JP3757385B2 - Film holding device in stretch wrapping machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
This invention relates to a stretch wrapping machine in which an end of a film extending from the periphery of an article is folded to the bottom side of the article after the article is lifted toward the stretch film held to cover the upper surface thereof, and above the article. The present invention relates to a film holding device that holds the film when the article is lifted toward the conveyed stretch film.
[0002]
[Prior art]
In a stretch wrapping machine that tightly wraps articles containing products in a container such as a tray with a stretch film, the stretch film drawn from the roll is cut to a predetermined length, and the side edges of the cut stretch film are cut. It is comprised so that a part may be clamped and it may convey above goods.
[0003]
As the transport means for the stretch film, a plurality of endless round belts wound between pulleys spaced apart by a predetermined distance are provided above and below, and the lower linear running portion of the upper endless round belt and the lower endless round belt The upper straight running parts are arranged so that they are alternately arranged on substantially the same plane, and the upper and lower endless round belts are placed in opposite directions with the side edges of the stretch film sandwiched between the round belts in a wave shape. What is comprised so that a stretch film may be conveyed by rotating is known.
[0004]
The stretch wrapping machine is configured such that the article is lifted toward the stretch film after the conveyance of the film above the article by the conveying means is stopped. At this time, the stretch film is held by holding means. For example, the holding means disclosed in Japanese Patent Application Laid-Open No. 61-14112 is a holding member capable of pinching the linear running portion of both endless round belts. And a pressure receiving plate, a solenoid for operating the pressing member, and the like. That is, in this holding means, when the article is lifted, the linearly running portion of both endless round belts holding the side edges of the stretch film as described above is clamped between the pressing member and the pressure receiving plate. In addition, by pressing the article against the stretch film held together with the endless round belt, the film is stretched to cover the upper surface of the article. Next, film folding is achieved by releasing the holding of the stretch film by the holding means at an appropriate timing during folding of the film end extending from the peripheral edge of the article to the bottom surface side of the article with the folding member. .
[0005]
As a means for transporting the stretch film, a flat belt may be used in addition to a round belt. That is, the conveying means is provided with an endless flat belt wound up and down between pulleys spaced apart by a predetermined distance, and a lower linear traveling portion of the upper endless flat belt and an upper linear traveling portion of the lower endless flat belt. Are arranged so as to be in contact with each other, and the upper and lower endless flat belts are rotated in opposite directions with the side edges of the stretch film being sandwiched between the flat belts to convey the stretch film. The
[0006]
For example, the holding means disclosed in Japanese Patent Application Laid-Open No. 8-119212 adopts the conveying means using the endless flat belt, and a clamp member capable of closely contacting the linear running portion of the endless flat belt in the above-mentioned contact state, and the clamp And a solenoid for operating the member. In this holding means, when the article is lifted toward the stretch film after the conveyance means stops the film conveyance above the article, the linear running portions of both endless flat belts in the contact state are clamped by the clamp member. The article is pressed against the stretch film that is in close contact with the endless flat belt from below, so that the film is stretched to cover the upper surface of the article. Next, film folding is achieved by releasing the holding of the stretch film by the clamp member at an appropriate timing during folding of the film end extending from the periphery of the article to the bottom side of the article by the folding member.
[0007]
[Problems to be solved by the invention]
In any of the above-described film holding means, the stretch film is held by sandwiching the upper and lower belts. Also, when the article is lifted, the film must be stretched by pressing the article against the stretch film from the bottom. At this time, the belt is strongly pinched so that the stretch film does not come out between the upper and lower belts. It is set to. In this case, since the stretch film has adhesiveness, even if the holding pressure on the belt is stopped and the holding on the stretch film is released, the film remains attached to the belt and is good from between the belt when the film is folded. It may not be possible to escape. Thus, when the release | release of holding | maintenance with respect to a stretch film is incomplete, the said folding member will tear a stretch film and there exists a problem which a packaging defect product generate | occur | produces. Further, the stretch film pressed by the folding member is strongly pressed against the article (tray or the like), and the article is damaged. In this case, a defective packaging product is also generated.
[0008]
OBJECT OF THE INVENTION
In view of the above-mentioned problems inherent in the prior art described above, the present invention has been proposed to suitably solve this problem, and a film in a stretch wrapping machine that can satisfactorily release the stretch film. An object is to provide a holding device.
[0009]
[Means for Solving the Problems]
  In order to solve the above-described problems and achieve the desired purpose suitably, the film holding device in the stretch wrapping machine according to the present invention is:
  Film extensionHold onTheFor the filmHoldPick upTheIn a stretch wrapping machine that covers the top surface of the article and folds the film end extending from the periphery of the article to the bottom side of the article,
  in frontWritingThe side edge of the filmWith upper and lower endless beltsPinchThe film extension sectionA pair of endless belt conveyors transported to
  In the film extension sectionin frontWritingFilmA pair of upper and lower holding members arranged to be held inside the upper and lower endless beltsHolding means and,
  A release means provided corresponding to the both endless belt conveyors, wherein the upper and lower endless belts are relatively spaced apart to release the film;With
  The film is held at the timing after the pair of endless belt conveyors has transported the film to the film extending section, and the film is sandwiched by the upper and lower endless belts in each of the endless belt conveyors before the end of the film is folded. Each of the holding means and the releasing means is controlled to be released.It is characterized by that.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, the film holding device in the stretch wrapping machine according to the present invention will be described below with reference to the accompanying drawings by giving a preferred embodiment. In the examples, the horizontal conveyance direction of the stretch film to the film spreading portion is referred to as the left-right direction, and the direction horizontally intersecting with this is referred to as the front-rear direction.
