Box unpacking device and box unpacking method

Abstract

To provide a box unpacking device and a box unpacking method capable of automating at least a part of a box unpacking work of peeling off an adhesive part made of a hot-melt adhesive to open a flap.SOLUTION: A box unpacking device 11 unpacks a box 13 in which a flap of the box 13 is fixed in a closed state by an adhesive part made of a hardened hot-melt adhesive.The box unpacking device 11 includes a heating part 31, a moving mechanism 33, and a control part. A heating part 31 heats a heated surface HP which is a surface opposite to the adhesive part of the flap in the closed state. The moving mechanism 33 moves at least one of the heating part 31 and the box 13, and positions the heating part 31 and the box 13 so as to have a relative positional relation during heating. The control part controls the heating part 31 and the moving mechanism 33. The control part controls the moving mechanism 33 to place the heating part 31 at a heating position with respect to the box 13, and controls the heating part 31 so that the heating part 31 placed at the heating position heats the heated surface HP.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a box unpacking device and a box unpacking method for unpacking a box in which flaps constituting the box are fixed in a closed state by adhesive portions made of hardened hot melt adhesive. [Background technology]

[0002] A conventional box unpacking device of this type is known that cuts tape attached to the box to open the flap. In this unpacking device, a cutter cuts the tape attached to the periphery of the flap to open the flap and open the box.

[0003] On the other hand, when opening a box in which the flaps are secured in a closed state by adhesive joints made of hardened hot melt adhesive, it is difficult to cut the adhesive joints with a cutter. For this reason, workers have traditionally used tools such as scrapers to manually peel the adhesive joints of the flaps and open the box. In this case, it is necessary to insert a tool such as a scraper into the gap between the outer and inner flaps to peel the adhesive joints.

[0004] For example, Patent Document 1 discloses a box with flaps attached with hot melt adhesive that ensures reliable sealing and ease of opening. Because the box is configured so that a release varnish is applied in a predetermined varnish pattern at regular intervals, and then the hot melt adhesive is applied, the hot melt adhesive can be peeled off with little force when the box is opened. However, this requires an extra step of applying the release varnish, and requires special equipment to apply the release varnish in the pattern at regular intervals. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-85751 Summary of the Invention [Problem to be solved by the invention]

[0006] However, because manual flap peeling requires time and labor, it is desirable to automate the flap peeling process. However, automating the peeling process requires the mechanization of the action of inserting a tool such as a scraper into the gap between two overlapping flaps and sliding it (peeling action). This requires high accuracy in detecting the gap in the flaps, which is the insertion position for the scraper or other tool, and high accuracy in inserting the scraper into the detected gap. For this reason, it has been difficult to automate the box unpacking process, including the peeling action of peeling off hot-melt adhesive.

[0007] In the case of an automated machine for peeling off hot melt adhesive parts coated with release varnish as described in Patent Document 1, it may be possible to open the flap by forcibly pulling it with a suction pad or the like. However, when opening a box that is bonded with a general-purpose hot melt adhesive part that is not coated with release varnish, the work of peeling off the adhesive part of the flap has to be done manually by a worker, as mentioned above. [Means for solving the problem]

[0008] The means for solving the above problems and their effects will be described below. A box unpacking device that solves the above problem is a box unpacking device that unpacks a box in which flaps that make up the box are fixed in a closed state via an adhesive joint made of hardened hot melt adhesive, and is equipped with a heating unit that can heat the heated surface, which is the surface of the flap opposite the adhesive joint when the flap is in the closed state, a moving mechanism that positions the heating unit and the box so that they are in a relative positional relationship during heating by moving at least one of the heating unit and the box so that the heating unit is positioned at a heating position relative to the box where it can heat the heated surface, and a control unit that controls the heating unit and the moving mechanism, and the control unit controls the moving mechanism to position the heating unit at the heating position relative to the box, and controls the heating unit so that the heating unit positioned at the heating position heats the heated surface.

[0009] According to this configuration, at least one of the heating unit and the box is moved by a movement mechanism, thereby positioning the heating unit at a heating position relative to the box. The heating unit positioned at the heating position heats the heated surface of the flap. This heating heats the adhesive portion located on the surface of the flap opposite the heated surface. The heated adhesive portion melts, or at least a portion of the adhesive melts and carbonizes, reducing its adhesive strength. As a result, when opening the flap, the adhesive portion becomes easier to peel compared to before heating. Therefore, the adhesive portion made of hot melt adhesive can be peeled with a relatively small force, making it possible to automate at least a portion of the box unpacking process by opening the flap. The heating position may be a position where the heating unit contacts the heated surface of the flap, or a position where the heating unit is separated from the heated surface of the flap.

[0010] In the above-mentioned box unpacking device, the heating unit may have a heater and a metal pressing member heated by the heater, and the moving mechanism may be configured to be able to position the heating unit at a pressing position where the pressing member presses the heated surface of the flap and a retracted position where the pressing member is moved away from the heated surface by moving at least one of the heating unit and the box.

[0011] According to this configuration, the heating unit heats the heated surface of the flap while pressing it with a metal pressing member. Therefore, the heating unit can heat the heated surface while in close contact with the heated surface at a predetermined pressure. As a result, the adhesive portion located on the surface opposite the heated surface can be heated more efficiently, melting it or promoting partial carbonization in addition to melting it. Furthermore, because the heating unit directly heats the heated surface of the box, the adhesive portion located on the opposite side of the heated surface can be heated more efficiently than in a configuration in which the heated surface is heated from a position away from the heated surface using a heating method such as hot air or heat radiation. Therefore, after heating, the adhesive portion can be peeled off simply by pulling the flap with a relatively small force, thereby reducing errors in opening the box.

[0012] In the above-mentioned box unpacking device, the heated area, which is the area of the heated surface that comes into contact with the heating surface of the heating unit, is divided into multiple divided areas, and the heating unit may be provided in multiple areas on one heated surface so that each of the multiple divided areas can be heated individually, and may have multiple swivel mechanisms that individually change the posture of the multiple heating units so that the heating surface follows the heated surface.

[0013] With this configuration, even when the multiple heating units contact the multiple flaps that form the heated surface across the heating unit, the heating units each individually change their position so that the heating unit conforms to the heated surface. Therefore, even if the heated surface of the box is curved, the multiple heating units can contact the multiple flaps over as wide a contact area as possible. Therefore, regardless of whether the heated surface of the box is curved, the adhesive areas located on the back (inner side) of the flaps can be efficiently heated through the wide contact area with the flaps. This reduces opening errors caused by inability to peel the adhesive areas due to uneven heating of the adhesive areas caused by uneven contact areas between the heating units and the flaps.

[0014] In the box unpacking device, the heating temperature at which the heating section heats the heated surface may be a predetermined temperature within a range of 300 to 350°C. According to this configuration, the heating unit heats the heated surface to a predetermined temperature within the range of 300 to 350°C. Here, at heating temperatures below 300°C, the heating time required to reduce the contact force of the adhesive bond to a level that allows easy peeling is long, reducing the efficiency of the unpacking process. On the other hand, heating times exceeding 350°C raise concerns about thermal damage to the heated surface of the box (e.g., cardboard) (e.g., carbonization in the case of paper, thermal deformation in the case of synthetic resin, etc.) and thermal effects on the contents of the box. Therefore, the heating temperature is preferably 300°C or higher and 350°C or lower. Note that, if the heating time is extended between 300°C and 350°C, the hot melt adhesive constituting the adhesive bond not only melts but also partially carbonizes. In this case, even if the hot melt adhesive re-adheres after melting due to heating, its adhesive strength is significantly lower than before heating. Therefore, the adhesive bond is easier to peel when opening the flap after heating. Furthermore, if the adhesive portion is a reactive hot melt adhesive that does not melt when heated after curing, the adhesive portion does not remelt even when heated, so the adhesive strength of the hot melt adhesive (adhesive portion) is unlikely to decrease. However, if the heating temperature is within the range of 300 to 350°C, the adhesive portion made of the reactive hot melt adhesive will partially carbonize, significantly reducing the adhesive strength of the adhesive portion. Therefore, the adhesive portion can be peeled off with a relatively small force when opening the flap. In this way, by setting the heating temperature to 300 to 350°C, the adhesive strength of the adhesive portion can be reduced to the required value for both hot melt adhesives that can be remelted by heating and reactive hot melt adhesives that cannot be remelted by heating.

