End sealing device for horizontal bag making and filling machines

Abstract

To provide an end seal device of a horizontal type bag-making filling machine, obtaining a plurality of bagged products at a time through end sealing with a plurality of pairs of seal bodies arranged successively in a front-rear direction, that prevents the respective seal bodies from shifting an end-sealing position corresponding to a region where no article is bagged and a region where a package contains an article.SOLUTION: A plurality of seal units 21 each comprising a pair of seal bodies 19, 20 are provided, side by side, in a film transfer direction. The seal units 21 hold a cylindrical film 10 between articles with the seal bodies 19, 20 and move in the film transfer direction to achieve end sealing. When the plurality of seal units 21 perform the end sealing on the cylindrical film 10, the seal units 21 are so brought under operation control that the seal units 21 perform end sealing on the front and rear sides of an empty bag part where an article 12 is present are at wider intervals than the seal units 21 which perform end sealing on the front and rear sides of a filling part where the article 12 is present.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an end sealing device in a horizontal bag making and filling machine that moves while clamping a tubular packaging material with a plurality of sealing bodies arranged in front and behind to end seal the tubular packaging material. [Background technology]

[0002] In a horizontal form-fill-seal machine, two sealing bodies that seal the end of a tubular film are arranged in a row, one behind the other, and the operation timing of each sealing body is controlled so that the tubular film is sealed and cut between each of the articles depending on the height of the articles supplied from the supply conveyor to the tubular film. If the supply of articles from the supply conveyor is interrupted, the sealing and cutting operation by the sealing body continues, and defective packages that have become empty bags with no articles in them are transported and collected. Even if the supply of articles is interrupted in this way, the operation of the sealing body is controlled according to a preset article height. Therefore, the position where the second downstream sealing body performs end sealing after the first upstream sealing body performs end sealing will differ between the part that becomes an empty bag and the parts before and after that where articles are supplied, due to the difference in the amount of squeezing of the tubular film by the sealing body depending on whether or not there is an article.

[0003] Therefore, a horizontal sealing device has been proposed in which a first sealing body end seals the tubular film each time one packaging length of tubular film is transported, and a second sealing body seals and cuts the end-sealed packaged product when it is transported a specified distance downstream.The timing of the end-sealing operation by the second sealing body is changed and controlled depending on the result of detecting the presence or absence of an article on the supply conveyor, so that the sealing and cutting positions of a packaged product containing an article and an empty bag containing no article do not shift (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3592589 Summary of the Invention [Problem to be solved by the invention]

[0005] The technical content of the conventional device disclosed in Patent Document 1 can only be applied to an end seal device in which sealing bodies are fixedly arranged at the front and rear, and cannot be applied to an end seal device in which multiple sealing bodies lined up in front and behind simultaneously clamp a tubular film and move in the film transport direction to end seal and cut, thereby producing multiple packaged products at one time.

[0006] The object of the present invention is to provide an end sealing device in a horizontal bag making and filling machine in which end sealing is performed all at once using an end sealing device having multiple pairs of sealing bodies lined up one behind the other to obtain multiple bagged products at once, which prevents the positions at which the end seals with each sealing body are shifted in correspondence with areas that will become empty bags with no articles and areas that will become packaged products with articles. [Means for solving the problem]

[0007] The end sealing device in the horizontal form-fill-seal machine of the invention according to claim 1 of the present application is: The end sealing device in a horizontal form-fill-seal machine has a plurality of sealing units (21) arranged in a packaging material transport direction, the sealing units (21) each having a pair of sealing bodies (19, 20) that face each other above and below across a transport path for a tubular packaging material (10) to which articles (12) are supplied and that sandwich the tubular packaging material (10) between the articles and move in the packaging material transport direction to perform end sealing, and the tubular packaging material (10) is end-sealed simultaneously by the plurality of sealing units (21) to obtain a plurality of packaged products (59) at one time, a detection means (25) for detecting whether or not an article (12) to be supplied to the tubular packaging material (10) is missing; When the tubular packaging material (10) is end-sealed by a plurality of sealing units (21), the operation of each sealing unit (21) and sealing body (19, 20) is controlled so that the interval between the front and rear sealing units (21) corresponding to the portion detected by the detection means (25) as being missing and resulting in an empty bag is set to an interval (L0) larger than the interval (L1) between the front and rear sealing units (21) corresponding to the portion detected by the detection means (25) as not missing and to which an item (12) of the tubular packaging material (10) has been supplied, and the operation of each sealing unit (21) and sealing body (19, 20) are clamped and end-sealed. In the invention according to claim 1, the front-to-back spacing between adjacent sealed bodies is changed and controlled to be different when an item is present and when an item is out of stock, so that the tubular packaging material can be clamped and end-sealed at the appropriate position for the empty bag section where no item is supplied and the filled section where an item is supplied.

[0008] The invention of claim 2 is characterized in that, for the preceding and following sealing units (21) corresponding to the portion to which the detection means (25) detects that there is no missing item and the item (12) of the tubular packaging material (10) has been supplied, the operation of the sealing units (21) and the sealing bodies (19, 20) is controlled so that the downstream sealing unit (21) approaches the upstream sealing unit (21) by narrowing the gap, and the tubular packaging material (10) is clamped and end-sealed by each sealing body (19, 20). According to the invention of claim 2, the end sealing can be performed satisfactorily without pulling the tubular packaging material downstream while squeezing it during the end sealing.

[0009] In the invention according to claim 3, the plurality of sealing units (21) sequentially seal the tubular packaging material (10) from the downstream side to the upstream side. Sandwich The seal bodies (19, 20) are arranged to operate in different phases so as to support each other and provide an end seal. According to the invention of claim 3, the tubular packaging material is clamped and pulled in order starting from the sealing body of the downstream sealing unit, so that the upstream tubular packaging material is not loosened during end sealing, and the end sealing can be performed satisfactorily by the sealing body of each sealing unit. Also, the air inside the tubular packaging material can be released to the upstream side of the unsealed tubular packaging material, and it is possible to prevent the internal air from being pushed and accumulated at the end side of the sealed tubular packaging material, resulting in an excessively inflated bag.