[0011]
(About film transport mechanism)
As shown in FIGS. 1 and 2, a machine casing 10 of a stretch wrapping machine in which the film holding device according to the embodiment is adopted is provided with a pair of transport mechanisms 11 and 12 that are spaced apart in the front-rear direction. The stretch film F having a predetermined size drawn out from the raw roll 13 as a source and cut by the cutter 14 is transported to the film extending portion S in a state where both side edges in the front-rear direction are sandwiched between the transport mechanisms 11 and 12. Configured to be. Since the basic configuration of the transport mechanisms 11 and 12 is the same, only the configuration of the transport mechanism 11 disposed on the front side will be described, and the same members of the transport mechanism 12 disposed on the rear side are the same. It shall be shown with a reference numeral.
[0012]
As shown in FIG. 12, a pair of guide shafts 15, 15 orthogonal to the film transport direction are disposed at positions separated in the left-right direction of the machine casing 10, and the left and right sides of the transport mechanism 11 are disposed between the shafts 15, 15. A conveying frame 16 extending in the direction is slidably installed via sliding cylinders 17 and 17 so as to be movable back and forth. As shown in FIG. 4, lower pulleys 18, 18 are rotatably supported on the transport frame 16 in the vicinity of both left and right ends, and a predetermined axial direction is provided between the lower pulleys 18, 18. A plurality of (three in the embodiment) lower endless round belts 19 are wound at intervals. An upper pulley 20 is rotatably supported on the upper side of each lower pulley 18, and a plurality of (two in the embodiment) upper pulleys 20 and 20 are spaced apart by a predetermined distance in the axial direction. An endless round belt 21 is wound around. As shown in FIG. 6, the lower endless round belt 19 and the upper endless round belt 21 are such that the lower straight running portion of the upper endless round belt 21 and the upper straight running portion of the lower endless round belt 19 are substantially flush with each other. The side edges of the stretch film F are sandwiched in a wave shape between the upper and lower endless round belts 19 and 21. In addition, meshing driven gears 18a and 20a are disposed on the upper and lower pulleys 18 and 20 so as to be integrally rotatable, and both pulleys 18 and 20 rotate in opposite directions. In the embodiment, the upper and lower endless round belts 19 and 21 constitute an endless belt conveyor 22. In FIG. 4, reference numeral 23 denotes an idle roller that changes the winding path of the upper endless round belt 21.
[0013]
As shown in FIG. 3, a pair of drive shafts 24, 24 perpendicular to the film transport direction are disposed at positions separated from each other in the left-right direction of the machine casing 10, and each drive shaft 24 is connected to a shaft via a key 24a. A drive gear 25 that rotates integrally with movement in a direction is allowed. The drive gear 25 meshes with the driven gear 18a of the corresponding lower pulley 18. In addition, driven pulleys 24b and 24b that extend rearward of the machine frame 10 in both drive shafts 24 and 24 are disposed so as to be integrally rotatable, and an endless belt 26 is wound between the pulleys 24b and 24b. It has been. The endless belt 26 is also wound around a drive pulley 28 that is rotated by a traveling servo motor 27 disposed in the machine frame 10. By rotating the motor 27 in a predetermined direction, Under the meshing action with the driven gear 18a, the lower straight running portion of the upper endless round belt 21 and the upper straight running portion of the lower endless round belt 19 run in the same direction, whereby the side edges are sandwiched. It is comprised so that the stretch film F may be conveyed toward the film expansion part S. FIG. In addition, the conveyance amount of the stretch film F by both the conveyance mechanisms 11 and 12 is controlled by the control means (not shown) by the traveling servo motor 27, so that the size of the article (the one in which the goods are stored in the tray) 29 (left and right) Depending on the length of the direction). Further, an engaging groove 25a is formed at the shaft end of the drive gear 25, and the corresponding end of the conveying frame 16 is engaged with the engaging groove 25a, and the conveying mechanism 11 moves back and forth as will be described later. In this case, the drive gear 25 can follow along the drive shaft 24 so that the meshed state with the driven gear 18a can be maintained.
[0014]
(Release means)
  Release means 30 for releasing the holding of the stretch film F by the upper and lower endless round belts 19 and 21 is provided at a position close to each pulley installation position in the transport frame 16. As shown in FIGS. 4 and 5, each release means 30 includes a swing lever 32 pivotally supported on a support shaft 31 disposed on the transport frame 16. Each endlessCircleA push-up roller 33 that faces the lower side of the lower straight running portion of the belt 21 is rotatably arranged. In addition, an operating lever 34 is disposed on the swing lever 32 so as to be swingable integrally, and an upward rod 35 a of a release solenoid 35 disposed on the transport frame 16 is provided on the operation lever 34. It is connected. A leaf spring 36 is elastically disposed between the actuating lever 34 and the conveying frame 16, and the push-up roller 33 is always moved from the lower linear traveling portion of the upper endless round belt 21 through the swing lever 32. It is set to be held at a retracted position that is spaced downward. Then, by energizing the release solenoid 35 and attracting the magnetic force of the rod 35a, the swing lever 32 swings against the elasticity of the leaf spring 36 so that the lift roller 33 moves upward, and the lift roller When the upper portion of the upper endless belt 33 is moved upward to the release position above the lower straight running portion of the upper endless round belt 21, the lower endless straight running portion of each upper endless round belt 21 is lowered by the push-up roller 33. The stretch film F is released from the upper straight running portion (see FIG. 7).
