Stretching packaging device

Abstract

This stretch packaging device (1) is provided with: a film transport unit (6) that transports a film (F) to a packaging area (A) while sandwiching both sides in the width direction; a lifting unit (20) that jacks up the film in a state in which the product is pushed against the film from below; a pair of folding plates (26, 27) for folding the peripheral edge of the jacked film into the bottom surface side of the product; a pair of pressing plates (38, 39) for pressing both ends of the film positioned below the folding plate in the conveying direction against the folding plate from below; a movement mechanism (36) that moves the pair of jigs; and a control unit (9) for controlling the movement of the pair of folding plates. The control unit pre-stretches the film by moving at least one of the pair of insertion plates in a direction in which the relative distance between the insertion plates is separated in a state in which the film is pressed by the pair of jigs.

Description

Technical Field

[0001] One aspect of the present invention relates to a stretch wrapping apparatus. Background Art

[0002] A stretch packaging device is known, which carries measured goods through a conveyor, and raises the goods through a lifting part provided inside, so that the goods lift up the film stretched above the lifting part, and fold the end of the film into the bottom surface of the goods for packaging (for example, Patent Document 1: Japanese Patent Publication No. 2017-57004). In such a stretch packaging device, there is a film conveying part, which clamps the film fed from the film roll on both sides of the width direction orthogonal to the conveying direction, and conveys the film to the packaging area. The film conveying part stretches the film in the width direction by moving in a manner such that the relative distance between the clamping parts on both sides is greater than the width direction dimension of the film. The stretch packaging device can perform packaging with fewer wrinkles by lifting up the film that has been stretched (pre-stretched) in the width direction in advance. Summary of the invention

[0003] However, in the above-mentioned conventional stretch packaging device, although the film is pre-stretched in the width direction, it is not pre-stretched in the conveying direction of the film. Therefore, in order to package with few wrinkles, it is necessary to use a film that is much longer than the length of the film covering the product.

[0004] Therefore, an object of one aspect of the present invention is to provide a stretch packaging device that can shorten the length of a film used and can perform packaging with few wrinkles.

[0005] (1) One aspect of the present invention relates to a stretch packaging device comprising: a film conveying section that clamps both sides of the film in a width direction perpendicular to the conveying direction and conveys the film to a packaging area; a lifting section that lifts the film by moving upward while pushing the product from the bottom of the film conveyed to the packaging area against the film; a pair of folding plates that fold the peripheral edge of the film lifted by the lifting section into the bottom side of the product; a pair of clamps that respectively hold both end portions of the film in the conveying direction located below the pair of folding plates; a moving mechanism that moves the pair of clamps; and a control section that controls the movement of the moving mechanism, the control section controlling the moving mechanism to move at least one of the pair of clamps in a direction that separates the relative distance between the pair of clamps, thereby pre-stretching the film in the conveying direction of the film.

[0006] In the stretch packaging device of this structure, the film in a state of being stretched in the conveying direction of the film (pre-stretched state) is lifted up by the commodity. Therefore, since the film is packaged in a state of being stretched in the conveying direction, the length of the film used can be shortened compared to when the film is packaged in a state of not being stretched in the conveying direction. That is, in this structure, the length of the film used can be shortened and packaging with few wrinkles can be performed.

[0007] (2) In the stretch packaging device described in (1) above, the pair of clamps may be composed of a pair of folding plates and a pair of pressing plates, the pair of pressing plates pressing the film against each of the pair of folding plates from below, the moving mechanism moving the pressing plates along with the movement of the folding plates, and the control unit moving at least one of the folding plates in a state where the two ends of the film in the conveying direction are pressed against each of the folding plates by the pair of pressing plates in a relative distance away from each other. In this structure, the existing folding plates and the moving structure of the folding plates can be used to fold the two ends of the film in the conveying direction into the bottom side of the commodity by approaching or moving away in the conveying direction of the film. Thus, there is no need to embed another moving mechanism for bringing the pair of clamps closer or farther in the conveying direction of the film, and the clamp holding the film can be constructed inexpensively. In addition, the pair of pressing plates can be moved along with the movement of the pair of folding plates by only using the left and right pressing plates to press the two ends of the film in the conveying direction against the left and right folding plates. Thus, there is no need to achieve synchronous control of the movement of each other, and the structure and control can be simplified.

[0008] (3) In the stretch packaging device described in (1) or (2), the film conveying unit may include a pair of clamping units arranged opposite to each other in the width direction of the film, and the control unit may move at least one of the pair of clamping units in a direction of separation from each other before the film is lifted by the product. In this configuration, the film can be pre-stretched in both the conveying direction and the width direction of the film, and as a result, the product lifts the film pre-stretched in both the conveying direction and the width direction, thereby achieving packaging with fewer wrinkles.