[0010] The invention of claim 4 is characterized in that, when end sealing the tubular packaging material (10), the operation of the sealing units (21) is controlled so that the downstream sealing unit (21) approaches the upstream sealing unit (21) before the sealing bodies (19, 20) of all the sealing units (21) clamp the tubular packaging material (10) and after the upper sealing body (19) of the most upstream sealing unit (21) moves to a position lower than the height of the article (12). According to the invention of claim 4, the tubular packaging material can be narrowed to a position lower than the height of the article, and the end seal can be performed by positioning the tubular packaging material in a taut state to a predetermined sealing position, thereby enabling stable end sealing without changing the sealing position.

[0011] The invention according to claim 5 is characterized in that the time when the downstream sealing unit (21) approaches the upstream sealing unit (21) is the time when the pair of sealing bodies (19, 20) in the downstream sealing unit (21) approach to a position where they clamp the tubular packaging material (10). According to the invention of claim 5, the spacing is changed when the sealing body approaches the position where the tubular packaging material is clamped, so that the end sealing can be performed so that the packaging material is aligned to the appropriate sealing position with less excess at the end of the squeezing of the tubular packaging material, and the end sealing can be performed in a more appropriate position.

[0012] In the invention according to claim 6, a conveyor (57) for transporting the end-sealed bags downstream is disposed between adjacent sealing units (21), The conveyor (57) is characterized in that it is configured to change the conveying length in response to the change in the interval between the sealing units (21). According to the invention of claim 6, even if the distance between the front and rear of the sealing units changes, end-sealed empty bags and packaged products can be smoothly transported downstream through multiple sealing units without causing transport problems. Effect of the Invention

[0013] According to the present invention, the spacing between the front and rear sealing units is changed depending on whether or not there is a shortage of items supplied to the tubular packaging material, and good packaging can be achieved without misaligning the end seal position between the area that will become an empty bag with no items and the area that will become a packaged product with items. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram of a horizontal bag making and filling machine. [Diagram 2] FIG. 2 is a schematic diagram showing an end seal device equipped with three seal units. [Diagram 3] FIG. 2 is a schematic perspective view of a seal unit. [Figure 4] FIG. 2 is a schematic side view of the seal unit. [Diagram 5] FIG. 2 is a control block diagram of a horizontal bag making and filling machine. [Figure 6] FIG. 13 is an explanatory diagram of the operation of the end seal device when there are no missing parts. [Figure 7] FIG. 11 is an explanatory diagram of the operation of the end seal device when one empty bag portion occurs. [Figure 8] FIG. 11 is an explanatory diagram of the operation of the end seal device when two empty bag portions are generated. [Figure 9] 13 is an explanatory diagram showing the movement trajectory of the upper sealing body when end sealing the tubular film. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Next, a preferred embodiment of an end sealing device in a horizontal bag making and filling machine according to the present invention will be described below with reference to the accompanying drawings. EXAMPLES

[0016] As shown in FIG. 1, a horizontal bag form-fill-seal machine (packaging machine) comprises: a bag making means 11 that forms a tubular film (tubular packaging material) 10 by overlapping both longitudinal edge portions of a strip of film (packaging material) pulled out from a raw roll in a palm-like shape; a supply conveyor 13 that supplies articles 12 toward the tubular film 10 at predetermined intervals; a vertical sealing device 14 that performs a center seal (vertical seal) on the overlapped portion of the tubular film 10 overlapped in the palm-like shape in the film transport direction (hereinafter referred to as the film transport direction (packaging material transport direction)); a film transport means 15 that clamps the overlapped portion of the tubular film 10 and feeds the tubular film 10 toward the vertical sealing device 14; and an end sealing device that clamps the tubular film 10 at the front and rear of the articles 12 supplied into the tubular film 10 at predetermined intervals, and end seals and cuts the articles in a direction intersecting the film transport direction (width direction). In addition, the packaging machine is configured such that upstream and downstream of the end sealing device, which are before and after the end sealing device in the film transport direction, items 12 supplied into the tubular film 10 are placed on a transport conveyor 17 and an output conveyor 18 which support the tubular film 10 from below and transport it downstream, and the bagged products (pillow packaged products 59) that have been end sealed and cut and separated from the upstream tubular film 10 are transported to the next process by the output conveyor 18.

[0017] 1 and 2, the end sealing device is provided with a plurality of (two or more, three in this embodiment) sealing units 21 arranged in the film transport direction, each of which has a pair of sealing bodies 19, 20 facing each other above and below across the transport path of tubular film 10 transported by transport conveyor 17. As shown in Figures 2 to 4, each sealing unit 21 is equipped with opening / closing movement means 22 that independently moves the pair of sealing bodies 19, 20 toward and away from each other, and reciprocating movement means 23 that independently moves sealing unit 21 back and forth along the film transport direction. Each sealing unit 21 is configured to perform a so-called box motion operation in which a pair of sealing bodies 19, 20 approach each other from an initial position where they are furthest apart across the transport path to clamp (hold at a clamping position) a position between the articles on tubular film 10, move downstream in the film transport direction of tubular film 10 in this clamped state, and then move away from each other and return to the initial position. Each sealing unit 21 is configured to end seal tubular film 10 in the width direction while clamping tubular film 10 fed by film conveying means 15 between sealing bodies 19, 20 and cut tubular film 10 in the width direction with cutting blade 24 built into one sealing body 19. In the embodiment, when distinguishing between the three sealing units 21 in the following description, they are referred to as first sealing unit 21A, second sealing unit 21B, and third sealing unit 21C in order from downstream to upstream in the film transport direction. Moreover, the seal bodies 19 and 20 corresponding to the seal units 21A, 21B, and 21C are referred to as first seal bodies 19a and 20a, second seal bodies 19b and 20b, and third seal bodies 19c and 20c, respectively, for ease of distinction.

