 36, a bearing 38 is arranged between the heat conducting cylinder 36 and the main connecting rod 351 and the auxiliary connecting rod 356, and a plurality of rolling balls 371 are arranged on both sides of the heat insulation cylinder 37 along the axial direction of the heat insulation cylinder 37, and the center of gravity of the rolling balls 371 is located in the heat insulation cylinder 37. The bearing 38 can reduce the friction resistance between the heat conducting cylinder 36 and the main connecting rod 351 and the auxiliary connecting rod 356, and the rolling balls 371 can reduce the friction resistance between the heat conducting cylinder 36 and the heat insulation cylinder 37, so that the heat conducting cylinder 36 can rotate smoothly.

[0040] Through the above technical scheme, when the heat sealing mechanism works, the heat conducting cylinder 36 will contact the edges of the top film and the bottom film and roll when the heat sealing mechanism 3 moves. After being powered on, heat will be transmitted to the edges of the top film and the bottom film along the heat conducting cylinder 36, so that the part of the edges of the top film and the bottom film in contact with the heat conducting cylinder 36 is heated and melted, thereby realizing heat sealing and sealing. The number of heat conducting cylinders 36 is set to be multiple, so that when the heat sealing mechanism works, multiple sealing edges can be formed on the edges of the top film and the bottom film, and the sealing performance is good. The heat insulation cylinder 37 is arranged between adjacent heat conducting cylinders 36, so that heat is not easily transmitted to the film cover along the gap between adjacent heat conducting cylinders 36, so as to avoid affecting the formation of multiple sealing edges. The rolling balls and the bearing can reduce the friction resistance when the heat conducting cylinder rotates, which is conducive to improving the rotation smoothness of the heat conducting cylinder. The positioning mechanism 355 and the limiting ring 354 can prevent the heat conducting cylinder 36 from being separated from the electric heating rod, and improve the integrity of the heat sealing roller.

[0041] According to the embodiments of the present disclosure, as shown in Figure 2 and Figure 3 , the heat sealing mechanism further comprises a rotating assembly 39 rotatably mounted on the bracket 313 and connected with the heat sealing roller, and the rotating assembly 39 is configured to drive the heat sealing roller to rotate relative to the bracket in a horizontal plane and / or adjust the distance between the two groups of heat sealing rollers.

[0042] According to the embodiments of the present disclosure, the rotating assembly 39 comprises a vertical rotating column 314, an adjusting assembly 5 and a locking assembly 6. The rotating column 314 is rotatably mounted in the bracket 313 through a rotating shaft 315, and one end of the heat sealing roller is connected to the rotating column 314; the adjusting assembly 5 is arranged on the rotating column 314 and is configured to drive at least one of the heat sealing rollers to move vertically to clamp or release the edges of the top film and the bottom film; and the locking assembly 6 is mounted on the bracket 313 and is configured to lock or unlock the rotating shaft 315.

[0043] By the above technical scheme, the rotating column 314 can rotate relative to the support 313, so that the axial direction of the heat sealing roller changes to adapt to edge sealing at different positions of the top film and the bottom film, or by controlling the rotation mode of the rotating column 314, the heat sealing roller rotates in place to form an arc-shaped edge seal at the edge, which is highly practical. After the position of the heat sealing roller is adjusted in place, the rotating shaft 315 is controlled by the stop assembly 6 to lock the rotating column 314, so that the heat sealing roller cannot rotate relative to the support, thereby forming a continuous and stable edge seal and improving the edge sealing effect.

[0044] In one embodiment, referring to Figure 3 , the circumferential side wall of the rotating column 314 is provided with a mounting screw hole 316 and an adjusting groove 317 located above the mounting screw hole 316. The extending direction of the adjusting groove 317 is parallel to the distribution direction of the first heat sealing roller 32 and the second heat sealing roller 33, i.e. the vertical direction. The connecting stud 352 in the first heat sealing roller 32 near the rotating column 314 is slidingly arranged in the adjusting groove 317, and the connecting stud 352 in the second heat sealing roller 33 near the rotating column 314 is threadedly connected to the mounting screw hole 316, so that the first heat sealing roller 32 can vertically slide relative to the rotating column 314, and the second heat sealing roller 33 is fixed relative to the rotating column 314.