[0009] According to one aspect of the present invention, the length of the film used can be shortened and packaging with few wrinkles can be performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a perspective view showing the appearance of a packaging device according to one embodiment.

[0011] Figure 2 It is shown Figure 1 A schematic front view of the interior of a stretch wrapping device.

[0012] Figure 3 It is along Figure 2 Schematic view of line III-III.

[0013] Figure 4 It is a schematic top view of a stretch packaging device.

[0014] Figure 5 It is shown Figure 1 A block diagram of the composition of the stretch packaging device.

[0015] Figure 6 It is a stereoscopic view of the stretching mechanism viewed from the right front obliquely.

[0016] Figure 7 It is a stereoscopic view of the stretching mechanism viewed from the left rear obliquely.

[0017] Figure 8 It is a stereoscopic view of the stretching mechanism viewed from the left rear obliquely.

[0018] Fig. 9 (A) is a perspective view showing an enlarged view of the first clamp located at the outer position and the origin position. Fig. 9 (B) is an enlarged perspective view showing the first clamp located at the outer position and the stretched position. Fig. 9 (C) is a perspective view showing the first clamp located at the inner side and the origin position in an enlarged manner.

[0019] Fig.10 This is a diagram showing the operation when packaging an object.

[0020] Fig.11 This is a diagram showing the operation when packaging an object.

[0021] Fig.12 This is a diagram showing the operation when packaging an object.

[0022] Fig.13 (A)~ Fig.13 (F) is a diagram showing the operation of the first clamp when pre-stretching the film. DETAILED DESCRIPTION

[0023] Hereinafter, a stretch packaging device 1 according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0024] like Figures 1 to 4 As shown, the stretch packaging device 1 is a device for film packaging of objects (commodities) W including commodities G such as food and a tray T on which the commodities G are placed. The stretch packaging device 1 wraps the objects W with the film F by pushing the objects W upward from below relative to the film F which holds the peripheral edge thereof in tension and folding the peripheral edge of the film F against the bottom surface of the tray T.

[0025] The stretch packaging device 1 includes a metering and carrying mechanism 2, a roll holding mechanism 4, a film feeding mechanism 5, a film conveying mechanism (film conveying unit) 6, a cutting mechanism 7, a lifting mechanism (lifting unit) 20, a folding mechanism 25, a sealing mechanism 8, a label issuing machine LI, and a control device (control unit) 9. The various mechanisms included in the stretch packaging device 1 are accommodated in the main body 1A and the housing 1B of the stretch packaging device 1. The housing 1B is mounted on the side of the main body 1A.

[0026] In the description of the present embodiment, "left and right" refers to left and right when the main body 1A of the stretch packaging device 1 is viewed from the front. The front side in the front-to-back direction of the stretch packaging device 1 is referred to as the "near front side", and the opposite side is referred to as the "back side". Films F1 and F2 refer to either the film F1 or the film F2, and are also simply referred to as film F. Film rolls R1 and R2 refer to either the film roll R1 or the film roll R2. "Upstream" and "downstream" refer to upstream in the conveying direction of the film F and downstream in the conveying direction, respectively.

[0027] like Figure 3 As shown, the weighing and carrying mechanism 2 includes a weighing device 2A, a carrying belt 2B, and a weighing plate 12. The weighing device 2A weighs the object W placed on the weighing plate 12 and sends the weighing data to the control device 9 (refer to Figure 1 ) outputs information indicating the weight of the object W. The carrying belt 2B is mounted between a pair of rollers. The carrying belt 2B is provided with a conveying rod 13 for pushing the object W. The conveying rod 13 moves toward the inner side by the movement of the carrying belt 2B, and pushes the object W toward the lifting mechanism 20 on the inner side. The weighing tray 12 is a rectangular shallow tray on which the object W is placed.

[0028] like Figure 2 As shown, the roll holding mechanism 4 is disposed in the housing 1B. The roll holding mechanism 4 has a structure for holding two film rolls R1 and R2 of the same or different types. Each film roll R1 and R2 is formed by multiple windings of films F1 and F2 of a specified width. The roll holding mechanism 4 includes: an upper roll holding portion 41 for holding the film roll R1, a lower roll holding portion 42 for holding the film roll R2, and a roll driving portion 43. The roll driving portion 43 selectively rotates either the upper roll holding portion 41 or the lower roll holding portion 42 to extract the film F1 or the film F2 from either the film rolls R1 and R2.