[0018] 1, a detection sensor (detection means) 25 capable of detecting the presence or absence of an article 12 (presence or absence of a missing article) is provided upstream of the position where the transfer of the articles 12 from the supply conveyor 13 to the tubular film 10 is completed and at a position at least one packaging cycle (one interval equal to the transport interval of the articles 12 by the supply conveyor 13) before the articles 12 are fed by the supply conveyor 13 to the tubular film 10 formed by the bag making means 11. The detection sensor 25 detects whether the articles 12 being transported by the supply conveyor 13 arrive in accordance with a preset feed timing for each packaging cycle, and outputs a detection signal to a control means 26 of the packaging machine.

[0019] 1, the transport conveyor 17 and the discharge conveyor 18 are composed of belt conveyors in which endless belts 17b, 18b are wound around a plurality of pulleys 17a, 18a, and the turning portion at the end of the endless belt 17b of the transport conveyor 17 and the turning portion at the beginning of the endless belt 18b of the discharge conveyor 18 face each other across three sealing units 21. The turning portion at the end of the transport conveyor 17 is connected to move horizontally following the approaching and separating movement of a pair of third sealing bodies 19c, 20c in the third sealing unit 21C located at the most upstream in the film transport direction, and the turning portion at the beginning of the discharge conveyor 18 is connected to move horizontally following the approaching and separating movement of a pair of first sealing bodies 19a, 20a in the first sealing unit 21A located at the most downstream in the film transport direction. That is, when a pair of sealing bodies 19a, 20a / 19c, 20c of the most downstream and most upstream sealing units 21A, 21C approach each other, the opposing ends of the corresponding transport conveyor 17 and discharge conveyor 18 move away from each other to allow passage of the tubular film 10 toward the clamping position where the pair of sealing bodies 19a, 20a / 19c, 20c clamps the tubular film 10, and when a pair of sealing bodies 19a, 20a / 19c, 20c of the most downstream and most upstream first and third sealing units 21A, 21C move away, the opposing ends of the corresponding conveyors 17, 18 move toward each other to allow unhindered transport of articles 12 downstream. In addition, a transition conveyor (conveyor) 57 is disposed between sealing units 21A, 21B, 21C adjacent to each other in the film transfer direction, on which articles 12 supplied to the tubular film 10 are placed and transported between the two sealing units. The transfer conveyor 57 is configured with an upstream conveying section 57a ​​and a downstream conveying section 57b, each of which consists of a number of endless belts spaced apart in the width direction, arranged alternately in the width direction. The conveying length can be changed by moving the upstream conveying section 57a ​​and the downstream conveying section 57b horizontally back and forth in the film transport direction.The transfer conveyor 57 is configured so that the upstream conveying section 57a ​​and the downstream conveying section 57b move horizontally back and forth in the film transport direction to change the conveying length in response to the approaching and separating movement of the pair of sealing bodies 19, 20 in each sealing unit 21A, 21B, 21C and the change in the spacing between adjacent sealing units 21A, 21B, 21C, thereby allowing the pair of sealing bodies 19, 20 to interlock and smoothly transfer articles 12 and empty bags before and after the sealing position, thereby enabling the articles 12 and empty bags to be smoothly conveyed downstream.

[0020] 3 and 4, a pair of side panels 27a, 27a are arranged on a machine frame 27 of the end seal device, spaced apart in the width direction intersecting the film transport direction, and each of the three seal units 21A, 21B, 21C is supported between the pair of side panels 27a, 27a so as to be movable along the film transport direction. Each seal unit 21 has a pair of support members 28, 28 spaced apart in the width direction, and a pair of holding members 29, 30 that face each other across the transport path and support each seal body 19, 20 are supported between the pair of support members 28, 28 so as to be movable in the vertical direction. A slide shaft 31 extending in the vertical direction is slidably inserted and supported by each support member 28, and a first holding member 29 facing upward from the transport path of the tubular film 10 is disposed at the upper ends of the pair of slide shafts 31 extending upward from the pair of support members 28, and the lower ends of the pair of slide shafts 31 extending downward from the pair of support members 28 are connected by a connecting member 32. In addition, a second holding member 30 facing downward from the transport path is slidably supported by supports 33, 33 on the slide shafts 31 between the first holding member 29 and the support members 28, 28, and the first holding member 29 and the second holding member 30 are configured to be able to approach or move away from each other while maintaining their posture by the slide shafts 31, 31.

[0021] An upper seal body 19, which is one of the pair of seal bodies 19, 20, is supported below the first holding member 29 so as to be movable in the vertical direction (the opposing direction of the pair of seal bodies 19, 20) with its sealing surface facing the transport path of the tubular film 10. That is, a pair of connecting shafts 34, 34 are disposed on the upper seal body 19 and spaced apart in the width direction, and the pair of connecting shafts 34, 34 are slidably inserted and supported by the first holding member 29 via holders 35, 35. The connecting shafts 34, 34 extending above the first holding member 29 are connected to an attachment member 36 extending in the width direction, and the attachment member 36 is configured to move vertically together with the upper seal body 19 relative to the first holding member 29. Furthermore, springs 37 serving as biasing means are disposed on the outer periphery of each connecting shaft 34 between first holding member 29 and upper seal body 19, so that downward movement of upper seal body 19 relative to first holding member 29 is restricted and upper seal body 19 is biased downward (toward lower seal body 20, described below) by springs 37, 37. Furthermore, cutting blade 24 is supported by upper seal body 19 so as to be movable back and forth in the vertical direction, and air cylinder 38 serving as advancing and retracting means for moving cutting blade 24 back and forth is disposed on mounting member 36, so that when tubular film 10 is clamped between upper seal body 19 and lower seal body 20, cutting blade 24 is moved back and forth by air cylinder 38 to cut tubular film 10. The cutting blade 24 is always housed in the upper seal body 19, and when the cutting blade 24 is lowered by the air cylinder 38, the cutting blade 24 protrudes from the sealing surface of the upper seal body 19, and the tip of the blade enters the receiving groove of the lower seal body 20, thereby cutting the clamped tubular film 10.