[0015] The above-mentioned box unpacking device may be provided with a flap opening mechanism that opens the multiple flaps whose heated surface is heated by the heating unit, and a removal mechanism that removes the contents through an opening formed in the box by opening the multiple flaps.

[0016] With this configuration, the flap opening mechanism opens the multiple flaps to form an opening in the box, and the removal mechanism removes the contents from the opening in the box. This automates the unpacking process, from removing the contents from the box to removing the contents.

[0017] A method for unpacking a box that solves the above problem is a method for unpacking a box in which flaps that constitute the box are fixed in a closed state via an adhesive joint made of hardened hot melt adhesive, and includes a positioning step in which a control unit moves at least one of the heating unit and the box to position the heating unit and the box so that they are in a relative positional relationship when heated, and a heating step in which the control unit causes the positioned heating unit to heat the heated surface, which is the surface of the flap opposite the adhesive joint.

[0018] According to this method for opening a box, the adhesive portion made of hot melt adhesive can be peeled off with a relatively small force, so that at least a part of the box opening work, which involves opening the flap, can be automated. [Effects of the Invention]

[0019] According to the present invention, it is possible to automate at least part of the box opening process, which involves peeling off the adhesive portion made of hot melt adhesive and opening the flap. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic plan view illustrating a box unpacking system according to one embodiment. [Figure 2] FIG. [Figure 3] This is an exploded view of the box. [Figure 4] FIG. 10 is a front view showing a positioning device for positioning a box at a flap peeling position. [Figure 5] 5 is a rear view of the heating unit taken along line 5-5 in FIG. 6. FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] 10(a) and 10(b) are schematic side views showing an example of a suction opening mechanism of a flap opening mechanism. [Figure 9] 10(a) and 10(b) are plan views illustrating the operation of the flap opening mechanism. [Figure 10]10(a) and 10(b) are plan views illustrating the operation of the extrusion mechanism. [Figure 11] FIG. 2 is a block diagram showing the electrical configuration of the box unpacking system. [Figure 12] 10 is a flowchart showing a box unpacking control routine. [Figure 13] FIG. 10 is a schematic perspective view illustrating a moving process before heating in the box unpacking operation. [Figure 14] FIG. 10 is a schematic perspective view illustrating a heating step in the box unpacking operation. [Figure 15] FIG. 10 is a schematic perspective view illustrating a flap opening step in the box unpacking operation. [Figure 16] FIG. 10 is a schematic perspective view illustrating a removal step in the box unpacking operation. DETAILED DESCRIPTION OF THE INVENTION

[0021] An embodiment of a box unpacking device and a box unpacking method will be described below with reference to the drawings. In Fig. 1, two directions defining the floor surface on which the box unpacking device 11 is installed are the X direction and the Y direction, respectively, and a direction intersecting the X direction and the Y direction and parallel to the direction of gravity is the vertical direction Z. The conveying direction in which boxes 13 are conveyed in the box unpacking device 11 is parallel to the X direction, and is therefore referred to as the conveying direction X1. Furthermore, a direction perpendicular to the conveying direction X1 in a horizontal plane is referred to as the width direction Y.

[0022] <Configuration of Box Unpacking System 10> The box unpacking system 10 shown in Fig. 1 is a system for unpacking a box 13 packed with contents C (see Fig. 2). The box 13 packs the contents C by having flaps 15 (see Fig. 2) adhered in a closed state with adhesive portions 16 (see Fig. 2) made of hardened hot melt adhesive.

[0023] A plurality of boxes 13 are loaded onto a pallet (not shown) and delivered to a factory by a transport vehicle such as a truck. Conventionally, in factories, the boxes 13 are removed one by one from the pallet, and multiple workers use tools such as scrapers to peel off the adhesive 16 made of hot melt adhesive, thereby opening the boxes 13 and manually removing the contents C from the boxes 13. This manual work requires a considerable amount of manpower and time. For this reason, in this embodiment, a box unpacking system 10 shown in FIG. 1 is introduced to automate the unpacking work of the boxes 13.

[0024] 1, the box unpacking system 10 includes a conveyor 20, a box unpacking device 11 as an example of a box unpacking device, and a packaging material disposal section 60 that discards the empty boxes 13 after the contents C have been removed from the boxes 13 opened by the box unpacking device 11. The conveyor 20 includes a first conveyor 21 that transports the boxes 13, and a second conveyor 22 that carries out the contents C removed from the boxes 13 opened by the box unpacking device 11.

[0025] The box unpacking device 11 sequentially performs unpacking work on boxes 13 transported by a first conveyor 21 at a plurality of positions P1 to P3. Specifically, the box unpacking device 11 includes a heating mechanism 30, a flap opening mechanism 40, and a removal mechanism 50. The first conveyor 21 is provided with positioning devices 23, 24, and 25 for positioning the boxes 13 at a plurality of positions P1 to P3 on the first conveyor 21. That is, the positioning device 23 positions the box 13 at a heated position P1, where the box 13 is heated by the heating mechanism 30. The positioning device 24 positions the box 13 at a flap open position P2, where the flap opening mechanism 40 performs a flap opening operation. The positioning device 25 positions the box 13 at a removal position P3, where the contents C are removed from the box 13 by the removal mechanism 50.

[0026] 1, the heating mechanism 30 includes a heating unit 31 and a cylinder 32 that reciprocates the heating unit 31. The heating mechanism 30 includes a movable heating unit 31 at a position facing the end face of the box 13 positioned at the heated position P1. The end face of the box 13 heated by the pair of heating units 31 is formed by the outer surfaces of the flaps 15 (see FIG. 2) to be opened. In other words, the pair of heating units 31 heat the outer surfaces of the flaps 15 of the box 13.

[0027] Two heating mechanisms 30 are provided, one on each side of the transport path of the boxes 13 transported on the first conveyor 21 in the width direction Y. The two heating mechanisms 30 simultaneously heat both end faces of the boxes 13 in the width direction Y using their respective heating sections 31. The detailed configuration of the heating mechanisms 30 will be described later.

[0028] 1, the flap opening mechanism 40 includes a cylinder 41 and a suction opening mechanism 42 that performs the flap opening operation. The cylinder 41 is driven to extend and retract, causing the suction opening mechanism 42 to move between a working position when performing the opening operation and a standby position when not performing the opening operation. The detailed configuration of the suction opening mechanism 42 will be described later.

[0029] As shown in FIG. 1 , the take-out mechanism 50 takes out the contents C from the opened box 13 at the take-out position P3. The take-out mechanism 50 includes a cylinder 51 and a pusher 52. The cylinder 51 extends and retracts, causing the pusher 52 to move between a retracted position shown in FIG. 1 and a push-out position, which is the stroke end when pushing the contents C out of the box 13. In this embodiment, the take-out method is such that the pusher 52 pushes the contents C out of the box 13. Therefore, the flap-opening mechanism 40 opens both flaps 15 located on both end faces of the box 13. The flap-opening mechanism 40 transports the box 13 with both flaps 15 on both sides of the width direction Y of the box 13 opened to the take-out position P3. The take-out mechanism 50 pushes out the contents C from the box 13 by reciprocating the pusher 52 in the width direction Y using the cylinder 51. In this manner, the contents C are pushed out onto the second conveyor 22.

[0030] The second conveyor 22 carries out the contents C removed from the boxes 13 by the box unpacking device 11. The second conveyor 22 is connected to the first conveyor 21 at the removal position P3, and transports the contents C removed by the removal mechanism 50 to the destination. Note that the conveyors 20 (21, 22) are not limited to roller conveyors having rollers 21A, 22A, and may be, for example, belt conveyors or mesh conveyors.