[0029] The film delivery mechanism 5 is a mechanism for transferring the film F1 drawn out from the film roll R1 or the film F2 drawn out from the film roll R2 to a pair of first feeder units 61 and second feeder units 62 of the film conveying mechanism 6. The film delivery mechanism 5 is arranged in the housing 1B. The film delivery mechanism 5 includes a loading unit 70. The loading unit 70 includes a first gripping unit 71, a second gripping unit 72, a rotating shaft 73, and a driving unit 74. The first gripping unit 71 and the second gripping unit 72 are mounted on the rotating shaft 73. When viewed from the front-to-back direction, the first gripping unit 71 and the second gripping unit 72 extend from the rotating shaft 73 in a V-shape.

[0030] like Figure 2 and Figure 4 As shown, the first holding unit 71 holds the film F1 using two plate members 71A and 71B. The second holding unit 72 holds the film F2 using two plate members 72A and 72B. The first holding unit 71 and the second holding unit 72 have a predetermined length in the depth direction of the housing 1B so that the films F1 and F2 can be fed to the film feeding mechanism 6. The driving unit 74 rotates the rotating shaft 73 to rotate the first holding unit 71 and the second holding unit 72.

[0031] like Figure 2 As shown, when the first gripping unit 71 transfers (feeds out) the film F1 to the film conveying mechanism 6, the rotation shaft 73 is rotated until the first gripping unit 71 becomes parallel to the horizontal plane. Thus, the film F1 is fed out in the horizontal direction from the front end of the first gripping unit 71 relative to the film conveying mechanism 6. When the second gripping unit 72 transfers the film F2 to the film conveying mechanism 6, the rotation shaft 73 is rotated until the second gripping unit 72 becomes parallel to the horizontal plane. Thus, the film F2 is fed out in the horizontal direction from the front end of the second gripping unit 72 relative to the film conveying mechanism 6.

[0032] The film conveying mechanism 6 receives the film F from the film feeding mechanism 5, clamps both sides of the film F in the width direction (front-back direction) from the vertical direction, and conveys the film F to the packaging area A above the lifting mechanism 20. In addition, the film conveying mechanism 6 holds the film F received from the film feeding mechanism 5 tightly in the central part of the packaging area A. The film conveying mechanism 6 includes a first feeder unit 61 (clamping unit), a second feeder unit (clamping unit) 62, Figure 4 The first conveying driving unit 63 , the first sliding mechanism 64 , the second sliding mechanism 65 , the second driving unit 66 and the third driving unit 67 are shown.

[0033] like Figure 2 and Figure 3As shown, the first feeder unit 61 is constructed to include a first feeder portion 61A and a pair of clamping portions 61B, 61C. The first feeder portion 61A conveys the film F delivered from the film delivery mechanism 5. The pair of clamping portions 61B, 61C clamp the film F delivered by the first feeder portion 61A from a vertical direction. The pair of clamping portions 61B, 61C operate by the on / off switching of a solenoid not shown. Specifically, the pair of clamping portions 61B, 61C clamps the film F or releases the film F by the on / off switching of the solenoid. The first feeder unit 61 may also be composed of a plurality of components (in the conveying direction) Figures 10 to 13 It is composed of three parts.

[0034] The second feeder unit 62 is configured to include a second feeder section 62A and a pair of clamping sections 62B and 62C. The second feeder section 62A feeds the film F fed from the film feeding mechanism 5. The pair of clamping sections 62B and 62C clamp the film F fed from the second feeder section 62A from a vertical direction. The pair of clamping sections 62B and 62C clamp the film F or release the film F by switching on / off a solenoid (not shown). The second feeder unit 62 may also be configured to include a plurality of components (in the conveying direction) Figures 10 to 13 It is composed of three parts.

[0035] Figure 2 The first feeder unit 61 shown is arranged near the front side in the front-to-back direction. The second feeder unit 62 is arranged at a position further in the front-to-back direction than the first feeder unit 61. The first feeder unit 61 and the second feeder unit 62 are arranged along the conveying direction (length direction) of the film F. The first feeder unit 61 and the second feeder unit 62 are composed of Figure 4 The first conveyance driving unit 63 shown is driven to convey the film F from the left side to the right side.

[0036] exist Figure 2 The first feeder unit 61 and the second feeder unit 62 are provided with a first slide mechanism 64 and a second slide mechanism 65 at both ends in the longitudinal direction, and the first slide mechanism 64 and the second slide mechanism 65 move the first feeder unit 61 and the second feeder unit 62 along the width direction of the film F. The first slide mechanism 64 is composed of Figure 3 The second driving section 66 shown is driven to move the first feeder unit 61 in the width direction of the film F. The second slide mechanism 65 is driven by the third driving section 67 to move the second feeder unit 62 in the width direction of the film F.

[0037] Figure 2The cutting mechanism 7 shown cuts the film F stretched between the film feeding mechanism 5 and the film conveying mechanism 6 after the film feeding mechanism 5 transfers the film F to the film conveying mechanism 6. The cutting mechanism 7 cuts the film F stretched between the film feeding mechanism 5 and the film conveying mechanism 6 after the film conveying mechanism 6 conveys the film F by a predetermined amount.