[0015]
(About the holding mechanism)
Holding mechanisms 37 and 38 for holding the both side edges of the stretch film F are disposed on the inner sides in the front-rear direction of the both transport mechanisms 11 and 12 (in the opposite direction of the endless belt conveyors 22 and 22). Since the basic structure of the holding mechanisms 37 and 38 is the same, only the structure of the holding mechanism 37 disposed on the front side will be described, and the same members as those of the holding mechanism 38 disposed on the rear side will be described. It shall be shown with a reference numeral.
[0016]
As shown in FIG. 8, the holding mechanism 37 is arranged on the upper side of the film conveying path on a holding frame 40 slidable in the front-rear direction via the sliding cylinders 39, 39 on the guide shafts 15, 15. A fixed holding member 41 positioned, a central movable holding member 42 located at the center of the film conveying direction (left-right direction) below the fixed holding member 41, and a pair of left and right sides of the central movable holding member 42 Side movable holding members 43 and 43 are disposed, and these holding members 41, 42, 43 and 43 are formed in a shape along the film transport direction. The central movable holding member 42 and the both side movable holding members 43 and 43 are disposed so as to be capable of opening and closing between a position separated from the fixed holding member 41 and a position in contact with the corresponding operating mechanisms 44 and 45, respectively. The side edge of the stretch film F is sandwiched between the fixed holding member 41 and the three movable holding members 42, 43, and 43 at a portion divided in three in the film transport direction. In the embodiment, the holding means for holding the stretch film F with the fixed holding member 41 and the three movable holding members 42, 43, 43 divided in the film conveyance direction is configured. The holding means, specifically, the film holding area where the holding means holds the stretch film F (the contact area between the fixed holding member 41 and the three movable holding members 42, 43, 43) is at the center in the film conveying direction. The article 29 to be lifted is disposed so as to correspond to the center of the film conveyance direction. Further, the length of the holding means, specifically the film holding area, in the film conveyance direction is set to be longer than the corresponding left and right lengths of the article 29 having the maximum dimension that can be wrapped by the stretch wrapping machine.
[0017]
As shown in FIGS. 8 and 10, the central movable holding member 42 is pivotally supported at one end of a substantially L-shaped first central lever 46 pivotally supported by the holding frame 40, and The other end of the central lever 46 is pivotally supported by one end of the central actuating member 47. The other end of the central actuating member 47 is pivotally supported by one end of a substantially L-shaped second central lever 49 pivotally supported by the holding frame 40. An upward rod 51a of the central solenoid 51 disposed on the holding frame 40 is connected to the end. A central coil spring 48 is stretched between the other end of the central operating member 47 and the holding frame 40, and the central operating member 47 always moves the central movable holding member 42 through the first central lever 46. It is set so as to be held at a retracted position separated from the fixed holding member 41. By energizing the central solenoid 51 and attracting the magnetic force of the rod 51a, the first central lever 46 rotates in a predetermined direction via the second central lever 49 and the central actuating member 47, whereby the central movable holding is performed. The member 42 is configured to be close to the fixed holding member 41 and sandwich the central portion of the side edge of the stretch film F. In the embodiment, the first central lever 46, the central operating member 47, the central coil spring 48, the second central lever 49 and the central solenoid 51 constitute a central operating mechanism 44 that opens and closes the central movable holding member 42.
[0018]
Each of the side movable holding members 43 is pivotally supported at one end of a substantially L-shaped first side lever 52 pivotally supported by the holding frame 40 as shown in FIGS. At the same time, the other end of the side lever 52 is pivotally supported by the side actuating member 53. A side coil spring 54 is stretched between an end of the side operation member 53 facing the side opposite to the side where the central coil valve 48 is disposed and the holding frame 40, and the side operation member 53. Is set so that the side movable holding members 43 and 43 are always held at the retracted position away from the fixed holding member 41 via the first side lever 52. The side operation member 53 is pivotally supported by one end of a substantially L-shaped second side lever 55 pivotally supported by the holding frame 40 and the other end of the side lever 55. An upward rod 56a of a side solenoid 56 disposed on the holding frame 40 is connected to the portion. Then, the first side levers 52 and 52 are rotated in a predetermined direction via the second side lever 55 and the side operation member 53 by exciting the side solenoid 56 and attracting the magnetic force of the rod 56a. Thus, both side movable holding members 43, 43 are configured to approach the fixed holding member 41 and sandwich the stretch film F between the left and right sides of the central movable holding member 42. In the embodiment, the side movable holding members 43 and 43 are opened / closed from the first side levers 52 and 52, the side operation member 53, the side coil spring 54, the second side lever 55 and the side solenoid 56. A side actuating mechanism 45 is configured.