[0031] On the other hand, the empty boxes 13 (packaging material) after the contents C have been removed are transported by the first conveyor 21 to the packaging material disposal section 60. The packaging material disposal section 60 crushes the empty boxes 13 using a pusher or the like (not shown). The crushed packaging material is stacked in multiple pieces and then collected in a container or the like.

[0032] <Box 13 Configuration> Next, the configuration of the box 13 will be described with reference to FIG. 2. As shown in FIG. 2, the box 13 has a rectangular parallelepiped shape. The box 13 has a rectangular tubular box body 14 and four flaps 15 (eight in total) extending from the opening edges on each side of the box body 14 to close the openings on both sides. The four flaps 15 include two inner flaps 15A and two outer flaps 15B. That is, the box 13 has two inner flaps 15A and two outer flaps 15B on each side of the rectangular tubular box body 14. For example, in a wrap-around type, the box body 14 is formed into a rectangular tubular shape by bonding connecting portions 14A located at the circumferential ends with adhesive portions 17 made of hot-melt adhesive. The four flaps 15 extending on each side of the box body 14 that encases the contents C are folded and bonded with adhesive portions 16 made of hot-melt adhesive.

[0033] <Expansion diagram of Box 13> Fig. 3 is an exploded view of box 13. As shown in Fig. 3, the cardboard sheet from which box 13 is exploded has a rectangular plate-shaped portion formed by expanding box body 14, and four flaps 15A, 15B extending from either side of box body 14, two on each side. Box body 14 has connecting margins 14A at its ends.

[0034] In a manufacturing plant where the contents C are produced, the contents C are packed into a box 13, for example, using a wrap-around caser. First, the contents C are placed on the box body 14 portion of the cardboard sheet shown in FIG. 3 . Next, the contents C are wrapped in the box body 14, and the connecting portions 14A at the ends of the box body 14 are adhered with adhesive portions 17 made of heat-melted liquid hot-melt adhesive. As a result, the contents C are wrapped in the rectangular tubular box body 14. Furthermore, of the four flaps 15 extending from both sides of the box body 14 that encase the contents C, two inner flaps 15A are folded in, and liquid hot-melt adhesive is applied to the surfaces of the inner flaps 15A. Next, the outer flaps 15B are folded in over the inner flaps 15A, and the inner flaps 15A and outer flaps 15B are adhered to each other with the hot-melt adhesive interposed therebetween. In this way, the contents C are packed into the box 13. The method of packing the boxes 13 to be opened is not limited to the wrap-around method, but may be other methods such as using a set-up caser.

[0035] <Positioning device 23> Next, the positioning device 23 will be described with reference to Fig. 4. Since the three positioning devices 23 to 25 (see Fig. 1) have almost the same basic configuration, the following describes the positioning device 23 that positions the box 13 at the heated position P1.

[0036] As shown in Figure 4, the positioning device 23 includes a cylinder 26 disposed below the first conveyor 21 and a stopper 27 fixed to the tip of the piston rod of the cylinder 26. When the cylinder 26 is in a retracted state, the stopper 27 is disposed in a retracted position below the first conveyor 21. When the cylinder 26 is extended from the retracted state, the stopper 27 passes through the gap between the rollers 21A of the first conveyor 21 and is disposed in a restricting position where it protrudes above the conveying surface of the first conveyor 21. When the box 13 comes into contact with the stopper 27 in the restricting position, further movement in the conveying direction X1 is restricted, and the box 13 is positioned at the heated position P1.

[0037] 1 have basically the same configuration as the positioning device 23. That is, the positioning devices 24 and 25, like the positioning device 23, are equipped with a cylinder 26 and a stopper 27. Therefore, the stopper 27 of the positioning device 24 positions the box 13 at the flap open position P2. Furthermore, the stopper 27 of the positioning device 25 positions the box 13 at the removal position P3. Note that the positioning devices 23 to 25 may be configured, for example, as a horizontal movement type in which the stopper 27 advances and retreats in the width direction Y, or as a rotation type in which the stopper 27 rotates between a restricting position and a retracted position.

[0038] As shown in Fig. 4, the pair of heating mechanisms 30 are arranged on both sides of the heated position P1 on the first conveyor 21 in the width direction Y. The heating mechanism 30 has a heating unit 31 and a cylinder 32 that moves the heating unit 31. When the pair of cylinders 32 are extended, the pair of heating units 31 are positioned at the heating positions indicated by the two-dot chain lines in Fig. 4, and heat the heated surfaces HP of the box 13 while in contact with the two heated surfaces HP located on both sides in the width direction Y.

[0039] <Configuration of heating mechanism 30> Next, the configuration of the heating mechanism 30 will be described with reference to FIG. 6. As shown in FIG. 6, a pair of heating mechanisms 30 are provided facing each other on both sides of the conveying path of the first conveyor 21. Since the pair of heating mechanisms 30 has the same configuration, only one of the heating mechanisms 30 will be described below. The heating mechanism 30 includes four heating sections 31 (only two are shown in FIG. 6) and two cylinders 32 that move the four heating sections 31 toward or away from the heated surface HP of the box 13 at the heated position P1 (in the width direction Y). The heating sections 31 are supported by the tip of the piston rod 32A of the cylinder 32 via a swing mechanism 35 so that their position can be changed. One of the four heating sections 31 includes a temperature sensor 34 that can detect the heating temperature of the heating section 31. The temperature sensor 34 outputs a temperature detection signal that detects the heating temperature of the heating section 31 to the control section 70 (see FIG. 11).

[0040] The heating mechanism 30 of this example includes a moving mechanism 33 that moves at least one of the box 13 and the heating unit 31 to position the box 13 and the heating unit 31 relative to each other during heating (the positional relationship indicated by the solid line in FIG. 6). In this embodiment, the moving mechanism 33 is composed of a cylinder 32, which is a driving source that moves the heating unit 31 from a retracted position indicated by the two-dot chain line in FIG. 6 to a heating position indicated by the solid line in FIG. 6, with respect to the box 13 positioned at the heated position P1. In other words, the cylinder 32 moves the heating unit 31, which is in the retracted position, to a heating position where it contacts the heated surface HP of the box 13. Note that the moving mechanism 33 may also include a conveying function of the first conveyor 21 that moves the box 13 to the heated position P1 in the conveying direction X1.

[0041] The heating unit 31 waits in a retracted position indicated by a two-dot chain line in FIG. 6. When the box 13 hits the stopper 27 and is positioned at the heated position P1, the first conveyor 21 is stopped. A box detection sensor (not shown) that detects when the box 13 approaches a predetermined position relative to the heated position P1 and a first sensor 76 (see FIG. 11) that detects when the box 13 reaches the heated position P1 are provided on the side of the first conveyor 21. When the box detection sensor detects the box 13, the cylinder 26 of the positioning device 23 is extended, thereby moving the stopper 27 from the retracted position to the regulating position. Then, when the first sensor 76 detects that the box 13 has reached the heated position P1, the cylinder 32 of the heating mechanism 30 is extended, thereby moving the heating unit 31 to the heating position indicated by a solid line in FIG. 6. Thus, the box 13 and the heating unit 31 are positioned to satisfy the relative positional relationship during heating shown in FIG. 6. In this example, the relative positional relationship during heating is a positional relationship in which the heating portion 31 can come into contact with the heated surface HP of the box 13.

