Horizontal form-fill-seal machine

Abstract

To provide a horizontal bag-making and filling machine that can prevent the thermal effect of the sealing units onto the packaging material when the feeding of the tubular packaging material is stopped, and also can track the transport position of the packaged product detached from the tubular packaging material by resumption of the feeding after the stop.SOLUTION: If sealing units 19, 20 stop at a position where they exert a thermal effect on a tubular film 10 when stopping the film feed, control means moves the sealing units 19, 20 to an open position where they do not exert a thermal effect on the film and stops, and the reciprocating movement of the sealing units is synchronized until the film feed is stopped and then stops. When the film feed is resumed, the control means begins to close the sealing units 19, 20 before the film feed is resumed and performs the operation control of the opening / closing moving means and the reciprocating moving means so as for the synchronous operation to be resumed in alignment with the film feed so that the sealing units move in the film feed direction with the tubular film 10 held by the sealing units 19, 20 at synchronous timing with the film feed.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a horizontal form-fill-seal machine equipped with an end sealing mechanism that clamps a tubular packaging material and moves together with the tubular packaging material in the packaging material feed direction to apply an end seal. [Background technology]

[0002] A horizontal form-fill-seal machine (packaging machine) is known that produces so-called pillow packages (packaged products) by sequentially feeding articles into a tubular film that is being formed into a tubular shape by a bag-making machine using a feed conveyor, applying a center seal to the overlapped portion of the longitudinal edge of the tubular film, and end sealing and cutting the tubular film before and after the article is sandwiched between the tubular film using an end seal mechanism. When such a packaging machine is stopped, it is preferable that the machine is set to stop at a position where the transfer of the articles from the feed conveyor to the tubular film is completed. This prevents the occurrence of a situation in which articles are not fed from the feed conveyor to the tubular film at regular intervals due to the operation of the packaging machine when it is stopped or when it is started after being stopped.

[0003] In addition, when the packaging machine is stopped, it is preferable that the pair of sealing bodies in the end seal mechanism that applies end seals to the tubular film is set to stop at a position where it does not contact the film. This makes it possible to obtain a good packaged product without the film melting due to the heat of the heated sealing bodies when the packaging machine is stopped. However, since the mechanical dimension from the position where the article is transferred to the tubular film by the supply conveyor to the end seal mechanism in the packaging machine is constant, depending on the end seal interval of the tubular film corresponding to the set film length for one package, the stopping position of the sealing body when the packaging machine is stopped may be a position where the sealing body contacts the film, or a position where the heat of the sealing body adversely affects the film.

[0004] To address this issue, a technology has been proposed in which a box motion type end seal mechanism is equipped with a drive means for opening and closing the sealing body and a drive means for moving the sealing body horizontally back and forth in the film feed direction, and the horizontal movement and opening and closing movement of the sealing body are performed independently.When the packaging machine stops, it stops at a position where the transfer of articles from the supply conveyor to the tubular film is completed, and the pair of sealing bodies can be stopped in an open position where there is no thermal effect on the film (see, for example, Patent Documents 1 and 2).

[0005] In the end seal mechanism disclosed in Patent Document 1, in response to the stop position where the seal body stops during empty bag prevention operation or when the packaging machine is stopped being the engagement position of the tubular film, the seal body is opened at least in the vertical direction and moved to a position separated from the tubular film after a predetermined sealing time has elapsed since the end seal mechanism stopped at the stop position. Also, in the end seal mechanism disclosed in Patent Document 2, when the packaging machine is stopped, the film feed is stopped at a position where the transfer of articles from the supply conveyor to the tubular film is completed, and the pair of seal bodies seal and cut the tubular film between the articles, and then move to the open position furthest apart in the vertical direction and stop, thereby stopping the pair of seal bodies at an open position where the film is not thermally affected. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5955542 [Patent Document 2] Patent No. 4497363 Summary of the Invention [Problem to be solved by the invention]

[0007] In the device disclosed in Patent Document 1, when the end seal mechanism stops (pauses) during an operation to prevent empty bags, etc., the heater block stops at the meshing position where the film is sandwiched between the heater block and the heater block is instructed to move to a retracted position where the heater block is opened up and down in response to the heater block stopping at the meshing position where the film is sandwiched between the heater block and the film. This device is capable of dealing with only the meshing position of the heater block, and is not devised as a device that can deal with a stop position where the heat of the heater block adversely affects the film, such as melting or thermal deformation of the tubular film, resulting in defective packages, not limited to positions where the heater block comes into contact with the packaging material before and after the meshing position, and the film feed is stopped during the period from when the end seal mechanism stops at the meshing position where the film is sandwiched between the heater block and when the heater block is opened, and the discharge conveyor that transports the end-sealed and cut packages downstream is generally already stopped. And because the unloading conveyor is stopped, no pulling force is applied downstream to the tubular film to which the articles are being fed, so when the heater block squeezes the tubular film to seal and cut it, the amount of packaged products returning upstream in the transport varies from normal, causing the placement position of the unloading conveyor to change. Even if the unloading conveyor continues to run during the end sealing and cutting, the packaged products are cut off from the tubular film without horizontal movement of the heater block in the feed direction of the tubular film, so the inertia of the packaged products at that time changes, resulting in different sealing conditions from those during continuous operation. Not only does the position of the packaged products being unloaded vary, but the timing of the packaged products being end sealed, cut, and separated from the tubular film differs, so unless the timing of the packaged products being unloaded downstream is changed, the packaged products transported to the subsequent process cannot be aligned and processed properly.

[0008] In addition, in the end seal mechanism disclosed in Patent Document 2, the distance from the bag making means to the center of movement of the end seal mechanism is changed, so there is a limit to the adjustment range of the center of movement of the sealing body, and in some cases there are packaging conditions that are outside the adjustment range.