[0022] 3 and 4, lower seal body 20, the other of the pair of seal bodies 19, 20, is disposed and fixed above the second holding member 30, with its sealing surface facing the transport path for the tubular film 10. Lower seal body 20 is disposed above second holding member 30 so as to face parallel to upper seal body 19, with the transport path for the tubular film 10 in between.

[0023] As shown in Figures 3 and 4, the opening / closing movement means 22 of each of the three sealing units 21A, 21B, and 21C includes a screw shaft 40 rotatably supported so as to extend in the width direction on a support frame 39 arranged between the pair of support members 28, 28, an opening / closing drive motor 41 consisting of a servo motor that rotates the screw shaft 40, and a toggle mechanism 42 as a link mechanism into which the screw shaft 40 is screwed and which connects the first and second retaining members 29, 30. The toggle mechanism 42 has a female screw member 43 that screws into the screw shaft 40, and the other end of a first link rod 45, one end of which is rotatably supported by the second retaining member 30, is rotatably supported at the upper end, which is one end of a movable member 44 that slides along a guide shaft 58 arranged parallel to the screw shaft 40, and the other end of a second link rod 46, one end of which is rotatably supported by the connecting member 32, is rotatably supported at the lower end, which is the other end of the movable member 44. The first link rod 45 and the second link rod 46 are positioned such that one end sides rotatably supported by the second holding member 30 and the connecting member 32 approach each other when the pair of seal bodies 19, 20 are separated from each other, and the opening / closing drive motor 41 rotates the screw shaft 40 to move the female screw member 43 and the moving member 44 in the width direction such that one end of the first link rod 45 and the second link rod 46 are separated from each other, thereby causing the pair of seal bodies 19, 20 to approach each other. That is, by rotating the screw shaft 40 in the forward and reverse directions by the opening / closing drive motor 41, the second holding member 30 and the connecting member 32 move toward and away from each other, and accordingly the upper and lower seal bodies 19, 20 move toward and away from each other across the transfer path.

[0024] 3 and 4, rail members 47 extending along the film transport direction are disposed in parallel on the opposing surfaces of the side panels 27a, 27a. Furthermore, sliders 49 are disposed via brackets 48 on the outer sides in the width direction of the support members 28, 28 of each sealing unit 21, and each slider 49 is slidably supported by the corresponding rail member 47, so that each sealing unit 21 is supported by the pair of rail members 47, 47 and the pair of sliders 49, 49 so as to be capable of horizontally reciprocating along the film transport direction.

[0025] 3 and 4, the reciprocating movement means 23 of each of the three sealing units 21A, 21B, 21C includes a movement mechanism 50 and a reciprocating drive motor 51 consisting of a servo motor that operates the movement mechanism 50. The movement mechanism 50 includes a drive shaft 52 rotatably supported between the pair of brackets 48, 48, a pair of drive pinions 53, 53 arranged to rotate integrally with the drive shaft 52 and spaced apart in the axial direction, and racks 54, 54 arranged on both side panels 27a, 27a and extending in the film transport direction, with which the drive pinions 53, 53 mesh. A reciprocating drive motor 51 disposed on one bracket 48 via a holder 55 is connected to a drive shaft 52, and the reciprocating drive motor 51 rotates the drive shaft 52 in the forward and reverse directions, so that the sealing unit 21 moves back and forth (upstream and downstream) in the film transport direction under the meshing action of the drive pinions 53, 53 and the racks 54, 54. Note that the racks 54, 54 constituting the movement mechanism 50 are made of a common member as the reciprocating movement means 23 disposed in each of the three sealing units 21A, 21B, 21C.

[0026] The reciprocating drive motor 51 is rotationally controlled so that the movement speed of each sealing unit 21 downstream in the film transport direction while tubular film 10 is clamped by the pair of sealing bodies 19, 20 is approximately the same as the film feed speed. In addition, the opening / closing drive motor 41 and the reciprocating drive motor 51 are set so that their speeds are variable and controlled in response to the feed speed of tubular film 10 obtained from the cut pitch (film length for one package) set corresponding to the size of articles 12 and the set packaging speed. An end seal device including three sealing units 21A, 21B, 21C is configured so that the operational phases of the first sealing body 19a, 20a, second sealing body 19b, 20b, and third sealing body 19c, 20c of each sealing unit 21A, 21B, 21C caused by each opening / closing moving means 22 are slightly different, and the operation of clamping and releasing the tubular film 10 is repeated starting from the first sealing body 19a, 20a in sealing unit 21A on the downstream side in the film transport direction (see FIG. 9). When the operational phases of each sealing body 19, 20 are made different, the phase shift between adjacent sealing bodies 19, 20 is set so that the downstream sealing body 19, 20 is clamping the tubular film 10, while the upstream sealing body 19, 20 is clamping the tubular film 10. When the operational phases of seal members 19, 20 are made different, the operational phases are not shifted so that tubular film 10 is clamped in order from the upstream side to the downstream side in the film transport direction.