[0045] The rotating column 314 is provided with an adjusting assembly 5. The adjusting assembly 5 includes an adjusting rod 51 and an adjusting motor 52 for driving the adjusting rod 51 to rotate circumferentially. The adjusting motor 52 is preferably a servo motor with an output shaft that can rotate in both directions. The body of the adjusting motor 52 is mounted on a bottom plate fixed to the rotating column 314, the output shaft faces upward and is fixedly connected to the adjusting rod 51, and the adjusting rod 51 is rotatably arranged on a top plate fixed to the rotating column 314. The adjusting rod 51 includes a threaded portion 511 and a light rod portion 512 integrally formed on the lower side of the threaded portion 511. The threaded portion 511 is threadedly connected to the heating rod in the first heat sealing roller 32, and the light rod portion 512 penetrates through the second heat sealing roller 33. When the adjusting motor 52 is working, the adjusting rod 51 will rotate synchronously with the output shaft of the adjusting motor 52, so that the first heat sealing roller 32 moves vertically relative to the second heat sealing roller 33, thereby changing the size of the heat sealing space 34 to adapt to edge sealing of different thicknesses.

[0046] By the above technical scheme, when the adjusting motor 52 is working, the adjusting rod 51 is controlled to rotate circumferentially, so that the heat sealing roller moves vertically, thereby changing the distance between the heat sealing rollers to adapt to heat sealing of edges of different thicknesses or facilitate moving the edges into or out of the heat sealing space 34. One end of the heat sealing roller is slidingly matched with the adjusting groove 317, so that when the adjusting rod 51 rotates, the heat sealing roller does not rotate synchronously, which is beneficial to accurately control the movement direction of the heat sealing roller.

[0047] According to an embodiment of the present disclosure, the stop assembly 6 comprises a linkage gear 61, a stop block 62, a first driving mechanism 64 and a locking mechanism 65. The linkage gear 61 is connected to the rotating shaft 315, and a circumferential side wall of the linkage gear 61 is formed with a plurality of stop grooves 611; the stop block 62 is provided with stop teeth (not shown in the figure) matched with the stop grooves 611; the first driving mechanism 64 is configured to drive the stop block 62 to move in the radial direction of the linkage gear 61, so that the stop teeth are inserted into or separated from the stop grooves 611; and the locking mechanism 65 is configured to lock the stop block 62 to the support 313 when the stop teeth are inserted into the stop grooves 611, so as to prevent the stop teeth from separating from the stop grooves 611.

[0048] Through the above technical solution, when the rotating column 314 needs to be locked, the stop block 62 is first moved towards the linkage gear 61 until the stop block 62 extends into the adjacent stop groove 611, and then the locking mechanism 65 is tightened, so that the locking mechanism 65 presses the stop block 62 against the vertical plate, at this time, the stop block 62 is difficult to slide relative to the support 313 under the pressing action of the locking mechanism 65, and the linkage gear 61 is also limited from rotating by the stop block 62, so as to achieve the locking of the rotating column 314, which is simple and convenient to operate and has good locking effect.

[0049] In an embodiment, referring to Figure 3 , Figure 5 The stop assembly 6 comprises the linkage gear 61 fixed on the rotating shaft 315, the stop block 62 slidingly connected to the top of the support 313, the extension block 63 fixedly connected to the upper side of the support 313, the first driving mechanism 64 abuttingly arranged between the extension block 63 and the stop block 62, and the locking mechanism 65 threadedly connected to the stop block 62, and the first driving mechanism 64 has a tendency to drive the stop block 62 to move towards the linkage gear 61. The first driving mechanism 64 is preferably a stop spring, and the locking mechanism 65 is preferably a stop bolt.

[0050] The circumferential side wall of the linkage gear 61 is formed with a plurality of stop grooves 611, and the end of the stop block 62 towards the linkage gear 61 is provided with a pointed stop tooth capable of extending into the stop groove 611, so that the stop block 62 can be inserted and matched with the adjacent stop groove 611, thereby limiting the rotation of the linkage gear 61 by the stop block 62. After the stop block 62 extends into the adjacent stop groove 611, the locking mechanism 65 is tightened, and the head of the locking mechanism 65 presses the stop block 62 against the support 313, so as to achieve the locking of the rotating column 314 and the heat sealing roller.

[0051] In order to accurately determine the moving direction of the stop block 62, a dovetail block 621 is fixed to the lower side of the stop block 62, a horizontally extending dovetail groove 318 is formed in the upper end surface of the support 313, the extending direction of the dovetail groove 318 is parallel to the extension direction of the first driving mechanism 64, and the dovetail block 621 is slidingly arranged in the dovetail groove 318.

[0052] By adopting the above technical scheme, on one hand, when the rotating column 341 is rotated, the first driving mechanism 64 drives the stopper 62 to automatically move to the linkage gear 61, thereby saving the worker from the trouble of manually pushing the stopper 62; on the other hand, after the rotating column 314 is locked, if the locking mechanism 65 is shaken due to vibration or other factors, the first driving mechanism 64 also has a certain pushing force on the stopper 62, so that the rotating column 314 is not easily moved at will.