[0009] The object of the present invention is to provide a horizontal form-fill-seal machine that prevents the thermal effect of the sealing body on the packaging material when the feeding of the tubular packaging material is stopped, and that can track the transport position of packaged products that have been separated from the tubular packaging material and transported downstream when feeding is resumed after the halt without losing sight of them, and can properly transmit position information to downstream processing devices, etc., so that, for example, defective packaged products can be properly discharged from the system. [Means for solving the problem]

[0010] The horizontal form fill and seal machine of the invention according to claim 1 of the present application is as follows: In a horizontal form-fill-seal machine having an end sealing mechanism (16) that sandwiches a tubular packaging material (10) between articles supplied at predetermined intervals to a tubular packaging material (10) by a supply conveyor (13) and moves in a packaging material feed direction to apply end seals therebetween, a sealing unit (21) that supports the sealing bodies (19, 20) and is capable of reciprocating along the packaging material feed direction; a reciprocating means (23) for reciprocating the sealing unit (21) along the packaging material feed direction; an opening / closing movement means (22) for opening and closing the pair of seal bodies (19, 20); and a control means (26) for controlling the operation of the reciprocating means (23) and the opening / closing means (22), When the feeding of the tubular packaging material (10) is stopped and the sealing bodies (19, 20) reach a stop position where they will have a thermal effect on the packaging material, the control means (26) controls the following in a motion locus of the end seal mechanism (16) during a period from when the sealing bodies (19, 20) are furthest apart from each other to when they move toward the meshing position: The movement of the seal body (19, 20) by the opening / closing moving means (22) is stopped. Opening position that does not cause thermal damage to the packaging material To Seal body (19, 20) By maintaining the above, the reciprocating means (23) The seal unit (21) The opening / closing movement means (22) and the opening / closing movement means (23) are adapted to continue the movement until the timing for stopping the feeding of the packaging material is reached. Controlling the reciprocating means (23); an article (12) that has been fed to a position where it will finish being transferred to the tubular packaging material (10) when the feeding of the tubular packaging material (10) is stopped; The feed conveyor (13) conveys Subsequent Goods (12) In order to ensure that the intervals between the next article (12) being fed into the tubular packaging material (10) are constant, the next article (12) is stopped before being fed into the tubular packaging material (10). Packaging material feed of Resume At the same time, the movement of the sealing unit (21) in the packaging material feeding direction is resumed. before The seal body (19, 20) stopped in the open position of Close The movement in the direction starts before the packaging material feed is resumed, and the seal bodies (19, 20) reach the engagement position by normal synchronous operation in accordance with the packaging material feed. Before the timing operation The cylindrical packaging material (10) is sandwiched between the sealing bodies (19, 20) at the timing, and the sealing unit (21) is moved in the packaging material feed direction. The sealing bodies (19, 20) are synchronized with the feeding of the packaging material. Periodic operation resumed This allows the same sealing time to be maintained as in normal synchronous operation. The reciprocating means (23) and the opening / closing means (22) are operated and controlled by a Ruko It is characterized by: In the invention according to claim 1, when the empty bag prevention control is in operation or when the packaging machine is out of operation and the feeding of the tubular packaging material is stopped and the waiting state is in place, the sealing body is prevented from exerting a thermal effect on the packaging material, and when the feeding of the tubular packaging material is resumed, the sealing body is kept in the position for a predetermined time period that can ensure an appropriate sealing time for the end seal. Seal body engagement position during normal synchronous operation To R timing For that timing, Previous operation Timing seal body By The packaging material is clamped, and then the packaging material conveying means, the opening / closing movement means and the reciprocating movement means in the sealing unit are synchronously controlled in the same manner as in normal operation, the sealing unit starts reciprocating, the sealing bodies then move away from each other, and the packaged product cut off from the end of the tubular packaging material during the turning movement of the sealing body is conveyed downstream by the discharge conveyor. During this operation, the operating conditions when the sealing body is used to separate the packaged product from the end of the tubular packaging material are the same as the operation of the packaging material conveying means during continuous operation, the opening / closing movement and the lateral movement of the sealing body of the sealing unit, and therefore the conveying conditions of the packaged product being separated and conveyed downstream can be tracked and detected based on the conveying position of the packaged product set during normal operation without changing. Therefore, for example, it is possible to appropriately manage the conveying position of a packaged product that has an error detected before being separated and sent out, and is discharged outside the system to be treated as a defective packaged product.

[0011] In the invention according to claim 2, the end seal mechanism (16) arranges N of the sealing units (21) in a line in the packaging material feed direction, and divides one packaging cycle into 1 / N cycles so that, after N packages of articles (12) are supplied to the tubular packaging material (10), the sealing bodies (19, 20) of the N sealing units (21) are equally spaced front-to-back corresponding to one cutting pitch to clamp the tubular packaging material (10) to perform end sealing, and the control means (26) controls the operation of the reciprocating movement means (23) and the opening / closing movement means (22) so that the packaging material is fed N times at one cutting pitch in response to the time when one package of articles (12) is fed from the supply conveyor (13) to the tubular packaging material (10). the control means (26) controls the operation of the opening / closing movement means (22) and the reciprocating movement means (23) so that, when the stop position of the sealing body (19, 20) of any one of the N sealing units (21) is a position that will have a thermal effect on the packaging material, the sealing body (19, 20) stops at the open position where it will not have a thermal effect on the packaging material and the reciprocating movement of all the sealing units (21) stops, while the packaging material feed is being repeated N times, When N packages of articles (12) are delivered from the supply conveyor (13) to the cylindrical packaging material (10), the packaging material feed is resumed, and all the sealed bodies (19, 20) stopped at the open position are The movement in the closing direction of the seal body (19, 20) begins before the packaging material feed is resumed, and the seal body (19, 20) reaches the meshing position by normal synchronized operation in accordance with the packaging material feed. Before Operation type The sealing unit (21) is moved in the packaging material feed direction while the cylindrical packaging material (10) is sandwiched between the sealing bodies (19, 20) in a timing manner. The seal body (19, 20) The reciprocating means (23) and the opening / closing means (22) are operated and controlled so that synchronous operation is resumed. Ruko It is characterized by: According to the invention of claim 2, even in an end seal mechanism equipped with a plurality of seal units, the operation can be controlled so that the seal body is positioned so as not to affect the heat of the packaging material during the operation of the empty bag prevention control or in a standby state such as when the packaging machine is out of operation, so that poor sealing can be avoided. Also, since the position to which a defective packaged product that has been separated from the tubular packaging material is conveyed downstream can be grasped, the conveying position can be appropriately managed so that the packaged product is discharged outside the system to be treated as a defective packaged product.

[0012] In the invention according to claim 3, a detection sensor (25) is provided for detecting the article (12) conveyed by the supply conveyor (13), the detection sensor (25) is disposed upstream of at least a position where the delivery of the article (12) to the tubular packaging material (10) is completed, the distance being at least one interval equal to the interval at which the article (12) is conveyed by the supply conveyor (13); The control means (26) is characterized in that, when the detection sensor (25) does not detect an article (12), it stops the feeding of the packaging material and performs empty bag prevention control by controlling the operation of the reciprocating movement means (23) and the opening / closing movement means (22) in the end seal mechanism (16). According to the invention of claim 3, by detecting the presence or absence of an article using a detection sensor arranged at a distance upstream from the position where the transfer of the article to the tubular packaging material is completed and performing empty bag prevention control, it is possible to obtain properly sealed packaged products without poorly sealed packages even in high-speed processing, prevent the occurrence of empty bags, and eliminate packaging waste.