[0027] In the three reciprocating means 23 shown in the embodiment, the clamping intervals at which the tubular film 10 is sealed by the sealing bodies 19a, 20a / 19b, 20b / 19c, 20c in the three sealing units 21A, 21B, 21C are set based on one packaging length set corresponding to the cutting pitch. The end seal device controls the reciprocating movement of the sealing units 21A, 21B, 21C and the opening and closing movement of the sealing bodies 19a, 20a / 19b, 20b / 19c, 20c based on a preset movement trajectory described below with reference to Fig. 9. In the embodiment, as the film is fed for three cutting pitches, the three sealing units 21A, 21B, 21C move forward together with the film feed in a state in which the tubular film 10 is clamped by the sealing bodies 19a, 20a / 19b, 20b / 19c, 20c in the three sealing units 21A, 21B, 21C for a predetermined time so as to obtain three packaged products 59 at a time. In other words, after three packages of articles 12 are supplied to the tubular film 10, the sealing bodies 19, 20 of each of the three sealing units 21A, 21B, 21C clamp and end seal the tubular film 10 at the above-mentioned clamping interval by dividing one packaging cycle into 1 / 3 cycles by three sealing units, and the opening / closing moving means 22 and the reciprocating moving means 23 are operated and controlled by the control means 26 in accordance with the film feed amount of cut pitch x 3 corresponding to the time when one package of articles 12 is sent from the supply conveyor 13 to the tubular film 10. Then, with sealing bodies 19, 20 in the three sealing units 21A, 21B, 21C clamping tubular film 10, they move downstream in the film transport direction to release tubular film 10, and then of the three sealing units 21A, 21B, 21C, starting with the most downstream sealing unit 21A, they move upstream in the film transport direction in sequence, clamping the sealing positions of tubular film 10 corresponding to the next three packages of tubular film 10 with each sealing body 19, 20, starting with the most downstream sealing unit 21A, and repeating this operation. In this way, the sealing bodies 19, 20 in the three sealing units 21A, 21B, 21C of the end seal device move with slightly different operational phases according to a preset operational trajectory, thereby obtaining three pillow-packaged products 59 at one time.That is, tubular film 10 is repeatedly fed by film transport means 15 in a number of cycles equal to the cutting pitch x the number of sealing units 21 installed (3 in this embodiment).

[0028] 5, the control means 26 of the packaging machine is connected to the first to third opening / closing drive motors 41a, 41b, 41c of the opening / closing movement means 22 of the three sealing units 21A, 21B, 21C and the first to third reciprocating drive motors 51a, 51b, 51c of the forward movement means 23, as well as the drive motor 13a of the supply conveyor 13, the drive motor 17c of the transport conveyor 17, the drive motor 18c of the carry-out conveyor 18, and the drive motor 15a of the film transport means 15. In addition, a detection signal from the detection sensor 25 is input to the control means 26.

[0029] Here, to end seal the tubular film 10, the upper and lower sealing bodies 19, 20 clamp the tubular film 10 at the center in the height direction corresponding to the height of the articles 12 at the front and rear positions of the articles 12, and therefore one packaging length is set short relative to the cutting pitch in accordance with the height and length of the articles 12. Furthermore, since the amount of shrinkage of one packaging length relative to the cutting pitch differs depending on whether or not the articles 12 are present in the tubular film, if the interval at which the sealing bodies 19, 20 of each sealing unit 21A, 21B, 21C clamp the tubular film 10 is set at a position corresponding to the state in which the articles 12 are contained when end sealing the tubular film 10 without the articles 12 contained therein, the end sealing will be performed at an inappropriate sealing position with a sealing interval shorter than the sealing position that should have been sealed. For this reason, the end sealing device of the embodiment detects whether or not there are any missing items 12 to be supplied toward the tubular film 10 based on a detection signal from the detection sensor 25, and the operation of the opening / closing moving means 22 and the reciprocating moving means 23 is controlled by the control means 26 so as to change the interval at which the tubular film is clamped by the sealing bodies 19, 20 in each sealing unit 21A, 21B, 21C.

[0030] The reference clamping interval (reference clamping interval L0) by the sealing bodies 19 and 20 of the three-base seal units 21A, 21B, and 21C is the bag length at the time of a missing item in the part (empty bag part) where the article 12 is not supplied to the tubular film 10, and is set to an interval slightly shorter than the cut pitch. And the control means 26 is detected as having a missing item based on the detection result by the detection sensor 25, and for the sealing bodies 19 and 20 in the seal units 21 before and after the part that becomes the empty bag part, the interval between the seal units 21 is set as the reference clamping interval L0, and the operation is controlled so that each sealing body 19, 20 clamps the tubular film 10 and performs end sealing. On the other hand, for the sealing bodies 19 and 20 of the seal unit 21 that performs end sealing before and after the part (filled part) where the article 12 of the tubular film 10 is supplied and is detected as having no missing item by the detection sensor 25, the downstream seal unit 21 is moved closer to the upstream seal unit 21, and the clamping interval by the sealing bodies 19 and 20 in each seal unit 21 is an interval narrower than the reference clamping interval L0, that is, an interval obtained by subtracting the shrinkage amount preset in relation to the height and length of the article 12, the adjusted clamping interval L1 (L1 < L0), and the operation is controlled so that each sealing body 19, 20 clamps the tubular film 10 and performs end sealing. That is, when end-sealing the tubular film 10, the interval of the seal unit 21 that is detected as having a missing item and end-seals the front and rear positions of the part that becomes the empty bag part is made wider than the interval of the seal unit 21 that is detected as having no missing item and end-seals the front and rear positions of the filled part where the article 12 is supplied to the tubular film 10, and the interval of each seal unit 21 is controlled. Further, in the embodiment, when changing the clamping interval of the tubular film 10 by the sealing bodies 19 and 20 in each seal unit 21, with the position of the uppermost stream third seal unit 21C as a reference, the intermediate second seal unit 21B and the lowermost stream first seal unit 21A following downstream are controlled to move closer to the seal units 21C and 21B following upstream, respectively.

[0031] Next, the operation of the end sealing device in the horizontal form-fill-seal machine according to the embodiment will be described with reference to Figures 6 to 8, in which the film is clamped and sealed in order from the sealing body on the downstream side of the three sealing units. Figures 6 to 8 are explanatory diagrams of the operation of the end sealing device, which show a schematic relationship between the reciprocating movement of each sealing unit 21 and the sealing operation of sealing bodies 19, 20 in response to the presence or absence of a missing item, and the spacing between each sealing unit 21 is set to be wider than the standard clamping spacing L0, and is narrowed as the operation when "missing item exists" and "not missing item exists". For each of sealing bodies 19, 20, only the initial position and clamping position of the operation cycle are shown.