[0053] According to the embodiment of the present disclosure, each set of flattening mechanism 4 comprises a flattening frame 41, a flattening block 42, a clamping assembly 43 and a second driving mechanism 44. The flattening frame 41 is configured to move on a horizontal plane, and the upper surface of the flattening frame is provided with a sliding groove 411; the flattening block 42 is slidingly arranged in the sliding groove; the clamping assembly 43 is installed on the flattening block 42 and is configured to clamp the corner of the top film and the bottom film; and the second driving mechanism 44 is configured to drive the flattening block 42 to move on the flattening frame 41 towards or away from the center of the top film and the bottom film.

[0054] In an embodiment, referring to Figure 6 , the second driving mechanism 44 is preferably a flattening cylinder, the cylinder barrel of the flattening cylinder is installed on the flattening frame 41, the piston rod (not shown in the figure) is horizontally arranged towards the center of the raised pad 2, and the flattening block 2 is fixedly connected with the piston rod of the flattening cylinder. When the second driving mechanism 44 works, the flattening block 42 drives the clamping assembly 43 to move towards or away from the center of the raised pad 2, so that the edges of the top film and the bottom film clamped by the clamping assembly 43 move accordingly, to realize automatic flattening and straightening of the edges. It should be noted that, in order to improve the synchronization of the second driving mechanism 44 in each flattening mechanism 4, the second driving mechanism 44 of each set of flattening mechanism 4 should be controlled by the same switch to realize synchronous action.

[0055] In order to improve the movement stability of the flattening block 42, a sliding block 421 is fixed to the lower side of the flattening block 42, and a sliding groove 411 is formed on the flattening frame 41 and slidingly cooperates with the sliding block 421, and the extension direction of the sliding groove 411 is parallel to the extension direction of the piston rod of the flattening cylinder.

[0056] In order to improve the smoothness of the movement of the flattening frame 41, a universal wheel 412 with brake pads is arranged at the bottom of the flattening frame, so as to facilitate the worker to adjust the position of the flattening mechanism 4.

[0057] The clamping assembly 43 further comprises two oppositely arranged clamping blocks 431 and a clamping cylinder 432 for driving the two clamping blocks 431 to move towards or away from each other, the cylinder barrel of the clamping cylinder 432 is arranged on the flattening block 42, and two piston rods are respectively fixedly connected with different clamping blocks 431. Rubber pads 433 are respectively fixed on the opposite side walls of the two clamping blocks 431. When the edges of the top film and the bottom film extend into the two clamping blocks 431, the clamping cylinder 432 is controlled to move the two clamping blocks 431 towards each other, so that the edges are clamped by the clamping blocks 431 and move synchronously with the clamping assembly 43 when the second driving mechanism works, thereby realizing the flattening and straightening of the edges of the top film and the bottom film.

[0058] Through the above technical scheme, when the clamping cylinder 432 works, the two clamping blocks 431 will move towards or away from each other synchronously, so as to clamp or release the edges of the top film and the bottom film. The structure is simple and convenient to operate. The rubber pads 433 can increase the friction between the clamping blocks 431 and the edges of the top film and the bottom film, so that the edges are not easy to move relative to the clamping blocks 431 after being clamped, which is beneficial to improve the clamping effect and stability of the clamping assembly 43.

[0059] According to another aspect of the present disclosure, an embodiment of a method for air conditioning and maintenance of a tobacco stack is provided, comprising: placing a bottom film on a heightening pad, placing a tobacco stack on the bottom film, covering a top film above the tobacco stack, and aligning the edges of the top film and the bottom film; sealing and heat-sealing the edges of the top film and the bottom film together by using the heat sealing device as described above, comprising: using the flattening mechanism to pull the corners of the top film and the bottom film and move towards or away from the center of the top film and the bottom film to flatten the top film and the bottom film; clamping the edges of the top film and the bottom film by the two groups of heat sealing rollers of the heat sealing mechanism; and driving the heat sealing mechanism to move along the edges of the top film and the bottom film and melt and heat seal the edges of the top film and the bottom film to form a film cover; and introducing a conditioning gas into the film cover to air condition and maintain the tobacco stack.

[0060] In one embodiment, referring to Figures 1 to 6 , when the edge sealing process is performed, a worker manually extends the corners of the edges into adjacent clamping assemblies 43 one by one, and starts the clamping cylinder 432 to clamp the edges by the clamping blocks 431; then presses the switch for synchronously controlling the opening and closing of each second driving mechanism 44, so that the second driving mechanism 44 drives the flattening block 42 to move away from the center of the top film and the bottom film, thereby flattening and straightening the top film and the bottom film.

[0061] After the edges are flattened, the first heat sealing roller 32 is driven to move upward by the adjusting assembly 5, and then the heat sealing frame 31 is moved to the edge, so that the edge extends into the heat sealing space 34. Then the first heat sealing roller 32 is driven to move downward by the adjusting assembly 5, so that the first heat sealing roller 32 and the second heat sealing roller 33 abut against the edge. Then the electric heating rod is powered on, and the heat generated by the electric heating rod is transmitted to the edge along the heat conducting cylinder 36 to heat seal the edge. When the edges are sealed, only one worker is needed to push the heat sealing frame 31 to walk around the edges of the top film and the bottom film, so that the heat sealing mechanism 3 performs heat sealing, which is low in labor intensity and high in working efficiency.