[0013] In the invention according to claim 4, the open position of the seal members (19, 20) is a position where the seal members (19, 20) are farthest apart in a movement locus of the pair of seal members (19, 20). Immediately after passing the mating position, the seal bodies (19, 20) move closer to each other toward the mating position. Move Place The device is characterized by being set in a position. According to the invention of claim 4, by setting the position immediately after the position where the pair of sealing bodies are furthest apart in the movement trajectory of the pair of sealing bodies as the open position, the packaging cycle in which the empty bag prevention control is performed can be performed by simple control that is distinguished from the immediately preceding packaging cycle. Also, by setting the position close to the position where the sealing bodies are furthest apart as the open position, even if the height dimension of the tubular packaging material changes due to a change in type, etc., it is possible to prevent thermal effects on the packaging material without changing the open position. Effect of the Invention

[0014] According to the present invention, during the standby state in which the feeding of the tubular packaging material stops during the operation of the empty bag prevention control or the operation of the packaging machine is stopped, the thermal effect of the sealing body on the packaging material can be prevented, and the end seal can be properly applied to the tubular packaging material. Furthermore, when the feeding of the tubular packaging material is resumed, the following is performed for a predetermined time period that can ensure an appropriate sealing time for the end seal: In normal synchronous operation Pre-set meshing reach position timing For that timing, Previous operation Timing seal body By The packaging material is clamped, and then the packaging material conveying means, the opening / closing movement means and the reciprocating movement means in the sealing unit are synchronously controlled in the same manner as in normal operation, the sealing unit starts reciprocating, the sealing bodies then move away from each other, and the packaged product cut off from the end of the tubular packaging material during the turning movement of the sealing body is conveyed downstream by the discharge conveyor. During this operation, the operating conditions when the sealing body is used to separate the packaged product from the end of the tubular packaging material are the same as the operation of the packaging material conveying means during continuous operation, the opening / closing movement and the lateral movement of the sealing body of the sealing unit, and therefore the conveying conditions of the packaged product being separated and conveyed downstream can be tracked and detected based on the conveying position of the packaged product set during normal operation without changing. Therefore, for example, it is possible to appropriately manage the conveying position of a packaged product that has an error detected before being separated and sent out, and is discharged outside the system to be treated as a defective packaged product. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram of a horizontal bag making and filling machine. [Diagram 2] FIG. 2 is a schematic perspective view of a seal unit. [Diagram 3] FIG. 2 is a schematic side view of the seal unit. [Figure 4] FIG. 2 is a control block diagram of a horizontal bag making and filling machine. [Diagram 5] 11 is an explanatory diagram showing the relationship between the film feed and the reciprocating motion and opening / closing motion of the sealing body during control to prevent empty bags, etc. FIG. [Figure 6] 11 is an explanatory diagram showing the movement of the seal body during empty bag prevention control. FIG. [Figure 7] FIG. 1 is a schematic diagram showing an end seal mechanism equipped with three seal units. [Figure 8] FIG. 11 is an explanatory diagram showing the stopping positions of the sealing bodies during empty bag prevention control in an end seal mechanism equipped with three seal units. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Next, a preferred embodiment of a horizontal bag making and filling machine according to the present invention will be described below with reference to the accompanying drawings. EXAMPLES

[0017] 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 applies a center seal (vertical seal) to the overlapped portion of the tubular film 10 overlapped in the palm-like shape in the film feed direction (hereinafter referred to as the film feed direction (packaging material feed 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 mechanism 16 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 applies end seals and cuts in a direction intersecting the film feed direction (width direction). In addition, the packaging machine is configured such that upstream and downstream of the end sealing mechanism 16, which are before and after the end sealing mechanism 16 in the film feed 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 output to the next process by the output conveyor 18.

[0018] 2 and 3, end seal mechanism 16 includes a sealing unit 21 in which a pair of sealing bodies 19, 20 are arranged facing each other above and below across the transport path of tubular film 10 transported by transport conveyor 17. Sealing unit 21 includes opening / closing movement means 22 that moves the pair of sealing bodies 19, 20 toward and away from each other, and reciprocating movement means 23 that moves sealing unit 21 back and forth along the film feed direction. Sealing unit 21 is configured to perform a so-called box motion operation in which, by operating opening / closing movement means 22 and reciprocating movement means 23, the pair of sealing bodies 19, 20 move toward each other from an initial position at which they are furthest apart across the transport path to clamp a position between the articles on tubular film 10 (clamp at an interlocking position), move downstream in the film feed direction of tubular film 10 in that clamped state, and then move away from each other and return to the initial position. The sealing unit 21 is configured to clamp the tubular film 10 fed by the film conveying means 15 between sealing bodies 19, 20 and apply an end seal in the width direction of the tubular film 10 while moving downstream in the film feed direction, and to cut the tubular film 10 in the width direction with a cutting blade 24 built into one of the sealing bodies 19.

[0019] 1, a detection sensor 25 capable of detecting the presence or absence of articles 12 is provided upstream of the position where the transfer of 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 articles 12 by supply conveyor 13) before the articles 12 are fed by supply conveyor 13 to the tubular film 10 formed by bag making means 11. The detection sensor 25 detects whether the articles 12 being transported by supply conveyor 13 arrive in accordance with a preset feed timing for each packaging cycle, and outputs a detection signal to control means 26 of the packaging machine. Then, in the case where there is no detection signal input from detection sensor 25, control means 26 issues an operation pause signal to temporarily halt the operation of film conveying means 15 and end seal mechanism 16 in accordance with the timing at which detected article 12, which was detected as missing in the packaging cycle prior to the packaging cycle detected as missing in relation to the position of detection sensor 25, reaches the position at which feeding into tubular film 10 is completed (the position at which delivery is completed). Then, in the subsequent operation cycle (the period during which tubular film 10 moves for one packaging cycle), if a detection signal is input from detection sensor 25 to control means 26 in the control means 26, an operation start signal to start the operation of film conveying means 15 and end seal mechanism 16 is set to be issued from control means 26.

[0020] 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 a turning portion at the end of the endless belt 17b of the transport conveyor 17 and a turning portion at the beginning of the endless belt 18b of the discharge conveyor 18 face each other across a sealing unit 21. The opposing ends of the conveyors 17, 18 (the turning portion at the end and the turning portion at the beginning) are configured to move horizontally following the opening and closing movement of a pair of sealing bodies 19, 20 in the sealing unit 21. In other words, when the pair of sealing bodies 19, 20 approach each other, the opposing ends of the two conveyors 17, 18 move away from each other to allow the pair of sealing bodies 19, 20 to pass toward the interlocking position where they clamp the tubular film 10, and when the pair of sealing bodies 19, 20 move away from each other, the opposing ends of the two conveyors 17, 18 approach each other to allow unhindered transport of the article 12 downstream.