[0042] <Configuration of heating unit 31> Next, the detailed configuration of the heating unit 31 will be described with reference to FIGS. 5 and 7. As shown in FIG. 5, N heating units 31 are provided so as to individually heat each of N divided regions obtained by dividing a heated region of one heated surface HP of the box 13. Here, the heated region refers to the region of the heated surface HP that is the target region for heating by the heating unit 31, and is the region that includes all of the adhesive portions 16 when the heated surface HP is viewed perpendicularly. The heating unit 31 heats the heated region of the heated surface HP in a contact state, thereby heating the multiple adhesive portions 16 located on the inner side of the flap 15 that contacts the outer surface. In this embodiment, N=4, and four heating units 31 are provided for one heated surface HP. The four heating units 31 have basically the same configuration, except that one of them has a temperature sensor 34.

[0043] As shown in Fig. 5, the heating section 31 is divided into four sections by dividing it into two sections each on the top, bottom, left, and right sides of the heated surface HP (i.e., in two directions, the conveying direction X and the vertical direction Z). In the example of Fig. 5, the two heating sections 31 arranged side by side (in the conveying direction X) heat the left and right regions of the outer surface of the same flap 15, respectively. In addition, the two heating sections 31 arranged side by side (in the vertical direction Z) straddle different flaps 15 and heat heated regions on the outer surfaces of different flaps 15, respectively.

[0044] 5 shows an example in which two outer flaps 15B forming one heated surface HP are arranged vertically, so the upper and lower heating sections 31 straddle the two outer flaps 15B and heat the heated area. On the other hand, in an example in which two outer flaps 15B are arranged horizontally, the left and right heating sections 31 straddle the two outer flaps 15B and heat the heated area. In either case, the pair of heating sections 31 that straddle and contact the two outer flaps 15B can individually change their position so as to follow the outer surfaces of the outer flaps 15B.

[0045] In FIG. 5, a pair of upper and lower heating units 31 are driven by a single cylinder 32 (see FIG. 6). Specifically, the two heating units 31 are individually supported at the tip of the piston rod 32A of the cylinder 32 via a swing mechanism 35. The swing mechanism 35 is composed of a universal connector 36 that connects the two heating units 31 to allow for changes in posture within a predetermined angular range, and multiple (e.g., four) elastic members 37 arranged around the universal connector 36. The universal connector 36 is, for example, a floating joint, but may also be a cross joint, universal joint, or the like. The elastic members 37 are, for example, composed of a spring such as a coil spring. The spring may also be a leaf spring, a torsion coil spring, or the like. The elastic members 37 may also be made of an elastic material such as rubber. As shown in FIG. 5, a pair of electrodes 39A is provided at the rear end of the heating unit 31, and is connected to wiring that supplies current to a heater 39 (see FIG. 7).

[0046] In this way, the heating units 31 can individually change their posture to follow the heated surface HP of the box 13 via the swing mechanism 35. Therefore, even if the heated surface HP of the box 13 is curved so as to bulge outward, the heating units 31 can individually change their posture to follow the curved surface. This makes it possible to ensure a wide contact area between the heating units 31 and the heated surface HP.

[0047] As shown in Fig. 7, the oscillating mechanism 35 is supported via a connecting part 32C to a support part 32B fixed to the tip of the piston rod 32A of the cylinder 32. The heating part 31 is supported via the oscillating mechanism 35 to the support part 32B. As described above, the oscillating mechanism 35 has a universal connecting part 36 arranged at the center of the back surface of the heating part 31, and four elastic members 37 (only two are shown in Fig. 7) arranged at four locations around the universal connecting part 36.

[0048] The heating unit 31 includes a back plate 38A connected to the oscillating mechanism 35, a pressing member 38, and a heater 39 sandwiched between the back plate 38A and the pressing member 38. The pressing member 38 is made of metal and has high thermal conductivity for conducting heat from the heater 39. The back plate 38A is also made of a thermal insulating material. The temperature sensor 34 detects the heating temperature of the heating unit 31 with its detection unit 34A inserted between the pressing member 38 and the heater 39. Because the pressing member 38, made of a metal material, has extremely high thermal conductivity, the heating temperature detected by the temperature sensor 34 can be considered to be approximately the surface temperature of the heating surface 31A, which is the surface of the heating unit 31 that comes into contact with the heated surface HP.

[0049] The temperature sensor 34 is, for example, a thermocouple. The four heating units 31 described above have the same basic configuration, and the control circuits for the heaters 39 are common, and the current and time for each are common, so the temperatures during heating can be considered to be the same. Therefore, only one of the four heating units 31 is provided with a temperature sensor 34. The temperature sensor 34 may be capable of detecting temperatures with the required detection accuracy, for example, in a temperature range from room temperature to 400°C, particularly in a range from 250 to 350°C. The temperature sensor 34 may be installed in another position as long as it can detect the heating temperature of the heating unit 31. The temperature sensor 34 may also be a thermistor or other temperature detection type.

[0050] <Configuration of flap opening mechanism 40> Next, the configuration of the flap opening mechanism 40 will be described with reference to Figures 9(a) and (b). As shown in Figure 9(a), the flap opening mechanism 40 includes the aforementioned cylinder 41 and suction opening mechanism 42. The suction opening mechanism 42 is attached to the tip of the piston rod 41A of the cylinder 41. When the piston rod 41A of the cylinder 41 is extended from the retracted position indicated by the two-dot chain line in Figure 9(a), the suction pad 43 of the suction opening mechanism 42 adsorbs the flap 15 that forms the heated surface HP of the box 13. Next, the suction opening mechanism 42 performs an opening operation to open the flap 15 (outer flap 15B) adsorbed by the suction pad 43. As a result of the opening operation of the suction pad 43, the two outer flaps 15B are opened, as shown in Figure 9(b).

[0051] 9(b), the suction-opening mechanism 42 includes suction pads 48 that open the inner flaps 15A. After opening the outer flaps 15B with the suction pads 43, the suction-opening mechanism 42 sucks the two inner flaps 15A with the suction pads 48, respectively, and opens the two inner flaps 15A by causing the suction pads 48 to perform an opening operation. In this way, the flap-opening mechanism 40 opens the four flaps 15 on each side of the box 13, thereby forming two openings 13A on each side of the box 13.

[0052] <An example of the suction opening mechanism 42> Next, an example of the suction opening mechanism 42 will be described with reference to Figures 8(a) and (b). The example of the suction opening mechanism 42 shown in Figure 8(a) includes a cylinder 44 that is a drive source for opening the suction pads 43, a pair of opening / closing members 45 on which the suction pads 43 are supported, and a pair of rotating levers 46 that rotate the opening / closing members 45 around a rotating shaft 46A. The cylinder 44 is mounted on a support plate 47 fixed to the tip end of the piston rod 41A of the cylinder 41 so as to be rotatable around the base end of each. The piston rod 44A of the cylinder 44 is rotatably connected to one end of the rotating lever 46 on the rotating shaft 46A side and the other end on the opposite side.

[0053] As shown in FIGS. 8(a) and 9(a), when the cylinder 41 is extended, the pair of suction pads 43 come into contact with the outer surfaces of the pair of flaps 15 of the box 13 and suction-hold the pair of flaps 15. Next, as shown in FIG. 8(b), the cylinder 44 is extended while the suction pads 43 are suction-holding the flaps 15. This causes the pair of suction pads 43 to open via the rotation of the rotary lever 46, thereby opening the pair of flaps 15. The suction-opening mechanism 42 includes a similar mechanism (not shown) that causes the pair of suction pads 48 (see FIG. 9(b)) to perform an opening operation.

[0054] <Configuration of the removal mechanism 50> Next, the configuration of the ejection mechanism 50 will be described with reference to Figures 10(a) and (b). As shown in Figure 10(a), the ejection mechanism 50 includes the above-mentioned cylinder 51, pusher 52, multiple guide shafts 53, and multiple guide members 54. The pusher 52 is fixed to the tip of the piston rod 51A of the cylinder 51. The multiple guide shafts 53 are fixed to the pusher 52 in a state where they extend parallel to the piston rod 51A. The multiple guide members 54 are fixed in predetermined positions while being supported by brackets (not shown) fixed to the frame 12, and guide the multiple guide shafts 53.