[0038] In the present embodiment, the film F cut by the cutting mechanism 7 is pre-stretched in the conveying direction and the width direction of the film F. The pre-stretching of the film F in the width direction is performed by driving the third driving unit 67 to move the second feeder unit 62 in the rear direction while the film F is clamped by the first feeder unit 61 and the second feeder unit 62. The pre-stretching of the film F in the conveying direction will be described in detail later.

[0039] The lifting mechanism 20 is provided at the lower part of the main body 1A. The lifting mechanism 20 supports the bottom surface of the tray T through a plurality of supporting members 23, and moves the supporting base 21 fixed to the supporting members 23 upward through the electric ball screw mechanism 24. Thus, the lifting mechanism 20 holds the bottom surface of the tray T and moves the object W upward. The lifting mechanism 20 moves the object W in the vertical direction while pushing the object W against the film F held tightly by the film conveying mechanism 6, thereby lifting the film F.

[0040] like Figure 2 and Figure 3 As shown, the folding mechanism 25 is provided at the upper part in the main body 1A. The peripheral part of the film F is folded into the bottom side of the object W lifted by the lifting mechanism 20 (that is, the bottom side of the tray T), so that the object W is covered with the film F. The folding mechanism 25 includes a first folding plate 26 and a second folding plate 27 which are provided to be movable in the horizontal direction along the conveying direction of the film F. The first folding plate 26 and the second folding plate 27 fold the film F from both ends in the conveying direction of the object W into the bottom side of the tray T. The folding mechanism 25 includes a third folding plate 28 which folds the side portion of the film F on the inner side in the width direction into the bottom side of the tray T. The folding mechanism 25 includes a front folding rod 29 which folds the side portion of the film F on the front side in the width direction into the bottom side of the tray T when the tray T is discharged to the sealing mechanism 8 side by the discharge push rod 29A. The first folding plate 26, the second folding plate 27, and the third folding plate 28 have a driving unit not shown in the figure, and are configured to be driven in conjunction with each other through a plurality of pulleys and a timing belt, etc. In addition, an independent driving unit for moving to a starting position corresponding to the size of the object W may be provided on the first folding plate 26, the second folding plate 27, and the third folding plate 28.

[0041] Figure 6The stretching mechanism 3 shown is a mechanism for keeping the film F in a state of being pulled (pre-stretched) in the conveying direction (left-right direction) before the object W is lifted up by the lifting mechanism 20. The stretching mechanism 3 is arranged at the rear of the main body 1A. Figures 6 to 8 As shown, the stretching mechanism 3 includes a support portion 31, a vertical movement mechanism 32, a first arm 34, a second arm 35, a movement mechanism 36, a first clamp 40A, and a second clamp 40B (a pair of clamps).

[0042] The first clamp 40A and the second clamp 40B respectively hold the first folding plate 26 and the second folding plate 27 (a pair of folding plates) (refer to Figure 2 and Figure 3 ) at both ends of the film F in the conveying direction below. The first clamp 40A is composed of the first pressing plate 38 and the first folding plate 26, and clamps one end of the film F in the conveying direction. The second clamp 40B is composed of the second pressing plate 39 and the second folding plate 27, and clamps the other end of the film F in the conveying direction.

[0043] The support portion 31 is a member that supports the first arm 34 and the second arm 35. The support portion 31 has a main surface portion 31A and a pair of side portions 31B, 31B, and is formed in a U-shape when viewed from above. A sliding mechanism 31D such as a linear guide or a cylinder is provided on the pair of side portions 31B, 31B of the support portion 31, and the support portion 31 is fixed to the main body 1A (see FIG. 1 ) so as to be movable in the vertical direction by the sliding mechanism 31D. Figure 1 The vertical movement mechanism 32 is a mechanism for moving the support portion 31 in the vertical direction relative to the main body 1A.

[0044] The vertical movement mechanism 32 has a link mechanism 32A and a main body driving unit 32B. The link mechanism 32A is composed of a support shaft 32As supported by the main body 1A, a swing arm 32Ad that moves up and down around the support shaft 32As, a crank mechanism 32Ae connected to the swing arm 32Ad and the rotation axis of the main body driving unit 32B, and a connecting rod 32Af that connects one end of the swing arm 32Ad to the support unit 31. The crank mechanism 32Ae is activated by rotating the rotation axis of the main body driving unit 32B, thereby moving the support unit 31 in the vertical direction. The main body driving unit 32B is mounted on the main body 1A via the bracket 3A and the like. The main body driving unit 32B is controlled by the control device 9 (refer to Figure 1 )control.