[0032] (Operation when there is no missing part) As shown in Fig. 6(a), when the detection result by the detection sensor 25 indicates that an article is missing and three articles 12 are supplied to the end sealing device, according to the movement trajectory of the sealing bodies described below with reference to Fig. 9, first sealing bodies 19a, 20a in the most downstream first sealing unit 21A move in accordance with the movement trajectory of the sealing bodies described below with reference to Fig. 9, so that the upper sealing body 19c of the third sealing body 19c, 20c in the most upstream third sealing unit 21C moves down to a position lower than the height of the articles 12, where the tip position that becomes the clamping surface of the film by the sealing bodies is lowered, and the first sealing bodies 19a, 20a move to a position approaching the clamping position, and the operation of the reciprocating means 23 is controlled so that the first sealing unit 21A approaches the upstream second sealing unit 21B. Then, the tubular film 10 is clamped and end sealed by the first sealing bodies 19a, 20a in the first sealing unit 21A that has approached the second sealing unit 21B (see Fig. 6(b)).

[0033] According to the motion trajectory of the sealing bodies described below, when upper sealing body 19c of third sealing bodies 19c, 20c in third sealing unit 21C, the most upstream, lowers its tip position, which becomes the clamping surface of the film between the sealing bodies, to a position lower than the height of article 12 and second sealing bodies 19b, 20b move to a position approaching the clamping position, reciprocating means 23 is operated and controlled so that second sealing unit 21B and first sealing unit 21A move closer to third sealing unit 21C, the most upstream. Then, second sealing bodies 19b, 20b in second sealing unit 21B, which has approached third sealing unit 21C, clamp and end seal tubular film 10 (see FIG. 6(c)). The amount by which the first sealing unit 21A and the second sealing unit 21B approach the third sealing unit 21C, the most upstream, is set to an amount of shrinkage that causes the clamping distance between the sealing bodies 19, 20 between the second sealing unit 21B and the first sealing unit 21A to become the adjusted clamping distance L1, and the tubular film 10 is end sealed and cut at appropriate positions before and after the filling section by the second sealing bodies 19b, 20b in the second sealing unit 21B and the first sealing bodies 19a, 20a in the first sealing unit 21A.

[0034] Then, when third sealing bodies 19c, 20c in the most upstream third sealing unit 21C clamp the tubular film 10, the clamping distance between them and second sealing bodies 19b, 20b in second sealing unit 21B shrinks to adjusted clamping distance L1, and the end seal is cut at an appropriate position corresponding to one package length (see FIG. 6(d)). In this way, by controlling the opening and closing of sealing bodies 19, 20 and the forward and backward movement of sealing unit 21, three pillow-packaged products 59 can be obtained, each with an appropriate length.

[0035] (Operation when one item is missing) As shown in FIG. 7(a), if the detection sensor 25 detects that a part is missing and the area between the intermediate second sealing unit 21B and the most downstream first sealing unit 21A end seals the tubular film 10 to form an empty bag portion, the opening / closing moving means 22 and the reciprocating moving means 23 of first sealing unit 21A and first sealing bodies 19a, 20a are operated and controlled so that first sealing bodies 19a, 20a clamp the tubular film 10 and end seal the front side of the empty bag portion and the rear position of the preceding filled section (see FIG. 7(b)).

[0036] In accordance with the movement trajectory of the sealing bodies described below with reference to Figure 9, the second sealing body 19b, 20b in the intermediate second sealing unit 21B moves to a position lower than the height of the article 12, and when the upper sealing body 19c of the third sealing body 19c, 20c in the most upstream third sealing unit 21C moves to a position approaching the clamping position, the opening / closing moving means 22 and the reciprocating moving means 23 of the second sealing body 19b, 20b and the first sealing body 19a, 20a are operated and controlled so that the second sealing unit 21B and the first sealing unit 21A approach the most upstream third sealing unit 21C. Then, second sealing bodies 19b, 20b of second sealing unit 21B approaching third sealing unit 21C clamp the tubular film 10, and the rear side of the empty bag portion is end sealed (see FIG. 7(c)). As second sealing unit 21B approaches third sealing unit 21C, the distance at which the empty bag portion is clamped by second sealing bodies 19b, 20b of second sealing unit 21B and third sealing bodies 19c, 20c of third sealing unit 21C becomes the standard clamping distance L0, and the empty bag portion is end sealed and cut at an appropriate position.

[0037] Then, when third sealing bodies 19c, 20c in third sealing unit 21C clamp tubular film 10, the clamping distance between them and second sealing bodies 19b, 20b in second sealing unit 21B approaching third sealing unit 21C is adjusted to an adjusted clamping distance L1 that corresponds to the filling portion, and tubular film 10 is clamped and end sealed and cut (see FIG. 7(d)). This results in two pillow-packaged products 59 with the appropriate length and one empty bag.

[0038] (Operation when 2 consecutive items are missing) As shown in Fig. 8(a), when the detection results of sensor 25 detect that no items are missing and then detect two consecutive items as missing, resulting in an empty bag portion in tubular film 10 between second sealing unit 21B and first sealing unit 21A and between third sealing unit 21C and second sealing unit 21B, reciprocating movement means 23 of the most downstream first sealing unit 21A and opening / closing movement means 22 of first sealing bodies 19a, 20a are controlled to follow a preset movement trajectory as shown in Fig. 9. Then, in front of the empty bag portion on the downstream side and at a position behind the filling portion for the preceding items to which items are being supplied to tubular film 10, tubular film 10 is clamped and end sealed by first sealing bodies 19a, 20a of first sealing unit 21A (see Fig. 8(b)).

[0039] The operation of opening / closing movement means 22 and reciprocating movement means 23 is controlled so that second sealing unit 21B and second sealing bodies 19b, 20b in the middle follow a preset movement trajectory as shown in Fig. 9. Then, second sealing bodies 19b, 20b in second sealing unit 21B clamp and end seal tubular film 10 at a rear position of the empty bag portion on the downstream side (see Fig. 8(c)). At this time, the clamping distance between sealing bodies 19b, 20b / 19a, 20a of second sealing unit 21B and first sealing unit 21A becomes reference clamping distance L0 corresponding to the empty bag portion, and second sealing bodies 19b, 20b clamp and end seal / cut tubular film 10 at an appropriate clamping position for the empty bag portion set corresponding to the cutting pitch.