[0055] As shown in FIG. 10(a), when the box 13 is in the removal position P3, the pusher 52, which is in the retracted position, faces the opening 13A of the box 13. When the piston rod 51A of the cylinder 51 is extended from the retracted position shown in FIG. 10(a), the pusher 52 pushes the contents C in the box 13 from one opening 13A in the removal direction Y1 (extrusion direction Y1), as shown in FIG. 10(b). As the pusher 52 continues to move a predetermined stroke, the contents C are pushed out from the other opening 13A of the box 13. The stroke of the pusher 52 is set to a value that allows the contents C to pass the tip of the flap 15 extending from the other opening 13A of the box 13. In addition, until the box 13 reaches the removal position P3 from the flap open position P2 and the push-out operation of the pusher 52 is completed, the four flaps 15 on each side of the box 13 are held in an open state by holding portions not shown.

[0056] <Electrical configuration of the box unpacking system> Next, the electrical configuration of the box unpacking system 10 will be described with reference to Fig. 11. The box unpacking system 10 is equipped with a control unit 70 that performs overall control thereof. The control unit 70 has, for example, a built-in computer (microprocessor). An operation panel 90 is electrically connected to the control unit 70. The operation panel 90 has an input unit 91 and a display unit 92. The operation panel 90 is used when an operator performs operations to input various setting data and give instructions to the box unpacking system 10, such as starting and stopping operation. Note that the operation panel 90 may be replaced by a personal computer connected to the control unit 70.

[0057] The control unit 70 is electrically connected to the first conveyor 21, the second conveyor 22, the positioning devices 23-25, the heating mechanism 30, the flap opening mechanism 40, the take-out mechanism 50, and the packaging material disposal unit 60. The control unit 70 is also electrically connected to three sensors 76-78 and a temperature sensor 34 that detect when a box 13 conveyed by the first conveyor 21 reaches each of positions P1-P3. The control unit 70 is also electrically connected to three sensors (not shown) whose detection positions are slightly upstream in the conveying direction X1 from the detection positions of the sensors 76-78. When these three sensors sequentially detect a box 13 before it reaches each of positions P1-P3, the control unit 70 drives the corresponding positioning device 23-25 to move the stopper 27 from the retracted position to the restricting position.

[0058] 11, when a first sensor 76 detects a box 13, the control unit 70 stops driving the first conveyor 21 and drives the heating mechanism 30, thereby heating the heated surface HP of the box 13 with the heating unit 31. When a second sensor 77 detects a box 13, the control unit 70 stops driving the first conveyor 21 and drives the flap-opening mechanism 40, thereby performing a flap-opening operation to open the flap 15 of the heated box 13. When a third sensor 78 detects a box 13, the control unit 70 stops driving the first conveyor 21 and drives the take-out mechanism 50, thereby performing a take-out operation to take out the contents C from the opened box 13. Note that when the control unit 70 detects with a sensor (not shown) that the empty box 13 has reached the disposal position after the take-out operation of the take-out mechanism 50, it drives the packaging material disposal unit 60 to crush and discard the empty box 13 (packaging).

[0059] 11 includes a heating control unit 71 that controls the heating unit 31, and a memory 72. More specifically, the heating control unit 71 is configured as software by a computer that executes a program PR stored in the memory 72. The heating control unit 71 includes a heating temperature control unit 81, a heating time control unit 82, and a pressure control unit 83.

[0060] The heating temperature control unit 81 controls the heating temperature of the heating unit 31. The worker can set the heating temperature of the heating unit 31 by operating the input unit 91. The worker operates the input unit 91 to select the heating temperature within the range of 300 to 350°C, for example.

[0061] The control unit 70 may also input box identification information. The box identification information includes information such as product number information of the product (contents C) and size information of the box 13. Based on the box identification information, the control unit 70 can identify information such as the size of the box 13, the product number of the contents C, and the weight of the box 13. The box identification information may be input by, for example, an operator operating the input unit 91. Alternatively, the control unit 70 may receive box identification information from another device, acquired from code information read from the box 13 when or after a device such as a palletizer (not shown) unpacks the boxes 13 from the pallet and transports them to a position upstream of the first conveyor 21. The control unit 70 may then set a heating temperature according to the box identification information.

[0062] Furthermore, the heating time control unit 82 controls the heating time of the heating unit 31. The control unit 70 is provided with a timer that measures the heating time. The control unit 70 measures the heating time, which is the time that the heating unit 31 is in contact with the heated surface HP, using the timer. The heating time may be set by an operator operating the input unit 91, or the control unit 70 may set the heating time according to the box identification information. In this embodiment, for example, a heating time within the range of 5 to 30 seconds is selected.

[0063] Furthermore, the pressure control unit 83 controls the pressure value when the heating unit 31 presses the heated surface HP. The pressure control unit 83 controls the pressure value when the heating unit 31 presses the box 13 by controlling the cylinder 32. The cylinder 32 is equipped with, for example, an electromagnetic pressure regulating valve (not shown) that controls air pressure. The control unit 70 controls the pressure value of the heating unit 31 by controlling the air pressure supplied to the cylinder 32 by adjusting the opening degree of the electromagnetic pressure regulating valve. The cylinder 32 may also be equipped with a pressure sensor that detects the pressure value of the heating unit 31. In this case, the control unit 70 may be configured to maintain the air pressure of the cylinder 32 at the value when the pressure value based on the pressure detection signal detected by the pressure sensor reaches a target value.

[0064] Here, the pressure value is set within the range of 10 to 30 kPa. The higher the pressure value, the more efficient the heat transfer from the heating unit 31 to the heated surface HP can be. However, if the pressure value exceeds 30 kPa, there is a risk of deformation of the box 13. For this reason, the pressure value is preferably 30 kPa or less. However, for boxes 13 that are unlikely to be deformed by pressure, the pressure value may exceed 30 kPa.

[0065] Furthermore, if the heated surface HP is curved, a pressure value of less than 10 kPa is likely to cause a gap between the heating unit 31 and the heated surface HP, which may reduce the contact area between them. Therefore, the pressure value should be 10 kPa or more. Note that for boxes 13 where a contact area can be easily secured even with a small pressure value, the pressure value may be less than 10 kPa.

[0066] The memory 72 stores a program PR shown in the flowchart of FIG. 12. The computer executes the program PR to control box unpacking. The box unpacking control includes heating control, flap opening control, removal control, and packaging material disposal control. The heating control in this embodiment includes heating temperature control, heating time control, and pressure control. Note that the heating control unit 71 may be configured as hardware using electronic circuits within the control unit 70 instead of software.

[0067] <Operation of the embodiment> Next, the operation of the box unpacking device 11 will be described with reference to FIGS. Box unpacking control executed by the control unit 70 will be described below with reference to the flowchart shown in Fig. 12. As shown in Fig. 1, boxes 13 stop at positions P1 to P3 while being transported on the first conveyor 21, and at each of positions P1 to P3, the boxes 13 are heated, their flaps are opened, and they are pushed out in sequence. The boxes 13 are positioned at positions P1 to P3 in the transport direction X1 by stoppers 27 of positioning devices 23 to 25. First, the boxes 13 stop at the heated position P1.

[0068] First, in step S11, the control unit 70 moves the box 13 and the heating unit 31 to the heating position. More specifically, the movement mechanism 33 moves the heating unit 31 to the heating position relative to the box 13, which is located at the heated position P1. More specifically, as shown in FIG. 13 , when the box 13 is located at the heated position P1, the four heating units 31 constituting each pair of heating mechanisms 30 face the two heated surfaces HP on both sides of the box 13 in the width direction Y. Then, the control unit 70 drives the movement mechanism 33, causing the heating units 31 to come into contact with and press against the outer surfaces of the multiple flaps 15 that form the heated surface HP of the box 13.