[0045] The first arm 34 is composed of a parallel link and is supported by the right end of the support portion 31. The base end 34A of the first arm 34 on the support portion 31 side is rotatably connected to the support portion 31. A first pressure plate 38 is provided at the front end 34B of the first arm 34 on the opposite side to the base end 34A via a mounting member 34C. Fig. 9As shown in (A), a guide member 34D is provided on the upper portion of the mounting member 34C to allow the first pressing plate 38 to slide. The guide member 34D is a member extending in one direction. Fig. 9 (A) and Fig. 9 As shown in (C), even when the first arm 34 is rotated in the horizontal direction, the mounting member 34C connected to the front end portion 34B of the first arm 34 is configured to be rotatable through the parallel connecting rod of the first arm 34 to maintain the guide member 34D extending in the left-right direction.

[0046] return Figures 6 to 8 The second arm 35 is also composed of a parallel link like the first arm 34, and is supported at the left end of the support portion 31. The base end 35A of the second arm 35 on the support portion 31 side is rotatably connected to the support portion 31. A second pressure plate 39 is provided at the front end 35B of the second arm 35 on the opposite side of the base end 35A via a mounting component 35C. Similar to the first arm 34, a guide component 35D is provided on the upper part of the mounting component 35C to enable the second pressure plate 39 to slidably move. The guide component 35D is a component extending in one direction. Even when the second arm 35 is rotated in the horizontal direction, the mounting component 35C connected to the front end 35B of the second arm 35 is provided to be rotatable through the parallel link of the second arm 35 to maintain the state in which the guide component 35D extends in the left-right direction.

[0047] In addition, the first arm 34 and the second arm 35 are provided with a moving mechanism 36 (described in detail later) for moving the first pressing plate 38 and the second pressing plate 39 to follow the first folding plate 26 and the second folding plate 27 moved to the starting position corresponding to the size of the object W. The second pressing plate 39 provided on the second arm 35 via the mounting member 35C becomes Fig. 9 The first pressing plate 38 provided on the first arm 34 via the mounting member 34C is in a state of being turned left and right as shown in (A). Fig. 9 (A)~ Fig. 9 (C) corresponds to a diagram of the second pressing plate 39 provided on the second arm 35 via the mounting member 35C.

[0048] Figure 7 and Figure 8 The moving mechanism 36 shown in the figure rotates with the base ends 34A and 35A of the first arm 34 and the second arm 35 as the base axis, so that the first pressing plate 38 installed at the front end 34B of the first arm 34 via the mounting member 34C and the second pressing plate 39 installed at the front end 35B of the second arm 35 via the mounting member 35C move closer to or away from each other in the left-right direction. The moving mechanism 36 has Figure 6 The illustrated rotation drive unit 36A, a plurality of pulleys 36B, and a timing belt 36C.

[0049] The moving mechanism 36 drives the synchronous belt 36C wound around the plurality of pulleys 36B by rotating the driving unit 36A to move the synchronous belt 36C so as to rotate the pulleys 36B, thereby causing the first arm 34 and the second arm 35 to move closer to or farther from each other in the horizontal direction in a synchronous state. Specifically, the moving mechanism 36 rotates the first arm 34 and the second arm 35 so as to move the first pressing plate 38 of the front end portion 34B of the first arm 34 to a position below the first folding plate 26 that has moved to the starting position, and moves the second pressing plate 39 of the front end portion 35B of the second arm 35 to a position below the second folding plate 27 that has moved to the starting position.

[0050] The first pressing plate 38 moved to the lower part of the first folding plate 26 is configured to be able to move in the same direction as the moving direction (left-right direction) of the first folding plate 26 while sandwiching the film F between the first folding plate 26. Specifically, the first pressing plate 38 moves to the right while sandwiching the film F between the first folding plate 26 (holding state), thereby pulling the film F to the right and tensioning (pre-stretching) the film F to the right. In addition, the second pressing plate 39 moved to the lower part of the second folding plate 27 moves to the left while sandwiching the film F between the second folding plate 27 (holding state), thereby pre-stretching the film F to the left.

[0051] like Fig. 9 (A) and Fig. 9 As shown in (B), the first pressing plate 38 is provided to be movable along the guide member 34D. The first pressing plate 38 has Fig.13 The elastic member 38A shown in (A) applies force in the direction of returning to the original position (left side) when the elastic member 38A moves in the direction away from the second pressure plate 39 (right side).