[0040] Then, third sealing body 19c, 20c in third sealing unit 21C clamps and end seals the rear position of the upstream empty bag portion among the successive empty bag portions at a position spaced apart by standard clamping distance L0 from second sealing body 19b, 20b in second sealing unit 21B. Then, second sealing body 19b, 20b and third sealing body 19c, 20c continuously end seal and cut at appropriate positions that correspond to the length of the empty bag portion set for one packaging length (see FIG. 8(d)).

[0041] 9 shows the movement trajectories of the midpoints of the clamping surfaces of the upper sealing bodies 19a, 19b, and 19c of the first sealing body 19a, 20a, the second sealing body 19b, 20b, and the third sealing body 19c, 20c in the first sealing unit 21A, the second sealing unit 21B, and the third sealing unit 21C when the article 12 is fed into the tubular film 10. For ease of explanation, the movement trajectories of the lower sealing bodies 20a, 20b, and 20c in each sealing unit 21A, 21B, and 21C are omitted in this example. The movement trajectories of the upper sealing bodies 19a, 19b, and 19c in the first sealing unit 21A, the second sealing unit 21B, and the third sealing unit 21C are shown as RA, RB, and RC, respectively. During the period in which a pair of sealing bodies 19, 20 move in a circular motion along the operating trajectory, the spacing at which each upper sealing body 19a, 19b, 19c and lower sealing body 20a, 20b, 20c clamps the front and rear of the tubular film 10 corresponds to a standard clamping spacing L0 corresponding to the empty bag portion and an adjusted clamping spacing L1 corresponding to the filled portion, and the reciprocating moving means 23 of the first sealing unit 21A, second sealing unit 21B, and third sealing unit 21C and the opening / closing moving means 22 of each sealing body 19, 20 are synchronously controlled. The time M at which the clamping interval of the sealing bodies 19, 20 is changed from the standard clamping interval L0 to the adjusted clamping interval L1 is set to be the time when, when the operating phase of each sealing body 19, 20 is the same or when each sealing body 19, 20 is in a different operating phase so that the tubular film 10 is clamped in order from the downstream side, the time when at least the upper sealing body 19c of the third sealing body 19c, 20c in the most upstream third sealing unit 21C among the multiple sealing units 21 has moved its tip position, which becomes the clamping surface of the tubular film 10 by the sealing body, to a position lower than the height of the article 12 to be packaged, and the time when the sealing bodies 19, 20 in the downstream sealing unit 21 approaching the upstream sealing unit 21 have moved to a position approaching the clamping position of the tubular film 10 (the time just before clamping the tubular film 10).In other words, it is preferable that this is a time when none of the sealing bodies 19, 20 in the multiple sealing units 21 are clamping the tubular film 10 (before the sealing bodies 19, 20 in all of the sealing units 21 clamp the tubular film 10) and when the sealing bodies 19, 20 of the most downstream sealing unit 21 are closest to the position where they clamp the tubular film 10.

[0042] In the end sealing device according to the embodiment, the front-to-back distance between the sealing bodies 19, 20 in adjacent sealing units 21 is changed depending on the result of detection of the presence or absence of a missing item, so that the tubular film 10 can be clamped and end sealed at appropriate end seal positions for the filled section to which articles 12 have been supplied and the empty bag section to which articles 12 have not been supplied, thereby obtaining a good pillow packaged product 59. Furthermore, of the two sealing units 21, 21 that end seal the front and rear of the filled section to which articles 12 have been supplied, the downstream sealing unit 21 is operated and controlled to approach the upstream sealing unit 21 to reduce the clamping distance of the tubular film 10 between the respective sealing bodies 19, 20, so that the tubular film 10 can be end sealed well without being pulled downstream while being squeezed.

[0043] In the end sealing device according to the embodiment, the operating phases of the sealing bodies 19, 20 are made different so that the tubular film 10 is clamped and end sealed in the order from the downstream to the upstream sealing bodies 19, 20 of the three sealing units 21A, 21B, 21C, so that the tubular film 10 is pulled downstream and end sealed satisfactorily by the sealing bodies 19, 20 in each of the sealing units 21A, 21B, 21C without slackening the upstream tubular film 10 during end sealing. In addition, air within the tubular film can be released to the upstream side of the unsealed tubular film 10, preventing the internal air from being pushed to and accumulating at the end of the sealed tubular film 10, resulting in an overly inflated bag. In addition, a crossover conveyor 57 is provided between adjacent sealing units 21, 21 in the front-to-rear direction, which changes its conveying length in response to changes in the distance between the sealing units 21, 21. Therefore, even if the distance between the front-to-rear sealing units 21, 21 changes, no conveying problems occur, and end-sealed empty bags and pillow-packaged products 59 can be smoothly transported downstream through multiple sealing units 21A, 21B, 21C.

[0044] In the end sealing device of the embodiment, the sealing bodies 19, 20 of the sealing unit 21, which clamp and end seal the tubular film 10 before and after the filling section where the articles 12 are supplied to the tubular film 10, control the operation of the downstream sealing units 21B, 21A so that the upper sealing body 19c of the third sealing body 19c, 20c in the most upstream third sealing unit 21C moves the tip position, which is the clamping surface of the tubular film 10 by the sealing body, to a position lower than the height of the articles 12, and then the downstream sealing units 21B, 21A approach the upstream sealing units 21C, 21B. Therefore, the tubular film 10 is squeezed to a position lower than the height of the articles and put into a taut state, and then end sealed by all of the sealing units 21. This means that the tubular film 10 can be positioned to the specified sealing position without changing the sealing position, and stable end sealing can be achieved. In addition, the time when the downstream sealing units 21B, 21A approach the upstream sealing units 21C, 21B is the time when, among the multiple sealing units 21, at least the upper sealing body 19c of the third sealing body 19c, 20c in the third sealing unit 21C, the most upstream one, has moved its tip position, which becomes the clamping surface of the tubular film 10 by the sealing body, to a position lower than the height of the article 12 to be packaged, and the time when the sealing bodies 19, 20 in the downstream sealing unit 21 approaching the upstream sealing unit 21 have moved to a position approaching the clamping position of the tubular film 10.This allows the tubular film 10 to be end sealed without any slack in the film at the end of the squeezing, and allows the end sealing to be in a more appropriate position.