[0069] In the next step S12, the control unit 70 heats the flaps 15. Specifically, the heating unit 31 is heated to a predetermined heating temperature. For example, the control unit 70 controls the power supply to the heater 39, setting the heating unit 31 to a heating temperature corresponding to the box identification information. The control unit 70 controls the heating temperature of the heater 39 based on feedback from the temperature sensor 34, controls the pressure of the heating unit 31 based on the air pressure of the cylinder 32, and controls the heating time based on the timing of an internal timer to maintain the heated state for a predetermined heating time. In this way, the heating unit 31 heats the heated area from the outer surfaces of the multiple flaps 15 that form the heated surface HP at a predetermined heating temperature, with a predetermined pressure strength, and for a predetermined heating time. As a result, the adhesive portions 16 in the heated area are heated by heat transferred from the heating unit 31 to the inner surfaces of the flaps 15 from the outer surfaces. Here, the contact of the heating unit 31 with the heated surface HP increases the heat transfer rate to the adhesive portions 16. Furthermore, by applying pressure, a wide contact area is ensured between the heating parts 31 and the outer surface of the flap 15. At this time, the N heating parts 31 change their posture individually via the swing mechanism 35 to follow the curved heated surface HP. Therefore, the heating parts 31 can ensure a wide contact area with the curved heated surface HP, and the adhesive part 16 can be heated effectively.

[0070] The heating temperature is set, for example, within a range of 300 to 350°C. The melting point of a hot melt adhesive is generally within a range of 80 to 150°C. For example, the melting point of an ethylene vinyl acetate (EVA) adhesive is 80 to 110°C, that of a polyolefin (PO) adhesive is 100 to 150°C, that of an acrylic (ACR) adhesive is approximately 90°C, and that of a polyamide (PA) adhesive is approximately 150°C. Therefore, the heating temperature is sufficiently higher than the melting point of the hot melt adhesive. For example, the heating temperature is set to a temperature 100°C or more higher than the melting point of the hot melt adhesive. Furthermore, since the heating temperature is transmitted via the flap 15, a certain amount of time is required for the heat transmission. Furthermore, because a temperature gradient occurs across the cross section of the flap 15, the actual heating temperature of the adhesive portion 16 is lower than the heating temperature of the heating portion 31. However, because the heating temperature on the heating surface 31A of the heating unit 31 is sufficiently higher than the melting point of the hot melt adhesive, the adhesive portion 16 is heated to a temperature exceeding the melting point of the hot melt adhesive. Therefore, by stopping the heating at intervals during the temperature rise of the adhesive portion 16, the amount of heat transferred to the adhesive portion 16 can be adjusted. As a result, the adhesive portion 16 can be melted in a short time. Furthermore, because the adhesive portion 16 is heated to a temperature sufficiently higher than the melting point, a portion of the melted adhesive portion 16 is carbonized. Here, carbonization refers to the phenomenon in which the adhesive composition that generates adhesive strength changes due to decomposition or compositional change when the hot melt adhesive is heated to a temperature that exceeds its melting point by a certain amount or more, resulting in an irreversible decrease in the adhesive strength of the adhesive portion 16. Therefore, the re-adhesion strength of the adhesive portion 16 is significantly reduced due to carbonization compared to when the adhesive portion 16 is simply melted. Therefore, even if the re-melted adhesive portion 16 hardens, its re-adhesion strength is significantly reduced.

[0071] The heating time is set, for example, in the range of 5 to 30 seconds. The heating time may be set according to the box identification information. The lower the heating temperature, the longer the heating time. In other words, the higher the heating temperature, the shorter the heating time. To achieve a particularly effective result, the heating time may be set in the range of 310 to 340°C and the heating time may be set in the range of 5 to 20 seconds. The pressure value is set in the range of 10 to 30 kPa. The pressure value is preferably as large as possible without deforming the box 13, but it does not need to be unnecessarily large. It is sufficient if the pressure value allows the heating unit 31 to change its position so as to conform to the curved heated surface HP. Therefore, the pressure value is preferably set in the range of 10 to 30 kPa. If the box 13 is packed with the contents C, the pressure value may be set to, for example, 20 to 30 kPa. If the volume of the contents C is significantly smaller than the volume of the box 13, the pressure value may be set to, for example, 10 to 20 kPa to avoid deforming the box 13. The heating temperature, heating time, and pressure value can be changed as appropriate depending on the type of hot melt adhesive, the material of the box 13, the type and state of the contents C, and the like.

[0072] In step S13, the control unit 70 performs a flap-opening operation. As shown in FIG. 9(a), when the heated box 13 is positioned at the flap-opening position P2, the control unit 70 drives the flap-opening mechanism 40, and first the suction pads 43 adsorb the flaps 15. Next, the suction-opening mechanism 42 performs a flap-opening operation on the suction pads 43, thereby opening the multiple flaps 15 adsorbed to the suction pads 43. In this way, two openings 13A are formed on both sides of the box 13 in the width direction Y, as shown in FIG. 9(b) and FIG. 15.

[0073] In step S14, the control unit 70 performs a take-out operation to take out the contents C from the box 13. As shown in FIG. 10(a), when the box 13 after the flap opening operation is positioned at the take-out position P3, the control unit 70 drives the cylinder 51 of the take-out mechanism 50 to extend. As a result, as shown in FIGS. 10(b) and 16, the pusher 52 extends in the take-out direction Y1, pushing out the contents C from the box 13. The pushed-out contents C are carried out to the destination by the second conveyor 22.

[0074] In step S15, the control unit 70 performs a box disposal operation. After the contents C have been removed, the empty box 13 is transported by the first conveyor 21 to the packaging disposal unit 60. The packaging disposal unit 60 crushes the empty box 13 with a pusher (not shown) that moves from above in the vertical direction Z. The plate-shaped boxes 13 (packaging material) that have been crushed into two or flattened parallelogram-shaped cylinders are, for example, stacked one on top of another.

[0075] <Box 13 heating experiment> Next, we will explain the heating experiment conducted to determine the appropriate heating conditions for box 13. The heating experiment, in which box 13 was heated by heating unit 31, was conducted under multiple conditions combining the heating temperature and heating time values of heating unit 31 in the range of 250°C to 360°C and the heating time in the range of 5 to 40 seconds. Box 13 used was one packed with solid contents C. For this reason, there was little concern about deformation of the heated surface HP due to pressure on box 13, so the pressure value was set to 25 kPa.

[0076] Heating experiments were conducted to determine heating conditions that could reduce the force required to peel the adhesive 16 below a target value. The target value for the force required to peel the adhesive 16 was assumed to be the force required to peel the adhesive 16 when the suction pad 43 was used to pull the flap 15. If the heating conditions met this target value, the box unpacking device 11 could automate the unpacking of the boxes 13. The heating conditions that met this target value were as follows: At 250°C, a heating time of more than 40 seconds was required; at 300°C, a heating time of approximately 30 seconds was required; at 310°C, a heating time of approximately 25 seconds was required; at 320°C, a heating time of 15 to 20 seconds was required; at 330°C, a heating time of 10 to 15 seconds was required; at 340°C, a heating time of approximately 10 seconds was required; and at 350°C, a heating time of approximately 5 seconds was sufficient. However, slight smoke was observed due to thermal damage to the cardboard of the boxes 13. At 360°C, a heating time of less than 5 seconds was required, but significant smoking was observed due to heat damage to the cardboard of box 13.

[0077] When the peeled surface of the peeled adhesive 16 was observed, a slight brownish discoloration was observed on the fracture surface, presumably due to carbonization of the hot melt adhesive, when heated at 320°C for 15 seconds or longer. Similar discoloration due to carbonization was also observed on the peeled surface of the adhesive 16 when heated at 330°C for 10 seconds or longer, 340°C for 5 seconds or longer, and 350°C for 3 seconds or longer. Partial carbonization of the adhesive 16 significantly reduces the adhesive strength of the hardened adhesive 16 after remelting. Therefore, even after a short time has passed since heating, the adhesive 16 peels off with a relatively small force when the flap 15 is pulled, allowing the flap 15 to be opened with a relatively small force.