[0021] 2 and 3, a pair of side panels 27a, 27a are disposed on a machine frame 27 of the end seal mechanism 16, spaced apart in a width direction intersecting with the film feed direction, and the seal unit 21 is supported between the pair of side panels 27a, 27a so as to be movable along the film feed direction. The seal unit 21 includes 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 of the seal bodies 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 above the transport path of the tubular film 10 is disposed at the upper ends of the pair of slide shafts 31, 31 extending upward from the pair of support members 28, 28, and the lower ends of the pair of slide shafts 31, 31 extending downward from the pair of support members 28, 28 are connected by a connecting member 32. In addition, a second holding member 30 facing below the transport path is slidably supported by supports 33, 33 on the slide shafts 31, 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.

[0022] A first 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 first 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 first 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 first seal body 19, so that downward movement of first seal body 19 relative to first holding member 29 is restricted and first seal body 19 is biased downward (towards second seal body 20, described below) by springs 37, 37. Furthermore, cutting blade 24 is supported by first 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 first seal body 19 and second 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 first sealing 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 first sealing body 19, and the tip of the cutting blade enters the receiving groove of the second sealing body 20, thereby cutting the clamped tubular film 10.

[0023] Second sealing body 20, the other of the pair of sealing bodies 19, 20, is disposed and fixed above second holding member 30, with its sealing surface facing the transport path for tubular film 10. Second sealing body 20 is disposed above second holding member 30 so as to face parallel to first sealing body 19, with the transport path for tubular film 10 in between.

[0024] 2 and 3, the opening / closing moving means 22 includes a screw shaft 40 rotatably supported on a support frame 39 disposed between the pair of support members 28, 28 so as to extend in the width direction, an opening / closing drive motor 41 such as 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 links the first and second holding members 29, 30. The toggle mechanism 42 includes a female screw member 43 that is screwed onto the screw shaft 40, and the other end of a first link rod 45, one end of which is rotatably supported by the second holding member 30, is rotatably supported at the upper end, which is one end of a moving member 44 that slides along a guide shaft 58 disposed 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 moving member 44. The first link rod 45 and the second link rod 46 are positioned such that one end side rotatably supported by the second holding member 30 and the connecting member 32 approaches 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 moves away 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 conveying path.

[0025] 2 and 3, rail members 47 extending along the film feed direction are disposed in parallel on the opposing surfaces of the side panels 27a, 27a. Sliders 49 are disposed on the outer sides of the support members 28, 28 in the width direction via brackets 48, and each slider 49 is slidably supported by the corresponding rail member 47, so that the seal 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 feed direction.

[0026] The reciprocating movement means 23 includes a movement mechanism 50 and a reciprocating drive motor 51 such as 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, a pair of drive pinions 53, 53 that are arranged to rotate integrally with the drive shaft 52 and are spaced apart in the axial direction, and racks 54, 54 that are arranged on both side panels 27a, 27a, extend in the film feed direction, and mesh with the drive pinions 53, 53. The reciprocating drive motor 51 arranged on one bracket 48 via a holder 55 is connected to the 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 reciprocates (reciprocates) back and forth (upstream and downstream) in the film feed direction under the meshing action of the drive pinions 53, 53 and the racks 54, 54.

[0027] The reciprocating drive motor 51 is rotationally controlled so that the speed at which sealing unit 21 moves downstream in the film feed direction with tubular film 10 clamped by the pair of sealing bodies 19, 20 is substantially the same as the film feed speed. In addition, the opening / closing drive motor 41 and the reciprocating drive motor 51 are set to be variable speed controlled in response to the cut pitch of tubular film 10 set corresponding to the size of articles 12, the feed speed of tubular film 10 obtained from the desired wrapping speed, and the set wrapping speed.

[0028] 4, the control means 26 of the packaging machine is connected to the opening / closing drive motor 41 of the opening / closing movement means 22, the reciprocating drive motor 51 of the forward movement means 23, the drive motor 13a of the supply conveyor 13, the drive motor 17c of the transport conveyor 17, the drive motor 18c of the discharge 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. In the packaging machine of the first embodiment, in response to the detection result of the detection sensor 25 and the determination result of the control means 26 that a missing item has been detected, the control means 26 outputs a film feed control signal (film feed stop signal, feed start signal) to the film transport means 15 while continuing the operation of the supply conveyor 17, and the film feed is repeatedly stopped and started. Then, in accordance with the film feed stopping operation of the film transport means 15, the operation of the end sealing mechanism 16 is temporarily stopped, and empty bag prevention control is executed to prevent the generation of empty bags obtained by end sealing and cutting in which no articles 12 are supplied. In addition to such empty bag prevention control, the control means 26 issues a signal to suspend the operation of the packaging machine in response to various signal inputs corresponding to the processing status of the preceding or succeeding process, and performs linked operation control to repeatedly stop and restart the operation of the film transport means 15 and the end sealing mechanism 16, including the supply conveyor 13. Note that the transfer conveyor 17 and the carry-out conveyor 18 are stopped and restarted in synchronization with the supply conveyor 13 in the empty bag prevention control and linked operation control.

[0029] The control means 26 controls the operation of the film transport means 15 and the end seal mechanism 16 to stop in accordance with the time when the transfer of the articles 12 from the supply conveyor 13 to the tubular film 10 is completed (the time when the articles 12 are sent from the supply conveyor 13 to the position where the transfer is completed (the completed position)) as the stopping position that is the starting point of the packaging cycle in the packaging machine, and at that time, the sealing unit 21 synchronously controls the supply conveyor 13, the film transport means 15, and the end seal mechanism 16 so that the sealing bodies 19, 20 are at their initial position (P1 in FIG. 6(a)) where they are furthest apart from each other. In a packaging machine that is synchronously controlled in this manner, if the film cut pitch is changed in relation to different article sizes, the stopping position relationship between the film transport means 15 and the end seal mechanism 16 will change at the starting point of the packaging cycle. As a result, when the transfer of articles 12 from supply conveyor 13 to tubular film 10 is completed, sealing bodies 19, 20 in end seal mechanism 16 may stop at a position where the heat of sealing bodies 19, 20 may adversely affect the film, including the position where they come into contact with tubular film 10. Therefore, in the empty bag prevention control in Example 1, if control means 26 detects a shortage when a detection signal is not input from detection sensor 25, film transport means 15 is controlled to stop in time for the transfer of articles 12 transported by supply conveyor 13 to tubular film 10 to be completed. To In response, sealing operation control is performed such that sealing bodies 19, 20 of sealing unit 21 in end seal mechanism 16 move and stop at an open position P2 on a movement trajectory from initial position P1, where sealing bodies 19, 20 are furthest apart from each other, toward the meshing position (solid line position in FIG. 6(d)), slightly past initial position P1, where sealing bodies 19, 20 do not have a thermal effect on the approaching tubular film 10. Open position P2 can be set to any position, and the set open position P2 is stored in control means 26.