[0052] The first pressing plate 38 is provided with a locking portion 26A (see Fig.13 The locked portion 38B of (A)). The locked portion 38B of the first pressing plate 38 that rises by the operation of the up-and-down moving mechanism 32 is located on the right side of the locking portion 26A of the first folding plate 26 in a state where the film F is sandwiched between the first folding plate 26 and the first folding plate 26. When the first folding plate 26 is moved to the right in this state, the locked portion 38B of the first pressing plate 38 is hooked on the locking portion 26A, thereby moving the first pressing plate 38 to the right. In addition, when the first pressing plate 38 is moved downward by the operation of the up-and-down moving mechanism 32, the locked portion 38B of the first folding plate 26 is separated from the locking portion 26A of the first folding plate 26, and thus the first pressing plate 38 is returned to the left end of the guide member 34D by the action of the elastic member 38A.

[0053] The second pressing plate 39 is raised together with the first pressing plate 38 by the operation of the vertical movement mechanism 32. Moreover, since the second pressing plate 39 is symmetrical with the first pressing plate 38, when the second folding plate 27 moves to the left side with the film F sandwiched between the second folding plate 27, the second pressing plate 39 moves to the left side as the second folding plate 27 moves to the left side. In addition, when the second pressing plate 39 is lowered together with the first pressing plate 38, the locking portion of the second pressing plate 39 is separated from the second folding plate 27 and returned to the left end of the guide member 34D by the force of the elastic member (not shown).

[0054] The sealing mechanism 8 heat-seals the film F folded by the folding mechanism 25 on the bottom surface of the object W. The sealing mechanism 8 includes a conveying roller and a heating roller, and heat-seals while conveying the object W pushed out by the discharge push rod 29A. The sealing mechanism 8 discharges the packaged object W toward the discharge table 82.

[0055] The label issuing machine LI has a sticking device that sticks the label printed by the label printer LP to the discharged packaged commodity. The label printer LP prints information related to the commodity on the label. The information related to the commodity is, for example, the commodity name and price.

[0056] The control device 9 is a computer disposed on the upper part of the main body 1A. Figure 5 As shown in FIG. 1 , the control device 9 controls the operation of each of the above mechanisms. The control device 9 has an input / output interface I / O for inputting and outputting signals with the outside, a ROM (Read Only Memory) storing programs and information for processing, a RAM (Random Access Memory) for temporarily storing data, a storage medium such as a HDD (Hard Disk Drive), a CPU (Central Processing Unit), and a communication circuit, etc. The control device 9 stores input data in the RAM according to the signal output by the CPU, loads the program stored in the ROM into the RAM, and executes the program loaded into the RAM, thereby realizing each function.

[0057] The control device 9 is connected to the display panel 16 and the operation unit 17. The display panel 16 is, for example, a touch panel display, and operation buttons are also displayed on the display. In the operation unit 17, the user performs various operations and inputs. The control device 9 refers to various data in the storage unit 9A, and calculates the price of the object W based on the weight and / or pallet size of the object W measured by the measuring and carrying mechanism 2. The control device 9 controls the operation of the label printer LP and the label issuing machine LI, and prints the weight or price of the object W on the label.

[0058] The control device 9 of this embodiment moves the second feeder unit 62 of a pair of feeder units (the first feeder unit 61 and the second feeder unit 62) in a direction away from the first feeder unit 61 (in the depth direction) before the film F is lifted by the object W. Thus, the film F arranged above the packaging area A is pre-stretched in the width direction. In addition, the control device 9 of this embodiment moves the first folding plate 26 and the second folding plate 27, and the first pressing plate 38 and the second pressing plate 39 to a position (starting position) corresponding to the size of the object W before the film F is lifted by the object W. Then, the first folding plate 26 and the second folding plate 27 are moved in a direction in which the relative distance between each other is separated while the first pressing plate 38 and the second pressing plate 39 are pressed by the first pressing plate 38 and the second pressing plate 39 by raising the first pressing plate 38 and the second pressing plate 39. Thus, the film F arranged above the packaging area A is pre-stretched in the conveying direction. The control device 9 causes the object W to lift up the film F pre-stretched in both the width direction and the conveying direction. That is, the control device 9 controls the lifting mechanism 20 to move the object W upward.

[0059] In addition, in the present embodiment, the left and right first folding plates 26 and the second folding plates 27 are separated from each other in the conveying direction of the film F while the ends of the film F are clamped respectively between the first folding plate 26 and the first pressing plate 38 and between the second folding plate 27 and the second pressing plate 39, thereby pre-stretching the film F in the conveying direction. However, this structure may be replaced by the following structure: a first clamp 40A and a second clamp 40B are provided to hold the ends of the film F from above and below, and the first clamp 40A and the second clamp 40B are separated from each other in the left and right directions by the above-mentioned moving mechanism 36, thereby pre-stretching the film F in the conveying direction.

[0060] Next, in the stretch packaging device 1 thus constructed, the main Figures 10 to 12 The operation of packaging the object W by pre-stretching the film F in both the width direction and the conveyance direction will be described.