[0078] Based on the results of this heating experiment, it is recommended that the heating temperature be set within the range of 300 to 350°C. This allows the heating time to be set within the range of 5 to 30 seconds. For example, in the past, it took 20 to 30 seconds to manually open one box 13 using a scraper. If the heating time can be reduced to within the range of 5 to 30 seconds, it is expected that the same or better effect can be achieved as with manual work. Furthermore, by setting the heating temperature to 350°C or less, thermal damage to the box 13 and its contents C can be suppressed.

[0079] These heating temperatures, heating times, and pressure values are merely examples and may be changed as appropriate depending on the composition (type) of the hot melt adhesive, the material of the box 13, the thickness and cross-sectional structure of the flap 15, the heat resistance of the contents C, etc. Combinations of heating temperatures and heating times outside the above ranges are also possible. Furthermore, combinations with pressure values outside the above ranges are also possible.

[0080] As described above in detail, according to this embodiment, the following effects can be obtained. (1) The box unpacking device 11 unpacks a box 13 in which flaps 15 constituting the box 13 are fixed in a closed state via adhesive portions 16 made of hardened hot melt adhesive. The box unpacking device 11 includes a heating unit 31, a movement mechanism 33, and a control unit 70. The heating unit 31 is configured to be able to heat a heated surface HP, which is the surface of the flap 15 in a closed state opposite the adhesive portion 16. The movement mechanism 33 positions the heating unit 31 and the box 13 so as to be in a relative positional relationship during heating by moving at least one of the heating unit 31 and the box 13 so that the heating unit 31 is positioned at a heating position relative to the box 13 where the heating unit 31 can heat the heated surface HP. The control unit 70 controls the heating unit 31 and the movement mechanism 33. The control unit 70 controls the movement mechanism 33 to position the heating unit 31 at the heating position relative to the box 13, and controls the heating unit 31 so that the heating unit 31 positioned at the heating position heats the heated surface HP. According to this configuration, at least one of the heating unit 31 and the box 13 is moved by the movement mechanism 33, and the heating unit 31 is positioned at the heating position relative to the box 13. The heating unit 31 positioned at the heating position heats the heated surface HP of the flap 15. This heating heats the adhesive portion 16 located on the surface of the flap 15 opposite the heated surface HP. The heated adhesive portion 16 melts, or at least a portion of it melts and is carbonized, thereby reducing its adhesive strength. As a result, when opening the flap 15, the adhesive portion 16 becomes easier to peel compared to before heating. Therefore, because the adhesive portion 16 made of hot-melt adhesive can be peeled off with a relatively small force, at least a portion of the unpacking operation of the box 13 by opening the flap 15 can be automated.

[0081] (2) The heating unit 31 has a heater 39 and a metal pressing member 38 that is heated by the heater 39. The movement mechanism 33 is configured to move at least one of the heating unit 31 and the box 13, thereby positioning the heating unit 31 between a pressing position where the pressing member 38 presses the heated surface HP of the flap 15 and a retracted position where the pressing member 38 is separated from the heated surface HP. With this configuration, the heating unit 31 heats the heated surface HP of the flap 15 while pressing the heated surface HP with the metal pressing member 38. Therefore, the heating unit 31 can heat the heated surface HP while in close contact with the flap 15 at a predetermined pressure. As a result, the adhesive portion 16 located on the surface opposite the heated surface HP can be heated more efficiently, thereby promoting melting or partial carbonization in addition to melting. Furthermore, because the heating unit 31 directly heats the heated surface HP of the box 13, the adhesive portion 16 located on the opposite side of the heated surface HP and the flap 15 can be heated more efficiently than in a configuration in which the heated surface HP is heated from a position away from the heated surface HP using a heating method such as hot air or heat radiation. Therefore, after heating, the adhesive portion 16 can be peeled off simply by pulling the flap 15 with a relatively small force, which in turn reduces the number of times the box 13 is opened.

[0082] (3) The heated area, which is the area of the heated surface HP that the heating surface 31A of the heating unit 31 contacts, is divided into multiple segments. A plurality of heating units 31 are provided on one heated surface HP so that each of the multiple segments can be individually heated. The heating units 31 have multiple swing mechanisms 35 that individually change the orientation of the heating units 31 so that the heating surface 31A conforms to the heated surface HP. With this configuration, even when the multiple heating units 31 contact across the multiple flaps 15 that form the heated surface HP, the heating surface 31A individually changes its orientation so that it conforms to the heated surface HP. Therefore, even if the heated surface HP of the box 13 is curved, the multiple heating units 31 can be brought into contact with the multiple flaps 15 over as wide a contact area as possible. Therefore, regardless of whether the heated surface HP of the box 13 is curved, the adhesive portions 16 located on the back (inner side) of the flaps 15 can be efficiently heated through a wide contact area with the flaps 15. Therefore, it is possible to reduce mistakes in opening a package caused by the adhesive portion 16 not being able to be peeled off due to variations in heating of the adhesive portion 16 caused by variations in the contact area between the heating portion 31 and the flap 15.

[0083] (4) The heating temperature at which the heating unit 31 heats the heated surface HP is a predetermined temperature within the range of 300 to 350°C. According to this configuration, the heating unit 31 heats the heated surface HP to a predetermined temperature within the range of 300 to 350°C. Here, at a heating temperature below 300°C, the heating time required to reduce the contact force of the adhesive portion 16 to a level that allows easy peeling is prolonged, reducing the efficiency of the unpacking process. On the other hand, at a heating time exceeding 350°C, there is a concern that the heated surface HP of the box 13 (e.g., cardboard) may be thermally damaged (e.g., carbonization if made of paper, or thermal deformation if made of synthetic resin) or that the contents C of the box 13 may be thermally affected. Therefore, the heating temperature is preferably between 300°C and 350°C. Note that, at temperatures above 300°C and below 350°C, prolonging the heating time not only melts the hot melt adhesive that constitutes the adhesive portion 16 but also partially carbonizes it. In this case, even if the hot melt adhesive re-adheres after being melted by heating, its adhesive strength is significantly reduced compared to before heating. Therefore, the adhesive portion 16 is easily peeled when the flap 15 is opened after heating. Furthermore, if the adhesive portion 16 is a reactive hot melt adhesive that does not melt when heated after curing, the adhesive portion 16 does not remelt when heated, and the adhesive strength of the hot melt adhesive (adhesive portion 16) is therefore less likely to decrease. However, if the heating temperature is within the range of 300 to 350°C, the adhesive portion 16 made of the reactive hot melt adhesive is partially carbonized, significantly reducing the adhesive strength of the adhesive portion 16. Therefore, the adhesive portion 16 can be peeled off with a relatively small force when the flap 15 is opened. Thus, by setting the heating temperature to 300 to 350°C, the adhesive strength of the adhesive portion 16 can be reduced to the required value for both hot melt adhesives that can be remelted by heating and reactive hot melt adhesives that cannot be remelted by heating.

[0084] (5) The box unpacking device 11 includes a flap opening mechanism 40 that opens the multiple flaps 15 whose heated surfaces HP are heated by the heating unit 31, and a removal mechanism 50 that removes the contents C through an opening 13A formed in the box 13 by opening the multiple flaps 15. According to this configuration, the flap opening mechanism 40 opens the multiple flaps 15, thereby forming the opening 13A in the box 13. The removal mechanism 50 removes the contents C from the opening 13A of the box 13. Therefore, the unpacking work up to the removal of the contents C from the box 13 can be automated.

[0085] (6) A method for opening a box 13 in which flaps 15 constituting the box 13 are fixed in a closed state via adhesive portions 16 made of hardened hot melt adhesive includes a positioning step and a heating step. In the positioning step, a control unit 70 moves at least one of the heating unit 31 and the box 13 to position the heating unit 31 and the box 13 so that they are in a relative positional relationship during heating. In the heating step, the control unit 70 causes the positioned heating unit 31 to heat a heated surface HP, which is the surface of the flap 15 opposite the adhesive portion 16. According to this method for opening a box 13, the adhesive portions 16 made of hot melt adhesive can be peeled off with a relatively small force, so that at least a part of the process of opening the box 13 by opening the flaps 15 can be automated.