[0019]
On the surface (the lower surface of the fixed holding member 41, the upper surface of the movable holding members 42, 43, 43) of the fixed holding member 41, the central movable holding member 42, and the side movable holding members 43, 43 that are in contact with the stretch films F. Each of the sheet materials 79 to which the stretch film F is not attached is attached. The sheet material 79 is flexible and functions as a cushion material when the stretch film F is sandwiched between the holding members 41, 42, 43, and 43. In addition, instead of sticking the sheet material 79, processing or processing that can prevent the stretch film F from adhering to the opposing surfaces of the fixed holding member 41 and the movable holding members 42, 43, 43, or The member can be attached.
[0020]
(About the pre-extension means and tension reduction means of the holding mechanism)
Holding shafts 57 are respectively disposed on the left and right sides of the machine casing 10 facing the front and rear holding mechanisms 37 and 38 (see FIG. 12), and each holding shaft 57 is spaced apart in the axial direction and has a first toothed pulley. 58 and a second toothed pulley 59 are rotatably arranged. As shown in FIG. 13, a first toothed pulley 58 that is paired on the front side of the machine casing 10 corresponding to the first toothed pulley 58 is rotatably arranged, and is wound between the first toothed pulleys 58, 58. A sliding cylinder 39 of the holding mechanism 37 on the front side is fixed at an appropriate position of the hooked endless first toothed belt 60. Further, a second toothed pulley 59 that is paired on the rear side of the machine frame 10 corresponding to the second toothed pulley 59 is rotatably disposed, and is endlessly wound between the two toothed pulleys 59, 59. The sliding cylinder 39 of the rear holding mechanism 38 is fixed to an appropriate position of the second toothed belt 61 having a shape.
[0021]
The first toothed pulleys 58, 58 located on the left and right sides located on the front side are connected to a first servo motor 62 disposed in the machine frame 10 by a first connecting means 63 such as a pulley-belt. The front holding mechanism 37 is configured to move in the front-rear direction by causing both the first toothed belts 60, 60 to move forward and backward in synchronization by forward and reverse rotation of 62. The second toothed pulleys 59, 59 located on the left and right sides located on the rear side are connected to a second servo motor 64 disposed in the machine frame 10 by a second connecting means 65 such as a pulley-belt. By moving both the second toothed belts 61 and 61 back and forth in synchronization by forward and reverse rotation of the servo motor 64, the rear holding mechanism 38 is configured to move in the front-rear direction. That is, the front and rear holding mechanisms 37 and 38 are configured to be able to move back and forth independently, so that the distance between the opposing holding mechanisms 37 and 38 can be increased or decreased.
[0022]
In the embodiment, the stretch film F is moved in the front-rear direction from the first toothed pulleys 58, 58, the first toothed belt 60, the first connecting means 63, and the first servomotor 62 that move the front holding mechanism 37 back and forth. Pre-stretching means and tension reducing means for performing pre-stretching and tension reduction (stretching amount reduction) are configured. Similarly, the stretch film F is preliminarily stretched in the front-rear direction from the second toothed pulleys 59, 59, the second toothed belt 61, the second connecting means 65, and the second servomotor 64 that move the rear holding mechanism 38 back and forth. And a pre-extension means and a tension reduction means for reducing the tension (decreasing the amount of extension).
[0023]
As shown in FIGS. 12 and 13, each sliding cylinder 39 of the front and rear holding mechanisms 37, 38 is provided with an engaging member 66 and a pressing member 67, and a corresponding conveyance between both members 66, 67. A sliding cylinder 17 of the mechanisms 11 and 12 is disposed. That is, when the holding mechanisms 37 and 38 move in the approaching direction, the conveying members 11 and 12 move as the engaging member 66 engages the sliding cylinder 17. Further, when both the holding mechanisms 37 and 38 move in the direction of separating, the pressing member 67 is configured to abut against the sliding cylinder 17 to push and move the transport mechanisms 11 and 12. As described above, the preliminary extension means and the tension reduction means for moving the transport mechanisms 11 and 12 back and forth in conjunction with the holding mechanisms 37 and 38 are distance adjusting means for adjusting the facing direction (front and rear direction) distance of the transport mechanisms 11 and 12. The distance between the two transport mechanisms 11 and 12 in the opposing direction can be adjusted in accordance with the length of the stretch film F in the same direction, that is, the width dimension. In this case, with the front holding mechanism 37 and the transport mechanism 11 as a reference, the rear holding mechanism 38 and the transport mechanism 12 are moved back and forth in accordance with the width dimension of the stretch film F to be used, and the rear transport mechanism. 12 is adjusted so as to sandwich the rear side edge of the stretch film F. Note that the front-rear distance between the engaging member 66 and the pressing member 67 is set to be slightly larger than the front-rear dimension of the sliding cylinder 17 of the transport mechanisms 11, 12, and when the holding mechanisms 37, 38 are moved in the front-rear direction, The moving amounts of the transport mechanisms 11 and 12 are configured to be slightly smaller than the moving amounts of the holding mechanisms 37 and 38.