[0061] When the object W is packaged with a film F, the film F is conveyed to the upper side of the packaging area A by the film conveying mechanism 6, and the upstream side of the film F in the conveying direction is cut by the cutting mechanism 7, thereby Fig.10 As shown in (1), the film F is covered on the object W. In this state, the second feeder unit 62 clamping the film F on one side in the width direction of the film F moves backward. Thus, the pre-stretching of the film F in the width direction is completed.

[0062] Then, if Fig.13 As shown in (A), the first pressing plate 38 and the second pressing plate 39 rise, as shown in Fig.10 (2) and Fig.13 As shown in (B), the film F is pressed against the lower surfaces of the first folding plate 26 and the second folding plate 27. As a result, the right end of the film F in the conveying direction is clamped by the first folding plate 26 and the first pressing plate 38, and the left end of the film F in the conveying direction is clamped by the second folding plate 27 and the second pressing plate 39.

[0063] exist Fig.10 In the state shown in (2), the first folding plate 26 is moved to the right, and the second folding plate 27 is moved to the left. Fig.13 As shown in (C), the first pressing plate 38 having the locked portion 38B hooked on the locking portion 26A of the first folding plate 26 moves to the right as the first folding plate 26 moves. In addition, the second pressing plate 39 having the locked portion 39B hooked on the locking portion 27A of the second folding plate 27 also moves to the left as the second folding plate 27 moves. Fig.11 As shown in (3), the two ends of the film F in the conveying direction are pulled toward each other, thereby completing the pre-stretching of the film F in the conveying direction.

[0064] Next, the object W is pushed against the pre-stretched film F in the width direction and the conveying direction of the film F, and the film F is lifted upward. Fig.11 (4) Fig.13 (D) and Fig.13 As shown in (E), the first pressing plate 38 and the second pressing plate 39 still press the film F against the lower surface of the first folding plate 26 and the lower surface of the second folding plate 27. That is, the position of the peripheral edge of the film F is still fixed.

[0065] Next, at an appropriate time after the object W reaches the uppermost position, the first feeder unit 61, the first pressing plate 38, and the second pressing plate 39 release the clamping of the peripheral edge of the film F. Specifically, in the first feeder unit 61, the gap between the pair of clamping parts 61B and 61C is widened to release the clamping of the film F. Fig.13 As shown in (F), the support portion 31 moves downward to expand the gap between the first pressing plate 38 and the first folding plate 26 and the gap between the second pressing plate 39 and the second folding plate 27, thereby releasing the clamping of the film F. At this time, the first pressing plate 38 and the second pressing plate 39 return to the original position due to the action of their respective elastic members 38A. Fig.10 The starting position shown in (1).

[0066] Then, if Fig.12As shown in (5) in FIG. 1 , the first folding plate 26 moves to the left, and the second folding plate 27 moves to the right, so that the peripheral edge of the film F in the conveying direction is folded into the bottom side of the object W. Next, as shown in FIG. Fig.12 As shown in (6) in FIG. 1 , the third folding plate 28 moves forward to fold the peripheral edge of the film F in the width direction into the bottom surface of the object W. Finally, the ejection push rod 29A moves forward to push the object W toward the sealing mechanism 8. At this time, the film F on the front side of the object W is folded into the bottom surface of the object W. Thus, the packaging of the object W with the film F is completed.

[0067] The effects of the stretch packaging device 1 of the above embodiment will be described. In the stretch packaging device 1 of the above embodiment, the film F in a state stretched in the conveying direction of the film F (in a state after pre-stretching) is lifted up by the object W. Thus, since the film F is packaged in a state stretched in the conveying direction, the length of the film F used can be shortened compared to when the film F is packaged in a state not stretched in the conveying direction. That is, in this configuration, the length of the film F used can be shortened and packaging with few wrinkles can be performed.

[0068] In the stretch packaging device 1 of the above-mentioned embodiment, the moving mechanism for moving the first pressing plate 38 and the second pressing plate 39 is configured such that the first pressing plate 38 and the second pressing plate 39 move along with the movement of the first folding plate 26 and the second folding plate 27. Thus, both ends of the film F in the conveying direction can be pulled, and the film F can be easily stretched in the conveying direction.