[0030] As shown in Figure 5, in controlling the sealing operation, the control means 26 controls the operation of the opening / closing drive motor 41 so that, when the film feed stops, the sealing bodies 19, 20 stop at the open position P2 where they do not thermally affect the film, and also controls the operation of the reciprocating drive motor 51 so that the downstream movement of the sealing bodies 19, 20 is stopped in accordance with the stop of the film feed. Then, when a detection signal for the succeeding (next) item 12 is input by the detection sensor 25 and film feed is resumed, the opening / closing drive motor 41 is operated and controlled to start moving the pair of sealing bodies 19, 20 at the open position P2 to the interlocking position at a predetermined time before the time when film feed is resumed, so that the distance between the item 12 that has been sent from the supply conveyor 13 to the position where transfer has been completed to the tubular film 10 whose transport has been stopped and the next item 12 to be sent into the tubular film 10 is a predetermined distance, and the opening / closing drive motor 41 and the reciprocating drive motor 51 are operated and controlled in synchronization with the time when film feed is subsequently resumed, so that synchronized operation in which the sealing bodies 19, 20 operate along a predetermined operating trajectory is resumed for the opening and closing movement of the sealing bodies 19, 20 in the end seal mechanism 16 and the reciprocating movement of the sealing unit 21.

[0031] Here, when the opening and closing operations of the sealing bodies 19, 20 and the film feeding operation are resumed, the film feeding starts and the closing operation of the sealing bodies 19, 20 starts. If normal synchronous operation is performed, the timing of the closing operation of the sealing bodies 19, 20 is as shown by the dotted lines in Fig. 5, in which the sealing bodies 19, 20 start moving from the open position toward the meshed position as the film feeding starts, and at the same time, the sealing unit 21 also starts moving forward. Then, at the synchronous return point, these become the same synchronous operation state as during continuous operation, and the sealing bodies 19, 20 clamp the tubular film 10 after a predetermined time has elapsed since the operation was resumed. For this reason, at the synchronous return point shown by the dotted lines in Fig. 5, the sealing bodies 19, 20 cannot reach the closed position, and the closing period of the sealing bodies 19, 20 is shorter than during normal continuous operation, making it impossible to perform proper end sealing. In contrast, in this example, the timing of the opening and closing operations of the sealing bodies 19, 20 is an operation timing prior to the normal synchronization return timing, and the sealing bodies 19, 20 start moving from the open position toward the meshing position before the sealing unit 21 starts moving forward with the film feed, and at the synchronization return point, the synchronization of the opening and closing operations of the sealing bodies 19, 20, the film feed operation, and the reciprocating operation of the sealing unit 21 is restored. At this synchronization return point, the operation timing of the sealing bodies 19, 20 reaches the meshing position. The operation timing of the opening and closing drive motor 41 is controlled. In this manner, the operation of the sealing bodies 19, 20 is controlled so that the sealing bodies 19, 20 move downstream with the film feed while holding the tubular film 10, and then open the sealing bodies 19, 20 to release the holding of the tubular film 10. In this manner, the operation of the opening and closing drive motor 41, the reciprocating drive motor 51, and the drive motor 15a of the film transport means 15 are each controlled. As a result, when the packaging operation is suspended and film feeding is stopped, the sealing time when the tubular film 10 is clamped and end sealed when the operation is resumed is maintained at an appropriate sealing time for applying the end seal.The control means 26 can know the time when the article 12 detected by the detection sensor 25 finishes being transferred to the tubular film 10 by using an encoder or the like provided in the rotation system of the supply conveyor 13. Then, at a predetermined timing before the subsequent article 12 detected by the detection sensor 25 and conveyed by the supply conveyor 13 is sent into the stopped tubular film 10, the film feed can be resumed, so that the article 12 can be sent into the tubular film 10 at regular intervals. The control means 26 controls the opening and closing movements of the sealing bodies 19, 20 in the end seal mechanism 16 and the reciprocating movement of the sealing unit 21 in relation to the conveying position of the article 12 obtained from the supply conveyor 13, and sets the timing for closing the pair of sealing bodies 19, 20 at the open position P2 prior to resumption of film feed so as to obtain a sealing time equal to the motion trajectory given as a predetermined box motion motion. Such sealing operation control of the end seal mechanism 16 is not limited to the empty bag prevention control in the first embodiment, but similar sealing operation control can also be adopted in linked operation control that pauses the operation of the packaging machine.

[0032] Next, the operation of the horizontal bag making and filling machine according to the first embodiment will be described. When the control means 26 determines that there is a shortage in relation to the signal input from the detection sensor 25 during the empty bag prevention control operation of the packaging machine under the condition that the stopping positions of the sealing bodies 19, 20 are positions that will cause thermal effects on the film, the control means 26 controls the sealing operation of the end seal mechanism 16 while continuing the article transport by the supply conveyor 13. In the sealing operation control, the opening / closing drive motor 41 and the reciprocating drive motor 51 are synchronously controlled under a preset operation locus from the initial position P1 shown by the two-dot chain line in Figure 6(a) to the stored open position P2 (the position hatched in Figure 6(a)). Then, when sealing bodies 19, 20 reach open position P2, opening / closing drive motor 41 is operated and controlled to maintain sealing bodies 19, 20 in open position P2 where no thermal effect is exerted on the film, and reciprocating drive motor 51 is operated and controlled until the timing for stopping film feed arrives. The operation of reciprocating drive motor 51 is controlled so that as tubular film 10 is fed by film transport means 15, sealing unit 21 moves upstream in the film feed direction and then downstream, and when film feed stops, reciprocating drive motor 51 is operated and controlled to stop sealing unit 21 from moving downstream. The operation of reciprocating drive motor 51 is controlled so that sealing bodies 19, 20 move horizontally toward the upstream side in the film feed direction to a lateral movement position (position hatched in FIG. 6(b)) P3 on the most upstream side of the motion locus set in end seal mechanism 16, while being maintained in the same open position as open position P2 indicated by the two-dot chain line in FIG. 6(b). Thereafter, as the film is fed, the reciprocating drive motor 5 is controlled so that the film moves horizontally downstream in the film feed direction from the lateral movement position P3 while maintaining the same open position, to an end position P4 (the hatched position in Figure 6(c)), at which the lateral movement is stopped.In other words, during the empty bag prevention control operation of the packaging machine or the linked operation control, when the sealing bodies 19, 20 open, close, and reciprocate along the motion trajectory of each sealing body 19, 20 set as the box motion operation of the end seal mechanism 16, only the operation of the opening / closing drive motor 41 is stopped, and then the reciprocating drive motor 51 is controlled to stop, thereby stopping the operation of the sealing bodies 19, 20 at the end position P4, which is an open position spaced above and below the next sealing position where the sealing bodies 19, 20 end seal the tubular film 10, and causing them to wait.