[0024]
(About folding members)
As shown in FIGS. 1 and 2, the machine frame 10 above the film extending portion S is outside the periphery of the article 29 at a position facing the lower side of the article 29 lifted to a raised position by a lift device 77 described later. A rear folding member 68 that folds the end of the film extending in the direction toward the bottom surface of the article 29 is disposed so as to be movable in the front-rear direction, and left and right side folding members 69, 69 are horizontally disposed below the rear folding member 68. Further, a front folding member 70 is disposed on the front side opposite to the rear folding member 68 with the film extending portion S interposed therebetween. Further, a discharge pusher 71 movable in the front-rear direction is provided on the machine casing 10 above the rear and side folding members 68, 69, 69, and film folding by the rear folding member 68 and the side folding members 69, 69 is performed. When the article 29 is moved forward by the discharge pusher 71 at the end timing, the film end portion extending outward from the front peripheral edge of the article 29 comes into contact with the front folding member 70 and the bottom side of the article 29 Configured to be folded into. Further, a carry-out conveyor 72 is disposed in front of the film spreading section S, and the article 29 moved by the discharge pusher 71 is carried out downstream via the conveyor 72.
[0025]
In addition, as shown in FIG. 3, the rotation fulcrums 69a and 69a of the left and right side folding members 69 and 69 are located behind the rear holding mechanism 38, and the both side folding members 69 and 69 At the time of film folding, the film edges extending outward from the left and right peripheral edges of the article 29 are folded by the side folding members 69, 69 in order from the rear corner of the article 29 toward the bottom side. Become. Accordingly, the release timing of the film holding by the front and rear holding mechanisms 37 and 38 at the time of film folding is set to be different depending on the folding order of the side folding members 69 and 69 with respect to the film end.
[0026]
(About the article supply conveyor)
Below the film spreading section S, as shown in FIG. 1, a first supply conveyor 73 and a second supply conveyor 74 are arranged in series in the front-rear direction perpendicular to the film transport direction. The article 29 placed on is conveyed by the conveyor 73 and the second supply conveyor 74 to just below the film spreading section S. The second supply conveyor 74 is composed of a plurality of endless belts 74a spaced apart in the left-right direction (see FIG. 2), and each mounting member 78 of a lift device 77 described later moves up and down between adjacent endless belts 74a and 74a. Configured to work. A stopper 75 is disposed above the downstream side of the second supply conveyor 74 in the article conveyance direction, and the article 29 conveyed by the conveyor 74 has its front end at the downstream end (front end) abutting against the stopper 75. Is set to be positioned directly below the film extension S.
[0027]
An article sensor 76 for detecting the article 29 is disposed on the side of the conveyance path of the article 29 in the first supply conveyor 73. Based on the detection signal of the sensor 76, the control means performs packaging by a stretch packaging machine. Is set to start.
[0028]
(About lift device)
The article 29 positioned by the stopper 75 is received and placed from the second supply conveyor 74 at a position facing the film extending portion S immediately upstream from the arrangement position of the stopper 75 in the article conveying direction. A lift device 77 that lifts the article 29 toward the film spreading section S is disposed so as to be movable up and down. The lift device 77 has a plurality of placement members 78 disposed at the upper end thereof in the front-rear and left-right directions, and the article placement surface of the placement member 78 is the article placement of the second supply conveyor 74. The stretch film F is set by the article 29 placed on the placing member 78 from the lowered position facing below the surface to the raised position exceeding the film extending portion S by a lifting mechanism (not shown). It is configured to be pushed up and cover its upper surface.
[0029]
(About control means)
The control means includes servo motors 62 and 64 that move the holding mechanisms 37 and 38 back and forth, a travel servo motor 27 that drives the endless round belts 19 and 21 of the transport mechanisms 11 and 12, and a release solenoid for the release means 30. 35, connected to solenoids 51, 56 for closing movable holding members 42, 43, 43 in the holding mechanisms 37, 38. The article sensor 76 is also connected to the control means.
[0030]
The control means is connected to an input unit for inputting various data for operating the stretch wrapping machine, and is provided with a storage unit for storing the data, and the article (the product on the tray) to be packaged via the input unit. These data are stored in the storage unit together with the product number for 29). Then, by calling the product number via the input unit during packaging, the servo motors and solenoids are actuated at preset timings, and the servo motors are controlled by a known control method. The data includes, for example, the size of the article (tray) 29, holding and releasing timings by the three movable holding members 42, 43, and 43 in the front and rear holding mechanisms 37 and 38, and the front and rear of each holding mechanism 37 and 38. The amount of movement in the direction can be mentioned. These data can be arbitrarily set and changed by the input unit.
[0031]
[Effect of the embodiment]
Next, the operation of the film holding device in the stretch wrapping machine according to the above-described embodiment will be described. First, the product number of the article 29 to be packaged is called by the input unit of the control means. As a result, the data stored in the storage unit is read for each product number, and various mechanisms are controlled based on the data.