[0069] In the stretch packaging device 1 of the above embodiment, the first pressing plate 38 is pressed against the first folding plate 26 at one end of the film F, and the second pressing plate 39 is pressed against the second folding plate 27 at the other end of the film F. When the first folding plate 26 and the second folding plate 27 move, the first pressing plate 38 and the second pressing plate 39 also follow the movement. In the above embodiment, the existing movement structure of the first folding plate 26 and the second folding plate 27 that fold the two ends of the film F in the conveying direction into the bottom surface side of the object W by approaching or moving away in the conveying direction of the film F can be utilized. Thus, it is not necessary to embed a separate moving mechanism that moves a pair of clamps holding the film F closer or farther in the conveying direction of the film F, and the clamps holding the film F can be constructed inexpensively. In addition, by only pressing the two ends of the film F in the conveying direction against the left and right first folding plates 26 and the second folding plates 27 by using the left and right first pressing plates 38 and the second pressing plates 39, respectively, the pair of first pressing plates 38 and the second pressing plates 39 can be moved along with the movement of the pair of first folding plates 26 and the second folding plates 27. Thus, there is no need to realize synchronous control of the movement, and the structure and control can be simplified.

[0070] In addition, in this embodiment, the first pressure plate 38 and the second pressure plate 39 are moved up and down by the up and down moving mechanism 32, but it can also be configured as follows: the first plate and the second plate that move up and down by the solenoid are arranged on the upper part of each of the first pressure plate 38 and the second pressure plate 39, and the end portions of the film F are respectively held between the first plate and the first pressure plate 38 and between the second plate and the second pressure plate 39.

[0071] In the stretch packaging device 1 of the above-described embodiment, the control device 9 moves the second feeder unit 62 in a direction of relative distance from the first feeder unit 61 before the film F is lifted by the object W. Thus, since the film F that is pre-stretched in both the conveying direction of the film F and the width direction of the film F is lifted by the object W, packaging with fewer wrinkles can be achieved.

[0072] Although one embodiment has been described above, one aspect of the present invention is not limited to the above embodiment and various modifications can be made without departing from the gist of the invention.

[0073] In the above embodiment, the stretch wrapping device 1 is described as an example which has a metering function and a value assigning function by attaching a label in addition to the film wrapping function. However, the stretch wrapping device 1 may be configured without at least one of the metering function and the value assigning function.

[0074] In the above-mentioned embodiment and the above-mentioned modification example, an example is given in which the first pressure plate 38 and the second pressure plate 39 are configured so that the relative distance between each other can be brought closer or farther away by moving the moving mechanism 36, but it can also be configured so that the relative distance between each other can be brought closer or farther away by moving only one of the first pressure plate 38 and the second pressure plate 39.

[0075] In the above-mentioned embodiment and the above-mentioned modification example, an example is given in which the relative distance between the first feeder unit 61 and the second feeder unit 62 can be brought closer or farther only by moving the second feeder unit 62, but it can also be configured so that the relative distance between them can be brought closer or farther by moving both the first feeder unit 61 and the second feeder unit 62.

[0076] In the above-mentioned embodiment and the above-mentioned modification, the first pressing plate 38 and the second pressing plate 39 are configured to move in accordance with the movement of the first folding plate 26 and the second folding plate 27, but the present invention is not limited thereto. For example, the first pressing plate 38 and the second pressing plate 39 may be driven and controlled in such a manner that the first pressing plate 38 and the second pressing plate 39 move away from each other in the left-right direction by the moving mechanism 36 that moves the first pressing plate 38 and the second pressing plate 39 closer to or farther from each other, so as to pre-stretch the film F in the conveying direction. In this case, the control device 9 only needs to control the first folding plate 26 and the first pressing plate 38 to move synchronously, and the second folding plate 27 and the second pressing plate 39 to move synchronously.

Claims

1. A stretch packaging device, comprising: A film conveying unit, clamping both sides of the film in a width direction perpendicular to the conveying direction, and conveying the film to a packaging area; a lifting part that pushes the product from below the film conveyed to the packaging area against the film and moves upward to lift the film; a pair of folding plates for folding the peripheral edge of the film lifted by the lifting portion into the bottom side of the product; a pair of clamps, respectively holding both ends of the film in the conveying direction below the pair of folding plates; a moving mechanism to move the pair of clamps; and a control unit, controlling the movement of the moving mechanism, The control unit controls the moving mechanism to move at least one of the pair of clamps in a direction in which the relative distance between the pair of clamps is separated from each other, thereby pre-stretching the film in a conveyance direction of the film.

2. The stretch packaging device according to claim 1, in, The pair of clamps is composed of the pair of folding plates and a pair of pressing plates, and the pair of pressing plates presses the film onto each of the pair of folding plates from below. The moving mechanism is configured to move the pressing plate as the folding plate moves. The control unit moves at least one of the folding plates in a state where both end portions of the film in the conveying direction are pressed against the folding plates by the pair of pressing plates, in a direction in which the relative distance between the plates is separated from each other.

3. The stretch packaging device according to claim 1 or 2, in, The film conveying section is configured to include a pair of clamping units arranged opposite to each other in the width direction. The control unit moves at least one of the pair of clamping units in a direction to separate from each other relative to each other before the film is lifted up by the product.

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