[0033] When a detection signal is input from the detection sensor 25 to the control means 26, or when various signal inputs from the previous or subsequent process that are the conditions for issuing a signal to suspend the operation of the packaging machine are no longer input, the control means 26, as shown in Figure 5, when resuming film feed, controls the operation of the opening and closing drive motor 41 to close the sealing bodies 19, 20, which are stopped at the end position P4, toward the engagement position before the start of film feed, for a predetermined period of time that ensures an appropriate sealing time for the end seal, and reaches the clamping position of the tubular film 10 in synchronization with the film feed (see Figure 6(d)). Then, the film conveying means 15, the opening / closing moving means 22, and the reciprocating moving means 23 in the sealing unit 21 are synchronously controlled (synchronous operation is resumed) in the same manner as in normal operation so that the sealing unit 21 moves in the film feed direction with the tubular film 10 sandwiched between the sealing bodies 19, 20, and the sealing unit 21 starts reciprocating, after which the sealing bodies 19, 20 move away from each other, and the packaged product 59 cut off from the end of the tubular film 10 during the turning operation of the sealing bodies 19, 20 is conveyed downstream by the discharge conveyor 18. That is, when the film feed stops, the sealing bodies 19, 20 wait in an open position where the film is not thermally affected, so that the generation of defective products due to thermal effects can be prevented. Also, the sealing bodies 19, 20 start closing before the start of film feed, and the synchronous operation with the film conveying means 15 is restored to start sealing the tubular film 10, so that a sealing time is ensured in which the end seal can be properly applied to the tubular film 10.

[0034] In addition, the packaging conditions at the time when the end seal is sealed and cut and separated as the packaged product 59 are performed without any difference from the conditions during normal operation, and the timing of the separation of the tubular film 10 at that time does not change forward or backward in the conveying direction, so that during the empty bag prevention control, it is not necessary to set the timing of the separation and start of conveying, or the timing of the conveying position of the packaged product 59 downstream in response to changes in the conveying conditions, etc. In this way, the conveying timing of the packaged product 59 that is end sealed, cut, and conveyed to the subsequent process does not change from the timing during normal operation. Furthermore, the packaged product 59 can be stably conveyed without any positional deviation of the discharge position. That is, even during the empty bag prevention control, the conveying position of the packaged product 59 conveyed during normal operation can be tracked and detected in the same way. For example, the conveying position management can be appropriately performed to discharge the packaged product 59 that has an error detected before being separated and sent out from the system to be treated as a defective packaged product. Since a detection sensor 25 for detecting the articles 12 is disposed upstream from the position where the delivery of the articles 12 to the tubular film 10 is completed, and the detection sensor 25 detects the presence or absence of the articles 12 to perform empty bag prevention control, it is possible to obtain properly sealed packages 59 that are not poorly sealed even in high-speed processing, prevent the occurrence of empty bags, and eliminate waste of packaging. Furthermore, by setting the opening position of the sealing bodies 19, 20 in the sealing operation control of the end seal mechanism 16 to the position immediately after the sealing bodies 19, 20 have passed the position where they are furthest apart from each other on the movement trajectory of the pair of sealing bodies 19, 20, the packaging cycle in which empty bag prevention control is performed can be performed by simple control that is distinguished from the immediately preceding packaging cycle. Furthermore, by setting the opening position to the position closest to where the sealing bodies 19, 20 are furthest from each other, even if the height dimension of the tubular film 10 changes due to a change in product type, etc., the film can be prevented from being thermally affected without having to change the opening position. EXAMPLES

[0035] 7 shows an end seal mechanism 56 in a horizontal form-fill-seal machine according to Example 2 as another embodiment, and the end seal mechanism 56 includes two or more (N units, three in Example 2) sealing units 21A, 21B, 21C arranged in the film feed direction. The configuration of each sealing unit 21A, 21B, 21C is the same as that of Example 1, and the same members are given the same reference numerals and detailed description is omitted. Each of the sealing units 21A, 21B, 21C includes an opening / closing movement means 22 that independently moves a pair of sealing bodies 19, 20 toward and away from each other, and a reciprocating movement means 23 that is arranged to independently move each sealing unit back and forth along the film feed direction.

[0036] In end seal mechanism 56 having three sealing units 21A, 21B, 21C, the operation phases of sealing bodies 19, 20 of each sealing unit 21A, 21B, 21C by each opening / closing moving means 22 are slightly different, so that a pair of sealing bodies 19, 20 move toward each other to clamp tubular film 10 in the order from downstream to upstream in the film feed direction, and each sealing body 19, 20 releases tubular film 10 in the order from downstream to upstream sealing units 21A, 21B, 21C. In this manner, tubular film 10 is clamped at multiple locations by multiple sealing units 21A, 21B, 21C at the same time to perform end sealing and cutting, thereby obtaining multiple packaged products 59 at one time. In addition, common members are used for racks 54, 54 constituting moving mechanism 50 as reciprocating moving means 23 disposed in each of the three sealing units 21A, 21B, 21C.