[0062] The above describes the embodiments of the present disclosure. However, these embodiments are only for illustrative purposes, and are not intended to limit the scope of the present disclosure. Although each embodiment is described above respectively, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A heat sealing device suitable for heat sealing edges of a top film and a bottom film together, comprising: a raised pad configured to horizontally support the edge-aligned top film and bottom film; a heat sealing mechanism configured to clamp the edges of the edge-aligned top film and bottom film and sealingly heat seal the edges of the top film and bottom film together along the edges of the top film and bottom film to form a film cover, the heat sealing mechanism comprising: a base configured to move on a horizontal plane; a support uprightly mounted to the base; two sets of heat sealing rollers vertically and rotatably connected to the same side of the support, the edges of the top film and bottom film being clamped between the two sets of heat sealing rollers, each set of the heat sealing rollers being configured to sealingly heat seal the edges of the top film and bottom film together along the edges of the top film and bottom film; a rotating assembly comprising: a rotating column uprightly rotatably mounted in the support, one end of the heat sealing rollers being connected to the rotating column; an adjusting assembly provided on the rotating column and configured to drive at least one of the heat sealing rollers to move vertically to clamp or release the edges of the top film and bottom film; and a stop assembly comprising: a linkage gear connected to the rotating shaft, a circumferential sidewall of the linkage gear being formed with a plurality of stop grooves; a stop block provided with stop teeth matching the stop grooves; a first driving mechanism configured to drive the stop block to move in a radial direction of the linkage gear so that the stop teeth are inserted into or detached from the stop grooves; and a locking mechanism configured to lock the stop block to the support when the stop teeth are inserted into the stop grooves to prevent the stop teeth from being detached from the stop grooves; and at least three sets of flattening mechanisms configured to be respectively connected to corner portions of the top film and bottom film and move towards or away from a center of the top film and bottom film to flatten the top film and bottom film. Each set of the heat sealing rollers comprises a main heat sealing roller, the main heat sealing roller comprising: a main connecting rod, a first end of the main connecting rod being connected to the support; and at least one main heat conducting cylinder rotatably sleeved on the main connecting rod and configured to heat the edges of the top film and bottom film by cooperating with a main heat conducting cylinder of another set of heat sealing rollers. Each set of the heat sealing rollers further comprises a sub heat sealing roller, the sub heat sealing roller comprising: a sub connecting rod, a first end of the sub connecting rod being detachably connected to a second end of the main heat sealing roller, a second end of the sub connecting rod being detachably connected to another sub connecting rod or a positioning mechanism; and at least one sub heat conducting cylinder rotatably sleeved on the sub connecting rod and configured to heat the edges of the top film and bottom film by cooperating with a sub heat conducting cylinder of another set of heat sealing rollers. Each set of the heat sealing rollers further comprises a heat insulation cylinder sleeved on the sub connecting rod and located between the main heat conducting cylinder and the sub heat conducting cylinder. Each set of the flattening mechanisms comprises: a flattening frame configured to move on a horizontal plane, an upper surface of the flattening frame being provided with a sliding groove; a flattening block slidingly arranged in the sliding groove; a clamping assembly mounted on the flattening block and configured to clamp corner portions of the top film and bottom film; and ​ ​ ​ 2. The heat sealing apparatus of claim 1, wherein, ​ ​ ​ 3. The heat sealing apparatus of claim 2, wherein, ​ ​ ​ 4. The heat sealing apparatus of claim 3, wherein, ​ 5. The heat sealing apparatus of claim 1, wherein, ​ ​ ​ ​ a second driving mechanism configured to drive the flattening block to move the top and bottom films towards or away from the center of the top and bottom films on the flattening frame.

6. A method for controlled atmosphere curing of a tobacco bale, comprising: placing a bottom film on a raised pad, placing a tobacco bale on the bottom film, covering the tobacco bale with a top film, and aligning edges of the top and bottom films; sealing and heat sealing the edges of the top and bottom films together using the heat sealing device of any one of claims 1-5, comprising: using the flattening mechanism to pull the corners of the top and bottom films and move the top and bottom films towards or away from the center of the top and bottom films to flatten the top and bottom films; clamping the edges of the top and bottom films using the two sets of heat sealing rollers of the heat sealing mechanism; and driving the heat sealing mechanism to move along the edges of the top and bottom films and melt and heat seal the edges of the top and bottom films to form a film cover; and introducing a curing gas into the film cover to control atmosphere curing of the tobacco bale. ​

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