[0032]
That is, when the article 29 is placed on the traveling first supply conveyor 73, the article 29 is conveyed downstream, delivered to the second supply conveyor 74, and conveyed to a position where it abuts against the stopper 75. . When the article sensor 76 detects the passage of the article 29 while the article 29 is being conveyed by the first supply conveyor 73, the endless belt conveyors 22 and 22 of the pair of conveying mechanisms 11 and 12 are pulled out from the original roll 13. The stretch film travels while sandwiching both ends in the front-rear direction, and the cutter 14 operates at an appropriate timing to cut the stretch film. Then, the transport mechanisms 11 and 12 transport only the cut stretch film F to the film spreading section S and stop. At this time, the central movable holding member 42 and the side movable holding members 43, 43 in the front and rear holding mechanisms 37, 38 are open to the fixed holding member 41 (see FIG. 6), and the fixed holding member 41 and each movable holding member The stretch film F is passed between the films 42, 43, and 43 and conveyed to the film spreading section S. In the film transport direction (left-right direction), the center of the stretch film F that has stopped transporting corresponds to the center of the holding means (fixed holding member 41, movable holding members 42, 43, 43).
[0033]
At the timing after the film conveyance by the conveyance mechanisms 11 and 12 is stopped, the central movable holding member 42 and the central solenoid 51 and the side solenoid 56 corresponding to the both side movable holding members 43 and 43 are excited, and each operation is performed. The central movable holding member 42 and the both side movable holding members 43, 43 are closed with respect to the fixed holding member 41 by the mechanisms 44, 45. As a result, as shown in FIG. 7, the stretch film F has a constant force between the fixed holding member 41 and the movable holding members 42, 43, and 43 at the portions separated in the front-rear direction inside the transport mechanisms 11 and 12, respectively. Is held between. Further, the release solenoids 35 of the release means 30 of both the transport mechanisms 11 and 12 are energized, and the push-up roller 33 moves up to the release position, so that the lower linear running portion of the upper endless round belt 21 is moved downward. The endless round belt 19 is pushed upward from the upper straight running portion, whereby the stretch film F is held between the round belts 19 and 21.
[0034]
At a required timing after the stretch film F is held by the holding mechanisms 37 and 38, the servo motors 62 and 64 that move back and forth through the both holding mechanisms 37 and 38 are rotated in a predetermined direction so that the both holding mechanisms 37 and 38 are mutually connected. The stretch film F is preliminarily stretched in the front-rear direction by being moved in a direction away from each other (a direction in which the facing direction interval is widened). Thereby, the stretch film F of the film expansion part S is hold | maintained in the state without a wrinkle, and favorable packaging becomes possible. Note that the amount of movement in the front-rear direction in both holding mechanisms 37, 38 during this pre-extension is set and stored according to the article 29 to be packaged, and the amount of movement of both holding mechanisms 37, 38 is the same. It may or may not be. In addition, it is possible to move only the front holding mechanism 37 or the rear holding mechanism 38 in the front-rear direction during preliminary extension. In this case, the movement amount of the non-moving holding mechanism is set and stored as 0. . In the case of the article 29 that does not need to be pre-stretched, the movement amounts in the front-rear direction of both the holding mechanisms 37 and 38 are both set to 0, so that they are not moved.
[0035]
When the article 29 comes into contact with the stopper 75, the lift device 77 is raised by the elevating mechanism, and the article 29 on the second supply conveyor 74 is placed on the plurality of placement members 78. When the lift device 77 is further lifted, the placed article 29 is lifted toward the stretch film F stretched in the pre-stretched state in the film spreading section S, and the film F is pushed up by the article 29. It reaches the ascending position while extending.
[0036]
Before the article 29 reaches the raised position, at the timing when the upper part of the article 29 is substantially in contact with the stretch film F, the servo motors 62 and 64 are reversed, and the holding mechanisms 37 and 38 are close to each other. It moves in the direction (direction in which the opposing direction interval is narrowed), reduces the stretch amount of the prestretched stretch film F by a predetermined amount, and reduces the tension. Therefore, when the article 29 pushes up the stretch film F, damage to the article 29 due to the tension of the stretch film F is reduced. It should be noted that the amount of movement in the front-rear direction in the holding mechanisms 37, 38 when the tension is reduced is set and stored according to the article 29, and the amount of movement is the same as the amount of movement during the preliminary extension, It can be large. Further, the movement amounts of both the holding mechanisms 37 and 38 may be the same or different, and furthermore, by setting and storing 0, only the front holding mechanism 37 or the rear holding mechanism 38 is tensioned. It is possible to move in the front-rear direction at the time of reduction, or not to reduce the tension without moving both the holding mechanisms 37 and 38.
[0037]
Here, the movement amount at the time of preliminary extension and tension reduction by the holding mechanisms 37 and 38 is not set and stored for each article 29, and any article can be set by setting a predetermined standard movement amount. The same movement operation can also be performed for 29. Further, in the above-described operation, if both the movement amounts related to the preliminary stretching of both the holding mechanisms 37 and 38 are set and stored as 0, both the holding mechanisms 37 and 38 do not perform the pre-stretching operation, and the article 29 holds the stretch film F. When pushing up, both the holding mechanisms 37 and 38 or one holding mechanism 37 and 38 can be moved only in the direction close to each other. Therefore, the damage of the soft article 29 and the tall article 29 due to the tension of the stretch film F is reduced.
[0038]
Regarding the movement amount when the tension of the holding mechanisms 37 and 38 is decreased, the article 29 is transported toward the lift device 77 in addition to the value set and stored for each article 29 and the standard movement amount as described above. The holding mechanisms 37 and 38 can be moved by a preset amount of movement according to the height of the article 29 detected by a height detection sensor (not shown) provided on the first supply conveyor 73. It has become.