[0037] In the three reciprocating means 23 shown in the second embodiment, the intervals at which the tubular film 10 is clamped by each of the sealing bodies 19, 20 in the three sealing units 21A, 21B, 21C are set to a package length (length of packaged products) corresponding to the cut pitch (length of packaging material for one package) of the tubular film 10, and the tubular film 10 is clamped at a predetermined timing. The end seal mechanism 56 is controlled to reciprocate between the sealing units 21A, 21B, 21C based on a preset movement trajectory and to open and close the sealing bodies 19, 20. In this manner, the operation of the end seal mechanism 16 is controlled so that the sealing bodies 19, 20 in the three sealing units 21A, 21B, 21C clamp the tubular film 10 and move forward with the film feed as the film is fed by three cut pitches, so that three packaged products 59 are obtained at once. 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 are equally spaced front-to-back corresponding to one cut pitch, and one packaging cycle is divided into 1 / 3 cycles to clamp the tubular film 10 to perform end sealing, and the opening / closing moving means 22 and the reciprocating moving means 23 are operated and controlled by the control means 26 so that the film feed of one cut pitch is repeated three times in correspondence with the time when one package of articles 12 is sent from the supply conveyor 13 to the tubular film 10. Then, after sealing bodies 19, 20 of three sealing units 21A, 21B, 21C that have moved downstream in the film feed direction while clamping tubular film 10 release tubular film 10, the three sealing units 21A, 21B, 21C, starting from the downstream sealing body 19, 20, move toward the most upstream side of tubular film 10 in the film feed direction, repeating the operation of clamping sealing positions of tubular film 10 corresponding to the next three packages of tubular film 10 with each sealing body 19, 20. In this manner, three packaged products 59 are obtained simultaneously by the sealing bodies 19, 20 of the three sealing units 21A, 21B, 21C moving in accordance with a preset motion trajectory with slightly different motion phases.In this manner, tubular film 10 is repeatedly fed by film transport means 15 in a number of increments equal to the cutting pitch multiplied by the number of sealing units 21 installed (three times in Example 2).

[0038] Between sealing units 21A, 21B, and 21C lined up in the film feed direction, there is disposed a transfer conveyor 57 for placing and transporting articles 12 supplied to tubular film 10 between the two sealing units. Transfer conveyor 57 is configured so that an article transport section expands and contracts in conjunction with the movement of a pair of sealing bodies 19, 20 in each sealing unit 21A, 21B, and 21C toward and away from each other, allowing the pair of sealing bodies 19, 20 to interlock and enabling smooth delivery of articles 12 before and after the sealing position, thereby enabling smooth transport of articles 12 downstream. The turning portion at the end of the transport conveyor 17 is connected to the sealing unit 21C at the most upstream position in the film feed direction so as to move horizontally in accordance with the movement of the pair of sealing bodies 19, 20 in the most upstream sealing unit 21C toward and away from each other, and the turning portion at the beginning of the discharge conveyor 18 is connected to the sealing unit 21A arranged at the most downstream position in the film feed direction so as to move horizontally in accordance with the movement of the pair of sealing bodies 19, 20 in the most downstream sealing unit 21A toward and away from each other.

[0039] As in the end seal mechanism 56 shown in the second embodiment, three sealing units 21A, 21B, and 21C are arranged in front of and behind each other to perform end sealing and cutting at the same time, thereby obtaining three packaged products 59 at one time. The operation is controlled so that one packaging cycle ends each time three articles 12 are supplied to the tubular film 10 as three packages of articles 12. The stopping positions of the sealing bodies 19 and 20, which should be set in accordance with the time when the transfer of the articles 12 from the supply conveyor 13 to the tubular film 10 is completed, are three stopping positions within the motion trajectory in one packaging cycle operation, equally divided by the number of sealing units 21 arranged. In the end seal mechanism 56 shown in Example 2, when one packaging cycle is converted into angles of 360 degrees, the operation of each sealing body 19, 20 is in units of 1 / 3 cycle, and when setting the stop positions of the sealing bodies 19, 20 arranged in the three sealing units 21A, 21B, 21C each time an item 12 runs out, as shown in Figure 8, if the position at which the sealing bodies 19, 20 are furthest from each other on the movement trajectory of the sealing bodies 19, 20 is divided equally into 120 degrees, with the position at which the sealing bodies 19, 20 are furthest from each other being 0 degrees, it is necessary to set these as the first stop position K1, the second stop position K2, and the third stop position K3. If the stop position of the seal bodies 19, 20 of any one of the seal units 21 is set to the second stop position K2 as the position furthest from each other, the seal bodies 19, 20 of the front and rear seal units 21 will be at stop positions that differ by 120 degrees, and all of these stop positions will have a thermal effect on the film. Even if the stop positions of at least two of the three seal units 21A, 21B, 21C can be set to stop positions that do not have a thermal effect on the film, it is unavoidable that the remaining seal unit 21 will have a stop position that has a thermal effect on the film. Therefore, in the second embodiment, when the empty bag prevention control or the linked operation control for pausing the operation of the packaging machine is performed, the control means 26 performs sealing operation control similar to that of the first embodiment for the sealing bodies 19, 20 arranged in any one of the three sealing units 21A, 21B, 21C, whose stopping position for the sealing bodies 19, 20 is in a position that causes thermal effects on the film.

[0040] In other words, when the operation of end seal mechanism 56 is stopped due to the cessation of film feed, if the number of sealing units 21 arranged is N and one or more of the sealing units 21 are in a stopped position that will have a thermal effect on the tubular film 10, the control means 26 controls the end seal mechanism 56 at the time when the article 12 is sent from the supply conveyor 13 to the tubular film 10, corresponding to the film feed time Na for the sealing unit 21 that is in a stopped position that will have a thermal effect on the tubular film 10 while repeating film feed of 1 / N cut pitches, to stop the sealing bodies 19, 20 at the open position that does not have a thermal effect on the tubular film 10, and controls the operation of the opening / closing movement means 22 and the reciprocating movement means 23 so as to stop the reciprocating movement of all sealing units 21A, 21B, 21C. In addition, the control means 26 begins to close all of the sealing bodies 19, 20 that are stopped in the open position at a predetermined timing that is a preset time before the time when film feeding is resumed in response to the delivery of the Nth item 12 to the tubular film 10 whose feeding has been stopped, and clamps the tubular film 10 when synchronized operation with the film conveying means 15 is restored, and resumes film feeding by the film conveying means 15 a predetermined period before the time when the Nth item 12 is delivered to the tubular film 10, and controls the operation of each moving means 22, 23 in all of the sealing units 21 so that synchronized operation with the reciprocating moving means 22 and the opening / closing moving means 23 is resumed after the synchronization point.

[0041] In this way, even in the packaging machine of Example 2 having a plurality (N units) of sealing units 21, the operation of sealing units 21A, 21B, 21C and sealing bodies 19, 20 are controlled so that sealing bodies 19, 20 are stopped at positions that do not thermally affect tubular film 10 during empty bag prevention control or in standby state such as when the packaging machine is not in operation, thereby avoiding sealing failure. As a result, in a packaging machine having a plurality of sealing units 21 and increasing production capacity per unit time, end sealing can be performed satisfactorily without the film melting or shrinking due to the thermal effect from sealing bodies 19, 20 when film feed is stopped. Furthermore, the packaging conditions at the time when the end seal is sealed, cut, and separated as packaged product 59 and the timing of separation of tubular film 10 are performed exactly the same as the conditions and timing during normal operation, so that the same effects as those of Example 1 can be obtained.