[0086] The above embodiment can also be modified into the following modified examples. Furthermore, a further modified example can be formed by appropriately combining the above embodiment and the modified examples shown below, or by appropriately combining the modified examples shown below.

[0087] The packaging material disposal unit 60 may also be configured as a part of the box unpacking device 11. Two of the heated position P1, the flap open position P2, and the removal position P3 may be the same position. For example, the heated position P1 and the flap open position P2 may be the same position. Also, the flap open position P2 and the removal position P3 may be the same position. Furthermore, the heated position P1, the flap open position P2, and the removal position P3 may be the same position.

[0088] The box unpacking device 11 may be configured to include only the heating mechanism 30. In this case, the operation of opening the flap and the operation of removing the contents C may be performed manually by an operator. The box unpacking device 11 may include only the heating mechanism 30 and the flap opening mechanism 40.

[0089] The heating temperature is not limited to the range of 300 to 350°C. For example, it may be 250°C. In this case, the heating time will be longer, but it is possible to remelt the adhesive portion 16. Once remelted, the adhesive strength of the adhesive that re-hardens when the temperature is subsequently lowered will be lower than before heating.

[0090] The heating time is not limited to the range of 5 to 30 seconds. For example, it may be 3 seconds or 40 seconds. One example of the moving mechanism 33 is the cylinder 32. Instead, the heating unit 31 may be fixed in a predetermined position, and the box 13 may be moved in the width direction Y to press the heated surface HP against the heating surface 31A of the heating unit 31. This configuration may also be combined with the configuration of the above embodiment. That is, one heating unit 31 is fixed, and the box 13 is pressed against it. This pressing operation is performed by pressing the other heating unit 31 against the heated surface HP on the opposite side of the box 13. With this configuration, the heated surfaces HP on both sides of the box 13 can be heated simultaneously by the heating units 31.

[0091] The moving mechanism 33 may be a motor or a linear moving mechanism instead of the cylinder 32. In the above embodiment, a heating unit 31 may be added to heat the connecting margin 14A, thereby heating both the adhesive portion 16 of the flap 15 and the adhesive portion 17 of the connecting margin 14A. In this case, the adhesive portions 16, 17 can be peeled off to unfold the box 13 into a flat packaging material. The removal mechanism 50 may be configured to remove the contents C exposed on the flat packaging material of the unfolded box 13.

[0092] The number of heating sections 31 divided for one heated surface HP may be two, three, five, six, etc. The heating section 31 may be divided into a plurality of sections in each of the conveying direction X and the vertical direction Z, as in the above embodiment. With this configuration, regardless of whether the two flaps 15 are aligned in the conveying direction X or the vertical direction Z, each heating section 31 can change its posture individually, thereby ensuring a wide contact area between the heating section 31 and the flap 15 even if the heated surface HP is curved or deformed.

[0093] The swing mechanism 35 may be omitted. Also, one heated surface HP may be heated by one heating section 31. The heating unit 31 may be provided at the tip of the arm of an industrial robot, and the heating unit 31 may be moved by the robot to position the box 13 and the heating unit 31 at a position that satisfies the relative positional relationship during heating. In this case, the robot constitutes an example of a movement mechanism.

[0094] The take-out unit of the take-out mechanism 50 may be a suction unit such as a suction pad instead of the pusher 52. The cylinder 51 is driven to extend and retract, and the contents C are adsorbed to the suction unit inserted from one opening of the box 13, and then the contents C adsorbed by the suction unit are taken out from one opening of the box 13. Also, instead of a suction unit, the take-out unit may be a gripping unit such as a zipper. When the contents C are taken out through one opening of the box 13, it is only necessary to open the flap 15 on one side of the box 13, so one heating mechanism 30 may be provided on one side of the first conveyor 21. [Explanation of symbols]

[0095] 10...Box unpacking system, 11...Box unpacking device, 12...Frame, 13...Box, 13A...Opening, 14...Box body, 14A...Connection margin, 15...Flap, 15A...Inner flap, 15B...Outer flap, 16...Glued portion, 17...Glued portion, 20...Conveyor, 21...First conveyor, 21A...Roller, 22...Second conveyor, 22A...Roller, 23-25...Positioning device, 26...Cylinder, 27...Stopper, 30...Heating mechanism, 31...Heating portion, 31A...Heated surface, 32...Cylinder, 33...Moving mechanism, 34...Temperature sensor, 35...Oscillating mechanism, 36...Free connecting portion, 37...Elastic member, 38...Pressing member, 38A...Back plate, 39...Heater, 40...Flap opening mechanism, 41...Cylinder, 41A...Piston rod, 42...Suction opening mechanism, 43...Suction Pad, 44...cylinder, 44A...piston rod, 45...opening / closing member, 46...rotating lever, 46A...rotating shaft, 47...support plate, 48...suction pad, 50...removal mechanism, 51...cylinder, 51A...piston rod, 52...pusher, 53...guide shaft, 54...guide member, 60...packaging disposal section, 70...control section, 71...heating control section, 72...memory, 76...first sensor, 77...second sensor, 78...third sensor, 81...heating temperature control section, 82...heating time control section, 83...pressure control section, 90...operation panel, 91...input section, 92...display section, P1...heated position, P2...flap open position, P3...removal position, HP...heated surface, C...contents, PR...program, X...conveying direction, X1...conveying direction, Y...width direction, Y1...removal direction, Z...vertical direction.

Claims

1. A box unpacking device for unpacking a box in which flaps constituting the box are fixed in a closed state via adhesive portions made of hardened hot melt adhesive, a heating unit capable of heating a heated surface, which is a surface of the flap in the closed state opposite to the adhesive portion; a swing mechanism that changes the attitude of the heating unit so that the heating surface of the heating unit follows the heated surface; a movement mechanism that moves at least one of the heating unit and the box so that the heating unit is positioned at a heating position relative to the box where the heating unit can heat the heated surface, thereby positioning the heating unit and the box in a relative positional relationship during heating; a control unit that controls the heating unit and the moving mechanism; Equipped with the control unit controls the moving mechanism to place the heating unit at the heating position relative to the box, and controls the heating unit so that the heating unit placed at the heating position heats the heated surface; a heated region, which is a region of the heated surface that comes into contact with the heating surface, is divided into a plurality of divided regions; A box unpacking device characterized in that the heating section is provided in plurality so as to be able to individually heat each of the divided areas of one heated surface.

2. the heating unit includes a heater and a metal pressing member that is heated by the heater; The box unpacking device according to claim 1, characterized in that the moving mechanism is configured to be able to position the heating unit at a pressing position where the pressing member presses the heated surface of the flap and a retracted position where the pressing member is separated from the heated surface by moving at least one of the heating unit and the box.

3. a flap opening mechanism for opening the flaps whose heated surfaces are heated by the heating unit; 3. The box unpacking device according to claim 1, further comprising a removal mechanism that removes contents through an opening formed in the box by opening the plurality of flaps.

4. A method for opening a box in which flaps constituting the box are fixed in a closed state via adhesive portions made of hardened hot melt adhesive, comprising: a positioning step in which a control unit moves at least one of the heating unit and the box to position the heating unit and the box so that they have a relative positional relationship during heating; a heating step in which the control unit causes the positioned heating unit to heat a heated surface of the flap, the heated surface being a surface opposite to the adhesive portion, The heating step includes a step in which the control unit controls the plurality of heating units to heat one of the heated surfaces individually for each of a plurality of divided areas into which a heated area, which is an area of the heated surface that is in contact with a heating surface of the heating unit, is divided; A method for unpacking a box, wherein the heating step includes a swinging step of individually changing the posture of the plurality of heating units so that the heating surface conforms to the heated surface.

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