[0039]
When the lift device 77 is stopped at the raised position, the left and right side folding members 69, 69 come close to each other, and the rear folding member 68 moves forward so that the left and right side edges of the article 29 are removed from the peripheral edges. The film end portion extending outward, and then the film end portion extending outward from the peripheral edge on the rear side are folded into the bottom surface side of the article 29, respectively. In this case, when the film is folded by the left and right side folding members 69, 69, first, the side solenoid 56 of the side actuation mechanism 45 of the rear holding mechanism 38 is excited and both side movable holding members 43, 43 are excited. Is moved away from the fixed holding member 41, and the film holding is released. Next, the side solenoid 56 of the side operating mechanism 45 of the front holding mechanism 37 is excited, and the movable holding members 43, 43 on both sides are fixed to the fixed holding member 41. The film holding by the side movable holding members 43, 43 is released away from the film. When the film is folded by the rear folding member 68, the central solenoid 51 of the central operating mechanism 44 of the rear holding mechanism 38 is excited, and the central movable holding member 42 is separated from the fixed holding member 41 to release the film holding. The
[0040]
Depending on the size of the article 29, when the film is folded by the left and right side folding members 69, 69, the film holding by the side movable holding members 43, 43 in the front and rear holding mechanisms 37, 38 may be simultaneously released. is there. Further, when the rear folding member 68 moves forward, the article 29 is transferred from the mounting member 78 of the lift device 77 onto the rear folding member 68.
[0041]
Next, when the discharge pusher 71 moves forward, the article 29 is transferred from the rear folding member 68 onto the front folding member 70 and moved forward, so that the article 29 is carried out toward the carry-out conveyor 72. The At this time, the central solenoid 51 of the central operating mechanism 44 of the front holding mechanism 37 is excited, the central movable holding member 42 is separated from the fixed holding member 41, and the film holding is released. The end of the film extending outward is folded into the bottom surface when the article 29 passes over the front folding member 70, and the packaging is completed.
[0042]
  Since the film holding by the fixed holding member 41 and the movable holding members 42, 43, 43 is not performed through the endless round belts 19, 21, the film holding by the holding members 41, 42, 43, 43 is performed. At the time of release, the stretch film F does not remain attached to the endless round belts 19 and 21. Also, the film clamping by the endless round belts 19 and 21 is performed by the release means 30 as described above.ForcedTherefore, the stretch film F is surely removed from between the endless round belts 19 and 21. Accordingly, when the film is folded by the folding members 68, 69, 69, and 70, the stretch film F can be easily removed from between the fixed holding member 41 and the movable holding members 42, 43, and 43, and a large force is applied to the film F. It is possible to reduce tearing due to the addition of or damage to the article 29. That is, the occurrence of defective packaging is suppressed.
[0043]
At an appropriate timing after the article 29 is transferred onto the rear folding member 68, the lift device 77 starts to descend and returns to the lowered position, and after the article 29 is unloaded from the rear folding member 68. At an appropriate timing, each of the rear folding members 68 and the side folding members 69 and 69 starts the returning operation and returns to the initial position, and waits for the next article 29 to arrive. Regarding the movement of the holding mechanisms 37 and 38 in the front-rear direction, the central movable holding member 42 on the front side releases the film holding when the tension reducing operation is not performed after the preliminary stretching operation or when only the tension reducing operation is performed. After that, it returns to the initial position at an appropriate timing.
[0044]
[Example of change]
  The present application is not limited to the configuration of the above-described embodiment, and other configurations can be appropriately employed.
1 With regard to the endless belt conveyor, an endless belt such as a flat belt or a toothed belt may be employed instead of the round belt.
2  The release means may be configured to lower the lower round belt instead of the upper round belt. Alternatively, the endless round belts in a wound state can be separated from each other. The same applies when the round belt is changed to a flat belt or a toothed belt.
3  Instead of the holding mechanism, the holding mechanism may be interlocked with the transport mechanism by moving the transport mechanism in the front-rear direction.
4  It is possible to adopt a configuration in which a driving source is also provided in the transport mechanism and is independently moved in the front-rear direction. In this case, when the holding mechanism moves outward, it is necessary to move the transport mechanism outward so as not to interfere with this, but when the holding mechanism moves inward, the transport mechanism is moved inward. It does not have to be.
5  Regarding the operation mechanism for opening and closing the movable holding member in the holding mechanism, a cylinder, a motor, or the like can be used instead of the solenoid as the drive source.
[0045]
【The invention's effect】
  As described above, claim 1 according to the present invention.And 2According to the film holding device in the stretch wrapping machineTheWhen the film is lifted by the article, the film is directly held only by holding means provided separately from the endless belt conveyor.NiSince the film is not retained, the film is less likely to adhere to the belt. ThereforeTheThe release of the film from the holding becomes good, and the film can be prevented from being broken or the article is damaged.Further, since the film clamping by the endless belt conveyor is forcibly released by the release means, the adhesion of the film to the belt can be further reduced. When the film end is folded, the film is not easily held by the endless belt conveyor by the releasing means, so that the film can be easily pulled out between the upper and lower endless belts, and a large force is applied to the film. It is possible to reduce tearing or breakage of articles, and to suppress the occurrence of defective packaging.