[0042] (Example of change) The present invention is not limited to the configurations of the examples, and can be modified as follows, for example. Furthermore, the configurations described in the examples can be modified in various ways within the scope of the present invention, without being limited to the following modifications. (1) The opening / closing movement means 22 for moving the pair of seal bodies 19, 20 in the seal unit 21 toward and away from each other may be any of various known means such as a crank mechanism or an air cylinder. (2) The reciprocating means 23 for reciprocating the seal unit 21 is not limited to the configurations in the respective embodiments, and various known means such as a linear slide mechanism can be used. (3) The opening position of the sealing bodies 19, 20 in the sealing operation control of the end seal mechanism 16 is most preferably near the initial position where the pair of sealing bodies 19, 20 are furthest from each other, but it should be set to a position on the operating trajectory from the initial position to the interlocking position that does not have a thermal effect on the packaging material. (4) In the second embodiment, three sealing units 21 are arranged in the film feed direction, but the number of sealing units 21 does not need to be limited to three. In an end seal mechanism 56 that includes multiple sealing units 21 and has multiple stop positions for sealing bodies 19, 20 in response to missing part detection, even if the stop position of any one of the multiple sealing bodies 19, 20 can be set to a position that does not have a thermal effect on the packaging material, the other sealing bodies 19, 20 will stop at a position that has a thermal effect on the packaging material. Therefore, by performing the sealing operation control of the present invention, it is possible to prevent the occurrence of empty bags, avoid poor sealing, and improve packaging capacity. (5) In Example 2, the operating phases of the sealing bodies 19, 20 in each sealing unit 21 operating along the same operating trajectory were shifted so that the tubular film 10 was clamped in order from the downstream side to the upstream side, and the timing of the end sealing was varied; however, the tubular film 10 may be clamped by the sealing bodies 19, 20 of all sealing units 21 simultaneously. [Explanation of symbols]

[0043] 10 tubular film (tubular packaging material), 12 item, 13 supply conveyor 16 end seal mechanism, 19 first seal body (seal body) 20 second seal body (seal body), 21 seal unit, 22 opening / closing movement means 23 reciprocating means, 25 detection sensor, 26 control means

Claims

1. In a horizontal form-fill-seal machine having an end sealing mechanism that sandwiches a tubular packaging material between articles supplied at predetermined intervals to the tubular packaging material by a supply conveyor and moves in a packaging material feed direction to apply end seals therebetween, a sealing unit capable of supporting the sealing body and reciprocating along a packaging material feeding direction; a reciprocating movement means for reciprocating the sealing unit along a packaging material feeding direction; an opening / closing movement means for opening and closing the pair of seal bodies; a control means for controlling the operation of the reciprocating means and the opening / closing means, the control means controls the opening / closing moving means and the reciprocating moving means so that, when the sealing body reaches a stop position that will cause a thermal effect on the packaging material when the feeding of the tubular packaging material is stopped, the movement of the sealing body by the opening / closing moving means is stopped during the movement of the sealing bodies from the position where they are furthest apart from each other to the engagement position in the operation locus of the end seal mechanism, so as to maintain the sealing body in an open position that will not cause a thermal effect on the packaging material, and so as to continue the movement of the sealing unit by the reciprocating moving means until a timing to stop feeding the packaging material is reached; the feeding of the packaging material, which has been stopped during the feeding of the tubular packaging material, is resumed before the subsequent article is fed into the tubular packaging material, and the movement of the sealing unit in the packaging material feeding direction is resumed, so that the interval between the article that has been fed to a position where it will be transferred to the tubular packaging material when the feeding of the tubular packaging material is stopped and the subsequent article being conveyed by the supply conveyor is kept constant; The movement of the sealing body stopped at the open position in the closing direction is started before the packaging material feed is resumed, and the synchronous operation of the sealing body with respect to the packaging material feed is resumed so that the sealing unit moves in the packaging material feed direction while holding the cylindrical packaging material with the sealing body at an operation timing before the timing when the sealing body reaches the meshing position by normal synchronous operation synchronized with the packaging material feed, thereby controlling the operation of the reciprocating movement means and the opening / closing movement means so that the same sealing time as in normal synchronous operation can be maintained. A horizontal bag making and filling machine.

2. the end seal mechanism arranges N of the sealing units in a line in a packaging material feed direction, divides the sealing body of each of the N sealing units into 1 / N cycles to form one packaging cycle so that, after N packages of articles are supplied to the tubular packaging material, the sealing body of each of the N sealing units is spaced equally front-to-back corresponding to one cut pitch to clamp the tubular packaging material and apply an end seal, and the control means controls the operation of the reciprocating movement means and the opening / closing movement means so that the packaging material is fed N times at one cut pitch in response to a time when one package of articles is fed from the supply conveyor to the tubular packaging material; the control means controls the operation of the opening / closing movement means and the reciprocating movement means so that, when the stop position of the sealing body in any one of the N sealing units is a position that will have a thermal effect on the packaging material when the feeding of the tubular packaging material is stopped during the N repetitions of the packaging material feeding, the sealing body stops at the open position where it will not have a thermal effect on the packaging material, and the reciprocating movement of all the sealing units is stopped; 2. A horizontal bag form-fill-seal machine as claimed in claim 1, wherein the reciprocating movement means and the opening / closing movement means are operated and controlled so that synchronized operation of the sealing bodies in relation to the packaging material feed is resumed in response to the time when N packages of articles are transferred from the supply conveyor to the tubular packaging material, and all of the sealing bodies that have stopped at the open position begin to move in the closing direction before the packaging material feed is resumed, so that the sealing bodies clamp the tubular packaging material and move the sealing unit in the packaging material feed direction at an operating timing prior to the timing at which the sealing bodies reach the engagement position by normal synchronized operation in accordance with the packaging material feed.

3. a detection sensor for detecting an article conveyed by the supply conveyor; the detection sensor is disposed upstream of a position where the delivery of the article to the tubular packaging material is completed, the detection sensor being spaced apart from the position by at least one interval equal to the interval at which the article is conveyed by the supply conveyor; 3. A horizontal bag form fill and fill machine as claimed in claim 1 or 2, characterized in that the control means performs empty bag prevention control by stopping the feeding of the packaging material and controlling the operation of the reciprocating movement means and the opening and closing movement means in the end sealing mechanism when an article is not detected by the detection sensor.

4. 3. A horizontal bag form-fill-seal machine according to claim 1, wherein the open position of the sealing bodies is set at a position where the sealing bodies move closer to each other toward the engagement position in the motion trajectory of the pair of sealing bodies immediately after the sealing bodies have passed the position where they are furthest apart.

Images