[0045] (Example of change) The present invention is not limited to the configurations of the examples and the like, and can be modified as follows, for example. Furthermore, the configurations described in the examples and the like are not limited to the following modifications, and various embodiments can be adopted within the scope of the gist of the present invention. (1) Instead of changing the front-to-rear spacing between sealing bodies 19, 20 when they move to a position approaching the clamping position of tubular film 10, sealing bodies 19, 20 are moved so that the seal spacing corresponds to the height and length of article 12, and then multiple sealing bodies squeeze tubular film 10 together to seal tubular film 10. Sandwich A configuration in which the end seal is formed by holding the end seal can be adopted. (2) The clamping interval of the tubular film 10 by the sealing bodies 19, 20 that end seal the front and rear of the filling section can be configured by storing data according to the height of the package type and recalling the data when changing the type. Also, the clamping interval of the sealing bodies 19, 20 can be calculated using a predetermined formula according to the input height and length of the article 12 and set as the data. (3) The configuration is not limited to the embodiment in which three sealing units 21 are arranged in the film transport direction, but may be such that two or more than three sealing units 21 are provided. (4) A configuration can be adopted in which the operation of the opening / closing moving means 22 and the reciprocating moving means 23 is controlled so that the gap between the sealing bodies 19, 20 of the upstream sealing unit 21 and the sealing bodies 19, 20 of the downstream sealing unit 21 is narrowed from the standard clamping gap L0 in the case where there is a missing part to an adjusted clamping gap L1, and the end hole is cut off without narrowing it to the standard clamping gap L0.With this configuration, it is necessary to change the gap only when there is no missing part, so the amount of movement of the sealing bodies 19, 20 can be reduced and the operational control can be simplified. (5) In the embodiment, the operating phases of the sealing bodies 19, 20 in each sealing unit 21 are shifted so that the tubular film 10 is clamped and end sealed in a sequence from the downstream side to the upstream side to vary the timing of end sealing. However, depending on the packaging conditions such as the material of the packaging material and the properties of the packaged item, the tubular film 10 may be clamped and end sealed simultaneously by the sealing bodies 19, 20 of all sealing units 21, except for shifting the operating phase so that the tubular film 10 is clamped and end sealed in a sequence from the upstream side to the downstream side. [Explanation of symbols]

[0046] 10 Cylindrical film (cylindrical packaging material), 12 Item, 19 Upper sealed body (sealed body) 20 Lower seal body (seal body), 21 Seal unit, 25 Detection sensor (detection means) 57 Transfer conveyor (conveyor), 59 Pillow packaged products (packaged products) L0 Standard clamping interval (interval), L1 Adjustable clamping interval (interval)

Claims

1. An end sealing device for a horizontal form-fill-seal machine, comprising a plurality of sealing units arranged in a packaging material transport direction, each of which has a pair of sealing bodies that face each other above and below across a transport path for a tubular packaging material to which articles are supplied, and that sandwich the tubular packaging material between the articles and move in the packaging material transport direction to perform end sealing, and the plurality of sealing units end seal the tubular packaging material simultaneously to obtain a plurality of packaged products at one time, A detection means for detecting whether or not an article is missing from the tubular packaging material, When the cylindrical packaging material is end-sealed by the plurality of sealing units, the operation of each sealing unit and sealing body is controlled so that the interval between the front and rear sealing units corresponding to the portion detected by the detection means as being missing and resulting in an empty bag is set to a larger interval than the interval between the front and rear sealing units corresponding to the portion detected by the detection means as not missing and to which the article in the cylindrical packaging material has been supplied, and the cylindrical packaging material is sandwiched and end-sealed by each sealing body. An end sealing device in a horizontal bag making and filling machine.

2. 2. An end sealing device in a horizontal bag form-fill-seal machine as described in claim 1, characterized in that for the preceding and following sealing units corresponding to the portion detected by the detection means as having no missing items and to which the tubular packaging material has been supplied, the operation of the sealing units and sealing bodies is controlled so that the downstream sealing unit narrows the gap so as to approach the upstream sealing unit, and the tubular packaging material is clamped and end-sealed by each sealing body.

3. 3. The end sealing device in a horizontal form-fill-seal machine according to claim 2, wherein the plurality of sealing units are arranged to differ in operational phase from each other so as to sandwich and end seal the tubular packaging material in sequence from the downstream side to the upstream side.

4. 4. An end sealing device in a horizontal bag form-fill-seal machine as described in claim 3, characterized in that, when end sealing the tubular packaging material, the operation of the sealing units is controlled so that the downstream sealing unit approaches the upstream sealing unit before the sealing bodies of all sealing units have clamped the tubular packaging material and after the upper sealing body of the most upstream sealing unit has moved to a position lower than the height of the article.

5. 5. An end sealing device in a horizontal form-fill-seal machine as described in claim 4, characterized in that the time when the downstream sealing unit approaches the upstream sealing unit is the time when a pair of sealing bodies in the downstream sealing unit approach to a position where they clamp the tubular packaging material.

6. A conveyor for transporting the end-sealed bags downstream is disposed between adjacent sealing units, 6. The end sealing device in a horizontal bag form filler and sealer according to claim 1, wherein the conveyor is configured to change a conveying length in response to a change in the spacing between the sealing units.

Images