[0046]
  Claim3According to the film holding device according toTheFilm can be pre-stretched by pre-stretching meansTheThe film can be removed to obtain a good packaging state. And claims4According to the film holding apparatus according to the present invention, since the film tension can be reduced by the tension reducing means, the article is not damaged during packaging, and the occurrence of defective packaging is reduced. In particular, it is effective for soft articles and tall articles.
[0047]
  Claim5According to the film holding device according to the present invention, the holding means is divided.TehuIt is configured to hold the film at multiple points in the film transport direction.Since the release timing of film holding by each divided holding means can be set individually,According to the timing when the film is folded, the timing for releasing the film holding by the holding means at the corresponding location can be set,In response to articles of various sizesA tight and beautiful packaging condition can be obtained.
[Brief description of the drawings]
FIG. 1 is a front view showing a schematic configuration of a stretch wrapping machine employing a film holding device according to a preferred embodiment of the present invention.
FIG. 2 is a side view showing a schematic configuration of a stretch wrapping machine according to an embodiment.
FIG. 3 is a plan view illustrating a schematic configuration of a film holding device according to an embodiment.
FIG. 4 is a side view illustrating a transport mechanism of the film holding device according to the embodiment.
FIG. 5 is a plan view of a principal part showing release means of the transport mechanism according to the embodiment.
FIG. 6 is a schematic front view showing the film holding device according to the embodiment in a film holding release state of the holding mechanism.
FIG. 7 is a schematic front view showing the film holding device according to the embodiment in a film holding state of a holding mechanism.
FIG. 8 is a longitudinal side view showing a holding mechanism of the film holding device according to the example.
FIG. 9 is a plan view showing the holding mechanism according to the embodiment with a part cut away.
FIG. 10 is a longitudinal front view showing a central movable holding member of the holding mechanism according to the embodiment.
FIG. 11 is a longitudinal front view showing a side movable holding member of the holding mechanism according to the embodiment.
FIG. 12 is a schematic plan view showing preliminary extension means (tension reduction means) according to the embodiment.
FIG. 13 is a schematic front view showing preliminary stretching means (tension reducing means) according to the embodiment.
[Explanation of symbols]
  19 Lower endless belt ( Lower endless belt )
  21 Upper endless round belt ( Upper endless belt )
  22 Endless belt conveyor
  29 articles
  30 Release means
  41 Fixed holding member (holding means)
  42 Central movable holding member (holding means)
  43 Side movable holding member (holding means)
  58 First toothed pulley (pre-extension means, tension reduction means)
  59 Second toothed pulley (pre-extension means, tension reduction means)
  60 First toothed belt (pre-stretching means, tension reducing means)
  61 Second toothed belt (pre-extension means, tension reduction means)
  62 1st servo motor (preliminary extension means, tension reduction means)
  63 First linkage means (preliminary extension means, tension reduction means)
  64 Second servo motor (preliminary extension means, tension reduction means)
  65 Second connecting means (preliminary extension means, tension reduction means)
  F Stretch film

Claims (5)

Towards off and kept at the film stretched portion (S) Irumu (F) covers the upper surface of the lifting Chiage was article (29), the film ends extending from the periphery of the article (29) article (29) In the stretch wrapping machine that folds into the bottom side,
The film stretched portion by sandwiching the side edge portion at the upper and lower endless belts (19, 21) before notated Irumu (F) and a pair of endless conveyor belt for conveying the (S) (22, 22),
The film stretched portion the upper and lower retaining member arranged to be held from inside the upper and lower endless belt pre notated Irumu (F) (19,21) in (S) (41,42,43,43) A pair of holding means (41, 42, 43) provided ;
Said provided corresponding to both the endless belt conveyor (22, 22), and a release means (30) for releasing the holding of the film relatively apart the upper and lower endless belts (19, 21) (F) Prepared,
At the timing after the film (F) is conveyed to the film spreading section (S ) by the pair of endless belt conveyors (22, 22) , while holding the film (F) , prior to folding the film end, Each of the holding means (41, 42, 43) and the releasing means (30) are operated so as to release the holding of the film (F) by the upper and lower endless belts (19, 21 ) in each endless belt conveyor (22) . A film holding device in a stretch wrapping machine, characterized by being controlled . Said release means (30) The upper endless belt (twenty one) Lower endless belt by moving the lower running part (19) And by film (F) The film holding device in the stretch wrapping machine according to claim 1, wherein the holding of the film is released. Pretension means to widen the opposite direction distance between the pair of holding means in the holding state with respect to the front notated Irumu (F) (41,42,43) (58,59,60,61,62,63,64,65 The film holding device in the stretch wrapping machine according to claim 1 or 2, wherein: Tension reducing means to narrow the opposite direction interval before notated Irumu pair of holding means in the holding state with respect to (F) (41,42,43) (58,59,60,61,62,63,64,65 The film holding device in the stretch wrapping machine according to any one of claims 1 to 3 . Said holding means (4 2, 43) is divided into a plurality me along the full Irumu conveying direction, hold releasing timing of their respective retaining means (42, 43) is, the claims are capable of setting an individual The film holding | maintenance apparatus in the stretch packaging machine in any one of 1-4 .

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